Approximate method of including finite particle number effects in relativistic heavy ion collisions

Abstract
We show that for large momenta the grand canonical ensemble is not an accurate enough approximation to the phase space integral to be used in calculating inclusive cross sections. In its place we propose a very general method based on the saddle point inversion of the Laplace transform integral. This method is shown to be quite accurate and is used to calculate deuteron inclusive spectra in conjunction with a two-fireball model.