Small angle particle-particle correlation measurements in the reactions 280 MeV Ar-40+Al-27 and 670 MeV Mn-55+C-12

Small-angle particle-particle correlations were measured in the two matchin g reactions 280 MeV Ar-40 + Al-27 and 670 MeV Mn-55 + C-12. These two react ions were used to produce the composite nucleus, Ga-67*, at the same initia l excitation energy of 127 MeV, but with different entrance channel angular momentum distributions. A simple trajectory model was used to compute the average emission times between various particle pairs, and comparisons with the data show that there is a significant difference in the deexcitation o f the composite nucleus formed from the two reactions. Statistical model ca lculations were compared to the experimental observations with the added co nstraint that the model input parameters were consistent with those derived from observed charged-particle energy spectra and angular distributions, I t was found that the calculated correlation functions were insensitive to t he input spin distributions, but agreed fairly well with the data from the lower-spin system. The higher-spin reaction data were poorly reproduced by the calculations. (C) 2001 Elsevier Science B.V. All rights reserved.