Speaker
Description
We study the behaviour of the η′ around above the pseudocritical temperature by use of lattice QCD simulations with two families of dynamical quarks. Due to its anomalous component the η′ carries significant informations on the nature of the phase transition, and the role of the anomaly. We contrast and compare the results for the η′ with the behaviour of chiral observables as well as with predictions of models. Results are obtained from the analysis of the gluonic defined topological charge density correlator after gradient flow. Our results indicate the growth of the η′ 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 η′ mass. The magnitude of the dip is compatible with the reduction of the η′ mass obtained by experimental analysis and suggests that η′ mass comes close to zero temperature non-anomalous contribution. We outline the current status of our study and the upcoming steps.
