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Keshavarzi, Alexander

Publications and source records attributed to Keshavarzi, Alexander.

Data-driven estimates for light-quark-connected and strange-plus-disconnected hadronic g − 2 window quantities

A number of discrepancies have emerged between lattice computations and data-driven dispersive evaluations of the RBC/UKQCD intermediate-window-hadronic contribution to the muon anomalous magnetic moment. It is therefore interesting to obtain data-driven estimates for the light-quark-connected and strange-plus-disconnected components of this window quantity, allowing for a more detailed comparison between the lattice and data-driven approaches. The aim of this paper is to provide these estimates, extending the analysis to several other window quantities, including two windows designed to focus on the region in which the two-pion contribution is dominant. Clear discrepancies are observed for all light-quark-connected contributions considered, while good agreement with lattice results is found for strange-plus-disconnected contributions to the quantities for which corresponding lattice results exist. The largest of these discrepancies is that for the RBC/UKQCD intermediate window, where, as previously reported, our data-driven result, a μ W 1 , lqc = 198.9 ( 1.1 ) × 10 − 10 , is in significant tension with the results of 8 different recent lattice determinations. Our strategy is the same as recently employed in obtaining data-driven estimates for the light-quark-connected and strange-plus-disconnected components of the full leading-order hadronic vacuum polarization contribution to the muon anomalous magnetic moment. Updated versions of those earlier results are also presented, for completeness. Published by the American Physical Society 2024

Benton, Genessa (ORCID:0009000515763654)↗

The Muon $g-2$ Experiment at Fermilab

The current ~ 3.5σ discrepancy between the experimental measurement and theoretical prediction of the muon magnetic anomaly, a µ , stands as a potential indication of the existence of new physics. The Muon g - 2 experiment at Fermilab is set to measure aµ with a four-fold improvement in the uncertainty with respect to previous experiment, with an aim to determine whether the g - 2 discrepancy is well established. The experiment recently completed its first physics run and a summer programme of essential upgrades, before continuing on with its experimental programme. The Run-1 data alone are expected to yield a statistical uncertainty of 350 ppb and the publication of the first result is expected in late-2019.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗