Contradiction of the DENSITY MATRIX notion in quantum mechanics

TL;DR

This paper demonstrates a fundamental contradiction in quantum mechanics, showing that the density matrix description of a nonpolarized neutron beam conflicts with experimental discrimination of quantization axes.

Contribution

It reveals a contradiction in the standard density matrix formalism when describing nonpolarized neutron beams in quantum mechanics.

Findings

Density matrix is invariant under axis choice

Experimental devices can discriminate between axes

Contradiction challenges the density matrix concept

Abstract

It is shown that description of a nonpolarized neutron beam by density matrix is contradictory. Density matrix is invariant with respect to choice of quantization axis, while experimental devices can discriminate between different quantization axes.