Topological Susceptibility in Nf = 2 QCD at Finite Temperature

We study the topological charge in Nf = 2 QCD at finite temperature using Mobius domain-wall fermions. The susceptibility Xt of the topological charge defined either by the index of overlap Dirac operator or a gluonic operator is investigated at several values of temperature T (> Tc ) varying the quark mass. A strong suppression of the susceptibility is observed below a certain value of the quark mass. The relation with the restoration of UA (1) is discussed.