First inverse kinematics measurement of resonances in $^7$Be($\alpha,\gamma$)$^{11}$C relevant to neutrino-driven wind nucleosynthesis using DRAGON

TL;DR

This study provides the first direct measurement of key resonances in the $^7$Be($,$)$^{11}$C reaction, significantly reducing the nuclear physics uncertainties affecting the $ u p$-process in supernova nucleosynthesis.

Contribution

It reports the first direct measurement of two resonances in the $^7$Be($,$)$^{11}$C reaction using an radioactive beam and recoil separator, reducing rate uncertainties.

Findings

Reaction rate uncertainty reduced to ~10%.

First direct measurement of resonances in $^7$Be($,$)$^{11}$C.

Implications for nucleosynthesis in supernovae.

Abstract

A possible mechanism to explain the origin of the light $p$-nuclei in the Galaxy is the nucleosynthesis in the proton-rich neutrino-driven wind ejecta of core-collapse supernovae via the $\nu p$-process. However this production scenario is very sensitive to the underlying supernova dynamics and the nuclear physics input. As far as the nuclear uncertainties are concerned, the breakout from the $pp$-chains via the $^7$Be($\alpha,\gamma$)$^{11}$C reaction has been identified as an important link which can influence the nuclear flow and therefore the efficiency of the $\nu p$-process. However its reaction rate is poorly known over the relevant temperature range, T = 1.5-3 GK. We report on the first direct measurement of two resonances of the $^7$Be($\alpha,\gamma$)$^{11}$C reaction with previously unknown strengths using an intense radioactive $^7$Be beam from the ISAC facility and the DRAGON recoil separator in inverse kinematics. We have decreased the $^7$Be($\alpha,\gamma$)$^{11}$C reaction rate uncertainty to $\sim$ 9.4-10.7% over the relevant temperature region.