Determination of [formula omitted] astrophysical S-factor via measurement of [formula omitted] reaction

Abstract

Angular distribution of the 11C(d, n) 12N reaction at E cm=9.8 MeV was measured in inverse kinematics with the secondary 11C beam. The experimental data were analyzed with DWBA calculations and thereby the asymptotic normalization coefficient, (C p eff 12 N ) 2=(C p 1/2 12 N ) 2+(C p 3/2 12 N ) 2 , was extracted to be 2.86±0.91 fm −1 for the virtual decay 12 N→ 11 C+ p . The zero energy astrophysical S-factor for the direct capture 11 C( p,γ) 12 N reaction was then derived to be 0.157±0.050 keV b. We have also estimated the contributions from resonant captures into the first- and second excited states of 12N and the interference between direct capture into the ground state and resonant capture into the second excited state. The temperature dependences of the direct capture, resonant capture and total reaction rates for 11 C( p,γ) 12 N were derived. The present work shows that the direct capture dominates the 11 C( p,γ) 12 N in the wide energy range of astrophysical interest except the ranges corresponding to two resonances.