A measurement has been proposed by B. d'Espagnat that would distinguish from one another some ensembles that are differently prepared but correspond to the same density matrix. Here, the idea is modified so that it becomes applicable to much more general situations. The method is illustrated in simple examples. Some matter of concern might then be that information could be transmitted by method...

In ultrarelativistic heavy ion collisions the produced high temperature, high energy density state will cross different phases of the strongly interacting matter. The original idea of quarkgluon plasma formation has been evolved and the weakly interacting gaseous state of massless partons has been replaced by the picture of strongly interacting massive constituent quarks. Experimental results a...