Recovering the chiral critical end-point via delocalization of quark interactions

Abstract

We show that for the lower branch of the quark condensate and values higher than approximately $-(250\mathrm{MeV}{)}^3$ the chiral critical end-point in the Nambu--Jona-Lasinio model does not occur in the phase diagram. By using lattice motivated non-local quark interactions, we demonstrate that the critical end-point can be recovered. We study this behavior for a range of condensate values and find that the variation in the position of the critical end-point is more pronounced as the condensate is increased.

Comments: title changed, minor changes in text, version to match the one published in PRD