Final state interaction in the pn and nn decay channels of $$^4_\varLambda $$He

We study the effects of final state interactions in non-mesonic weak decay $$\varLambda N \rightarrow nN$$ (n is a neutron and either or proton) hypernucleus $$_\varLambda ^4$$ He. Using three-body model distortion interaction emitted nucleon pair with residual nucleus considered. also influence between nucleons using Migdal-Watson model. The effect spin symmetries Based on our calculations, we conclude that play minor role kinetic energy spectrum pair.