Cross Sections and Angular Distributions for the ¹⁰B(e,p) and ¹⁰B(e,d) Reactions in the Giant Resonance Region

抄録

The cross sections and angular distributions of (γ,p) and (γ,d) reactions on ¹⁰B have been measured in the giant resonance region by the (e,p) and (e,d) reactions applying the virtual photon theory. The E2 cross section of the (γ,p₀) reaction derived by a model dependent analysis of the angular distributions shows contributions of 26.5±4.5% to the E2 energy weighted sum rule. The (γ,p_0,2) integrated cross section up to 27 MeV is 6.1±0.2% of the E1 sum rule value which is smaller than 30% for ¹⁰B(γ,n). This suggests that the (γ,p) reaction leaves high-lying residual states as the prediction of the shell model calculation. The E2 strength deduced from the ¹⁰B(γ,d₀) reaction is 0.14±0.05% of the E2 energy weighted sum rule, which is one order of magnitude smaller than the case of neighboring odd–odd nuclei; ⁶Li and ¹⁴N. This may be suppressed by a competition with (γ,d₁).