Topological susceptibility of QCD with dynamical Möbius domain-wall fermions

Abstract

We compute the topological susceptibility χt of lattice QCD with 2+1 dynamical quark flavors described by the Möbius domain-wall fermion. Violation of chiral symmetry as measured by the residual mass is kept at ∼1 MeV or smaller. We measure the fluctuation of the topological charge density in a “slab” sub-volume of the simulated lattice using the method proposed by W. Bietenholz, P. de Forcrand, and U. Gerber, J. High Energy Phys. 12, 070 (2015) and W. Bietenholz, K. Cichy, P. de Forcrand, A. Dromard, and U. Gerber, PoS LATTICE 2016, 321 (2016). The quark mass dependence of χt is consistent with the prediction of chiral perturbation theory, from which the chiral condensate is extracted as ΣMS¯¯¯¯¯¯¯¯(2 GeV)=[274(13)(29)MeV]3⁠, where the first error is statistical and the second one is systematic. Combining the results for the pion mass Mπ and decay constant Fπ⁠, we obtain χt=0.229(03)(13)M2πF2π at the physical point.