No abstract

The contribution of "hanged" diagrams into the reaction np → npπ + π − was considered. It was shown that taking into account of these diagrams permits to get better description of the effective mass spectrum of π + π − -combinations.

The measurement of Λ 0 hyperons polarization in nucleus-nucleus collisions is considered as one of possible tools to study the phase transition. Fixed target and collider experiments are discussed for the case of Λ 0 's production from Au − Au central collisions at √ s N N ∼ of several GeV.

The reaction np → npπ + π − was studied at the various momenta of incident neutrons. It was shown that the characteristics of the reaction at the momenta above 3 GeV/c could be described by the model of reggeized π exchange (OPER). At the momenta below 3 GeV/c, it was necessary to use additionally the mechanism of one baryon exchange (OBE).

The reactions np → npπ + π − , np → ppπ − π 0 and np → dπ + π − were studied at the various momenta of incident neutrons. It was shown that the characteristics of the reactions at the momenta above 3 GeV/c could be described by the model of reggeized π exchange (OPER). At the momenta below 3 GeV/c, it was necessary to use additionally the mechanismof one baryon exchange (OBE).