Fate of the ${\eta }^{\prime }$ in the Quark Gluon Plasma

Abstract

In this paper we study the ${\eta }^{\prime }$ in $N_f=2+1+1$ lattice QCD simulations at finite temperature. Results are obtained from the analysis of the gluonic defined topological charge density correlator after gradient flow. Our results indicate the growth of the ${\eta }^{\prime }$ mass above the pseudocritical temperature, associated with the chiral symmetry restoration. In the vicinity of the pseudocritical temperature the results are consistent with a small dip in the ${\eta }^{\prime }$ mass. The magnitude of the dip is compatible with the reduction of the ${\eta }^{\prime }$ mass obtained by experimental analysis and suggests that ${\eta }^{\prime }$ mass comes close to zero temperature non-anomalous contribution.

Comments: 8 pages, 6 figures