Exotic decay in cerium isotopes

Half life for the emission of exotic clusters like ⁸Be, ¹²C, ¹⁶O, ²⁰Ne, ²⁴Mg and ²⁸Si are computed taking Coulomb and proximity potentials as interacting barrier and many of these are found well within the present upper limit of measurement. These results lie very close to those values reported by Shanmugam et al using their cubic plus Yukawa plus exponential model (CYEM). It is found that ¹²C and ¹⁶O emissions from ¹¹⁶Ce and ¹⁶O from ¹¹⁸Ce are most favorable for measurement (T _1/2<10¹⁰ s). Lowest half life time for ¹⁶O emission from ¹¹⁶Ce stress the role of doubly magic ¹⁰⁰Sn daughter in exotic decay. Geiger-Nuttall plots were studied for different clusters and are found to be linear. Inclusion of proximity potential will not produce much deviation to linear nature of Geiger-Nuttall plots. It is observed that neutron excess in the parent nuclei slow down the exotic decay process. These findings support the earlier observations of Gupta and collaborators using their preformed cluster model (PCM).