  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.
