Bose-Einstein condensation in heavy ion collisions: importance of and uncertainties in the finite volume corrections

TL;DR

This paper investigates how finite volume corrections affect Bose-Einstein condensation of pions in heavy ion collisions, highlighting significant uncertainties due to boundary condition choices even at large volumes.

Contribution

It provides a detailed calculation of pion condensate densities under various boundary conditions, emphasizing the importance of finite volume effects in heavy ion collision models.

Findings

Condensate densities are much higher than thermodynamic predictions.

Results vary significantly with boundary condition choices.

Finite volume effects remain relevant at large system sizes.

Abstract

The density of the Bose-Einstein condensate for non-interacting pions in a cubic box, at given temperature and (average) total pion density, is calculaated for three sets of boundary conditions. The densities are much larger than predicted from thermodynamics and depend significantly on the choice of the boundary conditions, even for volumes as large as $6.4\cdot 10$fm$^3$.