Isovector nucleon form factors from 2+1-flavor dynamical domain-wall lattice QCD at the physical mass

Abstract

Nucleon isovector form factors calculated on a 2+1-flavor domain-wall-fermions ensemble with strange and degenerate up and down quarks at physical mass and lattice cut off, $a^{-1}$, of about 1.730(4) GeV, are reported. The ensemble was generated jointly by RBC and UKQCD collaborations with a spatial extent of $48a$ or about 5.5 fm. The form factors are calculated in collaboration with LHP collaboration as well. The resulting shape parameters of the form factors, such as vector-charge mean squared radius, $⟨r_1^2⟩$, or anomalous magnetic moment, $F_2(0)$ appear less dependent on possible excited-state contaminations than the corresponding charges. Preliminary estimates are $⟨r_1^2⟩\sim 0.142(13)\text{mbox}{fm}^2$ and $F_2(0)\sim 3.22(8)$.

Comments: 10 pages, 7 figures, talk presented at the 39th International Symposium on Lattice Field Theory - LATTICE2022, 8th-13th August 2022, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany