Alpha-resonance structure in ${}^{11}$C studied via resonant scattering of ${}^7$Be+$\alpha$ and ${}^7$Be($\alpha$, $p$) reaction

Abstract

The resonance structure in ${}^{11}$C is particularly of interest with regard to the astrophysical ${}^7$Be($\alpha$, $\gamma$) reaction, relevant at high temperature, and to the $\alpha$-cluster structure in ${}^{11}$C. The measurement was to determine unknown resonance parameters for the high excited states of ${}^{11}$C. In particular, the $\alpha$ decay width can be useful information to discuss $\alpha$ cluster structure in ${}^{11}$C. New measurements of the ${}^7$Be+$\alpha$ resonant scattering and the ${}^7$Be($\alpha$, $p$)${}^{10}$B reaction in inverse kinematics were performed for center-of-mass energy up to 5.5 MeV, and the resonances at excitation energies of 8.9--12.7 MeV in the compound ${}^{11}$C nucleus were studied. Inelastic scattering of ${}^7$Be+$\alpha$ and the ${}^7$Be($\alpha$, $p_1$)${}^{10}$B${}^{\ast }$ reaction were also studied with a simultaneous $\gamma$-ray measurement. The measurements were performed at the low-energy RI beam facility CRIB (CNS Radioactive Ion Beam separator) of the Center for Nuclear Study (CNS), the University of Tokyo. We obtained excitation functions of ${}^7$Be($\alpha$, ${\alpha }_0$)${}^7$Be (elastic scattering), ${}^7$Be($\alpha$, ${\alpha }_1$)${}^7$Be${}^{\ast }$ (inelastic scattering), ${}^7$Be($\alpha$, $p_0$)${}^{10}$B, and ${}^7$Be($\alpha$, $p_1$)${}^{10}$B${}^{\ast }$. Many resonances including a new one were observed and their parameters were determined by an R-matrix analysis. The resonances we observed possibly enhance the ${}^7$Be($\alpha$, $\gamma$) reaction rate but in a smaller magnitude than the lower-lying resonances. A new negative-parity cluster band, similar to the one previously suggested in the mirror nucleus ${}^{11}$B, is proposed.

References in corpus (10)

• Alpha cluster condensation in 12C and 16O
• Composition of the Innermost Core Collapse Supernova Ejecta
• Standard Big-Bang Nucleosynthesis up to CNO with an improved extended nuclear network
• Uncertainties in the nu p-process: supernova dynamics versus nuclear physics
• $2\alpha +t$ cluster structure in ${}^{11}$B
• Negative parity states of ${}^{11}$B and ${}^{11}$C and the similarity with $^{12}C
• Isovector and isoscalar spin-flip M1 strengths in ${}^{11}$B
• Cluster structures in ${}^{11}$B
• Production of Li, Be \& B from Baryon Inhomogeneous Primordial Nucleosynthesis
• alpha-decay of excited states in 11C and 11B

Cited by in corpus (6)

• Experimental investigation of a linear-chain structure in the nucleus 14C
• Signatures of $\alpha$ clustering in ultra-relativistic collisions with light nuclei
• A new study of ${}^{10}$B(p,$\alpha$)${}^7$Be reaction at low energies
• First measurement of ${}^{30}$S+$\alpha$ resonant elastic scattering for the ${}^{30}$S($\alpha$,p) reaction rate
• Impact of the ${}^7$Be($\alpha ,\gamma$)${}^{11}$C reaction on the primordial abundance of ${}^7$Li
• Effect of Magnetic Field Dissipation on Primordial Li Abundance