Resonance production in heavy-ion collisions at STAR

TL;DR

This paper investigates how hadronic resonances in heavy-ion collisions at STAR reveal properties of the hot, dense medium, including system size, lifetime, and partonic phase characteristics, using resonance spectra, yields, and elliptic flow measurements.

Contribution

It introduces new insights into resonance production and their sensitivity to medium properties, including a novel approach to probe early-stage signals via jet-selected resonances.

Findings

Resonance yields vary with system size and energy, indicating medium effects.

Elliptic flow measurements support constituent quark scaling for resonances.

Potential new method to detect early-stage signals through jet-resonance selection.

Abstract

Hadronic resonances are sensitive to the properties of a hot and dense medium created in a heavy ion collisions. During the hadronic phase, after hadronization of quark and gluons into hadrons, resonances are useful to determine the lifetime between chemical and thermal freeze-out, under the assumption that the re-scattering of the decay particles and the probability of regeneration of resonances from hadrons depends on the system properties and the resonance lifetime. The system size and energy dependence of resonance spectra and yields will be shown and discussed in the context of the lifetime and size of the hadronic phase. Elliptic flow measurement will extend the sensitivity of resonance yields to the partonic state through additional information on constituent quark scaling. We also explore a possible new technique to extract signals from the early, potentially chirally symmetric, stage through the selection of resonances from jets.