Resonance suppression during the hadronic stage from the FAIR to the intermediate RHIC energy regime

The energy and centrality dependence of the kaon resonance ratio (K∗0 + ¯K∗0 )/(K+ + K− ) is explored inthe RHIC-BES and CBM-FAIR energy regime. To this aim, the ultrarelativistic quantum molecular dynamicsmodel is employed to simulate reconstructable K∗ resonances in Au + Au and p + p collisions from √s NN =3–39 GeV. We obtain a good description of the resonance yields and mean transverse momenta over the wholeinvestigated energy range. The decrease of the K∗/K ratio with increasing centrality is in line with the availableexperimental data. We also observe the experimenatlly measured increase in 〈pT〉 with increasing centralitywhich is interpreted as a lower reconstruction probability of low-pT K∗ due to the pT dependent absorption of thedecay daughter hadrons. We conclude that the observed suppression of reconstructable K∗ resonances providesa strong sign of an extended hadronic rescattering stage at all investigated energies. Its duration increases fromperipheral to central reactions as expected. Following a method, suggested by the STAR experiment, a lowerbound on the duration of the hadronic stage is extracted using the K∗/K ratios at chemical and kinetic freeze-out.The resulting lifetimes are in good agreement with the experimental data, but shorter than the actual lifetime ofthe hadronic phase in the transport simulations.