THRESHOLD ANOMALY IN DOUBLET N-D SCATTERING

The behaviour of the doublet n-d scattering phase shift δ2(k) at energies close to the three-particle threshold is studied analytically and numerically. The scattering parameters possess an anomaly associated with the low energy of the singlet N-N virtual state. The anomaly manifests itself both as a bend in the energy dependence of the function k cot(Re δ2) in the range around 0.5 MeV and in the nonstandard behaviour of the break-up cross section near the threshold. © 1990 Springer-Verlag.