Bottomonia screening masses from $2 + 1$ flavor QCD

TL;DR

This paper introduces a new lattice QCD method to study bottomonium screening masses at high temperatures, providing insights into quark-gluon plasma signals beyond traditional NRQCD approaches.

Contribution

A novel approach using spatial screening masses and HISQ action to analyze bottomonium states in 2+1 flavor QCD at high temperatures.

Findings

Screening masses align with uncorrelated quark pairs above 500 MeV.

Method applicable for temperatures up to 1000 MeV.

Provides alternative to NRQCD at high temperatures.

Abstract

The sequential melting of the bottomonium states is one of the important signals for the existence of a quark gluon plasma. The study of bottomonia spectral functions on the lattice is a difficult task for many reasons. Calculations based on NRQCD, that are commonly used for such purpose, are not applicable at high temperatures. In this work we propose a new method to study this problem by calculating the spatial screening masses of bottomonium states. We calculate the spatial meson correlators and extract the screening masses for mesons in different quantum channels using highly improved staggered quark (HISQ) action for bottom quarks and dynamical $2+1$ flavor QCD HISQ gauge configurations. The typical lattices we choose are of size $N_s^3 \times N_\tau$ where $N_s=4 N_\tau$ and $N_\tau=8, 10, 12$. We consider the temperature range $T = 300$-$1000$ MeV. We show that for $T > 500$ MeV the temperature dependence of the screening masses of the ground state bottomonia are compatible with the expectations based on uncorrelated quark anti-quark pairs.