Measurement of the np total cross section difference $\Delta\sigma_{\mathrm L}(np)$ at 1.39, 1.69, 1.89 and 1.99 GeV

Updated analysis ofNNelastic scattering to 3 GeV

“…The IUCF group has done similar work at 194 MeV. Low energy (below 20 MeV) cross sections have come from Ohio University [11] and TUNL facility [10], with an additional medium energy piece coming from JINR [22]. …”

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

“…In the following sections a determination of the NN spin-dependent observables and some results of investigations under tile "Delta-Sigma experiment" program will be done. The last accurate data [1,2] on the neutron-proton spin-dependent total cross section difference AaL(np) at the neutron beam kinetic energies 1.4, 1.7, 1.9 and 2.0 GeV will be presented. A number of physical and methodical results on investigation of the elastic np ~ pn charge exchange process over the energy region under discussion will be also presented.…”

“…The general expression for the total cross section of a polarized nucleon beam trasmitted through a polarized proton target, with arbitrary directions of beam and target polarizations is Wtot = W0tot + Wltot(PB, PT) + W2tot(PB, k)(PT, k), (1) where PB and PT are the beam and target polarizations and k is a unit vector in the direction of the beam momentum. The term o-0tot is the total cross section for unpolarized particles, Wltot and W2tot are the spin-dependent contributions.…”

“…The values of AaL(np) were measured at neutron beam kinetic energies of 1.4, 1.7, 1.9 and 2.0 GeV. The measured -AaL(np) values are presented in [1,2] and shown in Fig. 1.…”

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 results obtained in the course of the experiments [2,3] allow to tbllow reliably AaL energy dependence peculiarities in the new energy region. One can see here a fast decrease of IAaLI while the energy increases beyond 1.1 GeV and the anomaly of energy dependence in the vicinity of 1.8 Gev with a suggested minimum, which is predicted by Lomon et al [4] in "Cloudy bag model" as the lowest lying exotic six-quark configuration in the isosinglet and the spin-triplet state 3S1 with the mass M -2.63 GeV.…”