Scalar correlators near the 3-flavor thermal critical point

TL;DR

This study examines scalar correlators and screening masses near the 3-flavor thermal critical point using lattice QCD techniques, revealing the behavior of meson masses approaching criticality.

Contribution

Introduces a hierarchical truncation method with stochastic probing to efficiently evaluate quark loops in lattice QCD simulations near the critical point.

Findings

Flavor singlet scalar meson mass is about half of the pion mass.

Scalar meson mass decreases as the critical endpoint is approached.

Method improves noise estimation efficiency in lattice calculations.

Abstract

We investigate screening masses at both sides of the first order finite temperature transition with 3 quark flavors using the nonperturbatively improved clover fermion action and the Iwasaki gauge action. We have developed the method of hierarchical truncations with stochastic probing to accelerate the noise estimator for evaluating quark loops at every spatial lattice slices. At parameter values we study, the flavor singlet scalar meson has a screening mass about half of the pion screening mass. It becomes lighter as the system approaches the critical endpoint.