Irreducible pionic effects in nucleon-deuteron scattering below 20 MeV

Abstract

The consequences of a recently introduced irreducible pionic effect in low energy nucleon-deuteron scattering are analyzed. Differential cross-sections, nucleon (vector) and deuteron (vector and tensor) analyzing powers, and four different polarization transfer coefficients have been considered. This 3N F -like effect is generated by the pion-exchange diagram in presence of a two-nucleon correlation and is partially cancelled by meson-retardation contributions. Indications are provided that such type of effects are capable to selectively increase the vector (nucleon and deuteron) analyzing powers, while in the considered energy range they are almost negligible on the differential cross sections. These indications, observed with different realistic nucleonnucleon interactions, provide additional evidences that such 3N F -like effects have indeed the potential to solve the puzzle of the vector analyzing powers. Smaller but non negligible effects are observed for the other spin observables. In some cases, we find that the modifications introduced by such pionic effects on these spin observables (other than the vector analyzing powers) are significant and interesting and could be observed by experiments.PACS numbers: 24.70+s, 21.30.Cb, 25.10.+s, 25.40.Dn, 21.45.+v, and 13.75.Cs

Three-Body Dynamics in One Dimension

“…It is seen that unlike the TPE, the OPE corrections have only a small effect on the 'triton' binding energies. In figure 1 we show the effect of an effective parameter required in the OPE 3NF [8,9] (set equal to one in Triton Energy [MeV] effective parameter c 2 Figure 1. Dependence of the binding energy on the parameter c2 for all three potentials including the diagonal correction terms.…”

Nuclear Theory - Nuclear Power

“…Using only the 3NF of Ref. [6], the contribution of this term is not visible in the energy range shown in Fig. 8.…”

“…This is discussed in Ref. [6] and affects mainly spin observables, though it may also affect cross-sections. Using only the 3NF of Ref.…”

“…Using the AGS formulation of the three-body equations, Canton et al [6] carried out calculations, between 3 and 19 MeV, of cross-sections and various spin observables in the (n+d) system using various nucleon-nucleon interactions. Here we extend these calculations, considering the Bonn-B NN interaction, to lower energy (down to 50 keV), for comparison with the available data and the nuclear DLs.…”

Re-evaluating low-energy neutron-deuteron elastic scattering using three-nucleon theory

“…Using the AGS re-formulation [5] of the Faddeev threebody equations, Canton et al [6] carried out calculations, between 3 and 19 MeV, of cross sections and various spin observables in the n + d system using various nucleon-nucleon interactions. Here we extend these calculations, using the Bonn-B NN interaction, to lower energy down to 50 keV, for comparison to available data and the nuclear DLs.…”