Dynamical Realizability for Quantum Measurement and Factorization of Evolution Operator

By building a general dynamical model for quantum measurement process,it is shown that the factorization of reduced evolution operator sufficiently results in the quantum mechanical realization of the wave packet collapse and the state correlation between the measured system and the measuring instrument-detector.This realizability is largely independent of the details of both the interaction and Hamiltonian of detector. The Coleman-Hepp model and all its generalizations are only the special cases of the more universal model given in this letter.An explicit example of this model is finally given in connection with coherent state.