First Direct Measurement of an Astrophysical p-Process Reaction Cross Section Using a Radioactive Ion Beam

TL;DR

This study provides the first direct measurement of an astrophysical p-process reaction cross section using a radioactive ion beam, revealing discrepancies with theoretical models and impacting nucleosynthesis predictions.

Contribution

It introduces a novel experimental approach to measure p-process reaction cross sections with radioactive beams, providing critical data for astrophysical models.

Findings

Measured cross section is smaller than theoretical predictions.

Results suggest higher abundance of 84Sr in supernovae.

Highlights need for further experimental studies on unstable isotopes.

Abstract

We have performed the first direct measurement of the 83Rb(p,g) radiative capture reaction cross section in inverse kinematics using a radioactive beam of 83Rb at incident energies of 2.4 and 2.7 A MeV. The measured cross section at an effective relative kinetic energy of Ecm = 2.393 MeV, which lies within the relevant energy window for core collapse supernovae, is smaller than the prediction of statistical model calculations. This leads to the abundance of 84Sr produced in the astrophysical p process being higher than previously calculated. Moreover, the discrepancy of the present data with theoretical predictions indicates that further experimental investigation of p-process reactions involving unstable projectiles is clearly warranted.