Systematic study of low-energy incomplete fusion: Role of entrance channel parameters

Abstract

An attempt has been made to investigate the role of various entrance channel parameters in low-energy ($\ensuremath{\approx}4\text{--}7$ MeV/nucleon) incomplete fusion reactions through excitation function measurements. The analysis of measured excitation functions, in the framework of statistical model code pace4, reveals that the $xn$/$pxn$ channels are populated, predominantly, via complete fusion processes. However, in the production of $\ensuremath{\alpha}$-emitting channels, even after correcting for the precursor decay contribution, a significant enhancement as compared to statistical model predictions has been observed, which may be attributed due to the contribution of breakup processes. The observed enhancement is found to increase with projectile energy. Further, the comparison of present work with literature data reveals the dependence of incomplete fusion on mass-asymmetry of interacting partners, $\ensuremath{\alpha}\text{\ensuremath{-}}Q$ value of the projectile, and also on ${Z}_{P}{Z}_{T}$ (the Coulomb factor). From the present analysis, it may be concluded that a single entrance channel parameter (i.e., mass asymmetry or ${Z}_{P}{Z}_{T}$ or $\ensuremath{\alpha}\text{\ensuremath{-}}Q$ value) is not able to explain, completely, the yields of the low-energy incomplete fusion component. Therefore, a combination of these parameters and/or a parameter which can incorporate all gross features of interacting partners should be chosen to get a systematics for such reactions.