The ultimate precision in the measurement of the muon anomaly, $a_\mu$ = (g – 2)/2, has been constantly pursued since the sixties, when CERN played a leading role in its determination with a series of pioneering experiments that ran until the late seventies. The present most accurate $a_\mu$ measurement was carried out by the E821 Experiment at Brookhaven (USA), resulting in a 3.7 standard deviation discrepancy with the theoretical prediction of the Standard Model of particle physics. This longstanding discrepancy is one of the most intriguing hints of new physics in particle physics. In order to understand this discrepancy a new Muon g-2 experiment has been approved at Fermilab (USA) and started taking data in 2018. After an overview on the status of theory calculations for the muon g-2 and the efforts of the Muon g-2 Theory Initiative, we will report the first results of the new Muon g-2 Experiment at Fermilab which measured $a_\mu$ with a precision slightly better than the BNL one.
M. Pepe-Altarelli, P. Silva