Thursday, April 27, 2023, 16:00
OSGA/EG06
Zoltan Fodor, Penn State University, Wuppertal University, FZ
Jülich, Eotvos Budapest, UC San Diego
Abstract:
Twenty years ago, in an experiment at Brookhaven National Laboratory,
physicists detected what seemed to be a discrepancy between measurements
of the muon's magnetic moment and theoretical calculations of what that
measurement should be, raising the tantalizing possibility of physical
particles or forces as yet undiscovered. The Fermilab team has just
announced that their precise measurement supports this possibility. The
reported significance for new physics is 4.2 sigma just slightly below
the discovory level of 5 sigma. However, an extensive new calculation of
the muon's magnetic moment using lattice QCD by the BMW-collaboration
reduces the gap between theory and experimental measurements. The
lattice result appeared in Nature on the day of the Fermilab
announcement. In this talk both the theoretical and experimental aspects
are summarized with two possible narratives: a) almost discovery or b)
Standard Model re-inforced. Some details of the lattice caluculation are
also shown.