Fluctuations in non-ideal pion gas with dynamically fixed particle number

E. E. Kolomeitsev, D. N. Voskresensky

Kolomeitsev Evgeni E. 1970- (50%) UMBFP06 - Katedra fyziky

Voskresensky Dmitri (50%)

Nuclear Physics A. Vol. 973, (2018), pp. 89-103. - Amsterdam : Elsevier B.V., 2018

heavy ion collisions

 

fluctuations

 

Hartree approximation

 

Bose-Einsteinova kondenzácia - Bose-Einstein condensation

 

angličtina

Holandsko

53

We consider a non-ideal hot pion gas with the dynamically fixed number of particles in the model with the λφ4interaction. The effective Lagrangian for the description of such a system is obtained after dropping the terms responsible for the change of the total particle number. Reactions π+π−↔π0π0, which deter-mine the isospin balance of the medium, are permitted. Within the self-consistent Hartree approximation we compute the effective pion mass, thermodynamic characteristics of the system and the variance of the particle number at temperatures above the critical point of the induced Bose–Einstein condensation when the pion chemical potential reaches the value of the effective pion mass. We analyze conditions for the con-densate formation in the process of thermalization of an initially non-equilibrium pion gas. The normalized variance of the particle number increases with a temperature decrease but remains finite in the critical point of the Bose–Einstein condensation. This is due to the non-perturbative account of the interaction and is in contrast to the ideal-gas case. In the kinetic regime of the condensate formation the variance is shown to stay finite also

43902

BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici

xpca - PUBLIKAČNÁ ČINNOSŤ