CERN: Feature https://home.cern/ en The Higgs boson: Revealing nature’s secrets https://home.cern/news/series/lhc-physics-ten/higgs-boson-revealing-natures-secrets <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation component-row__has-header effect_none is_full_height"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="cern-component-header-blocks component-header"> <div id="header-blocks--2" class="owl-carousel owl-theme component-header__carousel header-carousel"> <div class="header-block"> <div class="header-block__title"> <h3 class="header-block__name" > <span>The Higgs boson: Revealing nature’s secrets</span> <span class="header-block__name__underline"></span> </h3> <span class="header-block__subhead" ><p class="text-align-center">By: <a href="/authors/achintya-rao"><span class="cern-tag">Achintya Rao</span></a></p> <p class="text-align-center">4 JULY, 2020 · <i>Voir en <a href="/fr/news/series/lhc-physics-ten/higgs-boson-revealing-natures-secrets">français</a></i></p> <hr /><p class="text-align-center">Our third story in the <span class="cern-tag">LHC Physics at Ten</span> series takes us on a deeper dive into the Higgs boson</p> </span> </div> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="1102948" data-filename="oreach-2008-001" id="ATL-PHO-OREACH-2008-001-7"> <a href="//cds.cern.ch/images/ATL-PHO-OREACH-2008-001-7" title="View on CDS"> <img alt="Simulated production of a Higgs event in ATLAS" src="//cds.cern.ch/images/ATL-PHO-OREACH-2008-001-7/file?size=large"/> </a> <figcaption> <span> (Image: CERN)</span> </figcaption> </figure> </div> </div> </div> <span class="component-header__scroll"></span> </div> <a class="endof-cern-header-blocks"></a> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluidcenter section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="component-margin component-margin-small" ></div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <blockquote class="column-left image-align"> <p style="font-size: 1.3em !important;">“For me, it’s an incredible thing that it happened in my lifetime!”</p> </blockquote> <p class="column-left image-align"><strong>Peter Higgs</strong> was at a loss for words. The <a href="/science/experiments/cms">CMS</a> and <a href="/science/experiments/atlas">ATLAS</a> collaborations had just announced the discovery of a new, <a href="/science/physics/higgs-boson">Higgs-boson</a>-like particle at the Large Hadron Collider.</p> <figure class="cds-image align-right" id="CERN-HI-1207136-101"><a href="//cds.cern.ch/images/CERN-HI-1207136-101" title="View on CDS"><img alt="higgsjuly4,seminar,Milestones,Higgs Boson Discovery,360" src="//cds.cern.ch/images/CERN-HI-1207136-101/file?size=large" /></a> <figcaption>4 July 2012: François Englert (left) listens as Peter Higgs speaks, after ATLAS and CMS announce their discovery (Image: Maximilien Brice/CERN)</figcaption></figure><p class="column-left image-align">It had been 48 years since the publication of his paper that first predicted the existence of the particle that bears his name, not long after Robert Brout and François Englert proposed a new mechanism that would give mass to elementary bosons. More than 30 years had elapsed <a href="/news/series/lhc-physics-ten/lhc-physics-ten-entering-uncharted-waters">since the LHC was first conceived</a> and around 20 years since the ATLAS and CMS collaborations were formed. After those long years filled with anticipation, it only took the Swedish Academy of Sciences a little over one year to award <strong>Englert and Higgs the 2013 Nobel Prize in Physics</strong>.</p> <p class="column-left image-align">For Peter Higgs, the discovery of the Higgs boson was the end of a remarkable journey. For particle physics, it was the <strong>beginning of a new one</strong>.</p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation effect_background_parallax is_half_height"> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="2682635" data-filename="VHccmumu_plain" id="CMS-PHO-EVENTS-2019-006-12"> <a href="//cds.cern.ch/images/CMS-PHO-EVENTS-2019-006-12" title="View on CDS"> <img alt="Displays of candidate VHcc events" src="//cds.cern.ch/images/CMS-PHO-EVENTS-2019-006-12/file?size=large"/> </a> <figcaption> <span> (Image: CERN)</span> </figcaption> </figure> </div> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluidcenter section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <h1 id="higgs-like-higgs-ish-higgs-y">Higgs-like? Higgs-ish? Higgs-y?</h1> <p class="column-left image-align">“When you find something new, you have to understand exactly what it is that you have found,” remarks <strong>Giacinto Piacquadio</strong>, one of the conveners of the ATLAS collaboration’s Higgs group</p> <p class="column-left image-align">This understanding is built up gradually over time. Back in July 2012, physicists were cautious about calling the new particle <em>a</em> Higgs boson, let alone <em>the</em> Higgs boson predicted by the <strong><a href="/science/physics/standard-model">Standard Model of particle physics</a></strong>. And with good reason: while the simplest theoretical formulations required there to be only one kind of Higgs boson, some extensions of the Standard Model proposed that there could be as many as five kinds of bosons that are involved in the mass-giving mechanism. So for the first few months after the discovery, it was referred to as <strong>Higgs-<em>like</em></strong>, shorthand for “a particle that seems to behave like the Higgs boson predicted by the Standard Model but we need more data to be sure”.</p> <p class="column-left image-align">The identification of two quantum-mechanical properties of the particle – quantum spin and parity – gave credence to the Standard-Model interpretation. <strong>Spin</strong> is the intrinsic spatial orientation of quantum particles, and <strong>parity</strong> refers to whether the properties of the particle remain the same when some of its spatial coordinates are flipped, like comparing the particle with a hypothetical mirror image. In the Standard Model, the Higgs boson has no spin (“0”) and “even” parity. At the time of the discovery, the fact that the Higgs boson transformed into photons meant that – unlike all other elementary bosons we know – its spin could not be 1: photons have a quantum spin of 1 themselves, so a particle transforming into two photons would have a spin of 0 (with the two spins of the photon cancelling out) or 2 (if the two spins add up).</p> <figure class="align-right"><a href="//cds.cern.ch/record/1559925/files/figure_4a.png" title="View on CDS"><img alt="ATLAS Higgs spin/parity plot" src="//cds.cern.ch/record/1559925/files/figure_4a.png" /></a> <figcaption>Differences between the positive- and negative-parity theoretical scenarios (solid and dashed lines respectively) for a particle with spin 0. The data do not show evidence for the negative-parity scenario (Image: ATLAS/CERN)</figcaption></figure><p class="column-left image-align">In science, you can never know something with 100% certainty, but you can rule out things that are not likely. Because spin-2 particles or parity-odd particles with spin 0 would leave subtly different signatures in the ATLAS and CMS detectors than the spin-0-parity-even particle they were looking for, the scientists were eventually able to rule out these more exotic possibilities by examining many more collision events and finding no evidence to support them. “We had to analyse two-and-a-half-times more data to drop the ‘-like’,” Piacquadio adds. By March 2013, scientists were confident calling the particle <strong><em>a</em> Higgs boson</strong>.</p> </div> </div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <h1 class="column-right image-align" id="the-goldilocks-zone">The Goldilocks zone</h1> <p class="column-right image-align">The Higgs boson was the last missing piece in the Standard Model. Crucially, its mass would determine how it could be observed. At <strong>125 gigaelectronvolts (GeV)</strong>, it turned out to be <em>just right</em> for studying the particle at the Large Hadron Collider.</p> <p class="column-right image-align">We can never directly see a Higgs boson. Like most kinds of particle in nature, it is unstable and – immediately after being produced – transforms into lighter particles through a process known as particle decay. The ATLAS and CMS detectors can therefore see only the remnants of transformations, signatures that a Higgs boson might have been produced in the LHC’s collisions. Further, the downstream remnants of a Higgs transformation hold clues for how the particle was produced in the first place.</p> <p class="column-right image-align">The Higgs boson’s mass was not predicted precisely by the Standard Model, but theorists knew that the processes that produced it and the kinds of particles it transformed into would depend on how heavy the boson actually was. They had prepared elaborate plots calculating the various probabilities for a Higgs boson of a given mass to transform into particular pairs of particles. According to these so-called “<strong>branching fractions</strong>”, a light Higgs boson of around 125 GeV would have the largest variety of transformation candidates that ATLAS and CMS could detect: pairs of W bosons, Z bosons, photons, bottom quarks, tau leptons and many others. The greater the variety of observable particles the Higgs can transform into, the greater the ability of scientists to study the interplay between these particles and the Higgs boson.</p> <figure class="align-left"><a href="//cds.cern.ch/record/1546765/files/dYRHXS2_BR_Fig1.png" title="View on CDS"><img alt="Higgs branching fraction" src="//cds.cern.ch/record/1546765/files/dYRHXS2_BR_Fig1.png" /></a> <figcaption>The rates at which a Higgs boson could undergo certain transformations (vertical axis) depending on its mass (horizontal axis) (Image: CERN)</figcaption></figure><p class="column-right image-align">Although the Higgs field was conceived to explain the masses of the W and Z bosons, scientists realised that it could help account for the masses of the fermions, namely the particles of matter. If, due to its mass, they could only observe the interplay between the Higgs boson on one hand and the W and Z bosons on the other, the puzzle of the fermion masses would remain unsolved. Discovering the particle at a convenient mass was an unexpected kindness from nature. If it were slightly more massive, above 180 GeV or so, the options to study it at the time of its discovery would have been more limited.</p> <p class="column-right image-align">The variety of available transformation products means that data from the individual channels can be combined together through sophisticated techniques to build up a greater understanding of the particle. “Doing so is not trivial,” says <strong>Giovanni Petrucciani</strong>, co-convener of the Higgs analysis group in CMS. “You have to treat the uncertainties similarly across all the individual analyses and interpret the results carefully, once you have applied complicated statistical machinery.” <strong>Combining data</strong> from the transformation of the Higgs boson to pairs of Z bosons and pairs of photons allowed ATLAS and CMS to discover the Higgs boson in 2012.</p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation effect_background_parallax is_half_height"> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="2666332" data-filename="_DSC5418" id="OPEN-PHO-MISC-2019-001-1"> <a href="//cds.cern.ch/images/OPEN-PHO-MISC-2019-001-1" title="View on CDS"> <img alt="Photograph corresponding to CERN courier article: Inspired by software (2019MarApr)" src="//cds.cern.ch/images/OPEN-PHO-MISC-2019-001-1/file?size=large"/> </a> <figcaption> Photograph featured in the CERN courier article for issue 2019MarApr. Contains an image of ATLAS Higgs event, accompanied with a piece of event selection code of an CMS analysis reimplemented by theorists in open code CheckMATE. <span> (Image: CERN)</span> </figcaption> </figure> </div> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluidcenter section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <h1 id="generation-gaps">Generation gaps</h1> <p class="column-left image-align">The LHC started operations at a collision energy of 7 teraelectronvolts (TeV) before ramping up to 8 TeV over the course of its first run (2010–2013). The data collected over this period not only led to the discovery of the Higgs boson but showed the relationship (“coupling”) <strong>between the Higgs boson and elementary bosons</strong>: it was observed transforming into pairs of Ws, Zs and photons. And, while transformations to gluons are impossible to observe, the scientists could probe this coupling through the Higgs production itself: the most abundant way for a Higgs to be created in proton–proton interactions is for two gluons – one from each proton – to fuse together, accounting for nearly 90% of Higgs bosons produced at the LHC.</p> <figure class="cds-image align-right" id="CMS-PHO-EVENTS-2013-003-1"><a href="//cds.cern.ch/images/CMS-PHO-EVENTS-2013-003-1" title="View on CDS"><img alt="Real Events,Higgs,collision,event display,CMS event display,Higgs event display,Higgs boson event display,Higgsgammagamma,gammagamma" src="//cds.cern.ch/images/CMS-PHO-EVENTS-2013-003-1/file?size=large" /></a> <figcaption>A candidate for a Higgs boson transforming into two photons (Image: CMS/CERN)</figcaption></figure><p class="column-left image-align">The next challenge was to observe the <strong>coupling to fermions</strong>, to cement the role of the Higgs field as the origin of mass of all elementary massive particles. These couplings had been probed indirectly: the Standard Model tells us that the gluon-fusion production mechanism and the Higgs transformation to photon pairs require the creation and annihilation of “virtual” top–antitop pairs. However, a direct observation of Higgs couplings to fermions was lacking.</p> <p class="column-left image-align">Curiously, both kinds of fermions – quarks, which make up compound particles like protons, and leptons, like the familiar electron – come in <strong>three generations of particles, each heavier than the previous</strong>. And unlike bosons, whose coupling strengths to the Higgs are proportional to their masses, the Higgs-coupling strengths of fermions is proportional to the square of their masses.</p> <p class="column-left image-align">The third generation of fermions – the heaviest – are therefore the most likely particles to manifest in processes involving the Higgs boson. “The connection between the Higgs and the top quark in particular is very exciting to look into,” remarks <strong>María Cepeda</strong>, Petrucciani’s fellow convener on CMS. Despite their relative abundance in such processes, these particles are challenging to identify. Since quarks cannot exist freely, two bottom quarks (a quark and an antiquark) emerging from a Higgs transformation rapidly combine with other quarks pulled out of the vacuum and form jets of particles. The experimentalists have to then tag jets of particles that carry the signature of a bottom quark, in order to isolate the signal. The top quark on the other hand is heavier than the Higgs and so a Higgs can never be observed transforming into two top quarks. Scientists have to therefore measure its coupling with the Higgs by looking for collision events in which a Higgs boson is produced in association with two top quarks. The second run of the LHC (2015–2018) was at an energy of 13 TeV and the large data volume collected allowed ATLAS and CMS to observe the interplay between the Higgs boson and the bottom quark, the top quark and the tau lepton.</p> <figure class="cds-image align-right" id="ATLAS-PHOTO-2018-022-7"><a href="//cds.cern.ch/images/ATLAS-PHOTO-2018-022-7" title="View on CDS"><img alt="Higgs Candidates,Proton Collisions,Event Displays,Physics,ATLAS" src="//cds.cern.ch/images/ATLAS-PHOTO-2018-022-7/file?size=large" /></a> <figcaption>A candidate for a Higgs boson transforming into a b-quark and a b-antiquark (Image: ATLAS/CERN)</figcaption></figure><p class="column-left image-align">Couplings to the second generation of fermions are much weaker and neither ATLAS nor CMS have so far observed Higgs transformations into charm quarks, strange quarks or muons. The next run of the LHC (2021 onwards) is expected to provide enough data to begin to shed light on some of these interactions. “The LHC’s instantaneous luminosity – <strong>the rate at which it collides protons</strong> – has increased dramatically over its first two runs,” notes Piacquadio with excitement. “This means that the number of Higgs bosons produced by the LHC continues to rise, as do the odds that we observe them undergoing rarer transformations.”</p> <p class="column-left image-align">But for the second generation of fermions, the LHC’s data volume over its whole operational life may not be enough to breach the 5σ statistical threshold to claim a Higgs transformation to all these particles. Although the High-Luminosity LHC, which will be the collider’s incarnation from 2026, is expected to allow ATLAS and CMS to see the Higgs transforming into pairs of muons, transformations to second-generation quarks will probably remain out of reach.</p> </div> </div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <h1 id="more-data-more-precision">More data, more precision</h1> <p class="column-left image-align">The Higgs boson holds the key to our understanding of nature beyond what is shown by the Standard Model.</p> <p class="column-left image-align">ATLAS and CMS are, for example, looking for so-called “invisible decays” of the Higgs boson, in which it transforms into particles that the detectors cannot observe. These invisible particles might be manifestations of <strong>dark matter</strong>. And measurements of couplings that deviate from the theoretical predictions could provide an alternative explanation for the masses of the different generations of fermions, explaining why they exist in distinct generations to start with and possibly hinting at the existence of other Higgs bosons.</p> <p class="column-left image-align">Yet, the Brout-Englert-Higgs mechanism remains among the least-understood phenomena in the Standard Model. Indeed, while scientists have dropped the “-like” suffix and have understood the Higgs boson remarkably since its discovery, they still do not know if what was observed is the Higgs boson predicted by the Standard Model. Couplings to the second-generation fermions remain elusive and the couplings that <em>have</em> been observed are known with an uncertainty of 10 to 20%, expected to reduce to the 2–4% range with the <strong>High-Luminosity LHC</strong>. Observation of as-yet-unseen phenomena and precision measurements of those that have been seen may require data volumes far greater than the LHC can provide over its lifetime.</p> <p class="column-left image-align">The global particle-physics community is therefore keen on building a “Higgs factory”, a dedicated accelerator with a focus on producing Higgs bosons in unimaginably large quantities, to allow the continued exploration of this strange particle. A high-energy Higgs factory would also enable scientists to produce two Higgs bosons at a time, to address the question of the so-called “Higgs self-interaction”, the process through which the Higgs boson itself gains mass.</p> <p class="column-left image-align">Since its discovery nearly eight years ago, ATLAS and CMS have published hundreds of papers on the Higgs boson and our understanding of the particle has grown incrementally but greatly. Today, we know with great precision what its mass is, what its most abundant transformation channels are and how it is produced in the first place. But a lot remains unknown, about both the Higgs boson and the quantum world in general.</p> </div> </div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <hr /><p><em>The Higgs may be the most important discovery of the LHC so far, but there is much still to learn from this remarkable machine. Our next story in this series will take a look at searches for dark matter at the Large Hadron Collider.</em></p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> Our third story in the LHC Physics at Ten series takes us on a deeper dive into the Higgs boson </div> </div> </div> Mon, 08 Jun 2020 17:55:32 +0000 achintya 155006 at https://home.cern The Higgs boson: What makes it special? https://home.cern/news/series/lhc-physics-ten/higgs-boson-what-makes-it-special <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation component-row__has-header effect_none is_full_height"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="cern-component-header-blocks component-header"> <div id="header-blocks--2" class="owl-carousel owl-theme component-header__carousel header-carousel"> <div class="header-block"> <div class="header-block__title"> <h3 class="header-block__name" > <span>The Higgs boson: What makes it special?</span> <span class="header-block__name__underline"></span> </h3> <span class="header-block__subhead" ><p class="text-align-center">By: <a href="/authors/achintya-rao"><span class="cern-tag">Achintya Rao</span></a></p> <p class="text-align-center">4 MAY, 2020 · <em>Voir en <a href="/fr/news/series/lhc-physics-ten/higgs-boson-what-makes-it-special">français</a></em></p> <hr /><p class="text-align-center">Our second story in the <span class="cern-tag">LHC Physics at Ten</span> series visits the LHC’s most important discovery so far</p> </span> </div> <div class="background__veil"></div> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="2642472" data-filename="Hbb_v2" id="CMS-PHO-EVENTS-2018-008-1"> <a href="//cds.cern.ch/images/CMS-PHO-EVENTS-2018-008-1" title="View on CDS"> <img alt="Display of a event observed in the CMS detector in which a Higgs boson decays to bottom quarks" src="//cds.cern.ch/images/CMS-PHO-EVENTS-2018-008-1/file?size=large"/> </a> <figcaption> <span> (Image: CERN)</span> </figcaption> </figure> </div> </div> </div> <span class="component-header__scroll"></span> </div> <a class="endof-cern-header-blocks"></a> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluidcenter section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="component-margin component-margin-small" ></div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <blockquote class="column-left image-breakout"> <p style="font-size: 1.3em !important;">As a layman I would now say… I think we have it.</p> </blockquote> <p class="column-left image-breakout">“<em>It</em>” was the <a href="/science/physics/higgs-boson">Higgs boson</a>, the almost-mythical entity that had put particle physics in the global spotlight, and the man proclaiming to be a mere layman was none other than <strong>CERN’s Director-General</strong>, Rolf Heuer. Heuer spoke in the Laboratory’s main auditorium on <strong>4 July 2012</strong>, moments after <a href="/news/press-release/cern/cern-experiments-observe-particle-consistent-long-sought-higgs-boson">the CMS and ATLAS collaborations at the Large Hadron Collider announced the discovery of a new elementary particle</a>, which we now know is a Higgs boson. Applause reverberated in Geneva from as far away as Melbourne, Australia, where delegates of the International Conference on High Energy Physics were connected via video-conference.</p> <figure class="cds-image breakout-right" id="CERN-HI-1207136-57"><a href="//cds.cern.ch/images/CERN-HI-1207136-57" title="View on CDS"><img alt="higgsjuly4,seminar,Milestones,Higgs Boson Discovery,360" src="//cds.cern.ch/images/CERN-HI-1207136-57/file?size=large" /></a> <figcaption>4 July 2012: A packed auditorium at CERN listens keenly to the announcement from CMS and ATLAS (Image: Maximilien Brice/CERN)</figcaption></figure><p class="column-left image-breakout">So what exactly is so special about this particle?</p> <p class="column-left image-breakout">“<strong>Easy!</strong> It is the first and only elementary scalar particle we have observed,” grins <strong>Rebeca Gonzalez Suarez</strong>, who, as a doctoral student, was involved in the CMS search for the Higgs boson. Easy for a physicist, perhaps…</p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation effect_background_parallax is_half_height"> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="2312440" data-filename="ATLASHiggsbb" id="ATLAS-PHOTO-2018-010-1"> <a href="//cds.cern.ch/images/ATLAS-PHOTO-2018-010-1" title="View on CDS"> <img alt="ATLAS Event Display: Higgs boson decaying to a b-quark pair" src="//cds.cern.ch/images/ATLAS-PHOTO-2018-010-1/file?size=large"/> </a> <figcaption> <span> (Image: CERN)</span> </figcaption> </figure> </div> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluidcenter section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <h2 id="elegance-and-symmetries">Elegance and symmetries</h2> <p class="column-left image-breakout">At the subatomic scale, the universe is a <strong>complex choreography of elementary particles</strong> interacting with one another through fundamental forces, which can be explained using a term that physicists of all persuasions turn to: <em>elegance</em>.</p> <p class="column-left image-breakout">“In the 1960s, theoretical physicists were working on an <strong>elegant way</strong> of describing the fundamental laws of nature in terms of quantum field theory,” says <strong>Pier Monni</strong>, of CERN’s Theory department. In quantum field theory, both matter particles (<em>fermions</em> such as electrons, or the quarks inside protons) and the force carriers (<em>bosons</em> such as the photon, or the gluons that bind quarks) are manifestations of underlying, fundamental quantum fields. Today we call this elegant description the <a href="/science/physics/standard-model"><strong>Standard Model of particle physics</strong></a>.</p> <figure class="cds-image breakout-right" id="CERN-GE-0710029-07"><a href="//cds.cern.ch/images/CERN-GE-0710029-07" title="View on CDS"><img alt="ALEPH,John Ellis,Lagrangian,Higgs,Penguin,diagram" src="//cds.cern.ch/images/CERN-GE-0710029-07/file?size=large" /></a> <figcaption>The Standard Model of particle physics represented in a single equation<span> (Image: CERN)</span></figcaption></figure><p class="column-left image-breakout">The Standard Model is based on the notion of symmetries in nature, that the physical properties they describe remain unchanged under some transformation, such as a rotation in space. Using this notion, physicists can provide a unified set of equations for both electromagnetism (electricity, magnetism, light) and the weak nuclear force (radioactivity). The force which is thus unified is dubbed the electroweak force.</p> <p class="column-left image-breakout">But these very symmetries presented a glaring problem: “The symmetries explained the electroweak force but in order to keep the symmetries valid, they forbid its force-carrying particles from having mass,” explains <strong>Fabio Cerutti</strong>, who co-led Higgs groups at ATLAS on two separate occasions. “The photon, which carries electromagnetism, we knew was massless; the <strong><a href="/science/physics/w-boson-sunshine-and-stardust">W</a> and <a href="/science/physics/z-boson">Z</a> bosons</strong>, carriers of the weak force, could not be.” Although the W and Z had not been directly observed at the time, physicists knew that if they <em>were</em> to have no mass, processes such as beta decay would have occurred at infinite rates – a physical impossibility – while other processes would have probabilities greater than one at high energies.</p> <p class="column-left image-breakout">In 1964, two papers – one by <strong>Robert Brout and François Englert</strong>, the other by <strong>Peter Higgs</strong> – purported to have a solution: a new mechanism that would break the electroweak symmetry. The Brout-Englert-Higgs mechanism introduced a new quantum field that today we call the Higgs field, whose quantum manifestation is the Higgs boson. Only particles that interact with the Higgs field acquire mass. “It is exactly this mechanism,” Cerutti adds, “that creates all the complexity of the Standard Model.”</p> <p class="column-left image-breakout">Originally conceived to explain the masses of the W and Z bosons only, scientists soon found they could extend the Brout-Englert-Higgs mechanism to account for the mass of all massive elementary particles. “To accommodate the mass of the W and Z bosons, we don’t need the same Higgs field to give mass to any other particles such as electrons or quarks,” remarks <strong>Kerstin Tackmann</strong>, a co-convener of the Higgs group on ATLAS. “But it is a convenient way to do so!”</p> <p class="column-left image-breakout">The mathematical puzzle had been solved decades ago but whether the maths described physical reality remained to be tested.</p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation effect_background_parallax is_half_height"> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="1606851" data-filename="Higgsfield" id="OPEN-PHO-ACCEL-2013-052-1"> <a href="//cds.cern.ch/images/OPEN-PHO-ACCEL-2013-052-1" title="View on CDS"> <img alt="Artistic view of the Higgs Field" src="//cds.cern.ch/images/OPEN-PHO-ACCEL-2013-052-1/file?size=large"/> </a> <figcaption> Artistic view of the Brout-Englert-Higgs Field <span> (Image: CERN)</span> </figcaption> </figure> </div> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluidcenter section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <h2 id="something-in-nothing">Something in nothing</h2> <p>The Higgs field is peculiar in two particular ways.</p> <p>Imagine an empty region of space, a perfect vacuum, without any matter present in it. Quantum field theory tells us that this hypothetical region is not <em>really</em> empty: particle–antiparticle pairs associated with different quantum fields pop into existence briefly before annihilating, transforming into energy. However, the “expectation value” of these fields in a vacuum is zero, implying that on average we can expect there to be no particles within the perfect vacuum. The Higgs field on the other hand has a really high vacuum expectation value. “This non-zero vacuum expectation value,” Tackmann elaborates, “means that <strong>the Higgs field is everywhere</strong>.” Its omnipresence is what allows the Higgs field to affect all known massive elementary particles in the entire universe.</p> <p>When the universe had just come into being and was extremely hot, its energy density was higher than the energy associated with the vacuum expectation value of the Higgs field. As a result, the symmetries of the Standard Model could hold, allowing particles such as the W and Z to be massless. As the universe started to cool down, the energy density dropped, until – fractions of a second after the Big Bang – it fell below that of the Higgs field. This resulted in the symmetries being broken and certain particles gained mass.</p> <p>The other property of the Higgs field is what makes it impossible to observe directly. Quantum fields, both observed and hypothesised, come in different varieties. <strong>Vector fields</strong> are like the wind: they have both magnitude and direction. Consequently, vector bosons have an intrinsic angular momentum that physicists call quantum spin. <strong>Scalar fields</strong> have only magnitude and no direction, like temperature, and scalar bosons have no quantum spin. Before 2012 we had only ever observed vector fields at the quantum level, such as the electromagnetic field.</p> <p>“You can observe a field by observing a particle interacting with it, like electrons bending in a magnetic field,” Monni explains. “Or you can observe it by producing the quantum particle associated with the field, such as a photon.” But the Higgs field, with its constant non-zero value, cannot be switched on or off like the electromagnetic field. Scientists had only one option to prove it exists: create – and observe – the Higgs boson.</p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation effect_background_parallax is_half_height"> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="1459462" data-filename="eemm_run195099_evt137440354_ispy_rz-annotated-2" id="CMS-PHO-EVENTS-2012-004-6"> <a href="//cds.cern.ch/images/CMS-PHO-EVENTS-2012-004-6" title="View on CDS"> <img alt="CMS Higgs Search in 2011 and 2012 data: candidate ZZ event (8 TeV) with two electrons and two muons" src="//cds.cern.ch/images/CMS-PHO-EVENTS-2012-004-6/file?size=large"/> </a> <figcaption> r-z view (vertical plane containing the beam) with labels <span> (Image: CERN)</span> </figcaption> </figure> </div> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> <p> </p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluidcenter section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <h2 id="bump-hunting-at-the-large-hadron-collider">Bump-hunting at the Large Hadron Collider</h2> <p class="column-left image-breakout">Particle collisions at sufficiently high energies are necessary to produce a Higgs boson, but for a long time physicists were hunting in the dark: they did not know what this energy range was.</p> <p class="column-left image-breakout">They had searched for signs of the Higgs boson in particle-collision debris at the Large Electron–Positron collider (LEP), which was the Large Hadron Collider’s direct predecessor, and at Fermilab’s Tevatron in the US. The Large Hadron Collider had the capacity to explore the entire predicted energy range where the Higgs boson could appear, and the two general-purpose particle detectors at the LHC – ATLAS and CMS – were meant to provide a definitive answer on its existence. For some, like Monni, the LHC’s calling was irresistible, leading him to switch careers from aerospace engineering to theoretical physics.</p> <p class="column-left image-breakout">Gonzalez Suarez’s colleagues and friends were in the CMS and ATLAS control rooms when <a href="/news/series/lhc-physics-ten/lhc-physics-ten-entering-uncharted-waters">the LHC embarked on its high-energy journey on <strong>30 March 2010</strong></a>. She herself was in her office at CERN’s main site in Geneva. “I was writing my doctoral thesis on one screen and looking at the live stream of the collisions on a second. I wanted to know if the code I had written to identify particles produced in the collisions worked!”</p> <p class="column-left image-align">When two protons collide within the LHC, it is their constituent quarks and gluons that interact with one another. These high-energy interactions can, through well-predicted quantum effects, produce a Higgs boson, which would immediately transform – or “decay” – into lighter particles that ATLAS and CMS could observe. The scientists therefore needed to build up enough evidence to suggest that particles that <em>could</em> have appeared from a Higgs production and transformation were indeed the result of such a process.</p> <figure class="align-right"><a href="//cds.cern.ch/images/ATLAS-PHOTO-2012-001-2" title="View on CDS"><img src="https://cds.cern.ch/record/2230893/files/HiggsGammaGamma.gif" /></a> <figcaption>ATLAS (and CMS) observed the Higgs boson in transformations to two photons by collecting and analysing lots of data over time. (Image: ATLAS/CERN)</figcaption></figure><p class="column-left image-align">“When the LHC programme started, popular belief was that we would only see a Higgs boson after several years of data collection,” recounts <strong>Vivek Sharma</strong>, who co-led the CMS search when the LHC began operations. Sharma and his colleagues presented a plan to CMS in September 2010 of how to tackle the problem with half that data. It required not only a thorough understanding of one’s own detector hardware, its reach and its limitations, but also a team with a variety of technical expertise. “By the time ATLAS and CMS gave a joint talk to CERN’s Scientific Policy Committee in March 2011,” Sharma continues, “<strong>there was a force building up</strong> that the Higgs boson could be hunted with even smaller datasets.”</p> <p class="column-left image-align">A routine end-of-year seminar by ATLAS and CMS in December 2011 overloaded CERN’s webcast servers, as thousands tuned in to hear the latest updates from the collaborations. Early signs of the Higgs boson were there: both detectors had seen bumps in their data that were starting to look distinct from any statistical fluctuations or noise. But the results lacked the necessary statistical certainty to claim discovery. The world had to wait nearly seven months before Joe Incandela of CMS and Fabiola Gianotti of ATLAS could do so in July 2012. The collaborations had performed better than expected to discover the Higgs boson with just two years of data from the LHC.</p> <p class="column-left image-breakout">In CERN’s auditorium, Peter Higgs wiped away tears of joy, and François Englert paid tribute to his late colleague and collaborator, Robert Brout, who did not live to see proof of the mechanism that bears his name.</p> <p class="column-left image-breakout">Gonzalez Suarez celebrated with mixed emotions. Her post-doctoral research took her away from Higgs research before the discovery, and eventually from CMS, to the ATLAS collaboration. “The discovery of the Higgs boson was a historic event, but we are still only <strong>at the beginning</strong> in our understanding of this new particle.”</p> </div> </div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <hr /><p><em>The road from data to discovery was challenging. But what have we learnt about the Higgs boson since then? Find out more in part two of the Higgs saga (coming soon).</em></p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> Our second story in the LHC Physics at Ten series visits the LHC’s most important discovery so far </div> </div> </div> Mon, 04 May 2020 08:21:16 +0000 achintya 154643 at https://home.cern LHC Physics at Ten: Entering Uncharted Waters https://home.cern/news/series/lhc-physics-ten/lhc-physics-ten-entering-uncharted-waters <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation component-row__has-header effect_none is_full_height"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="cern-component-header-blocks component-header"> <div id="header-blocks--4" class="owl-carousel owl-theme component-header__carousel header-carousel"> <div class="header-block"> <div class="header-block__title"> <h3 class="header-block__name" > <span>LHC Physics at Ten: Entering Uncharted Waters</span> <span class="header-block__name__underline"></span> </h3> <span class="header-block__subhead" ><p class="text-align-center">By: <a href="/authors/achintya-rao"><span class="cern-tag">Achintya Rao</span></a></p> <p class="text-align-center">30 MARCH, 2020 · <i>Voir en <a href="/fr/news/series/lhc-physics-ten/lhc-physics-ten-entering-uncharted-waters">français</a></i></p> <hr /><p class="text-align-center">We start our <span class="cern-tag">LHC Physics at Ten</span> series with a trip down memory lane to the day when it all began</p> </span> </div> <div class="background__veil"></div> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="1255406" data-filename="" id="CERN-AC-1003061-112"> <a href="//cds.cern.ch/images/CERN-AC-1003061-112" title="View on CDS"> <img alt="CERN Control Centre on 30 March 2010" src="//cds.cern.ch/images/CERN-AC-1003061-112/file?size=large"/> </a> <figcaption> <span> (Image: CERN)</span> </figcaption> </figure> </div> </div> </div> <span class="component-header__scroll"></span> </div> <a class="endof-cern-header-blocks"></a> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__fluidcenter section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="component-margin component-margin-small" ></div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p class="column-left image-breakout">On 30 March 2010, <strong>exactly ten years ago</strong>, a metaphorical champagne bottle was smashed across the bow of the <a href="/science/accelerators/large-hadron-collider">Large Hadron Collider</a> (and several non-metaphorical ones were popped) as CERN’s flagship accelerator embarked upon its record-breaking journey to explore strange new worlds at the high-energy frontier: <a href="/news/press-release/cern/lhc-research-programme-gets-underway">it collided protons at an energy of <strong>3.5 teraelectronvolts (TeV) per beam</strong> for the first time</a>. Since then, the largest scientific instrument ever built has enabled scientists to study a variety of physics phenomena, with its crowning achievement being the <a href="/news/press-release/cern/cern-experiments-observe-particle-consistent-long-sought-higgs-boson">discovery of the Higgs boson in 2012</a>.</p> <figure class="cds-image breakout-right" id="CERN-HOMEWEB-PHO-2010-001-1"><img alt="A screenshot of a control screen showing the LHC’s status at 13:30 on 30 March 2010. The text on top says 'Proton Physics: Stable Beams' and the image shows a graph for two proton beams at 3.5 teraelectronvolts each." src="//cds.cern.ch/images/CERN-HOMEWEB-PHO-2010-001-1/file?size=large" /><figcaption>LHC Page 1 shortly after first high-energy collisions in the accelerator (Image: CERN)</figcaption></figure><p class="column-left image-breakout">The LHC wasn’t built just to find the Higgs boson – or prove that it didn’t exist! Over the last ten years, it has allowed scientists to test the <strong><a href="/science/physics/standard-model">Standard Model of particle physics</a></strong> with higher precision than ever before, demonstrating the theory’s robustness. In addition to the proton–proton collisions that are the LHC’s staple, scientists have used collisions of lead nuclei to recreate and examine the <strong>conditions that prevailed in the very early universe</strong>, when quarks and gluons existed freely. And the Higgs boson itself has brought entirely new perspectives to physics – an elementary particle with no intrinsic angular momentum, the first of its kind.</p> <p class="column-left image-breakout">The path to proton–proton collisions at the teraelectronvolt scale – whose story goes as far back as 1977, when such a machine was first conceived – was fraught with challenges. No hadron collider <strong>of this size and energy</strong> had been built before, and technical and scientific expertise had to be cultivated to bring it to fruition. Global collaborations were formed to design and build the detectors at each of the four collision points around the ring.</p> <p class="column-left image-breakout"><a href="/news/press-release/cern/first-beam-lhc-accelerating-science">Proton beams flew through the machine for the first time</a> on <strong>10 September 2008</strong>, but an electrical fault only nine days later put the accelerator out of action for over a year. The first low-energy collisions were achieved on 23 November 2009. A week later, the LHC <a href="/news/press-release/cern/lhc-sets-new-world-record">took over the mantle from Fermilab’s Tevatron as the world’s highest-energy collider</a>, achieving <strong>1.18 TeV in each beam</strong>. The following March, it left the shallow waters and entered uncharted territory by colliding beams at an energy of 3.5 TeV per beam. Tears of joy and relief accompanied thunderous applause in the CERN Control Centre and the experiments’ control rooms. That Tuesday, when all four of the LHC’s big detectors – <a href="/science/experiments/alice">ALICE</a>, <a href="/science/experiments/atlas">ATLAS</a>, <a href="/science/experiments/cms">CMS</a> and <a href="/science/experiments/lhcb">LHCb</a> – saw high-energy collision debris for the first time, was the culmination of <strong>over 30 years of dreams, plans and dedication</strong>. The first papers showing early results were presented days later and, within a few months, the LHC had helped “rediscover” Standard-Model particles that had originally taken decades to find.</p> <figure class="breakout-right"><div style="position: relative; padding-top: 56.25%;"><iframe allowfullscreen="" frameborder="0" src="https://www.youtube-nocookie.com/embed/cnJvpbLp4p8?rel=0&amp;hl=en&amp;cc_lang_pref=en&amp;cc_load_policy=1" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></div> <figcaption>Relive the moments leading up to the first high-energy collisions at the LHC (Credit: CERN)</figcaption></figure><p class="column-left image-breakout">In the ten years since, we have witnessed the awesome capabilities of not only the LHC but also the detectors that collect data from the collisions. While the accelerator has performed <strong>beyond expectations</strong>, so too have these experimental apparatuses, receiving far greater collisions every instant than they had been designed for and filtering out the interesting ones for analysis. The collaborations operating them have published <strong>hundreds of scientific papers</strong> using data that are unique in every sense.</p> <p class="column-left image-breakout">The LHC’s saga, though, has just begun. The machine is expected to operate until the end of the ’30s and nearly 95% of the LHC’s promised data volume is still to come. However, the analysis of the data collected thus far – in particular phenomena associated with the Higgs boson – has already begun to show where a future accelerator should point its bow.</p> <p class="column-left image-breakout">In the coming weeks, to mark the first ten years of one of <strong>humanity’s greatest scientific endeavours</strong>, we will publish a series of features on home.cern covering the physics results that have shaped our understanding of the universe – from probing the Standard Model and the early universe, to the new vistas that the Higgs boson has opened up, to the mysteries of dark matter and more. Celebrate <strong>ten years of LHC physics</strong> with us.</p> </div> </div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <hr class="column-left image-breakout" /><p class="column-left image-breakout"><i>Meanwhile, the celebrations have already begun: the latest issue of the </i><strong>CERN Courier</strong><i> has several stories that might interest you. <i><a href="https://cerncourier.com/a/bang-beam-bump-boson/">Bang, beam, bump, boson</a><i> describes life at the helm of the LHC; </i><a href="https://cerncourier.com/a/a-labour-of-love/">A labour of love</a><i> focuses on the lives of the experimentalists operating the gigantic detectors; and </i><a href="https://cerncourier.com/a/lhc-at-10-the-physics-legacy/">LHC at 10: the physics legacy</a><i> provides an in-depth look at the new knowledge we have gained from theory and experiment.</i></i></i></p> <p><i><i> </i></i></p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> The Large Hadron Collider began its physics programme on this day a decade ago </div> </div> </div> Mon, 30 Mar 2020 11:43:23 +0000 achintya 153509 at https://home.cern Coding has no gender https://home.cern/news/series/women-science/coding-has-no-gender <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__centered section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p>With 11 February marking the <a href="http://www.un.org/en/events/women-and-girls-in-science-day/" target="_blank">International Day of Women and Girls in Science</a>, female physicists, engineers and computer scientists from CERN and from <a href="http://www.fnal.gov/pub/about/index.html">Fermilab</a> share their experiences of building a career in science.</p> <h2><a id="Eva" name="Eva"></a>Evangelia Gousiou: “Nothing beats the rush you get when something that you designed works for the first time.”</h2> <figure><div><iframe allow="encrypted-media" allowfullscreen="" frameborder="0" gesture="media" height="315" src="https://www.youtube.com/embed/YpJXRPivg_A?rel=0"></iframe></div> <figcaption>Electronics engineer, Evangelia Gousiou, talks about what led her to a career in engineering. (Video: Jacques Fichet/CERN)</figcaption></figure><p>Electronics engineer, Evangelia Gousiou, began her career studying IT and Electronics in Athens, Greece, before beginning an internship at a manufacturing plant in Thailand. She came to CERN for a one-year position, and now, ten years later is still at CERN enjoying a job that is never boring.</p> <blockquote>“Work is never repetitive, which makes it very rewarding. I usually follow a project through all its stages from conception of the architecture, to the coding and the delivery to the users of a product that I have built to be useful for them. So I see the full picture and that keeps me engaged.” - <strong>Evangelia Gousiou</strong></blockquote> <p>For Evangelia, to be a good electronics engineer means knowing a range of disciplines, from software to mechanics. There is also the human aspect, as she works daily with people from many different cultures.</p> <p>At school, her favourite subjects were maths and physics, as she enjoyed finding out how things worked, yet Evangelia never dreamt of being an engineer when she grew up. When the time came to choose what to study, she felt that engineering would be something interesting and future-proof, and then she got hooked and now can’t imagine doing anything else. <em>“I would recommend engineering professions for their intellectual challenge and the empowerment that they bring,”</em> she beams.</p> <h2><a id="Jeny" name="Jeny"></a>Jeny Teheran: “What I love the most is to work with teams around the world.”</h2> <figure><div><iframe allow="encrypted-media" allowfullscreen="" frameborder="0" gesture="media" height="315" src="https://www.youtube.com/embed/nj2GWhxUD6M?rel=0"></iframe></div> <figcaption>Jeny Teheran shares the best parts of being a security analyst and cybersecurity researcher at Fermilab. (Video: Fermilab)</figcaption></figure><p>Jeny Teheran is a security analyst and cybersecurity researcher at Fermi National Accelerator Laboratory. That means keeping up with and taking care of hardware and software vulnerabilities so that the experiments can carry out their science in a secure manner. It’s a fast-paced job where you have to come up with the best solution you can put in place, right in the moment.</p> <blockquote>“I would recommend this job because it challenges you. It pushes you to be on top of your game. You have to improve your analytical skills; you have to react fast; you have to communicate better.” – <strong>Jeny Teheran</strong></blockquote> <p>Jeny came to Fermilab from the Caribbean coast of Colombia. She grew up in a house with few toys but lots of books, and says she has always felt close to science. With a degree in systems and computing engineering, she arrived at Fermilab four years ago as an intern to work in the offline production team for neutrino experiments. A year later, she was hired as a security analyst. <em>“And I’m loving it,”</em> she says.</p> <h2><a id="Sima" name="Sima"></a>Sima Baymani: “There is a lot of collaboration, and this, for me, is part of the joy of programming”</h2> <figure><div><iframe allow="encrypted-media" allowfullscreen="" frameborder="0" gesture="media" height="315" src="https://www.youtube.com/embed/38iHRuyPKAc?rel=0"></iframe></div> <figcaption>Computer science engineer, Sima Baymani, talks about the freedom, creativity and collaboration of computer programming. (Video: Jacques Fichet/CERN)</figcaption></figure><p>Computer science engineer, Sima Baymani was born in Iran before her family fled war when she was young to start a new life in Sweden. Her parents were academics, and Sima and her sisters were always encouraged to learn more about everything. Her mother, a physicist, had to restart her career in Sweden and chose to pursue database management and programming. Her enjoyment of her job, coupled with an inspiring Danish mathematics teacher, were two factors that helped lead Sima towards studying computer science.</p> <p><em>“In school I was interested in almost all subjects. But I can see that the IT boom in Sweden had an effect on me, and on other women, because when we started university it was one of the peaks of women studying computer science.”</em> At university, Sima wanted to understand how computers worked, so she specialised in hardware and embedded systems. After graduation she worked as an independent consultant for 10 years before joining CERN.</p> <blockquote>“You can work all over the world, because programming is the same everywhere. If you value freedom and flexibility then programming is something for you – it’s really something that anyone can pursue if they want to.” - <strong>Sima Baymani</strong></blockquote> <p>She has encountered challenges in fighting gender and ethnic stereotypes, and often felt that she had to work harder to prove herself. Yet part of her joy of programming is collaborating with colleagues to find creative solutions to complex problems and to develop new products or new functionality. <em>“Technology is everywhere in our society; the problems and solutions you can work with creatively are endless,”</em> she enthuses.</p> <h2><a id="Margherita" name="Margherita"></a>Margherita Vittone-Wiersma: “You feel connected with the research.”</h2> <figure><div><iframe allow="encrypted-media" allowfullscreen="" frameborder="0" gesture="media" height="315" src="https://www.youtube.com/embed/FsAO5FVKeOk?rel=0"></iframe></div> <figcaption>Margherita Vittone-Wiersma came to Fermilab as a physicist, but transitioned to the computing side of science. (Video: Fermilab)</figcaption></figure><p>Margherita Vittone-Wiersma came to Fermilab as a physicist in February 1985. Together with a group of researchers from Italy’s Institute of Nuclear Physics, she began a new experiment called E 687. But she soon learned that she preferred working on data acquisition and the many methods to store and access the huge amount of data coming out of science experiments. What was once mere megabytes of data is now terabytes of information – and experimental physicists need to be able to retrieve stored data and monitor data coming from the detectors in real-time.</p> <blockquote>It’s been an incredible change in scale of the amount of data that is handled by computers and has to be analyzed by the physicists. – <strong>Margherita Vittone-Wiersma</strong></blockquote> <p>Margherita migrated from physics to her new role in computing through lots of hands-on learning and classes in different programming languages and software development offered at Fermilab. She officially joined the lab’s computing division in 1989. <em>“It’s a great experience to work with the physicists,” </em>she says. Together physicists and computing experts iterate over tools <em>“to make sure that everything is working the way they expect. It’s very rewarding.”</em></p> <h2><a id="Sofia" name="Sofia"></a>Sofia Vallecorsa: “Technology is part of society, so learning computing can be empowering”</h2> <figure><div><iframe allow="encrypted-media" allowfullscreen="" frameborder="0" gesture="media" height="315" src="https://www.youtube.com/embed/kQCLNf3L3Oo?rel=0"></iframe></div> <figcaption>Physicist Sofia Vallecorsa talks about how computing changed from being a tool to being a passion. (Video: Jacques Fichet/CERN)</figcaption></figure><p>Italian physicist Sofia Vallecorsa always knew that she wanted to study science. Her mother was a physicist and her father a mathematician, so it felt natural to her to choose a physics degree. During her studies she saw computing simply as a tool, but as time went on her love for computing grew. Computing was interesting because it was challenging.</p> <blockquote>“Coding reminded me of being a kid playing with a challenging problem. It felt so rewarding when I found the solution.” - <strong>Sofia Vallecorsa</strong></blockquote> <p>After her studies she moved into computing and now works in the CERN physics department providing software tools for the experimental physicists. Coming to computing via a different background, meant making more effort to learn things for herself. But this taught her to face challenges one step at a time to reach her goal. <em>“I use a lot of machine-learning in my work and this was something that I had to learn from scratch. Yet it is so interesting and important to many fields and has really expanded my horizons to work with experts outside of particle physics,”</em> she exclaims.</p> <h2><a id="Krista" name="Krista"></a>Krista Majewski: “Programming lets you break down problems and solve things.”</h2> <figure><div><iframe allow="encrypted-media" allowfullscreen="" frameborder="0" gesture="media" height="315" src="https://www.youtube.com/embed/c1bajUSeswg?rel=0"></iframe></div> <figcaption>Krista Majewski had a biomedical engineering degree but kept returning to programming. (Video: Fermilab)</figcaption></figure><p>Krista Majewski came to Fermilab nine years ago as a software developer and now works in an operations role. She is a computing services specialist and part of the grid and cloud operations group, which manages computing clusters for the CMS experiment and other intensity frontier experiments at the lab.</p> <blockquote>“My typical day would be maintaining the services that our group is responsible for and the machines that they run on. So if there are problems with a computing cluster where a user can’t run their jobs, or they’re trying to run on resources on the grid and they’re unable to, then our group would be responsible for helping debug some of those issues.” – <strong>Krista Majewski</strong></blockquote> <p>Her path to programming at Fermilab has been winding. After receiving a degree in biomedical engineering, she worked in web development and programming for a large consulting firm, then moved to the financial industry. But programming called her back, and she earned a master’s degree in computer science to start her new career.</p> <p>For Krista, programming is similar to something she enjoyed as child: solving puzzles. <em>“I think it’s a skill that you use in a lot of different ways,” </em>she says.</p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> Showcasing female computer programmers from CERN and Fermilab to mark the International Day of Women and Girls in Science </div> </div> </div> Mon, 05 Feb 2018 10:12:23 +0000 everisdrupal 5090 at https://home.cern ISOLDE: 50 years of cutting-edge science benefitting society https://home.cern/news/series/meet-isolde/isolde-50-years-cutting-edge-science-benefitting-society <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__centered section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p>Last Monday, 16 October 2017, exactly 50 years to the day after the first radioactive beam was produced at <a href="http://home.cern/about/experiments/isolde">ISOLDE</a> in 1967, we celebrated 50 years of physics at the facility.</p> <p>ISOLDE is the longest-running experimental facility at CERN. What started as a small nuclear physics experiment, has now grown over half a century into a facility that provides beam for over 50 experiments, and 500 users. (Read: <a class="bulletin" href="https://home.cern/about/updates/2017/10/meet-isolde-where-did-it-all-begin">Meet ISOLDE: Where did it all begin?</a>).</p> <p>In this period, 113 isotopes have been discovered for the first time at ISOLDE, granting CERN fifth place worldwide on the <a href="https://people.nscl.msu.edu/~thoennes/isotopes/top-labs.pdf">Top 25 Labs for Nuclide Discovery</a> list. With the long-awaited HIE-ISOLDE upgrade (Read: <a class="bulletin" href="https://home.cern/about/updates/2017/10/meet-isolde-future-physics-hie-isolde">Future physics with HIE-ISOLDE</a>), due to be completed next year, the scientists at ISOLDE will have the chance to study ever more exotic nuclei, be able to answer more of our questions about our universe and perhaps discover even more isotopes.</p> <p>But ISOLDE does much more than make discoveries. The facility is helping to make computers faster with its research into <a href="http://iopscience.iop.org/article/10.1088/1361-6471/aa81ac?fromSearchPage=true">solid state physics</a>, and is currently contributing research on ways to treat cancer with radiation.</p> <p>With the advent of CERN-MEDICIS (Read: <a class="bulletin" href="https://home.cern/about/updates/2017/10/meet-isolde-what-can-isolde-do-cancer-research">What can ISOLDE do for cancer research?),</a> a new facility attached to ISOLDE, which will start producing isotopes later this year, ISOLDE will have even more scope for helping make breakthroughs in medical research.</p> <p>Radioactive isotopes are already widely used by the medical community, for imaging, diagnostics and radiation therapy. But many of the isotopes currently used are not perfect; they don’t target tumours closely enough, or a different type of radiation might be better suited for the imaging process. MEDICIS hopes to be able to produce isotopes that more accurately meet the needs of medical professionals.</p> <p>To mark the anniversary, ISOLDE’s user community came together to publish <a href="http://iopscience.iop.org/journal/0954-3899/page/ISOLDE%20laboratory%20portrait">a portrait of the Laboratory</a>, with multiple open access reports looking at the different physics and applications currently studied at ISOLDE.</p> <p>With fifty years of history and experience to back these new upgrades and clear benefits for our society ISOLDE is, and will remain, one of the best facilities in the world for nuclear physics research, and a jewel in CERN’s crown.</p> <p><em>Find out more about ISOLDE by reading </em><a class="bulletin" href="http://home.cern/about/updates/series/meet-isolde"><em>Meet ISOLDE</em></a><em> and watching the short documentary series below (subtitles available in English and French).</em></p> <figure><iframe allowfullscreen="" frameborder="0" height="415" src="//www.youtube.com/embed/ebH7DKoxX_s?list=PLAk-9e5KQYEqdW9xuRMYPgnlz0RFsoyDK" width="100%"></iframe></figure> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> 50 years ago, the first radioactive beam at ISOLDE was produced </div> </div> </div> Tue, 24 Oct 2017 21:31:07 +0000 everisdrupal 5096 at https://home.cern Meet ISOLDE: Fresh faces bring fresh ideas https://home.cern/news/series/meet-isolde/meet-isolde-fresh-faces-bring-fresh-ideas <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__centered section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p>Monika Piersa leans across the coffee table in CERN’s cafeteria like she’s sharing a secret:</p> <p>“Anytime someone’s surprised nuclear physics takes place at CERN, I tell them why it makes sense – it helps with astrophysics, nuclear power, etc. It’s just as important as the <a href="/topics/higgs-boson">Higgs</a>!”</p> <figure><iframe allowfullscreen="" frameborder="0" height="400" src="//www.youtube.com/embed/UV4LwRjj9tA?list=PLAk-9e5KQYEqdW9xuRMYPgnlz0RFsoyDK&amp;cc_load_policy=1&amp;rel=0" width="100%"></iframe> <figcaption>Low-energy physics is at the heart of the ISOLDE facility, and is where the collaboration has built its reputation as the best facility in the world for studying radioactive isotopes. In part three of our series about the ISOLDE facility we learn more about how low-energy physics at ISOLDE has evolved over the past half century. (Video: Christoph Madsen/CERN)</figcaption></figure><p>As a summer student in 2016, Monika worked at CERN’s longest running experimental facility, <a href="/about/experiments/isolde">ISOLDE</a> (Isotope mass Separator On-Line). This week, the facility celebrates fifty years of physics, low-energy nuclear physics to be precise.</p> <p>CERN is best known for physics at high energies. Indeed, the same accelerators that feed ISOLDE – originally the <a href="https://home.cern/about/accelerators/synchrocyclotron">Synchrocyclotron</a> (the SC) and now the Proton Synchrotron Booster (PSB) – also provide protons for CERN’s flagship <a href="http://home.cern/topics/large-hadron-collider">Large Hadron Collider</a> (LHC). But despite being less widely known, up to 60 per cent<a href="/about/accelerators"> of all the protons that enter the accelerator chain</a> go to ISOLDE.</p> <p>The low-energy facility uses so many of the protons because, by bombarding ISOLDE’s target<strong> </strong>with as many protons as possible, the facility can produce more exotic nuclear isotopes. These isotopes are then separated and delivered via a dozen low-energy beamlines to many experimental setups.</p> <figure class="cds-image breakout-right" id="CERN-EX-1301023-02"><a href="//cds.cern.ch/images/CERN-EX-1301023-02" title="View on CDS"><img alt="ISOLDE" src="//cds.cern.ch/images/CERN-EX-1301023-02/file?size=large" /></a> <figcaption>Looking down into the ISOLDE experimental hall it’s hard to differentiate between experiments but this isn’t a problem for many of the scientists who enjoy the collaborative nature of the facility. “You can’t be working on your own and say ‘oh look I discovered electricity’ you need to go to conferences, you need to share your work. If you appear out of nowhere people won’t trust your work. Whereas if you know someone who works carefully and hard and they produce a result you trust it because you’ve seen how they work,” explains Razvan Lica. <span> (Image: Maximilien Brice/CERN)</span></figcaption></figure><h2>Everything changes</h2> <p>ISOLDE is unique not just because it is able to bombard the target with high-energy protons at 1.4 GeV, but also because the experimental hall is in a constant state of flux. Over 50 different physics experiments are performed here each year.</p> <p>Some of these experiments are “travelling” systems, which come to ISOLDE shortly before their scheduled beam time, then leave again once their data collection finishes, while several other experiments have chosen ISOLDE as their home base and stay there permanently.</p> <blockquote>“Physics is a never-ending story, when you learn something, it leaves you with more questions.”<br /><strong>- Monika Piersa, summer student at ISOLDE</strong></blockquote> <p>“ISOLDE is special for its range of experiments. There are some in solid-state physics looking at superconductors that will lead to faster or more energy-efficient computers, or biophysics and medical physics experiments looking into new cancer treatments, or experiments in nuclear astrophysics that will teach us what’s going on inside a star. Nuclear physics is applied everywhere,” says Thomas Day Goodacre, who worked on the laser set up for the <a href="http://rilis.web.cern.ch/introduction">RILIS</a> ion source at ISOLDE.</p> <figure><img alt="" src="/sites/home.web.cern.ch/files/image/inline-images/hjarlett/screen_shot_2017-10-13_at_16.35.43.png" /><figcaption>Last month, the first African-led experiment took place at CERN, when students and staff from the University of the Western Cape (UWC) investigated the isotope selenium 70 at the ISOLDE facility. “When you’re really working on a project, the other problems, language, etc., fade away. You all have the same goal: physics,” says Marika Piersa on being part of an international community. (Image: Christoph Madsen/CERN)</figcaption></figure><p>“Fundamentally ISOLDE is a user facility and anyone can submit an idea for an experiment. Any countries who are members of the ISOLDE collaboration, whether or not they are members of CERN, can submit proposals to the ISOLDE Programme Advisory Board (called INTC). The ISOLDE INTC is made up of people from other facilities around the world and they’re the ones who decide if a new experiment should happen. It’s set up to avoid bias,” he continues.</p> <h2>Building communities</h2> <p>The travelling nature of the multiple experiments at the facility, as well as a high turnover of research groups contributes to a constant state of flux in the ISOLDE experimental hall.</p> <p>“It keeps things fresh, because of people coming and going. It’s flexible, you can’t settle into one way of running, we have around 500 users with constant turnover, which leads to new demands and the infrastructure being upgraded. The multiuser component is important to ISOLDE, for creativity and ideas,” says Karl Johnston, ISOLDE’s physics coordinator.</p> <figure class="cds-image breakout-left float-right" id="CERN-PHOTO-201704-100-5"><a href="//cds.cern.ch/images/CERN-PHOTO-201704-100-5" title="View on CDS"><img alt="ISOLDE,Experiments and Tracks" src="//cds.cern.ch/images/CERN-PHOTO-201704-100-5/file?size=large" /></a> <figcaption>ISOLDE is the only nuclear facility in the world that uses a beam with an energy of 1.4 GeV. Firing this higher energy proton beam at a target produces far more isotopes than if a lower energy beam was used. This is an image of the beamlines at ISOLDE.<span> (Image: Sophia Bennett/CERN)</span></figcaption></figure><p>“There is a huge community demand on ISOLDE, the demand for beam time is really high; we don’t physically have the time to study more isotopes. So it’s a good thing more facilities are being built around the world,” says Razvan Lica, a PhD student at ISOLDE, adding that the draw for some researchers to work at ISOLDE is helped by the opportunity to live somewhere filled with beautiful nature, Switzerland.</p> <p>Knowing there’s always more to find out, and with such diverse applications, ISOLDE researchers are pushing to learn even more with the next step for ISOLDE, an upgrade called High Intensity and Energy Isolde, or HIE-ISOLDE.</p> <p>“Physics is a never-ending story,” explains Monika. “When you learn something, it leaves you with more questions. You’re constantly reaching cliffhangers, asking what next?”</p> <p> </p> <p><em>This is part 3 of the series to celebrate fifty years of physics at ISOLDE. Read more about HIE-ISOLDE and the high-energy experiments taking place at CERN’s ISOLDE facility in part four. Or <a href="/about/updates/series/meet-isolde">read the rest of the series</a>. </em></p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> To celebrate 50 years of ISOLDE physics, the third article in our series looks at how people shape the facility and the importance of low-energy beams </div> </div> </div> Sun, 21 May 2017 23:00:13 +0000 everisdrupal 5099 at https://home.cern Meet ISOLDE Live: Celebrate 50 years of physics at ISOLDE https://home.cern/news/series/meet-isolde/meet-isolde-live-celebrate-50-years-physics-isolde <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__centered section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p>On this day 50 years ago, the beams at ISOLDE were turned on, and the experiment began taking physics data. Today, that experiment has grown into a facility that provides beams for more than 50 experiments and over 500 scientists. The research done at ISOLDE has helped us to build better, faster computers, taught us more about the stars, and is helping medical researchers improve radiation treatment, for cancer. </p> <p>Find out more about ISOLDE in our series, <a href="/about/updates/series/meet-isolde">Meet ISOLDE</a>, and in our Facebook Live below, from the ISOLDE control centre for a chance to have your questions answered by our scientists. </p> <figure><iframe allowfullscreen="true" allowtransparency="true" frameborder="0" height="715" scrolling="no" src="//www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2Fcern%2Fvideos%2F1484398328314174%2F&amp;show_text=0&amp;width=560" style="border:none;overflow:hidden" width="560"></iframe></figure> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> Join us on Facebook at 14:00 CEST from the ISOLDE control centre, for a chance to have your questions answered by our scientists </div> </div> </div> Sun, 15 Oct 2017 23:00:01 +0000 everisdrupal 5104 at https://home.cern Meet ISOLDE: Where did it all begin? https://home.cern/news/series/meet-isolde/meet-isolde-where-did-it-all-begin <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation component-row__has-header effect_none is_full_height"> <div class="background__veil"></div> <div class="background-component background__cds_media" style="height: 100%;"> <figure class="cds-image" data-record-id="2282571" data-filename="10_img197" id="CERN-PHOTO-201709-212-10"> <a href="//cds.cern.ch/images/CERN-PHOTO-201709-212-10" title="View on CDS"> <img alt="ISOLDE historic photos" src="//cds.cern.ch/images/CERN-PHOTO-201709-212-10/file?size=large"/> </a> <figcaption> ISOLDE historic photos <span> (Image: CERN)</span> </figcaption> </figure> </div> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="cern-component-header-blocks component-header"> <div id="header-blocks--6" class="owl-carousel owl-theme component-header__carousel header-carousel"> <div class="header-block"> <div class="header-block__title"> <h3 class="header-block__name" > <span>Meet ISOLDE: Where did it all begin?</span> <span class="header-block__name__underline"></span> </h3> <span class="header-block__subhead" ><p class="text-align-center">By: <a href="/authors/harriet-jarlett">Harriet Jarlett</a></p> <hr /><p class="text-align-center">The first in our <a href="/news/series/meet-isolde"><span class="cern-tag">Meet ISOLDE</span></a> series to celebrate 50 years of physics at CERN’s oldest experiment, the ISOLDE facility</p> </span> </div> </div> </div> <span class="component-header__scroll"></span> </div> <a class="endof-cern-header-blocks"></a> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__centered section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="component-margin component-margin-small" ></div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p>It turns out no one knows what the DE at the end of CERN’s <a href="/about/experiments/isolde">ISOLDE</a> facility stands for. “Damned expensive?” chuckles Björn Jonson, who has just charmed me with his experiences of serving on the Nobel committee, as I sit in awe opposite him in the CERN canteen.</p> <figure><p><iframe allowfullscreen="" frameborder="0" height="500" src="//www.youtube.com/embed/ebH7DKoxX_s?list=PLAk-9e5KQYEqdW9xuRMYPgnlz0RFsoyDK&amp;cc_load_policy=1&amp;rel=0" width="100%"></iframe></p> <figcaption><p>Today, ISOLDE celebrates 50 years of physics. On this day, half a century ago, the first beams were run through the ISOLDE experiment, and CERN's longest running experimental facility began its life. To document this achievement, we've made a short documentary series. Watch the first part, on the experiment's history here.(Video: Christoph Madsen/CERN)</p> </figcaption></figure><p class="ml-2">The first four letters of CERN’s longest-running experiment site, ISOLDE, which celebrates 50 years of physics today, stand for Isotope mass Separator On-Line. As one of the first students to work on the project, I assumed that Jonson could reveal the truth about the last two letters of the acronym but, when pushed, he teases: “or it might stand for Danish Engineering, which is, of course, the best.”</p> <p class="ml-2">Jonson joined ISOLDE in 1967, when the facility had yet to become a facility and was still just a single experiment. But ISOLDE’s extraordinary history began 17 years earlier, when two physicists in Copenhagen, Otto Kofoed-Hansen and Karl-Ove Nielson, had an idea.</p> <figure class="cds-image breakout-right" id="CERN-PHOTO-7504070-1"><a href="//cds.cern.ch/images/CERN-PHOTO-7504070-1" title="View on CDS"><img alt="nuclear spectroscopy,ISOLDE,SC" src="//cds.cern.ch/images/CERN-PHOTO-7504070-1/file?size=large" /></a> <figcaption><p>Björn Jonson started working at ISOLDE in 1967 as a fellow. Three years later he got a staff position and moved his wife and three daughters to Switzerland from Sweden in his brand new Volvo. This picture was taken five years later, in 1975, just before he became leader of the ISOLDE facility. Jonson is sitting at the console setting up surface barrier detectors for the study of a beta-decay particle emission. Winfried Grüter stands on the right.</p> <span></span> <p><span>(Image: CERN)</span></p> </figcaption></figure><p>The pair wanted to learn more about the atoms that make up every piece of matter in our Universe, by studying the properties of the nucleus at their centre. They wanted to study a type of radioactive decay that some of these nuclei undergo, called Beta decay, but their own equipment was unable to separate out the interesting nuclei from the others fast enough.</p> <p class="ml-2">In 1960, a proposal was made to use CERN’s<a href="/about/accelerators/synchrocyclotron"> Synchrocyclotron</a> (the SC) accelerator to produce a high-intensity proton beam that could be directed into specially developed targets to yield lots of different atomic fragments. Different devices could then be used to ionise, extract and separate these different nuclei according to their mass, forming a low-energy beam that could then be delivered to various experimental stations. Thus, the idea of “ISOLDE”, the Isotope Separator On-Line DEvice was born.</p> <h2>Curious legacy</h2> <p>Each year, ISOLDE scientists use the facility to push the boundaries of the nuclear chart. By discovering and expanding what we know about ever more exotic nuclei, they are answering fundamental questions about our world, while also helping society by applying this knowledge to real life.</p> <figure class="cds-image breakout-left float-right" id="CERN-PHOTO-7912213-1"><a href="//cds.cern.ch/images/CERN-PHOTO-7912213-1" title="View on CDS"><img alt="ISOLDE,People" src="//cds.cern.ch/images/CERN-PHOTO-7912213-1/file?size=large" /></a> <figcaption><p>Helge Ravn (right) was put in charge by the then Director-General, Carlo Rubbia, of moving the ISOLDE facility from the SC to the new PSB.(Image: CERN)</p> </figcaption></figure><p>Although CERN’s name is the European Organization for Nuclear Research, it’s now better known for collliding high-energy beams of protons to produce and study sub-atomic particles, like the Higgs boson. But despite the trend across the rest of the Laboratory towards particle physics, at ISOLDE the focus has remained on nuclear physics, where a low-energy proton beam (of <a href="/about/accelerators">1.4 GeV</a>) isused to produce and study exotic radioactive nuclei.</p> <div class="blockquote column-right image-breakout">“Curie was an inspiration, she drew so many women into a career of nuclear physics and chemistry that now ISOLDE has one of the best ratios of female scientists”<br /><strong>– Helge Ravn, Technical Group Leader from 1971 to 2000</strong></div> <p class="column-right image-breakout">“What we do at ISOLDE is directly in line with what Madame Curie did,” says Helge Ravn. As a student in CERN’s nuclear chemistry group before the ISOLDE experiment was built, his fascination with the subject shines through. “Curie was an inspiration, she drew so many women into a career of nuclear physics and chemistry that now ISOLDE has one of the best ratios of female scientists. It’s pioneering diversity at CERN and in science,” explains Ravn.</p> <figure class="cds-image" id="CERN-PHOTO-201709-212-28"><p><a href="//cds.cern.ch/images/CERN-PHOTO-201709-212-28" title="View on CDS"><img alt="ISOLDE,Experiments and Tracks" src="//cds.cern.ch/images/CERN-PHOTO-201709-212-28/file?size=large" /></a></p> <figcaption><p>In 1991, the Synchrocyclotron was shut down, and ISOLDE had to move to a new location and be connected to the new Proton Synchrotron Booster in order to continue. The new facility was built (you can see the work here) in record time, to prevent disruption to the physics community as much as possible.<span> (Image: CERN)</span></p> </figcaption></figure><p>The research undertaken, originally by Marie Curie and now continued by the scientists at ISOLDE, is not just helping to redress the gender balance but also contributing to treating cancer with radiation, teaching us about the stars, and even helping to make computers faster.</p> <h2>Narrow escape</h2> <p>Despite ISOLDE’s reputation and achievements, it almost came to a sudden death, when the decision was finally made to shut down the ageing, analogue SC, which, having been abandoned by other experiments long before, was only supporting the ISOLDE facility.</p> <figure class="cds-image breakout-both" id="CERN-PHOTO-201511-224-5"><p><a href="//cds.cern.ch/images/CERN-PHOTO-201511-224-5" title="View on CDS"><img alt="Photowalk 2015" src="//cds.cern.ch/images/CERN-PHOTO-201511-224-5/file?size=large" /></a></p> <figcaption><p>Fifty years on, the experimental hall at ISOLDE is unrecognisable. <span> (Image: Samuele Evolvi/CERN)</span></p> </figcaption></figure><p>“Less than two years later, we had beam and could run again. It was an amazing feat that could only be achieved thanks to the infrastructure and competences at CERN. There’s nowhere else like ISOLDE,” smiles Jonson, echoing the sentiments of virtually every scientist I’ve met who works there.</p> <p>ISOLDE was relocated and now beams are provided by the <a href="/about/accelerators/proton-synchrotron-booster">Proton Synchrotron Booste</a>r and ISOLDE’s physics was able to continue. The humble 1960s experiment grew and grew, and fifty years later the facility now provies beam for roughly 50 experiments per year, supported by more than 500 scientists.</p> <p> </p> <p><em>This is the first part of a series celebrating 50 years of ISOLDE physics. You can continue reading the series <a href="/about/updates/series/meet-isolde">here</a></em>.</p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> The first in our series to celebrate 50 years of physics at CERN’s oldest experiment, the ISOLDE facility </div> </div> </div> Sun, 15 Oct 2017 23:00:15 +0000 everisdrupal 5103 at https://home.cern Meet ISOLDE: Future physics with HIE-ISOLDE https://home.cern/news/series/meet-isolde/meet-isolde-future-physics-hie-isolde <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__centered section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p>This week, ISOLDE, CERN’s nuclear physics facility, is celebrating 50 years of physics. But after half a century of studying radioactive isotopes, the facility is on the brink of a new phase in its history, as its upgrade, HIE-ISOLDE, nears completion.</p> <p>“ISOLDE makes sure that it is always improving,” says Razvan Lica, a CERN PhD student working at the ISOLDE facility.</p> <figure class="breakout-both"><iframe allowfullscreen="" frameborder="0" height="500" id="video" src="//www.youtube.com/embed/pNpfiEKaeNs?list=PLAk-9e5KQYEqdW9xuRMYPgnlz0RFsoyDK&amp;cc_load_policy=1&amp;rel=0" width="100%"></iframe>. <figcaption>Watch the fourth part in our documentary series about ISOLDE to find out more about the HIE-ISOLDE upgrade and the people building it. (Video: Christoph Madsen/CERN)</figcaption></figure><p>The HIE-ISOLDE upgrade, which will allow ISOLDE to collide beams of isotopes into targets at higher energies, is a chance for the facility to reinvent itself. The HIE stands for High Intensity and Energy, and physicists hope that it will guarantee ISOLDE another ten to fifteen years at the forefront of this area of research.</p> <p>Currently, to produce radioactive isotopes, ISOLDE takes proton beams from one of CERN’s accelerators, the <a href="http://home.cern/about/accelerators/proton-booster">Proton Synchrotron Booster</a> (PSB) and fires them into a target. The target then sends out many radioactive isotopes, which can be directed down beamlines to various experiments. HIE-ISOLDE uses a new, unique, linear accelerator (linac) to take these beams and accelerate them again, before sending them on to secondary targets, where nuclear reactions occur. </p> <figure class="cds-image" id="CERN-PHOTO-201603-057-20"><a href="//cds.cern.ch/images/CERN-PHOTO-201603-057-20" title="View on CDS"><img alt="ISOLDE,HIE-ISOLDE,Experiments and Tracks" src="//cds.cern.ch/images/CERN-PHOTO-201603-057-20/file?size=large" /></a> <figcaption>The new linac had to fit into just 16 m of space. “We had to develop a very compact linac. That’s what makes it unique. In other facilities, every cavity has its own cryostat but if we had to do that it would be far too long, so we had to squeeze all of them into one cryomodule. We had to have the solenoids fitted too, they’re almost the same length as a cavity, so we had to do lots of design, research and development. The biggest challenge was to design in spaces with clearances of just 1 mm,” explains Yacine Kadi, project leader for HIE-ISOLDE.<span> (Image: Maximilien Brice/CERN)</span></figcaption></figure><p>“When we talk about elements we use their proton number. A heavy element is one with a higher proton number, but you can have many different isotopes of the same element. These have the same proton number but a different number of neutrons,” explains Liam Gaffney, who works on the Miniball set-up, attached to one of the HIE-ISOLDE beamlines.</p> <p>Physicists like Liam use these isotopes to research a range of topics, from astrophysics, by recreating reactions that happen in the stars, to the internal structure and shape of exotic nuclei, giving us an insight into the building blocks of the world around us.</p> <p>“Previously we couldn’t do as many of the reactions as we wanted to with radioactive isotopes, as the beam energy wasn’t high enough. To study the shape of the nuclei of the heaviest elements we need higher energies to overcome an increase in the nuclei charge. More protons means a higher positive charge, and since two positive nuclei repel each other, it means a higher energy is needed to collide them,” he continues.</p> <p>“Higher energy opens a new field. We had a stepping stone with the REX upgrade, when ISOLDE first introduced the possibility of reaccelerating isotopes, in 2001, but with the higher energies from HIE-ISOLDE, it’s a new realm,” says Karl Johnston, ISOLDE’s physics coordinator, who hopes the upgrade will mean even more applications are found for ISOLDE’s research.</p> <h2>Future-proofing</h2> <p>The energy upgrade means that ISOLDE can now collect information about the properties of nuclei that were previously not accessible. Eventually, researchers will also be able to study isotopes with even more or even fewer neutrons, which are less stable and harder to produce in a laboratory. So far these isotopes have been out of the reach of physicists.</p> <figure class="cds-image breakout-both" id="CERN-PHOTO-201707-167-18"><a href="//cds.cern.ch/images/CERN-PHOTO-201707-167-18" title="View on CDS"><img alt="ISOLDE,Experiment,Experiments and Tracks" src="//cds.cern.ch/images/CERN-PHOTO-201707-167-18/file?size=large" /></a> <figcaption>There are currently three spaces for experiments to be attached to HIE-ISOLDE, with the hope that seven or more will eventually run each year. There is one permanent station attached to the linac, called Miniball, seen here, which can be set up to run multiple different experiments <span> (Image: Julien Ordan/CERN)</span></figcaption></figure><p>“Higher energy gives us the chance to study many different things. We focus on fundamental questions concerning the structure of nuclei,” explains Liam. “Studying reactions inside the stars to learn more about how the different elements are produced. Asking questions like: why are there so many heavy elements, like uranium, on the planet?”</p> <p>“HIE-ISOLDE is a major breakthrough and is the result of almost eight years of research and development, of prototyping and design. It’s a huge adventure and what makes us most proud isn’t even that we managed to build the machine but that from the start we have seen new physics and new, enthusiastic users,” enthuses Maria Borge, who led the ISOLDE group from 2012 to 2017.</p> <h2>Challenge accepted</h2> <blockquote>“Engineers told me it was mission impossible”<br /><strong>- Yacine Kadi, leader of the HIE-ISOLDE project</strong></blockquote> <p>But building a machine of this scope hasn’t been easy. Yacine Kadi, who leads the HIE-ISOLDE project, starts to laugh as he spends minutes listing the challenges the project faced.</p> <figure class="cds-image breakout-left" id="OPEN-PHO-ACCEL-2016-016-9"><a href="//cds.cern.ch/images/OPEN-PHO-ACCEL-2016-016-9" title="View on CDS"><img alt="HIE-ISOLDE,superconducting solenoid,cryo-module,Accelerators" src="//cds.cern.ch/images/OPEN-PHO-ACCEL-2016-016-9/file?size=large" /></a> <figcaption>Each cryomodule contains more than 10 000 parts, which need to be carefully cleaned, calibrated and installed. <span> (Image: Maximilien Brice/CERN)</span></figcaption></figure><p>With scarce resources, the design and development phase of the project relied on early-career researchers to carry out the majority of the work. It was a risk that paid off: “We didn’t have the resources to hire virtually any staff, but we made sure we only took the absolute best – we couldn’t afford not to – and they did a fantastic job. But then they left before the project was finished!” he explains.</p> <p>With his fair share of challenges, Yacine had to rethink construction materials when the metal niobium proved too costly, and amend original plans to avoid a building crossing the border between Switzerland and France.</p> <p>“Engineers told me it was mission impossible,” exclaims Yacine. “It was a big, complex project and the choices we made weren’t things we had much experience of at CERN. This meant we had to develop novel ideas and at the same time profit from technological breakthroughs made at CERN, for the <a href="http://home.cern/about/accelerators/lep">Lepton Positron Collider</a> (LEP). In the end it was just a question of the imagination of our physicists and technical staff.”</p> <figure class="cds-image breakout-right" id="CERN-PHOTO-201707-167-7"><a href="//cds.cern.ch/images/CERN-PHOTO-201707-167-7" title="View on CDS"><img alt="ISOLDE,Experiment,Experiments and Tracks" src="//cds.cern.ch/images/CERN-PHOTO-201707-167-7/file?size=large" /></a> <figcaption>The inflatable T-Rex at HIE-ISOLDE is the mascot of the REX experiment, which was an earlier post-accelerator at ISOLDE.<span> (Image: Julien Ordan/CERN)</span></figcaption></figure><p>HIE-ISOLDE is unique in its design because it had to fit a lot of accelerating power into a very compact space. Linear accelerators use <a href="https://home.cern/about/engineering/radiofrequency-cavities">radiofrequency cavities</a> to accelerate a beam. Normally an accelerator will house each one of these cavities in its own cryostat – a vacuum chamber that supercools the cavity so that the helium needed for the superconductors to work stays liquid – but HIE-ISOLDE didn’t have the room for each cavity to have its own cryostat. Instead, one way the engineers kept the system compact was to build cryomodules that each contain five cavities but require only one cryogenic system.</p> <p>“Yes, HIE-ISOLDE was a challenge from a technical point of view, but it was a major human adventure for me. You increase your field of knowledge, and you work in different domains, so you meet many different people. I met people I wouldn’t ever have met even after spending forty years at CERN,” he continues.</p> <p>Currently, HIE-ISOLDE is nearing the completion of its energy upgrade and has already had two successful running periods with more than 15 experiments. The last of the four superconducting cryomodules is due to be installed over the winter shutdown in 2018, and will allow the machine to accelerate the radioactive beams to energies of 10MeV/u.</p> <p>“Others might get to that energy but no other facility in the world can accelerate very heavy nuclei. We can do that,” says Maria, emphasising the importance of this new upgrade, which cements ISOLDE’s role at the forefront of nuclear physics for the foreseeable future. </p> <p> </p> <p><em>This week, ISOLDE, CERN’s nuclear facility, is celebrating 50 years of physics with a series of articles and a short documentary series that takes a closer look at the facility and the people that work there. See <a href="https://test-home.web.cern.ch/about/updates/series/meet-isolde">the rest of the series here</a>.</em></p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> In the fourth part of our series, celebrating 50 years of physics at ISOLDE, we look at the almost-complete HIE-ISOLDE upgrade </div> </div> </div> Thu, 12 Oct 2017 23:00:08 +0000 everisdrupal 5098 at https://home.cern Meet ISOLDE: Targeting new discoveries https://home.cern/news/series/meet-isolde/meet-isolde-targeting-new-discoveries <div class="layout layout__region featured-story-page-node-layout-content"> <div class="field--items"> <div class="field--item"> <div class="component-row component-row__display__fluid section-navigation component-row__has-header effect_none is_full_height"> <div class="background__veil"></div> <div class="background-component background__image" style="background:url(&#039;/sites/home.web.cern.ch/files/2018-10/targets.jpg&#039;) no-repeat center top / cover; height: 100%;"></div> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="cern-component-header-blocks component-header"> <div id="header-blocks--8" class="owl-carousel owl-theme component-header__carousel header-carousel"> <div class="header-block"> <div class="header-block__title"> <h3 class="header-block__name" > <span>Meet ISOLDE: Targeting new discoveries</span> <span class="header-block__name__underline"></span> </h3> <span class="header-block__subhead" ><p class="text-align-center">By: <a href="/authors/harriet-jarlett">Harriet Jarlett</a></p> <hr /><p class="text-align-center">What is a target and how is it built? This is the second article in our <a href="/news/series/meet-isolde"><span class="cern-tag">Meet ISOLDE</span></a> series celebrating 50 years of physics at CERN’s longest running experimental facility</p> </span> </div> </div> </div> <span class="component-header__scroll"></span> </div> <a class="endof-cern-header-blocks"></a> </div> </div> </div> </div> </div> <div class="field--item"> <div class="component-row component-row__display__centered section-navigation effect_none"> <div class="component-row__row"> <div class="component-row__column component-row__center section-has-no-column col-md-12 col-sm-12 col-xs-12"> <div class="box-effects-wrapper "> <div class="component-margin component-margin-small" ></div> <div class="text-component text-component-page clearfix"> <div class="text-component-text cern_full_html"> <p>For Richard Catherall, the age-old alchemist’s dream of changing one element into another is a simple reality of his working day.</p> <figure><iframe allowfullscreen="" frameborder="0" height="400" src="//www.youtube.com/embed/6TgYIj4pVx0?list=PLAk-9e5KQYEqdW9xuRMYPgnlz0RFsoyDK&amp;cc_load_policy=1&amp;rel=0" width="100%"></iframe> <figcaption>Targets are vital for any experiment at ISOLDE, as it is within this component that the radioactive isotopes are produced. In part two of our series we look at the backbone of any ISOLDE experiment, the target production.(Video: Christoph Madsen/CERN)</figcaption></figure><p>Thirty-four years ago he began his career at CERN, and today he is one of just a handful of people here capable of building the targets – the crucial components in the production of exotic isotopes that are used in the low and high energy beams necessary for an ISOLDE experiment to run.</p> <figure class="cds-image breakout-right" id="CERN-PHOTO-201709-212-34"><a href="//cds.cern.ch/images/CERN-PHOTO-201709-212-34" title="View on CDS"><img alt="ISOLDE,Experiments and Tracks" src="//cds.cern.ch/images/CERN-PHOTO-201709-212-34/file?size=large" /></a> <figcaption>Richard Catherall (seen here on the far left) arrived at CERN in 1983. Now he is one of just a handful of people at ISOLDE capable of producing the targets that give the experiments the ability to change one element into another.<span> (Image: CERN)</span></figcaption></figure><p>As ISOLDE celebrates 50 years of cutting-edge physics, we delve deeper into what goes into building these vital elements of CERN’s longest-running facility.</p> <h2>Exploring exotic new realms</h2> <p>Each target is tailor-made for each of ISOLDE’s experiments. They are each built from different materials, to produce the required isotopes when the high-intensity proton beam from the Proton Synchrotron Booster (PSB) is directed into it. There are more than 100 combinations of materials and ion sources, which can be put together in a variety of ways to build targets that produce the different isotopes. It is here that protons from the bottle of hydrogen at the start of CERN’s accelerator chain produce the 1300 different isotopes being studied at ISOLDE.</p> <p>“I’m just there to make sure it works,” Richard says modestly.</p> <p>“I do find it challenging,” he explains. “Depending on the approved scientific proposal, we design and build the appropriate target for the requested nuclei. The challenge comes when we have to design a target and ion source combination to produce beams of nuclei that have never been produced before. If we look to the nuclear chart, the new and exciting physics often comes from the nuclei far from stability, where production rates of short-lived isotopes are extremely low and sometimes unknown. The exciting part is being able to produce pure beams of nuclei at the extremity of the nuclear chart.”</p> <figure class="cds-image breakout-left float-right" id="CERN-EX-0302006-01"><a href="//cds.cern.ch/images/CERN-EX-0302006-01" title="View on CDS"><img alt="ISOLDE,tantalum,tantale" src="//cds.cern.ch/images/CERN-EX-0302006-01/file?size=large" /></a> <figcaption>This is a target at ISOLDE for producing tantalum-232, after it has been irradiated. Once a target is irradiated it is handled by robots.<span> (Image: Maximilien Brice/CERN)</span></figcaption></figure><p>Richard’s enthusiasm for his role is infectious. I find myself captivated as he goes into detail describing a new technique the team have developed, to build a target that produces the rare isotope astatine, which involves reversing the polarity of the entire machine. It’s estimated that less than 30 grams of this unstable element are available on Earth at any one time, and it is incredibly difficult to reproduce in a laboratory as it decays so quickly, so the achievement is clear.</p> <p>“We build about thirty targets a year, on demand. Each target has to produce enough isotopes for the experiment to be successful, but this is hard to test before actually bombarding it with protons. We do a quality check with stable beams beforehand, but the quantity of radioactive nuclei is something we can only verify just before the experiment starts,” says Richard.</p> <p>But Richard and his colleagues can be proud, since their targets (along with the ion source) are able to produce the largest selection of isotope beams, and the most pure, of any ISOL physics laboratory in the world.</p> <h2>From car construction to nuclear discovery</h2> <p>The targets are handled by robots (two of many robots used at CERN for physics research). This is because once the targets are placed on the target station and hit with a beam of protons, they become radioactive. So, for safety reasons, they can only be handled by specially adapted robotic arms.</p> <figure class="cds-image" id="CERN-EX-0204007-03"><a href="//cds.cern.ch/images/CERN-EX-0204007-03" title="View on CDS"><img alt="ISOLDE,targets,robots" src="//cds.cern.ch/images/CERN-EX-0204007-03/file?size=large" /></a> <figcaption>The robot arms in ISOLDE’s target area allow the radioactive targets to be handled safely<span> (Image: Maximilien Brice/CERN)</span></figcaption></figure><p>These robots may look familiar if you’ve ever seen a TV advert of a car being built. They were originally designed to do just that, but in ISOLDE they have been adapted and made radiation-resistant to move the targets without human intervention.</p> <h2>Increasing intensity, increasing rarity</h2> <p>The targets, and the team that produce them, are a vital part of what makes ISOLDE such a unique facility at CERN. Soon the team will be pushed to produce more reliable targets, and harder-to-produce isotopes, as the arrival of the new Linac4 will increase the intensity and energy of the beam provided by the PSB.</p> <p>For Richard and his team, this just adds to the excitement of their daily work. As we look back over fifty years of physics at ISOLDE, we can also look forward to the bright future ahead. “There’s still lots of opportunity for new isotopes to be discovered,” he concludes.</p> <p> </p> <p><em>Find out more about ISOLDE, <a href="/about/updates/series/meet-isolde">read the rest of the Meet ISOLDE series </a>here.</em></p> </div> </div> </div> </div> </div> </div> </div> <div class="field--item"> What is a target and how is it built? The second article in a series celebrating 50 years of physics at CERN’s longest running experimental facility </div> </div> </div> Sun, 15 Oct 2017 23:00:14 +0000 everisdrupal 5102 at https://home.cern