Nucleon strangeness form factors and moments of PDF

TL;DR

This paper presents lattice QCD calculations of nucleon strangeness form factors and moments of PDFs, achieving improved precision and consistency with experimental data through advanced stochastic methods.

Contribution

It introduces an efficient stochastic approach with multiple sources to accurately compute nucleon strangeness form factors and moments of PDFs in lattice QCD.

Findings

Strangeness magnetic form factor at zero momentum transfer: G_M^s(0) = -0.017(25)(07)

Enhanced signal quality with increased nucleon sources

Results are consistent with experimental measurements

Abstract

The calculation of the nucleon strangeness form factors from N_f=2+1 clover fermion lattice QCD is presented. Disconnected insertions are evaluated using the Z(4) stochastic method, along with unbiased subtractions from the hopping parameter expansion. We find that increasing the number of nucleon sources for each configuration improves the signal significantly. We obtain G_M^s(0) = -0.017(25)(07), which is consistent with experimental values, and has an order of magnitude smaller error. Preliminary results for the strangeness contribution to the second moment of the parton distribution function are also presented.