* Extension of the GRWP model to translation symmetry breaking processes*

Found Phys. Lett. **9**, 521 (1996) (12* pages*)

M. H. Y. Moussa and A. O. Caldeira

Abstract

This work is concerned with the quantum measurement model proposed by Ghirardi-Rimini-Weber [1] (GRW) in its version presented by Pearle [2], as a stochastic modification of the Schrodinger evolution. These authors conjectured a spontaneous random hitting process which is described by a localization operator, a guassian function acting on microscopic particles which carries two free parameters; the frequency lambda and the localization width alpha(-1/2). These two parameters can be understood as new constants of nature if the spontaneous localization is considered as a fundamental physical process. We can extend the model by making new conjectures about the possible values of these parameters. In particular, assuming the localization width of order of the atomic distance, the breakdown of the translational symmetry demands that the hitting process must be applied to a non-isolated quantum system. In this way we show that in the present approach the suppression of the coherence of quantum states is mainly due to the dissipation/fluctuation process and not to the random hitting process introduced by the GRW model.