Discrimination of Three Nucleon Force Models via Proton-Deuteron Breakup Reactions

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One current interest for the investigations of few-nucleon system is the study of three-nucleon force (3NF) properties in the three nucleon systems. The 3NF of itself has a long history about 70 years. However, up to now, there has been little knowledge with which to constrain the 3NFs. That is due to the fact that the 3NFs are relatively weak compared to two-nucleon interactions and therefore it is hard to approach and also to find evidences for them experimentally.In order to explore 3NF effects, especially focusing on discrimination of two 3NF models, Tucson-Melbourne and Urbana we measured the vector analyzing powers for proton-deuteron breakup reactions (p+d→p+p+n) at 190 MeV/A at KVI, the Netherlands. For breakup reactions one can measure different kinematical configurations. Choosing a particular configuration one hopes to enhance the 3NF effects which are sensitive to the particular amplitude of 3NF. At KVI we have performed the breakup experiment with the detector BINA which c … More overs almost the whole angular range. We have successfully obtained about 1000 configurations for breakup reactions which cover the proton energies from 30 MeV to 130 MeV and the angular range from 10° to 165°. By direct comparison between the obtained data and rigorous numerical Faddeev calculations we obtained the potential information of 3NF and off the energy shell properties. The data have rather better agreement with the calculations with Urbana 3NF than Tucson-Melbourne 3NF.As a preparation for the breakup measurement at KVI, we performed the experiments on deuteron-proton elastic scattering at Dubna synchrotron facility in Russia where the polarized deuteron beams at the highest energy in the world are available. This experiment has been motivated by the theoretical predictions by our collaborator Prof.H.Witala that one should consider relativistic effects in order to discriminate 3NF models. To obtain the systematic information of relativistic effects quantitatively we measured in a wide incident energy range 135 MeV/A-800 MeV/A. By comparing the obtained data and the theoretical predictions incorporating relativistic effects, we found that the relativistic effects are visible at the very backward angles for elastic deuteron-proton scattering. Less