Proper Wilson flow time for calculating the topological charge density and the pseudoscalar glueball mass in quenched lattice QCD

The proper flow time for the Wilson flow in calculating the topological charge, topological susceptibility, and topological charge density correlator (TCDC) using the gluonic definition is analyzed. The proper flow time for the topological charge and TCDC is determined by different methods. The proper flow time may vary depending on whether the calculation is for the topological charge, topological density, topological susceptibility, or TCDC. Specifically, the flow time identified using the matching procedure is optimal for TCDC and a good choice for the topological susceptibility. Additionally, the pseudoscalar glueball is extracted from the TCDC using the bosonic definition at the identified proper flow time for three ensembles, and the continuum mass value is obtained through continuous extrapolation.