The notion of locality in (Quantum) Physics should be clearly defined

In summary, the thread about entanglement and Bell tests has been closed prematurely. It has not been clarified what "locality" means. Locality is the property of a relativistic theory that obeys the causality principle of relativistic spacetime. Locality is implemented by construction through the demand that local observables must commute at space-like separated arguments. This means that there cannot be any nonlocal (inter)actions between distant parts of a quantum system. However, in the mostly discussed case of entangled photon pairs you can of course have entangled photon states with the corresponding Bell-inequality violating correlations between the outcomes of measurements on the single photons in the pair at far distant places.
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My view would be that "non-local" in particle physics either means literal action at a distance, i.e. dynamical coupling between spacelike separated degrees of freedom, or that the fields in the Lagrangian are not point functions of spacetime.

In quantum foundations and quantum information it's a synonym for nonclassical correlations, although in the latter field "nonclassical correlations" seems to me to be more common.
 
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