Continuum coupling and single-nucleon overlap integrals

Abstract

The presence of a particle continuum, both of a resonant and non-resonant character, can significantly impact spectroscopic properties of weakly bound nuclei and excited nuclear states close to, and above, the particle emission threshold. In the framework of the continuum shell model in the complex momentum-plane, the so-called Gamow Shell Model, we discuss salient effects of the continuum coupling on the one-neutron overlap integrals and the associated spectroscopic factors in neutron-rich helium and oxygen nuclei. In particular, we demonstrate a characteristic near-threshold energy dependence of the spectroscopic factors for different ℓ-waves. We show also that the realistic radial overlap functions, which are needed for the description of transfer reactions, can be generated by single-particle wave functions of the appropriately chosen complex potential.

Asymptotic normalization coefficients and continuum coupling in mirror nuclei

“…Note that k and η are complex [12], as the state in Aparticle systems is unbound. At the limit of vanishing width, k, I a bc;ℓj and H + ℓ,η (kr) become real, so that C ℓj given by Eq.…”

“…This approximation has been tested successfully in Ref. [12] for both bound and unbound states. Moreover, as only narrow resonant states are involved, we will consider that the potential entering the equation defining I a bc;ℓj (r) is real.…”

“…Moreover, as only narrow resonant states are involved, we will consider that the potential entering the equation defining I a bc;ℓj (r) is real. This simplification breaks down for resonant states bearing a sizeable width, for which complex potentials must be used [12], but is sound for narrow resonances.…”

“…Indeed, for near-threshold states, the configuration mixing involving scattering states strongly depends on the positions of particle emission thresholds in mirror systems (the binding energy effect) [9], and on different asymptotic behavior of neutron and proton wave functions. The latter effect leads to the universal behavior of cross sections [10,11] and overlap integrals [12][13][14] in the vicinity of the reaction threshold.…”

Emergence of theN=16shell gap inO21

“…The single-particle properties can be modified in light neutron-rich nuclei by the combined action of the central component and the tensor part of the effective nucleon-nucleon (NN) interaction [2,3]. Furthermore, near the drip line, other effects become important including many-body correlations [4][5][6], and the influence of the scattering to the continuum [7][8][9].…”