Measurement of 4 HeÑp ¢ , nÖ at 100 and 200 MeV: Analysis with recoil-corrected continuum shell model

Double-differential cross sections d2s / sdVdExd and spectra of analyzing powers, Ay, for the 4HespW ,nd reaction were measured at Tp<100 and 200 MeV at forward angles between ulab=0° and 44°, and were analyzed using wave functions from the recoil-corrected continuum shell model (RCCSM). The steep rise of the cross-section spectra just above the p+ 3He rest energy threshold results from the excitation of the 2− and 1− resonances in 4Li and is well reproduced by the RCCSM at both incident energies. At higher excitation energies, the predicted cross sections fall off faster than the experimental values at forward angles. The absolute cross sections from the RCCSM were renormalized by factors of 1.3 and 1.6 at 100 MeV and 200 MeV, respectively, in order to fit the cross section summed over the lowest 10 MeV of excitation at the peak of the angular distribution. The 100 MeV Ay, averaged over the lowest 10 MeV of excitation, are well reproduced by the RCCSM but not the 200 MeV Ay, nor are the details of the Ay spectra well described at either energy.