Perturbative Treatment of Three-Nucleon Force Contact Terms in Three-Nucleon Faddeev Equations

AbstractWe present a perturbative approach to solving the three-nucleon continuum Faddeev equation. This approach is particularly well suited to dealing with variable strengths of contact terms in a chiral three-nucleon force. We use examples of observables in the elastic nucleon-deuteron scattering as well as in the deuteron breakup reaction to demonstrate high precision of the proposed procedure and its capability to reproduce exact results. A significant reduction of computer time achieved by the perturbative approach in comparison to exact treatment makes this approach valuable for fine-tuning of the three-nucleon Hamiltonian parameters.

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The Role of the Isospin 3/2 Component in Elastic Neutron-Deuteron Scattering and in the Deuteron Breakup Reaction

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194518600509 ◽

2018 ◽

Vol 46 ◽

pp. 1860050

Author(s):

H. Witała ◽

J. Golak ◽

R. Skibiński ◽

K. Topolnicki ◽

H. Kamada

Keyword(s):

Nucleon Nucleon ◽

Breakup Reaction ◽

Nucleon Force ◽

Elastic Neutron ◽

Deuteron Breakup ◽

Deuteron Scattering ◽

Nucleon Potential ◽

Charge Independence ◽

Charge Independence Breaking ◽

Text Component

We discuss the importance of the three-nucleon isospin [Formula: see text] component in elastic neutron-deuteron scattering and in the deuteron breakup reaction. The contribution of this amplitude originates from charge-independence breaking of the nucleon-nucleon potential. We study the magnitude of that contribution to the elastic scattering and breakup observables, taking the Av18 nucleon-nucleon potential alone or combined with the Urbana IX three-nucleon force as well as the locally regularized chiral N4LO nucleon-nucleon potential alone or supplemented by the chiral N2LO three-nucleon force. We find that the isospin [Formula: see text] component is important for the breakup reaction and the proper treatment of charge-independence breaking in this case requires the inclusion of the [Formula: see text] state with isospin [Formula: see text]. For neutron-deuteron elastic scattering the [Formula: see text] contributions are insignificant and charge-independence breaking can be accounted for by neglecting [Formula: see text] component and using the effective t-matrix generated with the so-called [Formula: see text] rule.

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Three-nucleon force effects in inclusive spectra of the neutron-deuteron breakup reaction

Physical Review C ◽

10.1103/physrevc.101.054002 ◽

2020 ◽

Vol 101 (5) ◽

Author(s):

H. Witała ◽

J. Golak ◽

R. Skibiński ◽

V. Soloviov ◽

K. Topolnicki

Keyword(s):

Breakup Reaction ◽

Nucleon Force ◽

Deuteron Breakup

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Efficient emulator for solving three-nucleon continuum Faddeev equations with chiral three-nucleon force comprising any number of contact terms

The European Physical Journal A ◽

10.1140/epja/s10050-021-00555-z ◽

2021 ◽

Vol 57 (7) ◽

Author(s):

H. Witała ◽

J. Golak ◽

R. Skibiński

Keyword(s):

Integral Equations ◽

High Precision ◽

Short Range ◽

Computational Scheme ◽

Exact Results ◽

Nucleon Force ◽

Faddeev Equations ◽

Deuteron Scattering ◽

Type Integral ◽

Theoretical Predictions

AbstractWe demonstrate a computational scheme which drastically decreases the required time to get theoretical predictions based on chiral two- and three-nucleon forces for observables in three-nucleon continuum. For a three-nucleon force containing N short-range terms all workload is reduced to solving N+1 Faddeev-type integral equations. That done, computation of observables for any combination of strengths of the contact terms is done in a flash. We demonstrate on example of the elastic nucleon-deuteron scattering observables the high precision of the proposed emulator and its capability to reproduce exact results.

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Three-nucleon force effects in the FSI configuration of the d(n, nn)p breakup reaction

SciPost Physics Proceedings ◽

10.21468/scipostphysproc.3.046 ◽

2020 ◽

Author(s):

Kamada Hiroyuki ◽

Henryk Witała ◽

Jacek Golak ◽

Roman Skibiński

Keyword(s):

Cross Section ◽

Final State Interaction ◽

Breakup Reaction ◽

State Interaction ◽

Breakup Cross Section ◽

Nucleon Force ◽

Final State ◽

Deuteron Scattering ◽

Scattering Cross ◽

Incoming Nucleon

We investigated three-nucleon (3N) force effects in the final state interaction (FSI) configuration of the d (n,nn) pd(n,nn)p breakup reaction at the incoming nucleon energy E_nEn= 200 MeV. Although 3N force effects for the elastic nucleon-deuteron scattering cross section at comparable energies are located predominantly in the region of intermediate and backward angles, the corresponding 3N force effects for the integrated FSI configuration breakup cross section are found also at forward scattering angles.

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