Speaker
Description
The phase diagram of QCD is investigated by varying number of colors N_c within a Polyakov loop quark-meson chiral model. In particular, our attention is focused on the critical point(s); the critical point present for N_c =3 moves toward the μq-axis and disappears as soon as the number of color is increased. Yet, a distinct critical point emerges along the temperature axis for N_c =53 and moves toward finite density when increasing N_c further. Thus, the phase diagram at large N_c looks specular with respect to the N_c=3 results, with the first-order transition in the upper-left and crossover in the lower-right regions of the (μq,T)-plane. The pressure is also evaluated in dependence of N_c, showing a scaling with N_c^0 in the confined and chirally broken phase and with N_c^2 in the deconfined one. Moreover, the presence of a chirally symmetric but confined “quarkyonic phase” at large density and moderate temperature with a pressure proportional to N_c is confirmed.
