Experimental search for the bound state singlet deuteron in the radiative n-p capture
Résumé
We performed an experimental search for the bound-state singlet deuteron predicted in some microscopic calculations. The predicted energy of this metastable level is in the vicinity of the deuteron disintegration threshold. This state should manifest itself in a two-photon transition following thermal neutron capture by protons. The experiment consists in the search for the second γ ray in the cascade through a high-statistics measurement of γ-ray spectra after cold neutron capture by hydrogen nuclei. The upper limit 2μb(2σ level) is obtained for the cross section of the singlet deuteron production with the binding energy in the range 10–125 keV.