Gamow-Teller strength for the analog transitions to the first T=1/2,Jπ=3/2- states in C13 and N13 and the implications for type Ia supernovae

The Gamow-Teller strength for the transition from the ground state of C13 to the T=1/2,Jπ=3/2- excited state at 3.51 MeV in N13 is extracted via the C13(He3,t) reaction at 420 MeV. In contrast to results from earlier (p,n) studies on C13, 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 N13(e-,νe)C13 reaction, which plays a role in the pre-explosion convective phase of type Ia supernovae. Although the differences between the results from the (He3,t) and (p,n) data significantly affect the deduced electron-capture rate and the net heat deposition in the star resulting from this transition, the overall effect on the pre-explosive evolution is small.