Ja n 20 04 Analysis of charged particle emission sources and coalescence in E / A = 61 MeV 36 Ar + 27 Al , 112 Sn and 124 Sn collisions

Single-particle kinetic energy spectra and two-particle small angle correlations of protons (p), deuterons (d) and tritons (t) have been measured simultaneously in 61A MeV Ar + Al, Sn and Sn collisions. Characteristics of the emission sources have been derived from a “source identification plot” (βsource–ECM plot), constructed from the single-particle invariant spectra, and compared to the complementary results from two-particle correlation functions. Furthermore, the source identification plot has been used to determine the conditions when the coalescence mechanism can be applied for composite particles. In our data, this is the case only for the Ar + Al reaction, where p, d and t are found to originate from a common source of emission (from the overlap region between target and projectile). In this case, the coalescence model parameter, p̃0 – the radius of the complex particle emission source in momentum space, has been analyzed. PACS number(s): 24.10.-i,25.70.Pq, 29.30.Hs