Scaling region of the Ising universality class in two and three dimensions (with applications in finite temperature QCD).

by Marianna Sorba (SISSA)

Aula Magna

Aula Magna


A precise charting of the critical region of the Ising universality class is of central interest in the context of high energy physics, as one can find examples of Ising-like behaviour in finite temperature QCD. For the specific case of the critical ending point in the QCD phase diagram, we know that Monte Carlo simulations are not possible, thus making essential a direct comparison between experimental results and QFT/Statistical Mechanics predictions. To this purpose, we introduce a universal combination of magnetic susceptibility and correlation length in the Ising model both in two and three dimensions. This quantity, chosen for its simplicity from a theoretical point of view and its accessibility in experiments and numerical simulations, considers both magnetic and thermal perturbations in the neighbourhood of the critical point. It can hence be used as a sort of “reference frame”, extending to the whole scaling region previous results which were limited to the presence of only one of the two perturbing operators.