Scalar condensate and light quark masses from overlap fermions

TL;DR

This paper uses overlap fermions to study pseudoscalar correlation functions, confirming Chiral Perturbation Theory predictions and extracting key low-energy constants and quark masses with non-perturbative renormalization.

Contribution

It provides a novel analysis of scalar condensate and light quark masses using overlap fermions and non-perturbative renormalization, validating ChPT predictions.

Findings

Quark mass dependence matches ChPT predictions

Scalar condensate agrees with previous finite-size scaling results

Strange quark mass and low-energy constants extracted successfully

Abstract

We have studied pseudoscalar correlation functions computed using the overlap operator. Within the accuracy of our calculation we find that the quark mass dependence agrees with the prediction of lowest-order Chiral Perturbation Theory (ChPT) for quark masses in the range of m ~ m_s/2-2m_s. We present the results of an analysis which assumes lowest-order ChPT to be valid to extract the low-energy constants Sigma and f_P, as well as the strange quark mass. Non-perturbative renormalization is implemented via a matching procedure with data obtained using Wilson fermions in the Schroedinger functional set-up. We find that the scalar condensate computed here agrees with the one obtained previously through a finite-size scaling analysis.