2021/01/25 by Blaschke, D., Friesen, A. V., Kalinovsky, Yu. L. +1
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2101.10084
The behaviour of pseudoscalar mesons within the SU(3)PNJL-like models is considered for finite T and μB. We compare the pole approximation (Breit-Wigner) with the Beth-Uhlenbeck approach. We evaluate the K/π ratios along the phase transition line in the T-μB plane with constant and T/μB-dependent pion and strange quark chemical potentials. Using the model, we can show that the splitting of kaon and anti-kaon masses appears as a result of introduction of density and this explains the difference in the K+/π+ ratio and K-/π- ratio at low √sNN and their tendency to the same value at high √sNN. A sharp "horn" effect in the K+/π+ ratio is explained by the enhanced pion production which can be described by occurrence of a nonequilibrium pion chemical potential of the order of the pion mass. We elucidate that the horn effect is not related to the existence of a critical endpoint in the QCD phase diagram.