Abstract

A thermal QCD Finite Energy Sum Rule (FESR) allows us to obtain the temperature dependence of the axial vector coupling of the nucleon, g(A)(T). It turns out that this coupling is essentially constant for the wide range 0 less than or equal to T less than or equal to 0.9T(c), being T-c the critical deconfining temperature. In contrast to other effective hadronic couplings, g(A)(T) diverges when T --> T-C. At finite temperature, g(A) developes also a q(2) dependence. This led us to explore the mean squared radius associated to g(A), finding that it diverges at the critical temperature, thus signalling quark deconfinement. Finally, as a byproduct of our analysis, we study the thermal evolution of the Goldberger-Treiman relation.