Solving the large discrepancy between inclusive and exclusive measurements of the ${}^8{\rm Li}+{}^4{\rm He}\to{}^{11}{\rm B}+n$ reaction cross section at astrophysical energies

TL;DR

This paper resolves a significant discrepancy between inclusive and exclusive measurements of the ${}^8{ m Li}+{}^4{ m He} o{}^{11}{ m B}+n$ reaction cross section at low energies, with implications for astrophysics, by applying a novel comprehensive analysis method.

Contribution

It introduces a new technique to analyze existing data, establishing that inclusive measurements are more reliable and revealing new signatures related to nuclear structure effects.

Findings

Inclusive measurements are confirmed as more reliable.

Identified non-uniformities near excited state thresholds.

Discussed cluster structure influence on reaction cross section.

Abstract

A solution of the large discrepancy existing between inclusive and exclusive measurements of the ${}^8{\rm Li}+{}^4{\rm He}\to{}^{11}{\rm B}+n$ reaction cross section at $E_{cm} <3$ MeV is evaluated. This problem has profound astrophysical relevance for this reaction is of great interest in Big-Bang and r-process nucleosynthesis. By means of a novel technique, a comprehensive study of all existing ${}^8{\rm Li}+{}^4{\rm He}\to{}^{11}{\rm B}+n$ cross section data is carried out, setting up a consistent picture in which all the inclusive measurements provide the reliable value of the cross section. New unambiguous signatures of the strong branch pattern non-uniformities, near the threshold of higher ${}^{11}{\rm B}$ excited levels, are presented and their possible origin, in terms of the cluster structure of the involved excited states of ${}^{11}{\rm B}$ and ${}^{12}{\rm B}$ nuclei, is discussed.