Analysis of critical parameters in the scheme of Björk, Jonsson, and Sánchez-Soto

Björk, Jonsson, and Sánchez-Soto describe an interesting (gedanken-)experiment which demonstrates that single photons can indeed lead to effects which have no local realistic description. We study the critical values of parameters of some possible features of a non-perfect realization of the experiment (especially the channel transparency, which could be looked at as the detection efficiency), that need to be satisfied so that the experiment can be considered as a valid test of quantum mechanics versus local realism. Interestingly, the scheme turns out to be robust against photon loss.