Subtraction of ``accidentals'' and the validity of Bell tests
Abstract
Description
In some key Bell experiments, including two of the well-known ones by Alain Aspect, 1981-2, it is only after the subtraction of ``accidentals'' from the coincidence counts that we get violations of Bell tests. The data adjustment, producing increases of up to 60% in the test statistics, has never been adequately justified. Few published experiments give sufficient information for the reader to make a fair assessment. There is a straightforward and well known realist model that fits the unadjusted data very well. In this paper, the logic of this realist model and the reasoning used by experimenters in justification of the data adjustment are discussed. It is concluded that the evidence from all Bell experiments is in urgent need of re-assessment, in the light of all the known ``loopholes''. Invalid Bell tests have frequently been used, neglecting improved ones derived by Clauser and Horne in 1974. ``Local causal'' explanations for the observations have been wrongfully neglected.
Section on Clauser and Horne's 1974 Bell test derivations corrected and extended. One ref added, and other minor improvements. Submitted to Phys Rev A. See also quant-ph/9611037, quant-ph/9711044 and other documents at <http://www.aber.ac.uk/~cat>. Material expands that of 9711044 and includes derivation of Clauser and Horne's experimentally useful 1974 Bell test
Section on Clauser and Horne's 1974 Bell test derivations corrected and extended. One ref added, and other minor improvements. Submitted to Phys Rev A. See also quant-ph/9611037, quant-ph/9711044 and other documents at <http://www.aber.ac.uk/~cat>. Material expands that of 9711044 and includes derivation of Clauser and Horne's experimentally useful 1974 Bell test