Excited States of ^4He Observed in the ^6Li+d Reaction

Energy spectra of alpha particles from the 6 Li(d, α) 4 He * reaction at 13.6 MeV were observed at extremely forward angles. Angular correlations between alpha particles and deuterons were obtained for the 6 Li(d, αd)D reaction when the alpha particles were detected at 20° using coincidence method. Energy spectrum of alpha particles shows a broad peak corresponding to the excited state of 25.52 MeV in 4 He with the width of 2.26 MeV. The spin-parity of this state is assigned to be 0 + from the facts that the angular distributions of the emitted alpha particles are reproduced with DWBA theory assuming the angular momentum transfer of 2 and that the angular correlation function shows an isotropic distribution. In the coincidence energy spectrum of alpha particles a peak corresponding to the excited state of 27.5 MeV in 4 He was observed. The angular correlation for the excited state of 27.5 MeV is consistent with the assignment of odd parity.