The first day of the European Physical Society's High Energy Physics 2013 conference presented us with more precise measurements of several particles and particle decays - including the Higgs, W and Z bosons, as well as many others - from the Large Hadron Collider (LHC) and the Tevatron. With a year of studies behind us, the Higgs boson results indicate that though the particle behaves, at first sight, much like what is predicted by the Standard Model, the possibility of exploring new physics is still an exciting quest.
One such quest involves gravity, a force not explained by the Standard Model. Physicists in ATLAS and CMS are testing explanations as to why gravity, one of nature’s fundamental forces, is so weak. Scientists are looking for evidence of two possible causes- either gravity is propagated elsewhere and we feel just a whisper of its true strength or we need to push it to become stronger using the immense energy of the LHC. New results from ATLAS and CMS were also presented on searches for new particles that decay to top quarks - the heaviest elementary particles discovered so far.
Turning to the sky with astrophysics, the IceCube collaboration reported detecting 28 extremely energetic neutrinos. They first reported two events earlier this year, each one measuring at an energy above 1 Petaelectronvolt, much higher than what was reached with the LHC.
The Fermi Large Area Telescope collaboration reported on a puzzling gamma ray signal, first reported by Christoph Weniger and collaborators using publicly released LAT data, with an energy of 130 GeV. One interesting possibility is that these gamma rays could be generated when dark matter particles annihilate but another cause could be an instrumental effect. Interpretation is difficult though, so more analysis is necessary. The HESS 2 experiment is currently accumulating data and will soon be able to cross-check these results.