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The double-differential cross sections for the ${}^{116}$Cd$(p,\phantom{\rule{-0.16em}{0ex}}n)$ and ${}^{116}$Sn$(n,\phantom{\rule{-0.16em}{0ex}}p)$ reactions were measured at 300 MeV for studying the nuclear matrix element of the ${}^{116}$Cd $\ensuremath{\beta}\ensuremath{\beta}$ decay. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) component. The integrated GT strengths up to an excitation energy of 30 MeV in the intermediate nucleus ${}^{116}$In are $40\ifmmode\pm\else\textpm\fi{}6$ and $11\ifmmode\pm\else\textpm\fi{}1$ in the $(p,\phantom{\rule{-0.16em}{0ex}}n)$ and $(n,\phantom{\rule{-0.16em}{0ex}}p)$ spectra, respectively, including the component from the isovector spin monopole (IVSM). The spectra are compared with those obtained from a theoretical calculation with a quasiparticle random phase approximation, where the contribution from the IVSM component as well as the interference effect between the GT and IVSM components are fully taken into account.

The vector analyzing power has been measured for the elastic scattering of neutron-rich 6He from polarized protons at 71 MeV/nucleon making use of a newly constructed solid polarized proton target operated in a low magnetic field and at high temperature. Two approaches based on local one-body potentials were applied to investigate the spin-orbit interaction between a proton and a 6He nucleus. An optical model analysis revealed that the spin-orbit potential for 6He is characterized by a shallow and long-ranged shape compared with the global systematics of stable nuclei. A semimicroscopic analysis with a alpha+n+n cluster folding model suggests that the interaction between a proton and the alpha core is essentially important in describing the p+6He elastic scattering. The data are also compared with fully microscopic analyses using non-local optical potentials based on nucleon-nucleon g-matrices., 20 pages, 20 figures, accepted by Physical Review C

Vector analyzing power for the proton-{sup 6}He elastic scattering at 71 MeV/nucleon has been measured for the first time, with a newly developed polarized proton solid target, which works at a low magnetic field of 0.09 T. The results are found to be incompatible with a t-matrix folding model prediction. Comparisons of the data with g-matrix folding analyses clearly show that the vector analyzing power is sensitive to the nuclear structure model used in the reaction analysis. The {alpha}-core distribution in {sup 6}He is suggested to be a possible key for understanding the nuclear structure sensitivity.

The deuteron to proton polarization transfer coefficients ${K}_{\mathit{yy}}^{{y}^{'}}$ and ${K}_{y}^{{y}^{'}}$ together with the deuteron analyzing powers are measured in three coplanar configurations of the deuteron-proton breakup reaction with a 135-MeV/nucleon polarized deuteron beam at the RIKEN Accelerator Research Facility. The data are compared with theoretical predictions based on exact solutions of the three-nucleon ($3N$) Faddeev equations with high-precision nucleon-nucleon ($\mathit{NN}$) forces, alone or combined with two $3N$ force (3NF) models, the $2\ensuremath{\pi}$-exchange Tucson-Melbourne${}^{'}(99)$ (${\mathrm{TM}}^{'}99$) and Urbana IX. Large 3NF effects have been found for all the measured observables. Predicted effects are supported by the data, with the exception of the vector analyzing power ${A}_{y}^{d}$. For this observable, theory based on only $\mathit{NN}$ forces is sufficient to explain the data. The behavior of the breakup analyzing powers is found to be different from the corresponding observables in elastic nucleon-deuteron scattering.

Gamow-Teller (GT) unit cross sections, ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$, are obtained at 198 and 297 MeV by measuring the double differential cross sections at ${0}^{\ifmmode^\circ\else\textdegree\fi{}}$ for the $(p,n)$ reaction on $^{58}\mathrm{Ni}$, $^{70}\mathrm{Zn}$, $^{114}\mathrm{Cd}$, $^{118}\mathrm{Sn}$, and $^{120}\mathrm{Sn}$. The mass dependence of ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ and the ratio of ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ to the Fermi unit cross section, ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{F}}$, $({R}^{2})$ are also derived in the mass region of $58\ensuremath{\leqslant}A\ensuremath{\leqslant}120$. The ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ value for $^{90}\mathrm{Zr}$ at 297 MeV interpolated using the $A$-dependence obtained herein agrees with that used in a previous analysis where the GT transition strength over a wide energy region up to the continuum was discussed. However, the deduced $^{64}\mathrm{Ni}$${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ value at 198 MeV is 20% smaller than that obtained from the analysis of a previous $(n,p)$ measurement. The present ${R}^{2}$ values in the mass region heavier than $^{42}\mathrm{Ca}$ are larger than those in the region up to $^{42}\mathrm{Ca}$ and increase as a function of $A$.

The differential cross sections and vector analyzing powers for $\mathit{nd}$ elastic scattering at ${E}_{n}=248$ MeV were measured for $10\ifmmode^\circ\else\textdegree\fi{}--180\ifmmode^\circ\else\textdegree\fi{}$ in the center-of-mass (c.m.) system. To cover the wide angular range, the experiments were performed separately by using two different setups for forward and backward angles. The data are compared with theoretical results based on Faddeev calculations with realistic nucleon-nucleon ($\mathit{NN}$) forces such as AV18, CD Bonn, and Nijmegen I and II, and their combinations with the three-nucleon forces (3NFs), such as Tucson-Melbourne 99 (TM99), Urbana IX, and the coupled-channel potential with \ensuremath{\Delta}-isobar excitation. Large discrepancies are found between the experimental cross sections and theory with only $2N$ forces for ${\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}g90\ifmmode^\circ\else\textdegree\fi{}$. The inclusion of 3NFs brings the theoretical cross sections closer to the data but only partially explains this discrepancy. For the analyzing power, no significant improvement is found when 3NFs are included. Relativistic corrections are shown to be small for both the cross sections and the analyzing powers at this energy. For the cross sections, these effects are mostly seen in the very backward angles. Compared with the $\mathit{pd}$ cross section data, quite significant differences are observed at all scattering angles that cannot be explained only by the Coulomb interaction, which is usually significant at small angles.

Supernarrow dibaryons (SNDs) have been searched for by the $\mathit{pd}\ensuremath{\rightarrow}\mathit{ppX}$ and $\mathit{pd}\ensuremath{\rightarrow}\mathit{pdX}$ reactions at ${E}_{p}=295$ MeV over a mass range of 1898 to 1953 MeV, where three candidates of SNDs were found at the Moscow Meson Factory. The experiment was carried out at the Research Center for Nuclear Physics using a two-arm magnetic spectrometer system and a liquid deuterium target. A good mass resolution of 1 MeV and a low background condition were achieved. No resonance structure was observed in the missing mass spectra. Upper limits of the SND production cross section were determined.