Experimental tests for randomness of quantum decay examined as a Markov process

The number of decays from four distinct nuclear disintegration processes we re recorded over a long succession of counting intervals, converted into se quences of binary outcomes based on parity, and examined as a discrete two- state Markov process. The difference in single-step transition probabilitie s was found to be null to within an uncertainty of order 10(-3). supporting the proposition that quantum particles decay at random unaffected by their past history. (C) 2000 Elsevier Science B.V. All rights reserved.