Study of the Excited States in ⁴He through the ⁴He(γ, p)³H Reaction

抄録

Proton spectra from the ⁴He(γ, p)³H reaction with 32 MeV bremsstrahlung X-rays were measured at 45°, 90° and 135° lab angles. Two broad peaks were found at 24 and 27 MeV, and a local minimum at 26 MeV in the excitation function. The sin²θ angular distribution at the two peaks suggests that the reaction proceeds mainly through E1 absorption. An analysis of the data in terms of two non-interfering resonances shows that the lower 1⁻ T=1 state at 25 MeV in ⁴He is mainly a ¹P₁ configuration.