Strange form factors of nucleon with nonlocal chiral effective Lagrangian

TL;DR

This paper investigates the strange form factors of the nucleon using a nonlocal chiral effective Lagrangian, including loop contributions and gauge invariance, and compares results with lattice simulations.

Contribution

It introduces a nonlocal Lagrangian approach with gauge links to study nucleon strange form factors, providing results consistent with lattice data.

Findings

Charge form factor is positive.

Magnetic form factor is negative.

Strange magnetic moment is approximately -0.041.

Abstract

The strange form factors of nucleon are studied with the nonlocal chiral effective Lagrangian. One loop contributions from both octet and decuplet intermediate states are included. The relativistic regulator is obtained by the nonlocal Lagrangian where the gauge link is introduced to guarantee the local gauge symmetry. With the kaon loop, the calculated charge form factor is positive, while the magnetic form factor is negative. The strange magnetic moment is $-0.041^{+0.012}_{-0.014}$ with $\Lambda=0.9 \pm 0.1$ determined from the nucleon electromagnetic form factors. Our results are comparable with the recent lattice simulation.