Muon g-2/EDM experiment at J-PARC

Abstract

The recent measurement of the muon anomalous magnetic moment, 𝑎 𝜇 = (𝑔 𝜇 − 2)/2, with a precision of 0.46 ppm at the Fermilab National Accelerator Laboratory (FNAL) confirmed the anomaly observed at the Brookhaven National Laboratory (BNL) from more than a decade ago. The value of this anomaly between the measurements and the Standard Model (SM) prediction has been reported to be 4.2 standard deviations. Though this may indicate the existence of new physics beyond the SM, it should be verified through other measurements. The J-PARC experiment aims to measure 𝑎 𝜇 and the electric dipole moment (EDM) in a completely different way from the BNL and FNAL experiments, using a low-emittance muon beam realized through the acceleration of the thermal muons. This paper reports the current status of each experimental component. *** The 22nd International Workshop on Neutrinos from Accelerators (NuFact2021) ***

Hadronic Light-by-light contribution to muon (g-2)

“…Beside the current Fermilab's experimental effort, a J-PARC experiment aims to measure 𝑎 𝜇 and the electric dipole moment (EDM) in a completely different way, by using a low-emittance muon beam realized by acceleration of the thermal muons. [10,11] This quite significant deviation motivate further improvements in reducing the uncertainties of the theoretical prediction of muon 𝑔 − 2. For a very long time, the HLbL contribution is estimated by models.…”