Influence of hadronic resonances on the chemical freeze-out in heavy-ion collisions
Paolo Alba, V. M. Sarti, Jacquelyn Noronha-Hostler, Paolo Parotto, Israel Portillo, Claudia Ratti, Jamie M. Stafford
Abstract
Detailed knowledge of the hadronic spectrum is still an open question, which has phenomenological consequences on the study of heavy-ion collisions. A previous lattice QCD study concluded that additional strange resonances are missing in the currently tabulated lists provided by the Particle Data Group (PDG). That study identified the list labeled $\text{PDG2016}+$ as the ideal spectrum to be used as an input in thermal-model-based analyses. In this work, we determine the effect of additional resonances on the freeze-out parameters of systems created in heavy-ion collisions. These parameters are obtained from thermal fits of particle yields and net-particle fluctuations. For a complete picture, we compare several hadron lists including both experimentally discovered and theoretically predicted states. We find that the inclusion of additional resonances mildly influences the extracted parameters---with a general trend of progressively lowering the temperature---but is not sufficient to close the gap in temperature between light and strange hadrons previously observed in the literature.