Evaporation residue cross sections and average neutron multiplicities in the 64Ni+ 92Zr and 12C+ 144Sm reactions leading to 156Er

Abstract

Evaporation residue cross sections and neutron multiplicity distributions have been measured for the 12C + 144Sm and 64Ni + 92Zr reactions leading to the same compound nucleous 156Er. Statistical model calculations can account for the data in the 12C-induced reaction. In contrast, the inhibition of neutron emission with respect to statistical model predictions seen in 64Ni + 92Zr cannot be explained even with the inclusion of the broad angular momentum distributions required to describe the fusion cross section data.