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A selection of measured cross sections and vector analyzing powers, A x and A y , are presented for the p → d break-up reaction. The data are taken with a polarized proton beam with a kinetic energy of 135 MeV using the Big Instrument for Nuclear-polarization Analysis (BINA) at KVI, the Netherlands. With this setup, A x is extracted for the first time for a large range of energies as well as polar and azimuthal angles of the two outgoing protons. For most of the configurations, the results at small and large relative azimuthal angles differ in behavior when comparing experimental data with the theoretical calculations. We also performed a more global comparison of our data with theoretical calculations. The cross-section results show huge values of χ 2 /d.o.f.. The absolute values of χ 2 /d.o.f. for the components of vector analyzing powers, A x and A y , are smaller than the ones for the cross section, partly due to larger uncertainties for these observables. However, also for these observables no satisfactory agreement is found for all angular combinations. This implies that the present models of a three-nucleon force are not able to provide a satisfactory description of experimental data. [ABSTRACT FROM AUTHOR]

Vector-analyzing powers, A x and A y , of the proton–deuteron break-up reaction have been measured by using a polarized-proton beam at 135 MeV impinging on a liquid-deuterium target. For the experiment, the big instrument for nuclear-polarization analysis (BINA) was used at KVI, Groningen, the Netherlands. The data are compared to the predictions of Faddeev calculations using state-of-the-art two- and three-nucleon potentials. Our data are reasonably well described by calculations for the kinematical configurations at which the three-nucleon force (3NF) effect is predicted to be small. However, striking discrepancies are observed at specific configurations, in particular in the cases of symmetric configurations, where the relative azimuthal angle between the two protons is small which corresponds to the d (p → , 2 He) n channel. The vector-analyzing powers of these configurations are compared to the proton–deuteron elastic scattering to study the spin–isospin sensitivity of the 3NF models. The results are compared to the earlier results of the proton–deuteron break-up reaction at 190 MeV proton-beam energy [1]. Disagreement is observed for both proton-beam energies between data and calculations which points to a deficiency in the treatment of spin–isospin part of the 3NF. [ABSTRACT FROM AUTHOR]