Sign of the Singlet (np)-Scattering Length, Neutron Radiative Capture by the Proton and Problem of the Virtual Level of the (np) System

Abstract

It is shown that, taking into account the process of neutron radiative capture by the proton and the negative sign of the length of singlet (np)-scattering (as = −fs (0) 0}\)). This means that a singlet state of the (np) system, which would decay into the deuteron in the ground state and the γ quantum (“singlet deuteron”) does not exist, and the pole \({\widetilde{E}_s}\) corresponds to the virtual but not true quasistationary level.