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This paper discusses some of the recent results obtained in a deuteron-deuteron scattering experiment using a polarized beam of deuterons with an incident energy of 130 MeV. A 4π detection system allowed to measure cross sections and spin observables for various final-state configurations. Here, we discuss the quasi-free elastic deuteron-proton scattering process in deuteron-deuteron scattering which has been observed by analyzing kinematical configurations for which the target neutron acts as a spectator particle. This part of the data can be compared directly to three-nucleon calculations and with existing data for the elastic deuteron-proton scattering process. The results for the polarization observables iT11 and T22 agree well with elastic scattering data published so-far and measured concurrently using a proton target. Surprisingly, the tensor observable T20 shows significant discrepancies with data taken using a proton target.

Three-nucleon system dynamics can be investigated quantitatively by comparing observables calculated with the use of Faddeev equations with results of precise measurements. Proper description of the experimental data can be achieved only if the dynamical models include, in addition to the nucleon-nucleon interaction, subtle effects of suppressed degrees of freedom, effectively introduced by means of genuine three-nucleon forces. A large set of high precision, exclusive cross-section data for the (1)H(d,pp)n breakup reaction at 130 MeV contributes significantly to constrain the physical assumptions underlying the theoretical interaction models. Comparison of nearly 1,800 cross section data points with the predictions using nuclear interactions generated in various ways, allowed to establish importance of including both, the three-nucleon and the Coulomb forces to significantly improve the description of the whole data set.

We have studied spin observables in the three-body break-up reaction in deuteron-deuteron scattering in the phase-space regime that corresponds to the quasi-free deuteron-proton scattering process with the neutron as spectator. The data are compared to measurements of the elastic deuteron-proton scattering process and state-of-the-art Faddeev calculations. The results for iT(11) and T-22 for the quasi-free scattering data agree very well with previously published elastic-scattering data. A significant discrepancy is found for T-20, which could point to a break-down of the quasi-free assumption. (C) 2013 Elsevier B.V. All rights reserved.

Presented at the 21st European Conference on Few-Body Problems in Physics, Salamanca, Spain, 30 August–3 September 2010. 2010. This work was partially supported by the Polish 2009–2011 science founds as a research project No. N N202 034836., High precision data for vector and tensor analyzing powers of the 1H( d, pp)n breakup reaction at 130 and 100 MeV deuteron beam energies have been measured in a large fraction of the phase space. They are compared to the theoretical predictions based on various approaches to describe the three nucleon (3N) system dynamics. Theoretical predictions describe very well the vector analyzing power data, with no need to include any three-nucleon force effects for these observables. Tensor analyzing powers can be also very well reproduced by calculations in most of the studied region, but locally certain discrepancies are observed. At 130 MeV for Axy such discrepancies usually appear, or are enhanced, when model 3N forces are included. Predicted effects of 3NFs are much lower at 100 MeV and at this energy equally good consistency between the data and the calculations is obtained with or without 3NFs.

High-precision measurements of the proton-deuteron elastic and break-up reaction have been performed in the past at KVI and elsewhere with the aim to study three-nucleon force (3NF) effects. In the present work, we explored 3NF effects in the break-up scattering process by performing a measurement of vector analyzing powers and differential cross sections using a 135 MeV polarized-proton beam impinging on a liquid-deuterium target. For this study, we used a new experimental setup, Big Instrument for Nuclear-polarization Analysis, BINA, which covers almost the entire kinematical phase space of the break-up reaction. The results are interpreted with the help of state-of-the-art Faddeev calculations.