Circa 2016 o,.o.
An international group of physicists has observed Z-boson production with two associated photons with later Z decay to electrons, muons or neutrinos at the ATLAS experiment at the Large Hadron Collider (LHC) in CERN.
Observation of this extremely rare physics process, predicted theoretically in 1960s, further validates the Standard Model ℠, according to ATLAS experiment contributor Dimitrii Krasnopevtsev.
“Such a rare process as the Z-boson production with two associated photons is an important test of the electro-weak sector of the Standard Model. Currently, our group has not found any deviations from theoretical predictions—in other words, we have once again confirmed Standard Model,” he explained.