Lee-Yang zeros in lattice QCD for searching phase transition points

We report Lee-Yang zeros behavior at finite temperature and density. The quark number densities, < n >, are calculated at the pure imaginary chemical potential i mu(qI), where no sign problem occurs. Then, the canonical partition functions, Z(C)(n, T, V), up to some maximal values of n are estimated through fitting theoretically motivated functions to < n >, which are used to compute the Lee-Yang zeros. We study the temperature dependence of the distributions of the Lee-Yang zeros around the pseudo-critical temperature region T/T-C = 0.84-1.35. In the distributions of the Lee-Yang zeros, we observe the Roberge-Weiss phase transition at T/T-C >= 1.20. We discuss the dependence of the behaviors of Lee-Yang zeros on the maximal value of n, so that we can estimate a reliable infinite volume limit. (C) 2019 The Authors. Published by Elsevier B.V.