New measurement of the $E_{c.m.}=323$ keV resonance in the ${}^{19}$F$($p,γ$)$^{20}$Ne reaction

Abstract

At temperatures below 0.1 GK the ${}^{19}$F$(p,{\hat{I}}^3{)}^{20}$Ne reaction is the only breakout path out of the CNO cycle. Experimental studies of this reaction are challenging from a technical perspective due to copious ${\hat{I}}^3$-ray background from the far stronger ${}^{19}$F$(p,\hat{I}\pm {)}^{16}$O reaction channel. Here we present the first inverse kinematics study of the ${}^{19}$F$(p,{\hat{I}}^3{)}^{20}$Ne reaction, in which we measure the strength of the 323-keV resonance. We find a strength value of $\ddot{I}‰{\hat{I}}^3=3.3_{-0.9}^{+1.1}$ meV, which is a factor of two larger than the most recent previous study. The discrepancy is likely the result of a direct to ground state transition which previous studies were not sensitive to. We also observe the transition to the first $2^{-}$ state, which has not been observed for this resonance in previous studies. A new thermonuclear reaction rate is calculated and compared with the literature.

arXiv admin note: text overlap with arXiv:1910.01698