The energy dependence of various particle ratios is calculated within the Ultra-relativistic Quantum
Molecular Dynamics approach and compared with the hadron resonance gas (HRG) model and measurements
from various experiments, including RHIC-BES, SPS and AGS. It is found that the UrQMD
particle ratios agree well with the experimental results at the RHIC-BES energies. Thus, we have utilized
UrQMD in simulating particle ratios at other beam energies down to 3 GeV, which will be accessed at
NICA and FAIR future facilities. We observe that the particle ratios for crossover and first-order phase
transition, implemented in the hybrid UrQMD v3.4, are nearly indistinguishable, especially at low energies
(at large baryon chemical potentials or high density). |
