Aug 8 – 13, 2022
Hörsaalzentrum Poppelsdorf
Europe/Berlin timezone

The muon anomalous magnetic moment with staggered fermions: is the lattice spacing small enough?

Aug 12, 2022, 6:00 PM
20m
CP1-HSZ/Ground-0.001 - HS3 (CP1-HSZ)

CP1-HSZ/Ground-0.001 - HS3

CP1-HSZ

50
Oral Presentation Hadron Structure QCD in searches for physics beyond the Standard Model

Speaker

Maarten Golterman (San Francisco State University)

Description

We present new results for the light-quark connected part of the leading order hadronic-vacuum-polarization (HVP) contribution to the muon anomalous magnetic moment, using staggered fermions. We have collected more statistics on previous ensembles, and we added two new ensembles. This allows us to reduce statistical errors on the HVP contribution and related window quantities significantly. We also calculated the current-current correlator to next-to-next-to-leading order (NNLO) in staggered chiral perturbation theory, so that we can correct to NNLO for finite-volume, pion-mass mistuning and taste-breaking effects. We discuss the applicability of NNLO chiral perturbation theory, emphasizing that it provides a systematic EFT approach to the HVP contribution, but not to short- or intermediate-distance window quantities. This makes it difficult to assess systematic errors on the standard intermediate-distance window quantity that is now widely considered in the literature. In view of this, we investigate a longer-distance window, for which EFT methods should be more reliable. Our most important conclusion is that new high-statistics computations at lattice spacings significantly smaller than 0.06 fm are indispensable. The ensembles we use have been generously provided by MILC and CalLat.

Primary authors

Prof. Christopher Aubin (Fordham University) Maarten Golterman (San Francisco State University) Prof. Santiago Peris (Universtitat Autonoma de Barcelona) Prof. Thomas Blum (University of Connecticut)

Presentation materials