Y. Sakemi

Study of energy dependence of pion production by proton on copper target near 350 MeV

New measurement of the energy dependence of pion production on a copper target near 350-MeV proton energy has been performed. The E-170 experiment has been carried out at the Ring Cyclotron Facility of the Research Center for Nuclear Physics, Osaka University, Japan. A small enhancement of the low-energy pion production cross section was observed near the incident proton energy of 352 MeV.

Proton Induced Coherent Pion Production

The short range component of the nucleon‐nucleus interaction is phenomenologically described by effective interaction including the so‐called Landau‐Migdal parameters g′, among which only gΔΔ′ has been left unfixed because of the scarcity of experimental information. We propose Coherent Pion Production (CPP) measurement 12C(p, nπ+)12C(g.s.) to get quantitative information on gΔΔ′. A preliminary CPP experiment was performed at the RCNP neutron time of flight facility by involving exclusive measurement of pions and neutrons. We have specially developed for this purpose a new pion counter and embedded it in the beam swinger magnet of the neutron time of flight facility. We describe the experiment and preliminary result from the pion‐neutron coincidences.

Gamow-Teller transitions in the Ni-64(He-3, t)Cu-64 reaction

In order to study the Gamow–Teller (GT) transitions in the fp-shell nucleus 64Cu, the 64Ni(3He, t)64Cu charge-exchange reaction was investigated at MeV/nucleon [1]. The outgoing tritons were momentum analysed by the Grand Raiden spectrometer at 0°. The very high energy resolution of 35 keV (FWHM) allowed the separation of individual levels in the excitation energy region from 0 to 3.5 MeV. An angular distribution analysis was performed for the observed transitions to these states. In addition to the ground state (g.s.), known to be a Jπ = 1+ GT state, several excited states showed L = 0 nature, making them candidates of GT states. At higher excitation energies, the level density becomes very high and a bump-like structure, the so-called GT Giant Resonance, dominates the spectrum.