The muon g-2 and lattice QCD hadronic vacuum polarization may point to new, long-lived neutral hadrons

by Glennys Farrar (NYU)

Friday 14 Oct 2022, 14:00 → 16:00 Europe/Zurich

4/3-006 - TH Conference Room (CERN)

The experimental value the muon g-2 is 4.2 sigma larger than the Standard Model prediction, when the hadronic vacuum polarization contribution (HVP) is determined from the measured R-ratio.  At the same time, the HVP calculated in lattice QCD also significantly exceeds the measured R-ratio value.  A review of existing e+e experiments reveals that the contribution of certain types of hadronic final states would not have been counted, due to the event selection and trigger requirements of experiments to date.  We further show that the lattice HVP and g-2 discrepancies can be naturally explained by an undetected contribution to e+e—> hadrons from production of previously unidentified neutral, long-lived hadrons.  We suggest two potential candidates for the new hadrons and propose several experimental tests.  There are favorable cosmological and astrophysical impacts of Dark Matter having hadronic interactions, which will be discussed as time permits.

g-2_CERN_101422.pdf