Lattice Charge Overlap I: Elastic Limit of Pi and Rho Mesons

TL;DR

This study uses lattice QCD to analyze the charge overlap functions of pion and rho mesons, providing insights into their electromagnetic properties and comparing different computational approaches.

Contribution

It introduces lattice QCD calculations of charge overlap functions for pion and rho mesons, highlighting differences in signal quality and extracting form factor ratios and the rho g-factor.

Findings

Good signal for pion charge overlap functions.

Rho meson results are noisier but yield a g-factor of approximately 2.25.

Charge overlap ratios suggest monopole mass to rho mass ratios close to unity.

Abstract

Using lattice QCD on a $16^{3}\times 24$ lattice at $\beta=6.0$, we examine the elastic limit of charge overlap functions in the quenched approximation for the pion and rho meson; results are compared to previous direct current insertion calculations. A good signal is seen for the pion, but the electric and magnetic rho meson results are considerably noisier. We find that the pion and rho results are characterized by a monopole mass to rho mass ratio of $0.97(8)$ and $0.73(10)$, respectively. Assuming the functional form of the electric and magnetic form factors are the same, we also find a rho meson g-factor of $g=2.25(34)$, consistent with the nonrelativistic quark model.