Locality hypothesis, direct test

However, the low efficiency of the photomultipliers used in all these experiments leaves open the possibility that the results could be explained in terms of local realistic theories if the no-enhancement hypothesis is not made. Consequently, no experiment to date can be considered to have provided grounds for a completely unequivocal rejection of such theories, and, indeed, if such an assumption is not made, it has been shown by several authors that it is possible to explain all existing experimental results in local realistic terms. Thus it seems likely that, in future, experimental work will be carried out either in situations where it is not necessary to make the no-enhancement hypothesis, for example in experiments of the type suggested by Lo and Shimony or Selleri, or in situations where the no-enhancement hypothesis can be subjected to direct experimental test, for example in experiments of the type suggested by Garuccio and Selleri. ... 

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