The scalar does not decay at finite temperatures

TL;DR

This study examines how mesonic screening lengths behave at finite temperatures in QCD with two flavors, revealing that the scalar meson remains stable and does not decay within the temperature range studied.

Contribution

It provides new lattice QCD results on the stability of scalar mesons and their behavior across the hadronic to quark-gluon plasma transition.

Findings

Chiral symmetry restoration occurs near T_c in the vector channel.

Scalar channel shows symmetry restoration only above 1.33 T_c.

Scalar meson remains stable and does not decay at finite temperatures.

Abstract

We investigate medium effects on mesonic screening lengths for QCD with 2-flavours of dynamical staggered quarks on lattices with cutoff a=1/6T. Denoting the cross-over temperature by $T_c$, we vary the temperature T from 0.89$T_c$ to 1.92$T_c$, spanning both the hadronic and quark gluon plasma phases. While chiral symmetry restoration in the vector channel appears to take place near $T_c$, it is seen in the scalar channel only above 1.33 $T_c$. Varying spatial lattice sizes, we find very little volume dependence in our results at 0.94 $T_c$. We discuss the stability of the scalar meson at these temperatures.