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Threshold Effects in Multi-channel Coupling and Spectroscopic Factors in Exotic Nuclei

N. Michel·W. Nazarewicz·M. Ploszajczak
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Abstract

In the threshold region, the cross section and the associated overlap integral obey the Wigner threshold law that results in the Wigner-cusp phenomenon. Due to flux conservation, a cusp anomaly in one channel manifests itself in other open channels, even if their respective thresholds appear at a different energy. The shape of a threshold cusp depends on the orbital angular momentum of a scattered particle; hence, studies of Wigner anomalies in weakly bound nuclei with several low-lying thresholds can provide valuable spectroscopic information. In this work, we investigate the threshold behavior of spectroscopic factors in neutron-rich drip-line nuclei using the Gamow Shell Model, which takes into account many-body correlations and the continuum effects. The presence of threshold anomalies is demonstrated and the implications for spectroscopic factors are discussed.

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N. Michel, W. Nazarewicz, M. Ploszajczak. 2007-02-08. Threshold Effects in Multi-channel Coupling and Spectroscopic Factors in Exotic Nuclei. https://doi.org/10.1103/physrevc.75.031301

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