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摘要
Background: The resonance structure in C-11 is of particular interest with regard to the astrophysical Be-7(alpha, gamma) reaction, relevant at high temperature, and to the alpha-cluster structure in C-11. %26lt;br%26gt;Purpose: The measurement was made to determine the unknown resonance parameters for the high excited states of C-11. In particular, the alpha-decay width can be useful information to discuss the alpha-cluster structure in C-11. %26lt;br%26gt;Methods: New measurements of Be-7 + alpha resonant scattering and the Be-7(alpha, p)B-10 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 C-11 nucleus were studied. Inelastic scattering of Be-7 + alpha and the Be-7(alpha, p(1))B-10* reaction were also studied with a simultaneous gamma-ray measurement. The measurements were performed at the low-energy radioactive ion beam facility CRIB (CNS Radioactive Ion Beam separator) of the Center for Nuclear Study, the University of Tokyo. %26lt;br%26gt;Results: We obtained excitation functions of Be-7(alpha,alpha(0))Be-7 (elastic scattering), Be-7(alpha,alpha(1))Be-7* (inelastic scattering), Be-7(alpha,p(0))B-10, and Be-7(alpha, p(1))B-10*. Many resonances including a new one were observed and their parameters were determined by using an R-matrix analysis. %26lt;br%26gt;Conclusions: The resonances we observed possibly enhance the Be-7(alpha,gamma) reaction rate but with a smaller magnitude than the lower-lying resonances. A new negative-parity cluster band, similar to the one previously suggested in the mirror nucleus B-11, is proposed. DOI: 10.1103/PhysRevC.87.034303
- 出版日期2013-3-4
