N. Matsui

Unbound excited states in 19,17C

The neutron-rich carbon isotopes 19,17C have been investigated via proton inelastic scattering on a liquid hydrogen target at 70 MeV/nucleon. The invariant mass method in inverse kinematics was employed to reconstruct the energy spectrum, in which fast neutrons and charged fragments were detected in coincidence using a neutron hodoscope and a dipole magnet system. A peak has been observed with an excitation energy of 1.46(10) MeV in C, while three peaks with energies of 2.20(3), 3.05(3), and 6.13(9) MeV have been observed in C. Deduced cross sections are compared with microscopic DWBA calculations based on p-sd shell model wave functions and modern nucleon-nucleus optical potentials. Jπ assignments are made for the four observed states as well as the ground states of both nuclei.

(p, p′) and (p, n) reactions on halo nuclei

We have measured the 1H(19C,18C+n)1H and 1H(14Be,13B+n)n reactions at 70 MeV/nucleon using the invariant mass method in inverse kinematics. A new state was identified at 1.49 MeV in 19C. In the latter (p, n) reaction, a resonance peak corresponding to the 1.28 MeV state in 14B recently reported in a beta-decay study was clearly observed. Forward peaked character in the differential cross section supports the 1+assignment for this state.

Experimental test of Bell’s inequality via the 1H(d,2He)n reaction

To test Bell’s inequality, measurements of spin correlations between two protons in the spin singlet state have been performed. Proton pairs in the singlet state were produced by the 1H(d,2He)n reaction at Ed = 270 MeV.

6He scattering with polarized proton target

A new type of the spin polarized solid proton target has been constructed which can be operated under a low magnetic field of 0.08 T and a high temperature of 100 K. First polarization asymmetry measurement with an unstable beam of 6He with an energy of 71 MeV/u has been successfully carried out.