Direct measurement of resonances in $^7$Be($\alpha,\gamma$)$^{11}$C relevant to $\nu p$-process nucleosynthesis
/ Authors
A. Psaltis, A. Chen, R. Longland, D. Connolly, C. Brune, B. Davids, J. Fallis, R. Giri, U. Greife, D. Hutcheon
and 11 more authors
L. Kroll, A. Lennarz, J. Liang, M. Lovely, M. Luo, C. Marshall, S. Paneru, A. Parikh, C. Ruiz, A. Shotter, M. Williams
/ Abstract
We have performed the first direct measurement of two resonances of the 7 Be( α, γ ) 11 C reaction with unknown strengths using an intense radioactive 7 Be beam and the DRAGON recoil separator. We report on the first measurement of the 1155 and 1110 keV resonance strengths of 1 . 73 ± 0 . 25( stat. ) ± 0 . 40( syst. ) eV and 125 +27 − 25 ( stat. ) ± 15( syst. ) meV, respectively. The present results have reduced the uncertainty in the 7 Be( α, γ ) 11 C reaction rate to ∼ 9 . 4 − 10 . 7% over T = 1.5-3 GK, which is relevant for nucleosynthesis in the neutrino–driven outflows of core–collapse supernovae ( νp –process). We find no effect of the new, constrained reaction rate on νp –process nucleosynthesis.