On particle number fluctuations in an interacting pion gas with dynamically fixed number of particles

摘要

We consider a hot isospin-symmetric pion gas with the dynamically fixed number of particles in the model with a λΦ~4 interaction. In the thermodynamic limit, for temperature above the critical value for the Bose-Einstein condensation we calculate the effective pion mass, the chemical potential and the normalized variance. In contrast to the ideal gas, the normalized variance remains finite in the critical point of the Bose-Einstein condensation.