Speaker
Описание
We summarise recent theoretical results on the QCD phase diagram and the properties
of QCD's critical point based on a combination of lattice QCD and Dyson-Schwinger
equations.
Using lattice input for the quenched gluon propagator, our approach correctly reproduced
and predicted Nf=2+1 flavour lattice results for the quark condensate and the unquenched
electric and magnetic gluon propagator at zero chemical potential. At chemical potential
up to $\mu_B/T$<3 our approach and extrapolations using lattice QCD both confirm an
analytic crossover from the hadronic phase into the QGP. Beyond this region we see a
critical end point at ($T^c,\mu_B^c$)=(120,500) MeV, which is neither very sensitive
to additional charm quark contributions nor to corrections from virtual baryons.
We furthermore present new results for baron number fluctuations. We discuss the changes
of ratios of fluctuations up to fourth order along and below the transition line for
temperatures and baryon chemical potential up to and beyond the critical end point.
Comparing with preliminary STAR data for the skewness and kurtosis ratios,
our results are compatible with the scenario of a critical end point at
large chemical potential and slightly offset from the freeze-out line.
We also discuss the caveats involved in this comparison.
