Broad structures in γ-ray multiplicity gated p and α spectra in low energy 12C+93Nb and 16O+89Y reactions

Abstract

Gamma ray multiplicity gated proton spectra have been measured in the reactions 12C+93Nb at E(12C)= 40 and 45.5 MeV and 16O+89Y at E(16O)= 51 and 54 MeV populating the CN 105 Ag at EX between 35 and 40 MeV. Broad structures are seen in all spectra at high gamma ray multiplicities. The present data, along with those from our earlier work on the former reaction at E(12C)= 42.5 MeV, establish the compound nuclear origin of the structures. The data can be explained by incorporating a localised enhancement of nuclear level density in the excitation energy and angular momentum space. Multiplicity gated Îś spectra have also been measured in the same reaction at E(12C)= 37.5 – 45 MeV. Broad structures seen in these spectra seem to have contribution from other reaction mechanisms also.