Measurement and pion exchange analysis of the inclusive spectra np→pX0 between 1.4 and 1.9 GeV/c and determination of the differential cross sections np→pΔ330

First measurement of the cross-section ratioR dp(0) in charge-exchange (np) reactions on H2/D2 at 0o andT n = 1 GeV Dubna “Delta-Sigma experiment”

“…The ratio Rdp(0) was obtained by the extrapolation of the direct line aproximating of experimental Rdp(0) data (with X 2 ~ 0.5 ). Our preliminary results on the momentum spectra of elastic charge exchange protons whith H2 target and corresponding da/d~(np) at 1.0 GeV are in agreement with the existing data [6,7]. The obtained ratio Rdp(0) = 0.5020.02 is significantly less than the value 2/3, which is expected in the case, when the cross-section of np -~ pn charge-exchange at 0 ~ is free of the non spin-flip contribution [5,8].…”

Measurements of energy behaviour of spin-dependentnp—observables over 1.2–3.7 GeV energy region Dubna “Delta-Sigma” Experiment

“…A sufficient statistics to determine the differential cross sections fbr np ~ pn process at 0 o were accumulated over 1-2 GeV energy region, using liquid H2 and D2 t/~rgets. Our preliminary results on the momentum spectra of elastic charge exchange protons and da/d~2(np) at 1.0, 1.2 GeV are in good agreement with the existing data [22,23]. The accumulated data treatment and analyzis are in progress.…”

Veto-system in measurement of the elastic (n,p) charge exchange using H2/D2-target at energies Tn=1–2 GeV Dubna “Delta-Sigma” experiment

“…In the energy range of 1 to 2 GeV the inelastic n p charge exchange peak consists basically of the fast protons (recharged neutrons). Recoil particles emerge mainly by excited A-resonances of a target [4,5]. The longitudinal momentum of A ~ is small in comparison with momentum of a beam neutron, but it gives a small shift of decay products angular distribution in the Lab-system.…”

“…There is also an inelastic peak in the momentum spectrum. Inelastic np-interaction over the energy range of 1-4 GeV is related with the A-resonance excitation and energy loss for pion production [4,5]. The inelastic peak maximum is displaced relative to the elastic one by .~ 400 MeV/c.…”