A Quenched Study of SU(3) Glueballs at Finite Temperature

TL;DR

This study investigates the thermal behavior of SU(3) glueballs across a wide temperature range, revealing that their masses stay stable below the critical temperature but decrease above it, with widths expanding significantly after crossing the phase transition.

Contribution

It provides the first detailed analysis of glueball pole masses and widths at finite temperature using variational methods and Breit-Wigner fits in SU(3) Yang-Mills theory.

Findings

Glueball pole masses remain nearly constant below T_c.

Widths are small below T_c and increase sharply above T_c.

Masses decrease gradually after T_c is exceeded.

Abstract

Thermal properties of glueballs in SU(3) Yang-Mills theory are investigated in a large temperature range from $0.3T_c$ to $1.9T_c$ on anisotropic lattices. The glueball operators are optimized for the projection of the ground states by the variational method with a smearing scheme. Their thermal correlators are calculated in all 20 symmetry channels. It is found in all channels that the pole masses $M_G$ of glueballs remain almost constant when the temperature is approaching the critical temperature $T_c$ from below, and start to reduce gradually with the temperature going above $T_c$. The correlators in the $0^{++}$, $0^{-+}$, and $2^{++}$ channels are also analyzed based on the Breit-Wigner $\emph{Ansatz}$ by assuming a thermal width $\Gamma$ to the pole mass $\omega_0$ of each thermal glueball ground state. While the values of $\omega_0$ are insensitive to $T$ in the whole temperature range, the thermal widths $\Gamma$ exhibit distinct behaviors at temperatures below and above $T_c$. The widths are very small (approximately few percent of $\omega_0$ or even smaller) when $T<T_c$, but grow abruptly when $T>T_c$ and reach values of roughly $\Gamma\sim \omega_0/2$ at $T\approx 1.9T_c$.