Topology across the finite temperature transition studied by overimproved cooling in gluodynamics and QCD. Physical Review D - Particles, Fields, Gravitation and Cosmology Volume 87, Issue 11, 17 June 2013, Article number 114508

Gluodynamics and two-flavor QCD at nonzero temperature are studied with the so-called overimproved cooling technique under which caloron solutions may remain stable. We consider topological configurations either at the first occuring stable plateau of topological charge or at the first (anti-) self-dual plateau and find the corresponding topological susceptibility at various temperatures on both sides of the thermal transition or crossover. In pure gluodynamics the topological susceptibility drops sharply at the deconfinement temperature, while in full QCD it decreases smoothly at temperatures above the pseudocritical one. The results are close to those calculated by other methods. We interpret our findings in terms of the (in)stability of calorons with nontrivial holonomy and their dyon constituents against overimproved cooling.