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Title: Continuum effects in nuclear transfer reactions

Abstract

We develop a semiclassical calculation for nuclear transfer reactions where the continuum is treated in an exact way, and compare the results with those of a treatment in which the continuum is neglected. We conclude that the influence of the continuum is very important for weakly bound reactants.

Authors:
 [1];  [2];  [3];  [4];  [3]
  1. Instituto de Fisica, Facultad de Ingenieria, C.C. 30, C.P. 11000 Montevideo (Uruguay)
  2. Instituto de Fisica, Universidade Federal do Rio de Janeiro, C.P.68.528, 21941-972 Rio de Janeiro (Brazil)
  3. Laboratorio TANDAR, Comision Nacional de Energia Atomica, Avenida del Libertador 8250, 1429 Buenos Aires (Argentina)
  4. (Argentina)
Publication Date:
OSTI Identifier:
21054864
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 884; Journal Issue: 1; Conference: 6. Latin American symposium on nuclear physics and applications, Iguazu (Argentina), 3-7 Oct 2005; Other Information: DOI: 10.1063/1.2710626; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BINDING ENERGY; COMPARATIVE EVALUATIONS; EXACT SOLUTIONS; SEMICLASSICAL APPROXIMATION; TRANSFER REACTIONS

Citation Formats

Marta, H. D., Donangelo, R., Fernandez Niello, J. O., Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin, and Pacheco, A. J. Continuum effects in nuclear transfer reactions. United States: N. p., 2007. Web. doi:10.1063/1.2710626.
Marta, H. D., Donangelo, R., Fernandez Niello, J. O., Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin, & Pacheco, A. J. Continuum effects in nuclear transfer reactions. United States. doi:10.1063/1.2710626.
Marta, H. D., Donangelo, R., Fernandez Niello, J. O., Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin, and Pacheco, A. J. 2007. "Continuum effects in nuclear transfer reactions". United States. doi:10.1063/1.2710626.
@article{osti_21054864,
title = {Continuum effects in nuclear transfer reactions},
author = {Marta, H. D. and Donangelo, R. and Fernandez Niello, J. O. and Escuela de Ciencia y Tecnologia, Universidad Nacional de San Martin and Pacheco, A. J.},
abstractNote = {We develop a semiclassical calculation for nuclear transfer reactions where the continuum is treated in an exact way, and compare the results with those of a treatment in which the continuum is neglected. We conclude that the influence of the continuum is very important for weakly bound reactants.},
doi = {10.1063/1.2710626},
journal = {AIP Conference Proceedings},
number = 1,
volume = 884,
place = {United States},
year = 2007,
month = 2
}
  • In the usual treatment of transfer nuclear reactions, the continuum states of the transferred particle are neglected. Here we perform a semiclassical calculation that treats the continuum in an exact way. For comparison purposes, we perform a second calculation in which the continuum is completely disregarded. The results of these two calculations indicates that the influence of the continuum states may be very important in systems with weakly bound reactants.
  • We exploit a model describing the break-up of weakly-bound nuclei that can be used as a laboratory for testing different prescriptions that have been advanced in the literature to take into account the near-by presence of continuum states. In the model we follow the evolution of a single particle wave function in one dimension, initially bound by a Woods-Saxon type potential and then perturbed by a time- and position-dependent external field. Proper choices of this potential can simulate the effect of the interaction between reaction partners in a nuclear collision. These processes generate inelastic excitation probabilities that--distributed over the boundmore » and continuum states of the system--lead to either a partial or a total fragmentation of the final wave function. The comparison with the exact calculations shows that standard coupled channel descriptions based on discretization of the continuum can be accurate only when a proper choice is made of the number of discrete states, of the energy mesh and of the energy cutoff. This may imply, even in simplified cases, the use of a rather large (and unpracticable) number of channels. The use of a more restricted number of channels may lead to misleading results.« less
  • It is shown that, at large momentum transfers, one can extract nuclear structure information from the response (function) of the nucleus to an external scalar probe by factorizing the on-shell form factor associated to the struck nucleon. This result, derived both for elastic and inelastic scattering, arises from compensations between off-shell effects and exchange current effects generated by the (local) nucleon-nucleon interaction. The corrections to this on-shell factorization are in general found to be small at large momentum transfers. The role of the final state interaction in the nuclear transition form factor is then investigated and it is shown howmore » one can, for instance, correct the orthogonality defect introduced by using a plane wave approximation for the struck nucleon.« less