Explicit Calculations with a Hidden-Variable Spin Model

  • O. A. Barut
Part of the Physics of Atoms and Molecules book series (PAMO)


The basic problem we study here is whether the two-spin correlation experiments together with the theoretical Bell inequalities have already excluded the possibility of introducing hidden variables into quantum theory, as is often concluded. This question is answered negatively by explicitly reproducing the quantum-mechanical two-spin correlation function by a classical model, where the spin is associated with a classical dipole-moment vector. We then study the behavior of single events in classical and quantum models and conclude that the detector efficiency may be a fundamental limitation rather than just a technical problem to be overcome by better techniques. We further show that the assumptions underlying the derivation of Bell inequalities involve statements about single events which are consistent with neither the classical nor quantum models. It is important therefore to work with explicit physical situations rather than with abstract assumptions.


Poisson Bracket Hide Variable Spin Component Bell Inequality Magnetic Dipole Moment 


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Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • O. A. Barut
    • 1
  1. 1.International Center for Theoretical PhysicsTriesteItaly

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