The pion form factor on the lattice at zero and finite temperature

TL;DR

This paper computes the pion electromagnetic form factor using quenched lattice QCD at zero and finite temperature, analyzing charge radius and temperature effects with improved lattice actions.

Contribution

It presents new lattice QCD calculations of the pion form factor at different temperatures and pion masses, including extrapolation to the physical point.

Findings

Charge radius increases as pion mass decreases.

Finite temperature effects alter the pion form factor.

Results are consistent with previous zero-temperature studies.

Abstract

We calculate the electromagnetic form factor of the pion in quenched lattice QCD. The non-perturbatively improved Sheikoleslami-Wohlert lattice action is used together with the consistently O(a) improved current. We calculate the pion form factor for masses down to m_pi = 360 MeV, extract the charge radius, and extrapolate toward the physical pion mass. In the second part, we discuss results for the pion form factor and charge radius at 0.93 T_c and compare with zero temperature results.