Interaction and Measuring Process in Quantum Theory

Fritz Haake, Wolfgang Weidlich

Frank Kaschluhn

Abstract A statistical law for interaction processes in quantum theory is presented. It states that the final state of the scattered systems, evaluated on the basis of quantum theory, reduces alternatively to different substates provided correlation states are produced by the interaction. Such processes also underlie the measuring process (interaction system‐apparatus). To test the modified scattering theory experiments are proposed. The consequences for the description of the interaction between a system and a macroscopic body, in particular a measuring apparatus, are discussed. The reduction of the wave function needed here comes out quite naturally.

Hans H. Diel

The so-called measurement problem of quantum theory (QT) is still lacking a satisfactory, or at least widely agreed upon, solution. A number of theories, known as interpretations of quantum theory, have been proposed and found differing acceptance among physicists. Most of the proposed theories try to explain what happens during a QT measurement using a modification of the declarative equations that define the possible results of a measurement of QT observables or by making assumptions outside the scope of falsifiable physics. This paper proposes a solution to the QT measurement problem in terms of a model of the process for the evolution of two QT systems that interact in a way that represents a measurement. The model assumes that the interactions between the measured QT object and the measurement apparatus are ''normal" interactions which adhere to the laws of quantum field theory.

Michael L. G. Redhead

J. M. Burgers

Von Neumann's finding that the outcome of a measuring process is independent of the description of the measuring apparatus effect is examined in terms of quantum theory by using two methods for calculating the outcome of an interaction of a system of particles with the measuring systems. The results obtained are equivalent. (D.C.W.)

L. E. Ballentine