Non-perturbative renormalization of bilinear operators with dynamical overlap fermions

TL;DR

This paper non-perturbatively calculates renormalization factors for quark bilinear operators using overlap fermions on the lattice, accounting for dynamical light quarks and chiral symmetry effects.

Contribution

It introduces a method to accurately determine renormalization factors with overlap fermions, including effects from dynamical quarks and chiral symmetry suppression.

Findings

Renormalization factors are computed with dynamical overlap fermions.

Chiral symmetry breaking effects are effectively suppressed near the chiral limit.

Finite volume effects are managed by subtracting chiral condensate contributions.

Abstract

Using the non-perturbative renormalization technique, we calculate the renormalization factors for quark bilinear operators made of overlap fermions on the lattice. The background gauge field is generated by the JLQCD and TWQCD collaborations including dynamical effects of two or 2+1 flavors of light quarks on a 16$^3\times$32 or 16$^3\times$48 lattice at lattice spacing around 0.1 fm. By reducing the quark mass close to the chiral limit, where the finite volume system enters the so-called $\epsilon$-regime, the unwanted effect of spontaneous chiral symmetry breaking on the renormalization factors is suppressed. On the lattices in the conventional $p$-regime, this effect is precisely subtracted by separately calculating the contributions from the chiral condensate.