Evolution of symmetric decay in A = 60 compound nuclei

The quantum mechanical fragmentation theory based dynamical cluster decay model (DCM) has been applied to study the symmetric decay of compound nuclei (CN) 60Zn*, 60Ni* and 60Fe*. The effect of neutron to proton (N/Z) ratio in the decay of CN with A = 60, but formed through different reactions induced by same projectile 4He having same incident energy, have been investigated. Although the contributions of light particles and intermediate mass fragments is more prominent than Symmetric mass fragments (SMFs) in this mass region. But in the present work we have explored the evolution of symmetric decay with changing N/Z for A = 60 CN, under study. We see that the value of preformation probability P0 and penetrability P for SMFs decreases with increase in N/Z ratio, consequently symmetric breakup goes out of favor for higher N/Z values i.e. symmetric decay is highly favored in the case of 60Zn* only having N=Z. Hence, the SMFs cross section σSMFs decreases with increasing N/Z, i.e., highest for N/Z =1. The effect of rising temperature on SMFs cross sections σSMFs have also been studied at three different values. Quite interestingly, the symmetric channel 30P + 30P, 30Si+ 30Si and 30Al+ 30Al, respectively, from CN 60Zn*, 60Ni* and 60Fe*, in the σSMFs, is largest for 60Zn* and smallest for 60Fe*. Moreover, the contributions of symmetric channels increase with increasing temperature of CN, except in the case of Fe*, for which it decreases then increase with rising temperature.