The N-13(p, gamma)O-14 thermonuclear reaction rate and the hot CNO cycle

Abstract

In many astrophysical environments explosive hydrogen burning may occur at very high temperatures, and energy generation is mainly achieved via the normal CNO cycle. However, there exists also a variant of this CNO cycle, which is referred to as the hot- or beta-limited CNO cycle. The nucleosynthetic yield and the details of the transition from the normal to hot CNO cycle will depend upon the relative reaction rates in the cycle. An important reaction cross section is expected to be dominated by a resonance from an excited state in O-14. The reaction rate can be approximated from the properties of this resonance, taking into account the radiative and proton decay widths. The present investigation utilizes a nuclear reaction model to infer the proton and radiative widths of the considered resonance. These quantities provide a basis for the determination of the thermonuclear reaction rate, and the transition temperatures between the 'normal' and 'hot' CNO cycles.