Evidence for evolution from pure states to mixed states in pion creation process pi(-) p -> pi(-)pi(+) n on polarized target and its physical interpretation

TL;DR

This paper tests Hawking's hypothesis that quantum fluctuations induce non-unitary evolution from pure to mixed states in particle interactions, using CERN data on pion production and analyzing recoil nucleon polarization.

Contribution

It develops a spin formalism to analyze recoil polarization and provides evidence that pion creation is an open quantum system undergoing non-unitary evolution.

Findings

Pure states evolve into mixed states in pion production.

The process is time-irreversible and violates CPT symmetry.

Evidence supports the open quantum system interpretation.

Abstract

In 1982 Hawking suggested that quantum fluctuations of space-time metric will induce a non-unitary evolution from pure initial states to mixed final states in particle interactions at any energy. This hypothesis can be tested using existing CERN data on pi(-) p -> pi(-)pi(+) n on polarized target at 17.2 GeV/c. The purity of the final state is controlled by the purity of recoil nucleon polarization. We develop a spin formalism to calculate expressions for recoil nucleon polarization for two specific pure initial states. Imposing conditions of purity on the recoil nuclon polarization we obtain conditions on the amplitudes which are violated by model independent amplitude analysis of CERN data at large t. We conclude that pure states can evolve into mixed states in pi(-) p -> pi(-)pi(+) n. In quantum theory such non-unitary evolution occurs in open quantum systems interacting with an environment. We present evidence to validate the view of the pion creation process as an open quantum system interacting with a quantum environment. The observed process is time-irreversible and violates CPT symmetry.