Delta electromagnetic form factors and quark transverse charge densities from lattice QCD

TL;DR

This paper uses lattice QCD to compute the electromagnetic form factors of the Delta baryon, revealing its deformation and providing insights into its internal structure through transverse charge densities.

Contribution

It introduces techniques for extracting Delta form factors in lattice QCD with dynamical fermions and analyzes the deformation via electric quadrupole form factors.

Findings

Electric quadrupole form factor indicates deformation of the Delta

Magnetic moment extrapolated using chiral effective field theory

Transverse charge densities show deformation in the Delta

Abstract

We discuss the techniques to extract the electromagnetic Delta form factors in Lattice QCD. We evaluate these form factors using dynamical fermions with smallest pion mass of about 350 MeV. We pay particular attention to the extraction of the electric quadrupole form factor that signals a deformation of the Delta. The magnetic moment of the $\Delta$ is extrapolated using a chiral effective field theory. Using the form factors we evaluate the transverse density distributions in the infinite momentum frame showing deformation in the Delta.