Gamow-Teller strength for the analog transitions to the first T=1/2, J^pi=3/2- states in 13C and 13N and the implications for Type Ia supernovae

TL;DR

This study measures the Gamow-Teller strength for specific nuclear transitions in 13C and 13N, compares results with models, and assesses implications for Type Ia supernovae, finding minimal impact on pre-explosive evolution.

Contribution

It provides new experimental data on Gamow-Teller strength using (3He,t) reactions and compares it with previous (p,n) results, improving understanding of nuclear processes in supernovae.

Findings

Good agreement with shell-model calculations.

Differences between (3He,t) and (p,n) data affect electron-capture rates.

Overall impact on supernova pre-explosive evolution is small.

Abstract

The Gamow-Teller strength for the transition from the ground state of 13C to the T=1/2, J^pi=3/2- excited state at 3.51 MeV in 13N is extracted via the 13C(3He,t) reaction at 420 MeV. In contrast to results from earlier (p,n) studies on 13C, a good agreement with shell-model calculations and the empirical unit cross section systematics from other nuclei is found. The results are used to study the analog 13N(e-,v_e)13C reaction, which plays a role in the pre-explosion convective phase of type Ia supernovae. Although the differences between the results from the (3He,t) and (p,n) data significantly affect the deduced electron-capture rate and the net heat-deposition in the star due to this transition, the overall effect on the pre-explosive evolution is small.