Limiting temperature of pion gas with the van der Waals equation of state

作者：Poberezhnyuk R V; Vovchenko V; Anchishkin D V; Gorenstein M I

来源：Journal of Physics G: Nuclear and Particle Physics , 2016, 43(9): 095105.

DOI：10.1088/0954-3899/43/9/095105

• pion gas
• limiting temperature
• van der Waals

The grand canonical ensemble formulation of the van der Waals equation of state that includes the effects of Bose statistics is applied to the equilibrium system of interacting pions. If the attractive interaction between pions is large enough, a limiting temperature T-0 emerges, i.e., no thermodynamical equilibrium is possible at T> T-0. The system pressure p, particle number density n, and energy density e remain finite at T = T0, whereas for T near T-0 both the specific heat C = d epsilon/dT and the scaled variance of particle number fluctuations omega[N] are proportional to (T-0 - T)(-1/2) and, thus, go to infinity at T -> T-0. The limiting temperature also corresponds to the softest point of the equation of state, i. e., the speed of sound squared cs = dp/d epsilon goes to zero as (T-0 - T)(-1/2). Very similar thermodynamical behavior takes place in the Hagedorn model for the special choice of a power, namely m(-4), in the pre-exponential factor of the mass spectrum rho(m).

• 出版日期2016-9