Analysis of excited quark propagator effects on neutron charge form factor

TL;DR

This paper investigates how including excited quark states in the perturbative chiral quark model affects the neutron's charge form factor and radius, showing significant improvements and agreement with lattice QCD data.

Contribution

It introduces a method to incorporate excited quark states into PCQM, significantly enhancing the accuracy of neutron charge form factor predictions.

Findings

Excited quark states increase the neutron charge radius by nearly four times.

Theoretical results align well with recent lattice QCD data at low pion mass.

Including excited states improves the model's predictive power.

Abstract

The charge form factor and charge radius of neutron are investigated in the perturbative chiral quark model (PCQM) with considering both the ground and excited states in the quark propagator. A Cornell-like potential is extracted in accordance with the predetermined ground state quark wavefunction, and the excited quark states are derived by solving the Dirac equation with the extracted PCQM potential numerically. The study reveals that the contributions of the excited quark states are considerably influential in the charge form factor and charge radius of neutron as expected, and the total results are significantly improved and increased by nearly four times by including the excited states in the quark propagator. The theoretical PCQM results are found, including the ground and excited quark propagators, in good agreement with the recent lattice QCD values at pion mass of about 130 MeV.