Probing Models of Quantum Decoherence in Particle Physics and Cosmology

Abstract

In this review we first discuss the string theoretical motivations for induced decoherence and deviations from ordinary quantum-mechanical behaviour; this leads to intrinsic CPT violation in the context of an extended class of quantum-gravity models. We then proceed to a description ofprecision tests of CPT symmetry and quantum mechanics using mainly neutral kaons and neutrinos. We also emphasize the possibly unique role of neutral meson factories in providing specific tests of models where the quantum-mechanical CPT operator is not well-defined, leading to modifications of Einstein-Podolsky-Rosen particle correlators. Finally, we discuss experimental probes of decoherence in a cosmological context, including studies of dissipative relaxation models of dark energy in the context of non-critical (non-equilibrium) string theory and the associated modifications of the Boltzmann equation for the evolution of species abundances.