The dipole resonances in the light nucleus Be11 were studied measuring the energy spectra and angular distributions of charged pions in the spin-flip charge-exchange reaction B11(e,π+)11Be at Ee=200 MeV. The ground state and eight excited states below Ex=18 MeV in Be11 were observed. The angular distributions were analyzed within the framework of the distorted-wave impulse approximation. A considerable amount of the deduced E1 strengths is distributed over excitation energies much lower than 18 MeV in Be11. The energy distributions of the E1 strengths of transitions to the s- and d-shell states were compared with the results of theoretical calculations with the effect of loosely bound neutron states.
ASJC Scopus subject areas
- Nuclear and High Energy Physics