Nucleon and gamma N -> Delta lattice form factors in a constituent quark model

TL;DR

This paper extends a covariant quark model to match lattice QCD data for nucleon and gamma N -> Delta form factors by introducing a single adjustable parameter, achieving qualitative agreement for light pions.

Contribution

The study introduces a novel extension of a covariant quark model to unphysical lattice regions using one extra parameter, enhancing the model's applicability to lattice QCD data.

Findings

Qualitative agreement with lattice data for light pions.

Successful extension of the model to unphysical lattice regions.

Use of a single adjustable parameter to match data.

Abstract

A covariant quark model, based both on the spectator formalism and on vector meson dominance, and previously calibrated by the physical data, is here extended to the unphysical region of the lattice data by means of one single extra adjustable parameter - the constituent quark mass in the chiral limit. We calculated the Nucleon (N) and the gamma N -> Delta form factors in the universe of values for that parameter described by quenched lattice QCD. A qualitative description of the Nucleon and gamma N -> Delta form factors lattice data is achieved for light pions.