Hagedorn States and Thermalization

Abstract

In recent years Hagedorn states have been used to explain the physics close to the critical temperature within a hadron gas. Because of their large decay widths these massive resonances lower $\eta /s$ to near the AdS/CFT limit within the hadron gas phase. A comparison of the Hagedorn model to recent lattice results is made and it is found that for both Tc =176 MeV and Tc=196 MeV, the hadrons can reach chemical equilibrium almost immediately, well before the chemical freeze-out temperatures found in thermal fits for a hadron gas without Hagedorn states. In this paper we also observe the effects of Hagedorn States on the $K^{+}/{\pi }^{+}$ horn seen at AGS, SPS, and RHIC.

8 pages, 2 figures, conference proceeding for DM2010, International Workshop on High Density Nuclear Matter, Cape Town, South Africa 6 - 9 April, 2010

References in corpus (14)

• The QCD equation of state with dynamical quarks
• The QCD Equation of State with almost Physical Quark Masses
• Equation of state and QCD transition at finite temperature
• Chemical freeze-out in ultra-relativistic heavy ion collisions at sqrt(s)_NN = 130 and 200 GeV
• Hadron Mass Spectrum from Lattice QCD
• Fast Equilibration of Hadrons in an Expanding Fireball
• Dynamics of Chemical Equilibrium of Hadronic Matter Close to $T_c$
• The order, shape and critical point for the quark-gluon plasma phase transition
• Chemical equilibration due to heavy Hagedorn states
• Particle Ratios as a Probe of the QCD Critical Temperature
• Strangeness and threshold of phase changes
• Particle Ratios and the QCD Critical Temperature
• Chemical Equilibration at the Hagedorn Temperature
• Chemical Equilibration and Transport Properties of Hadronic Matter near $T_c$