Role of event multiplicity on hadronic phase lifetime and QCD phase boundary in ultrarelativistic collisions at energies available at the BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider
Abstract
Hadronic resonances, having very short lifetimes, like ${\mathrm{K}}^{*0}$, can act as useful probes to understand and estimate the lifetimes of hadronic phases in ultrarelativistic proton-proton, $p$-Pb, and heavy-ion collisions. Resonances with relatively longer lifetime, like $\ensuremath{\phi}$ mesons, can serve as tools to locate the quark-gluon plasma (QGP) phase boundary. We estimate a lower limit of hadronic phase lifetime in Cu-Cu and Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC) and in $pp, p$-Pb, and Pb-Pb collisions at different Large Hadron Collider (LHC) collision energies. Also, we obtain the effective temperature of $\ensuremath{\phi}$ mesons using the Boltzmann-Gibbs blast-wave function, which gives insight into locating the QGP phase boundary. We observe that the hadronic phase lifetime strongly depends on final-state charged-particle multiplicity, whereas the QGP phase and hence the QCD phase boundary shows very weak multiplicity dependence. This suggests that the hadronization from a QGP state starts at a similar temperature irrespective of charged-particle multiplicity, collision system, and collision energy, while the endurance of hadronic phase is strongly dependent on final-state charged-particle multiplicity, system size, and collision energy.