Experimental determination of the Ne-19(p, gamma)Na-20 reaction rate and the breakout problem from the hot CNO cycle

Abstract

The nuclear levels of Na-20 are studied experimentally using the (He-3, t) and (p, n) reactions on Ne-20. The spin parities and excitation energies are determined for the states near and above the p + Ne-19 threshold. The stellar reaction rate of the Ne-19(p, gamma) process is evaluated based on the data. The calculation shows a more than two orders of magnitude larger rate than the previous theoretical predictions. The finding of s-wave resonance just above the capture threshold may change the onset temperature of breakout from the CNO cycle and explains the strong enhancement of Ne and heavier elements in observations of nova V1370 Aql 1982.