Study of Three Nucleon Force Effects via the n + d Elastic Scattering at 250 MeV

摘要

To study the three-nucleon force (3NF) effects without ambiguities from the Coulomb effect, the differential cross sections and the vector analyzing powers for the n + d elastic scattering at E_n = 250 MeV have been measured at θ_(cm) = 10° - 180°. To cover the wide angular region, the experiments were performed by two different kinds of method at the (n,p) facility and at the NTOF facility at the Research Center for Nuclear Physics (RCNP). The results were compared with the theoretical predictions based on the Faddeev calculations with the realistic nucleon-nucleon (NN) forces combined with three-nucleon forces (3NF). The inclusion of 3NFs leads to a good description of the cross section except for the backward angles. The results were also compared with the theoretical predictions based on the Faddeev calculations with relativistic corrections. The results of the vector analyzing powers have large statistical uncertainties. All predictions cannot reproduce the angular distribution of them around θ_(cm)= 120°. The direct data-to-data comparison of the cross sections of the n + d and p + d is performed.