Publication

Abstract : With the discovery of a large number of superheavy nuclei undergoing decay througha emissions, there has been a revival of interest in α decay in recent years. In the theoretical study of α decay the a-nucleus potential, which is the basic input in the study of a-nucleus systems, is also being studied using advanced theoretical methods. In the light of these, theWentzel-Kramers-Brillouin (WKB) approximation method often used for the study of a decay is critically examined and its limitations are pointed out. At a given energy, theWKB expression uses barrier penetration formula for the determination of the transmission coefficient. This approach utilizes the a-nucleus potential only at the barrier region and ignores it elsewhere. In the present era, when one has more precise experimental information on decay parameters and better understanding of a-nucleus potential, it is desirable to use a more precise method for the calculation of decay parameters. We describe the analytic S-matrix (SM) method which gives a procedure for the calculation of decay energy and mean life in an integrated way by evaluating the resonance pole of the S-matrix in the complex momentum or energy plane. We make an illustrative comparative study of WKB and S-matrix methods for the determination of decay parameters in a number of superheavy nuclei. © Indian Academy of Sciences.