Study of the 8Be first T = 2 state with 4He + α and 7Li + p initiated excitation functions

Abstract In a high resolution study of the 4 He + α initiated excitation functions in the region of the 8 Be first T = 2 state, weak resonance excursions have been observed in some reaction channels yielding the total width Γ = 14.7 ± 4.0 keV. No resonance excursion has been observed in the 4 He + α elastic scattering yielding the branching ratio Γ α /Γ ≦ 0.003 for the decay of the 8 Be first T = 2 state into two α-particles. For the decay to the low-lying states of 6 Li and 7 Li lower limits of the branching ratio are given. The reinvestigation of the 7 Li+p initiated excitation functions revealed no resonance anomaly in the region of the 8 Be first T = 2 state. The upper limit Γ p /Γ ≦ 0.023 has been derived for the proton decay to the 7 Li g.s. . The results are compared with previous measurements and with shell-model calculations.