Analysing spectra on production of light clusters in heavy-ion collisions and reflections on the average phase space density

Abstract

In the recent past the NA44 Collaboration reported measurements on production of deuteron spectra in SS , SPb and PbPb collisions at the CERN-SPS. This has opened up an avenue, within the confines of the coalescence model, for calculating the source radii of protons, antiprotons and the average phase space densities (APSD) which are being projected, of late, as a reliable observable for studying the freeze-out behaviour of high-energy nuclear collisions. Instead of the thermal or thermodynamical model, we have applied in the present work a set of two models with a new parametrisation which yielded in the past a fair description of some observations on the APSD nature for pion production in nuclear collision. The combination provides here a satisfactory analysis of the p T spectra for both proton and deuteron production and allows us to obtain the values of the hypothesized radii of the assumed spheres of the expansion dynamics and also of the average phase space densities for protons. The values thus arrived at are also quite consistent with the RQMD predictions in the standard literature.