I=2 $\pi$-$\pi$ scattering length with dynamical overlap fermion

TL;DR

This paper presents a lattice QCD calculation of the I=2 pion-pion scattering length using overlap fermions, comparing results with chiral perturbation theory and analyzing finite volume effects.

Contribution

It provides a novel lattice QCD computation of the I=2 pion-pion scattering length with overlap fermions, including finite volume corrections and chiral perturbation theory comparison.

Findings

Results are consistent with NNLO chiral perturbation theory.

Finite volume effects are carefully analyzed and corrected.

Overlap fermions effectively reproduce scattering length data.

Abstract

We report on a lattice QCD calculation of the I=2 $\pi\pi$ scattering length using the overlap fermion formulation for both sea and valence quarks. We investigate the consistency of the lattice data with the prediction of the next-to-next-to-leading order chiral perturbation theory after correcting finite volume effects. The calculation is performed on gauge ensembles of two-flavor QCD generated by the JLQCD collaboration on a $16^3\times 32$ lattice at a lattice spacing $\sim$ 0.12 fm.