SPIN CORRELATIONS IN 2-PARTICLE QUANTUM-SYSTEMS

Spin correlations displayed by spin-1/2 particles in the detection of nonfactorable two-particle spin states are analyzed. Such correlations are associated with the general quantum-mechanical effect predicted b y Einstein, Podolsky, and Rosen. Specific features of spin correlation s in singlet and triplet states are discussed in detail. Correlations of the polarizations of two protons with low relative momenta and neut ron-proton spin correlations in deuteron breakup are considered. It is shown that the spins of the final particles from the reaction pi(+) He-4 --> p + He-3 are strongly correlated. Correlations of the scatte ring planes for two particles scattered off spinless or unpolarized ta rgets are studied. The relation between correlations of the polarizati ons of two spin-1/2 particles in the initial and final states is analy zed for direct and inverse binary reactions.