Temperature dependence of cluster decay

TL;DR

This paper develops a universal decay law for light cluster decay in excited nuclei, accounting for excitation energy effects on decay half-lives, with implications for nucleosynthesis and heavy-ion collision studies.

Contribution

It introduces a new universal decay law that incorporates excitation energy dependence into cluster decay half-life predictions for the first time.

Findings

Half-lives decrease with increasing excitation energy difference.

Decay rates can be enhanced by several orders of magnitude in hot environments.

The model aids in understanding nucleosynthesis in extreme conditions.

Abstract

A universal decay law (UDL) for light cluster decay of excited nuclei is formulated by fitting the UDL half-lives to those evaluated within an excitation energy-dependent double folding model (DFM). The half-lives are evaluated within a preformed cluster model. The excitation energy dependence is introduced both in the energy of the emitted cluster and in the interaction potential through the density distributions of the interacting nuclei. The half-lives are found to decrease when the difference between the excitation energies of the parent and daughter nuclei, $\Delta E^{*} > $ 0, increases, with the reduction being a few orders of magnitude for higher values of $\Delta E^{*}$. This can be of importance for nucleosynthesis calculations of heavy elements formed in extremely hot environments, as well as in highly energetic heavy-ion collisions. The UDL for excited nuclei is used to provide an estimate of the enhancement in the cluster decay rates of thermally excited nuclei such as those produced in r-process nucleosynthesis.