Two-Particle Correlations and Meson-Antimeson Mixing Effects

TL;DR

This paper analyzes two-particle correlations in neutral meson systems, exploring how deviations from quantum coherence, parameterized by a decoherence parameter, affect observable asymmetries without relying on common approximations.

Contribution

It provides a general analysis of meson-antimeson correlations and decoherence effects, extending previous results beyond the Weisskopf-Wigner approximation.

Findings

Identifies features of asymmetry dependence on decoherence parameter

Derives general results applicable to various meson systems

Highlights deviations from quantum coherence effects

Abstract

We discuss 2-particle correlations which arise in the time evolution of C-odd and C-even meson--antimeson states of flavoured neutral mesons. In order to keep our discussion general, we do not use the Weisskopf -- Wigner approximation. Possible deviations from quantum-mechanical coherence effects are parameterized by a so-called decoherence parameter $\zeta$. In particular, we study the $\zeta$-dependence of the asymmetry of unlike and like-flavoured events which was recently observed experimentally in the $K^0 \bar{K}^0$ system. In this $\zeta$-dependence, we point out some important general features which do not rely on the Weisskopf -- Wigner approximation. Some other related results are derived more generally than in the literature.