出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Lattice simulations employing reweighting and Taylor expansion techniques have predicted a
(m;T)-phase diagram according to general expectations, with an analytic quark-hadron crossover
at m =0 turning into a rst order transition at some critical chemical potential mE. By contrast, recent
simulations using imgainary m followed by analytic continuation obtained a critical structure
in the fmu;d;ms;T;mg parameter space favouring the absence of a critical point and rst order line.
I review the evidence for the latter scenario, arguing that the various raw data are not inconsistent
with each other. Rather, the discrepancy appears when attempting to extract continuum results
from the coarse (Nt =4) lattices simulated so far, and can be explained by cut-off effects. New (as
yet unpublished) data are presented, which for Nf = 3 and on Nt = 4 conrm the scenario without
a critical point. Moreover, simulations on ner Nt = 6 lattices show that even if there is a critical
point, continuum extrapolation moves it to signicantly larger values of mE than anticipated on
coarse lattices.
