scattering measurements at intermediate energies and three nucleon force effects

The effects of three-nucleon force (3NF) has been actively studied by using the nucleon-deuteron (Nd) scattering states. The differential cross sections of the elastic Nd scattering at the energy below 150 MeV can be well reproduced by the Faddeev calculation based on modern nucleon-nucleon (NN) interactions and 3NF. On the other hand, the data at 250 MeV was underestimated by the Faddeev calculations with 3NF by 50%. And this large discrepancy between the data and the theory was also shown in the ²H(p, p)pn inclusive breakup reaction at Ep = 250 MeV.

For the systematic study to understand the missing picture of 3NF, we performed the measurements of the pd inclusive breakup reactions at 170MeV and the exclusive breakup reactions at 250 MeV.  The experiment was carried out at RCNP, Osaka University. The polarized proton beam of 170MeV or 250 MeV was injected to the deuterated polyethylene (CD2) target.  In the inclusive breakup measurements, scattered neutrons were detected by using the neutron detector NPOL3.  In the exclusive breakup measurements, scattered and recoil protons were detected by double arm spectrometer GR and LAS.  The data was compared with the results of the Faddeev calculations with and without the 3NF.