Study of single-particle poles in shell-model reaction theory

doi:10.1016/0375-9474(69)91117-8

Nuclear Physics A

Volume 139, Issue 2, 22 December 1969, Pages 385-406

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Abstract

In the shell-model approach for nuclear reactions all possible reaction channels are divided into the group of strongly coupled and the group of weakly coupled channels A channel is strongly coupled if it contains a single-particle pole near the real axis of the complex k-plane. In all other cases a channel is said to be weakly coupled All physical characteristics are represented as a perturbation series with regard to the contribution of the weakly coupled channels In zero order, (only strongly coupled channels are considered) all channel characteristics were found to be analogous to those of the R-matrix theory In the first order, modified expressions of the familiar formulae of the shell-model approach are obtained In the second order the continuum-continuum coupling between the weakly coupled channels is taken into consideration It is shown that in the zero order the mean influence of the weakly coupled channels on the reaction process in the subspace of strongly coupled channels may be taken into consideration by the introduction of complex potentials in the strongly coupled channels As a numerical example the photodisintegration of the nucleus ¹⁶O is studied in the zero order of perturbation theory

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Overlaps, used in calculation of nuclear one- and two-particle transfer are reviewed in chapters 2 and 3 respectively. Their role in the reaction amplitudes is discussed in the framework of DWBA and other reaction descriptions. General equations for the overlap factors are derived, and the asymptotic behaviour demonstrated in both cases. In the two-particle case, correlations are also evaluated and reviewed. Chapter 1 gives a less technical synopsis of the situation.
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Recent developments in the theory of stripping to unbound states
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Separation approximation in the continuum shell model and application to the giant resonance of <sup>12</sup>C
1972, Nuclear Physics, Section A
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Resonance wave functions and resonance parameters from the coupled-channel method
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Spectroscopy of unbound levels with the aid of Weinberg's quasiparticles
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^†: On leave from the ZfK Rossendorf, near Dresden

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Study of single-particle poles in shell-model reaction theory

Abstract

Nucl Phys

Nucl Phys

Nucl Phys

Nucl Phys

J Nucl Phys (USSR)

Nucl Phys

Nucl Phys

Rev Mod Phys

Ann of Phys

Nucl Phys