Proton capture on $^{30}$P in novae: On the existence of states at $6.40$ MeV and $6.65$ MeV in $^{31}$S

Abstract

We use a high resolution 32 S(d, t) measurement to investigate the claimed existence of a 6401(3) keV state in 31 S that may affect the 30 P(p, γ) nuclear reaction rate in oxygen-neon (ONe) novae. Our data are shown to exclude the null hypothesis -that the state does not exist -with high significance. Additionally, the data also suggest the existence of a hitherto unreported state at 6648(4) keV. This state corresponds to a 30 P(p, γ) resonance at 517(4) keV, located below the higher edge of the Gamow window for peak nova temperatures of about 0.4 GK.