Title: Three-body Faddeev equations in two-particle Alt-Grassberger-Sandhas form with Distorted-Wave-Born-approximation amplitudes as effective potentials

Journal Article · · Physical Review C
 [1]
  1. Texas A & M Univ., College Station, TX (United States); Cyclotron Institute, Texas A&M University

A(d, p)B reactions on heavier nuclei are peripheral at sub-Coulomb energies and can be peripheral even at energies above the Coulomb barrier due to the presence of the distorted waves in the initial and final channels. Usually, to analyze such reactions the distorted-wave-Born-approximation (DWBA) is used. The DWBA amplitude for peripheral reactions is parametrized in terms of the asymptotic normalization coefficient (ANC) of the bound state B = (n A). However, in the DWBA, the coupling of the different channels is not taken into account explicitly. The three-body Faddeev equations written as the two-particle Alt-Grassberger-Sandhas (AGS) equations are very suitable for the analysis of the A(d, p)B reactions because they take into account explicitly the coupling of the different channels. It is well known that the overall normalization of the DWBA amplitude or even of the more advanced continuum-discretized coupled channels (CDCC) amplitude for peripheral reactions (both sub-Coulomb and above the Coulomb barrier) is determined by the ANC. However, it is not apparent that it is the case for the AGS solution due to the coupling of the (d, p) channel to other channels. In this paper, it is proved that the sub-Coulomb A(d, p)B reaction amplitude, which is a solution of the two-body AGS equations, is peripheral and is parametrized in terms of the ANC of the bound state B = (nA) if the corresponding DWBA amplitude is peripheral. Both nonlocal separable and local nuclear interaction potentials between the constituent particles are considered. To prove the peripheral character of the AGS amplitude for the sub-Coulomb A(d, p)B reactions the effective potentials are expressed in terms of the corresponding sub-Coulomb DWBA amplitudes of the different channels. The analysis of the A(d, p)B reactions above the Coulomb barrier requires the inclusion of the optical potentials. Hence, to analyze such reactions, the AGS equations are generalized by including the optical nuclear potentials in the same manner as it is done in the DWBA. The obtained AGS equations contain the DWBA effective potentials with distorted waves generated by the sum of the nuclear optical and the channel Coulomb potentials. It is shown that if the DWBA amplitude is peripheral than it is also the case for the AGS amplitude, which is also parametrized in terms of the ANC of the bound state B = (nA). Furthermore, the inclusion of the coupling of the different channels in the AGS formalism allows one to improve the treatment of the peripheral sub-Coulomb and above the Coulomb (d, p) reactions compared to the DWBA and CDCC method.

Research Organization:
Texas A & M Univ., College Station, TX (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
FG02-93ER40773; NA0003841
OSTI ID:
1471708
Journal Information:
Physical Review C, Journal Name: Physical Review C Journal Issue: 4 Vol. 98; ISSN 2469-9985
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English

References (18)

Relation between the projection operator formalism and the Faddeev theory journal February 1969
Effects of the deuteron D state in sub-Coulomb (d, p) reactions journal July 1977
Coupled reaction channels calculations in nuclear physics journal April 1988
Continuum-discretized coupled-channels calculations for three-body models of deuteron-nucleus reactions journal October 1987
Reduction of the three-particle collision problem to multi-channel two-particle Lippmann-Schwinger equations journal June 1967
Nuclear Reactions for Astrophysics: Principles, Calculation and Applications of Low-Energy Reactions book January 2009
Indirect techniques in nuclear astrophysics: a review journal October 2014
Contribution of Deuteron Breakup Channels to Deuteron Stripping and Elastic Scattering journal March 1970
Coulomb effects in three-body reactions with two charged particles journal June 1978
Momentum space integral equations for three charged particles: Nondiagonal kernels journal May 2000
Proton-deuteron elastic scattering from 2.5 to 22.7 MeV journal June 2002
Momentum-space treatment of the Coulomb interaction in three-nucleon reactions with two protons journal May 2005
Deuteron elastic scattering and stripping processes off C 12 as a three-body problem journal May 2007
Three-body description of direct nuclear reactions: Comparison with the continuum discretized coupled channels method journal December 2007
Three-body direct nuclear reactions: Nonlocal optical potential journal February 2009
Derivation of a formula for the A ( d , p ) B transition amplitude from the Faddeev equations of three-body scattering theory journal October 2009
Generalized Faddeev equations in the Alt-Grassberger-Sandhas form for deuteron stripping with explicit inclusion of target excitations and Coulomb interaction journal September 2012
Study of Nuclear Structure by Electromagnetic Excitation with Accelerated Ions journal October 1956

Similar Records