The cross section, the deuteron vector A(d)(y) and tensor analyzing powers A(ij), the polarization transfer coefficients K(y('))(ij), and the induced polarization P(y(')) were measured for the dp elastic scattering at 270 MeV. The cross section and A(d)(y) are well reproduced by Faddeev calculations with modern data-equivalent nucleon-nucleon forces plus the Tucson-Melbourne three-nucleon force. In contrast, A(ij), K(y('))(ij), or P(y(')) are not described by such calculations. These facts indicate the deficiencies in the spin dependence of the Tucson-Melbourne force and call for extended three-nucleon force models.

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Double differential cross sections between 0 • -12 • were measured for the 90 Zr(n, p) reaction at 293 MeV over a wide excitation energy range of 0-70 MeV. A multipole decomposition technique was applied to the present data as well as the previously obtained 90 Zr(p, n) data to extract the Gamow-Teller (GT) component from the continuum. The GT quenching factor Q was derived by using the obtained total GT strengths. The result is Q = 0.88 ± 0.06, not including an overall normalization uncertainty in the GT unit cross section of 16%.The (p, n) reaction at intermediate energies (T p > 100 MeV) provides a highly selective probe of spin-isospin excitations in nuclei due to the energy dependence of the isovector part of nucleon-nucleon (NN ) t-matrices [1]. The

Vector analyzing power for the proton-6 He elastic scattering at 71 MeV/nucleon has been measured for the first time, with a newly developed polarized proton solid target working at 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 α-core distribution in 6 He is suggested to be a possible key to understand the nuclear structure sensitivity. PACS numbers: 24.70.+s, 29.25.Pj Spin observables in scattering experiments have been rich sources of our understanding of nuclear structure, reaction, and interactions. One of the good examples is spin asymmetry in proton-proton and proton-nucleus (p-A) scatterings which is a direct manifestation of spinorbit coupling in the system. The first spin asymmetry measurements carried out by use of a double scattering method [1,2] clearly demonstrated that the spin-orbit coupling in nuclei is an order of magnitude stronger than that due to the relativistic effect [3]. At present the spin-orbit coupling in p-A scattering is quantitatively established through numerous experiments using polarized proton beams for stable targets.It is interesting to use spin asymmetry measurements to study unstable nuclei. Nuclei locating near the neutron drip line occasionally show distinctive structure such as halos or skins. The neutron rich 6 He nucleus is one of the typical nuclides with an extended neutron distribution. Since the extended neutron distribution is prominent at the nuclear surface and the spin-orbit coupling is, in nature, a surface phenomenon, it is stimulating to see how the extended neutron distributions affect the spin asymmetry, i.e., vector analyzing power in proton elastic scattering.In this Letter, we report new results of vector analyzing power for the p-6 He elastic scattering at 71 MeV/nucleon, measured with a newly developed polarized proton target. The results are compared with microscopic folding model calculations.Although cross sections in proton elastic scattering from 6 He have been extensively measured over a wide range of energies [4][5][6][7][8][9], until recently there had been no measurement of vector analyzing power. Since unstable nuclei are produced as secondary beams, we need a polarized proton target, practically in the solid state, for the spin-asymmetry studies. In addition, the solid polarized proton target should work under a low magnetic field of B ∼ 0.1 T for detection of recoiled protons with magnetic rigidity as low as 0.3 Tm. The traditional dynamical nuclear polarization technique [10], demanding a magnetic field higher than a few Tesla, can not be applied therefore. Although this difficulty might be overcome by applying a "spin frozen" operation, efforts to do so have not been successful so far. An alternative approach to overcome the problem is to develop a polarized target based on a new principle which...

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Ab-initio calculations of light nuclei require three-nucleon potentials in addition to realistic two-nucleon forces to obtain the empirical binding energies. The current status of the Illinois three-nucleon potentials used with Argonne vig is presented.

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High precision vector and tensor analyzing powers of elastic deuteron-proton (d + p) scattering have been measured at intermediate energies to investigate effects of three-nucleon forces. Angular distributions in the range of 70 • -120 • in the center-of mass frame for incident-deuteron energies of E lab d = 130 and 180 MeV were obtained using the RIKEN facility. The beam polarization was unambiguously determined by measuring the 12 C(d, α) 10 B(2 + ) reaction at 0 • . Results of the measurements are compared with state-of-the-art three-nucleon calculations. The present modeling of nucleon-nucleon forces and its extension to the three-nucleon system is not sufficient to describe the high precision data consistently and requires, therefore, further investigation.