Unstable Hadrons in Hot Hadron Gas in Laboratory and in the Early Universe

Abstract

We study kinetic master equations for chemical reactions involving the formation and the natural decay of unstable particles in a thermal bath. We consider the decay channel of one into two particles, and the inverse process, fusion of two thermal particles into one. We present the master equations the evolution of the density of the unstable particles in the early Universe. We obtain the thermal invariant reaction rate using as an input the free space (vacuum) decay time and show the medium quantum effects on $\pi +\pi \leftrightarrow \rho$ reaction relaxation time. As another laboratory example we describe the $K+K\leftrightarrow \varphi$ process in thermal hadronic gas in heavy-ion collisions. A particularly interesting application of our formalism is the ${\pi }^0\leftrightarrow \gamma +\gamma$ process in the early Universe. We also explore the physics of ${\pi }^{\pm }$ and ${\mu }^{\pm }$ freeze-out in the Universe.

13 pages, 9 figures, published in Physical Review C

References in corpus (5)

• Measurements of $\varphi$ meson production in relativistic heavy-ion collisions at RHIC
• Heavy Flavor Hadrons in Statistical Hadronization of Strangeness-rich QGP
• Pion and muon production in electron-positron photon plasma
• Enhanced Production of Delta(1230) and Sigma(1385) Resonances
• Resonance Production in Heavy Ion Collisions: Suppression of $\Lambda (1520)$ and Enhancement of $\Sigma (1385)$

Cited by in corpus (12)

• Equilibrium Statistical-Thermal Models in High-Energy Physics
• Connecting QGP-Heavy Ion Physics to the Early Universe
• A short survey of matter-antimatter evolution in the primordial universe
• Boltzmann Equation Solver Adapted to Emergent Chemical Non-equilibrium
• Cosmological Strangeness Abundance
• Metastable pions in dense media
• The muon abundance in the primordial Universe
• Entropy production in the early-cosmology pionic phase
• Probing the QGP Phase Boundary with Thermal Properties of $\varphi$ Mesons
• Temperature Dependence of the Neutron Lifespan
• Quarks to Cosmos: Particles and Plasma in Cosmological evolution
• Higgs Thermal Nonequilibrium in Primordial QGP