Background: Experimental and theoretical investigation of breakup coupling effects due to different cluster structures (⁸Be+n and ⁵He+α), relative importance of neutron or ⁵He/α transfer, and their contribution to α production are important to understand reaction mechanism in a weakly bound projectile (⁹Be) near the Coulomb barrier.
Purpose: Breakup coupling effect on elastic scattering and measurement of angular distributions and energy spectra of α particles produced through breakup, transfer, and complete fusion processes to disentangle their relative contributions and to investigate the relative importance of breakup followed by fusion (breakup-fusion) are compared to transfer.
Methods: Elastic scattering, inclusive α production, lithium, and boron production cross sections have been measured for the ⁹Be+⁵¹V system above Coulomb barrier energies. Continuum-discretized-coupled-channels (CDCC) breakup coupling effect using ⁸Be+n and ⁵He+α cluster configurations have been investigated. Coupled reaction channels (CRC) calculations for 1p, 1d, and 1n stripping and 1p, 1d pickup leading to ⁸Li+⁵²Cr, ⁷Li+⁵³Cr, ⁸Be+⁵²V, and ¹⁰B+⁵⁰Ti, ¹¹B+⁴⁹Ti, respectively, were performed and compared with the experimental data. Theoretical calculations for the estimation of various reaction channels contributing to α production have been performed with CDCC and CRC methods using the FRESCO code.
Results: Global optical model parameters for the ⁹Be projectile describe the elastic scattering data very well and the optical model fit improves the χ² slightly. CRC calculations show a major contribution in the production of lithium through 1p, 1d stripping and boron through 1p, 1d pickup reactions. α production angular and energy distributions are obtained, and direct α production is described with contributions from noncapture breakup, breakup-fusion, and transfer reactions.
Conclusions: Breakup coupling for ⁵He+α and ⁸Be+n cluster structures shows a repulsive and attractive coupling effect on elastic scattering, respectively. The ⁸Be+n cluster structure also shows a dipole polarization effect by suppressing the Coulomb rainbow compared to the ⁵He+α cluster structure. Kinematic analysis of the α particles energy spectra suggest that α production is dominated by breakup-fusion over cluster transfer. CRC calculations suggest that 1p, 1d stripping and pickup reactions are a major contributor to lithium and boron production cross sections.