Fast Equilibration of Hadrons in an Expanding Fireball

Abstract

Due to long chemical equilibration times within standard hadronic reactions during the hadron gas phase in relativistic heavy ion collisions it has been suggested that the hadrons are "born" into equilibrium after the quark gluon plasma phase. Here we develop a dynamical scheme in which possible Hagedorn states contribute to fast chemical equilibration times of baryon anti-baryon pairs (as well as kaon anti-kaon pairs) inside a hadron gas and just below the critical temperature. Within this scheme, we use master equations and derive various analytical estimates for the chemical equilibration times. Applying a Bjorken picture to the expanding fireball, the kaons and baryons as well as the bath of pions and Hagedorn resonances can indeed quickly chemically equilibrate for both an initial overpopulation or underpopulation of Hagedorn resonances. Moreover, a comparison of our results to $(B+\bar{B})/{\pi }^{+}$ and $K/{\pi }^{+}$ ratios at RHIC, indeed, shows a close match.

4 pages, 5 figures

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• Thermalization of Hadrons via Hagedorn States
• Freezeout conditions in proton-proton collisions at the top RHIC and LHC energies
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• Equilibration of hadrons in HICs via Hagedorn States
• Asymptotic Regge Trajectories of Non-strange Mesons
• Shear viscosity from perturbative Quantum Chromodynamics to the hadron resonance gas at finite baryon, strangeness, and electric charge densities
• Strangeness at finite temperature from Lattice QCD
• Statistical Fluctuations and Correlations in Hadronic Equilibrium Systems
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• Resonances and fluctuations in the statistical model
• Testing the hadronic spectrum in the strange sector
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