Welcome to the digital edition of the May/June 2021 issue of CERN Courier.

In April, a keenly awaited measurement from Fermilab strengthened the longstanding tension between the measured and predicted values of the muon’s anomalous magnetic moment, generating media coverage worldwide (p7). Physicists now look forward to further data (p49) and to a deeper understanding of the tricky QCD calculations (p25) before weighing up possible signs of new physics.

Meanwhile, in March, a new LHCb measurement of a parameter called RK, which compares the rate of certain B-meson decays to muons and electrons, reinforces hints that lepton-flavour universality may be violated in the B sector (p17).

Also generating headlines this spring were the discovery of the odderon 50 years after its prediction (p8), and the demonstration of laser-cooled antihydrogen by the ALPHA collaboration (p9).

Elsewhere in this issue: upgrades to the beam-intercepting devices at the heart of CERN’s accelerator complex (p38); ALICE makes strides towards understanding the extreme conditions of the early universe (p31); news from Moriond (p21); careers advice from accelerator physicist Suzie Sheehy (p52); assessing the economic impact of particle physics (p55); and much more.

j CERN Courier May/June 2021