Study of di-electron production in quasi-free n-p interactions at HADES set-up

The study of e+e−-pairs production in n-p interactions was carried out at HADES set-up due to irradiation of proton target by deuteron beam at Tkind = 2.5 AGeV. The momentum and angular distributions of proton-spectator an effective masses of e+e−-pairs were satisfactory described by a sum of various reactions of quasi-free n-p and p-p interactions.