Small angle particle–particle correlation measurements in the reactions 280 MeV ArAl and 670 MeV MnC

Abstract Small-angle particle–particle correlations were measured in the two matching reactions 280 MeV 40 Ar + 27 Al and 670 MeV 55 Mn + 12 C. These two reactions were used to produce the composite nucleus, 67 Ga∗, at the same initial 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 of the composite nucleus formed from the two reactions. Statistical model calculations were compared to the experimental observations with the added constraint that the model input parameters were consistent with those derived from observed charged-particle energy spectra and angular distributions. It was found that the calculated correlation functions were insensitive to the 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.