Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Faddeev-type calculation of nonelastic breakup in deuteron-nucleus scattering

A. Deltuva

TL;DR

This work addresses nonelastic breakup (NEB) in deuteron-nucleus scattering, a major channel in inclusive (d,p) reactions with discrepancies among theoretical approaches. It develops a rigorous momentum-space Faddeev-AGS framework with an extended Hilbert space to include target excitations and Coulomb screening, enabling NEB to be computed from the imaginary part of the undetected-pair optical potential via three-body transition operators. The results yield well-converged NEB energy distributions, with peaks 10–35% higher than some prior calculations, and show that nonlocality in the optical potential enhances NEB near the peak while spin-dependent terms have little effect. By extending to heavier targets up to $Z=40$, the study demonstrates feasibility of the method for medium-mass nuclei and sets the stage for incorporating preequilibrium and CN contributions, potentially supported by machine-learning approaches.

Abstract

The nonelastic breakup (NEB), one of channels in $(d,p)$ inclusive reactions, is studied using the Faddeev-type scattering theory. The NEB differential cross section is obtained in terms of the imaginary part of the neutron-nucleus optical potential sandwiched between the Alt-Grassberger-Sandhas three-body transition operators. The momentum-space calculations including the Coulomb force are extended to higher charge numbers. Well converged numerical results are obtained for the energy distribution of the NEB cross section, being roughly consistent with previous works. The spin-dependent interaction terms do not play a significant role. The optical potential nonlocality effect shows up at higher proton energies, but is comparable to local potential uncertainties.

Faddeev-type calculation of nonelastic breakup in deuteron-nucleus scattering

TL;DR

This work addresses nonelastic breakup (NEB) in deuteron-nucleus scattering, a major channel in inclusive (d,p) reactions with discrepancies among theoretical approaches. It develops a rigorous momentum-space Faddeev-AGS framework with an extended Hilbert space to include target excitations and Coulomb screening, enabling NEB to be computed from the imaginary part of the undetected-pair optical potential via three-body transition operators. The results yield well-converged NEB energy distributions, with peaks 10–35% higher than some prior calculations, and show that nonlocality in the optical potential enhances NEB near the peak while spin-dependent terms have little effect. By extending to heavier targets up to , the study demonstrates feasibility of the method for medium-mass nuclei and sets the stage for incorporating preequilibrium and CN contributions, potentially supported by machine-learning approaches.

Abstract

The nonelastic breakup (NEB), one of channels in inclusive reactions, is studied using the Faddeev-type scattering theory. The NEB differential cross section is obtained in terms of the imaginary part of the neutron-nucleus optical potential sandwiched between the Alt-Grassberger-Sandhas three-body transition operators. The momentum-space calculations including the Coulomb force are extended to higher charge numbers. Well converged numerical results are obtained for the energy distribution of the NEB cross section, being roughly consistent with previous works. The spin-dependent interaction terms do not play a significant role. The optical potential nonlocality effect shows up at higher proton energies, but is comparable to local potential uncertainties.
Paper Structure (5 sections, 21 equations, 4 figures)

This paper contains 5 sections, 21 equations, 4 figures.

Table of Contents

  1. Introduction
  2. Three-body transition operators and NEB
  3. Results
  4. Conclusions
  5. Many-body approach to NEB

Figures (4)

  • Figure 1: (Color online) The convergence of the semi-inclusive NEB cross section with the Coulomb screening radius $R$. 50 MeV (80 MeV) deuteron scattering from ${}^{12}$C (${}^{90}$Zr) nucleus is shown in the top (bottom) panel. KD optical potential is used.
  • Figure 2: (Color online) The semi-inclusive NEB cross section for 80 MeV deuteron scattering from ${}^{58}$Ni, ${}^{74}$Ge, ${}^{84}$Kr, and ${}^{90}$Zr nuclei as a function of the proton energy in c.m. frame. KD optical potential is used. In the case of ${}^{58}$Ni also the EB cross section is displayed by dashed curve.
  • Figure 3: (Color online) The semi-inclusive NEB cross section for deuteron-${}^{12}$C scattering at 50 and 100 MeV beam energy as a function of the proton energy in c.m. frame. Results with several neutron-proton and nucleon-nucleus optical potential parametrizations are compared.
  • Figure 4: (Color online) The semi-inclusive NEB cross section for deuteron-${}^{40}$Ca scattering at 50 and 100 MeV beam energy as a function of the proton energy in c.m. frame. Results with several optical potential parametrizations are compared.