ATLAS finds first evidence of the Higgs boson decaying to two leptons and a photon. This is one of the rarest Higgs boson decays yet seen at the LHC, with striking features that presented unique challenges for the ATLAS experiment.
Despite the huge challenges of the COVID-19 pandemic, last year saw excellent successes for the ATLAS Collaboration, including first-of-a-kind physics results and great headway made on detector upgrades.