# Fate of the $\eta'$ in the Quark Gluon Plasma

## TL;DR

This study investigates the behavior of the $ ext{eta'}$ meson in quark-gluon plasma using lattice QCD simulations, revealing its mass increases above the pseudocritical temperature and shows a small dip near this transition.

## Contribution

First lattice QCD analysis of the $ ext{eta'}$ in finite temperature conditions using gluonic topological charge correlators and gradient flow techniques.

## Key findings

- $ ext{eta'}$ mass increases above the pseudocritical temperature.
- A small dip in $ ext{eta'}$ mass occurs near the transition.
- Results align with experimental observations of $ ext{eta'}$ mass reduction.

## Abstract

In this paper we study the $\eta'$ 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 $\eta'$ 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 $\eta'$ mass. The magnitude of the dip is compatible with the reduction of the $\eta'$ mass obtained by experimental analysis and suggests that $\eta'$ mass comes close to zero temperature non-anomalous contribution.