Relative proton and \gamma widths of astrophysically important states in 30S studied in the \beta-delayed decay of 31Ar
G. T. Koldste, B. Blank, M. J. G. Borge, J. A. Briz, M. Carmona-Gallardo, L. M. Fraile, H. O. U. Fynbo, J. Giovinazzo, J. G. Johansen, A. Jokinen, B. Jonson, T. Kurturkian-Nieto, J. H. Kusk, T. Nilsson, A. Perea, V. Pesudo, E. Picado, K. Riisager, A. Saastamoinen, O. Tengblad, J.-C. Thomas, and J. Van de Walle
Accepted
Resonances just above the proton threshold in \S affect the \rec reaction under astrophysical conditions. The (p,$\gamma$)-reaction rate is currently determined indirectly and depends on the properties of the relevant resonances. We present here a method for finding the ratio between the proton and gamma partial widths of resonances in \S. The widths are determined from the $\beta$2p- and $\beta$p$\gamma$-decay of \Ar, which is produced at ISOLDE, CERN. Experimental limits on the ratio between the proton and gamma partial widths for astrophysical relevant levels in \S have been found for the first time. A level at $\SIE{4689.2}{24}{keV}$ is identified in the gamma spectrum, and an upper limit on the \GG ratio of $\num{0.26}$ ($\SI{95}{\%}$ C.L.) is found. In the two-proton spectrum two levels at $\SIE{5227}{3}{keV}$ and $\SIE{5847}{4}{keV}$ are identified. These levels were previously seen to gamma decay and upper limits on the \GGr ratio of $\num{0.5}$ and $\num{9}$, respectively, ($\SI{95}{\%}$ C.L.) are found, where the latter differs from previous calculations.