Speaker
Dr
Christian Schmidt
(Universitaet Bielefeld)
Description
We calculate ratios of up to $4^{th}$ order cumulants of net baryon number
fluctuations in (2+1)-flavor QCD using
next-to-leading order Taylor expansions in terms of temperature and the
the baryon number, strangeness, and electric charge chemical potentials.
We establish relations between these cumulant ratios, which hold at
small values of the chemical potentials. These QCD results are in contrast
to hadron resonance gas model calculations where, for instance, the
kurtosis ratio, $\kappa_B\sigma_B^2=\chi_4^B/\chi^2_B$ and the skewness
ratio $S_B\sigma_B=\chi_3^B/\chi^1_B$ are unity
at all values of the temperature and baryon chemical potential. We show
that the experimentally observed pattern
of net proton-number fluctuations for beam energies larger than 19.6 GeV
is in qualitative agreement with the next-to-leading order lattice QCD
calculations.
We also present updates of our calculation of the QCD equation of state
in a $6^{th}$ order Taylor expansion.
Author
Dr
Christian Schmidt
(Universitaet Bielefeld)
