The critical point in QCD and pion fluctuations in heavy ion collisions

A critical point of second order, belonging to the universality class of 3d Ising model, has been recently advocated as a strong candidate for the critical behaviour of QCD with non-zero quark masses. The implications of this conjecture are investigated, in the multi-particle environment of relativistic heavy ion collisions. A universal intermittency pattern of pion density fluctuations in momentum space is found reflecting the fractal structure...