CP Asymmetries in Many-Body Final States in Beauty & Charm Transitions

TL;DR

This paper discusses the importance of measuring CP asymmetries in multi-body final states of beauty and charm decays, emphasizing the need for refined theoretical tools and the complexity of underlying dynamics.

Contribution

It highlights the necessity of precise measurements and advanced theoretical approaches to understand CP violation in multi-body decays of beauty and charm hadrons.

Findings

CP violation in charm decays remains unestablished.

Correlations between final states are complex due to CPT invariance.

Strong re-scattering significantly affects decay dynamics.

Abstract

Our community has focused on two-body final states in $B$ & $D$ decays. The SM produces at least the leading source of CP violation in $B$ transitions, none has been established yet in charm decays. It is crucial to measure three- and four-body FS with accuracy and to compare with predictions based on refined theoretical tools. Correlations between different final states (FS) based on CPT invariance are often not obvious, how to apply them and where. We have to probe regional asymmetries and use refined parametrization of the CKM matrix. One uses (broken) U- & V-spin symmetries for spectroscopy. The situations with weak decays of hadrons are much more complex. The impact of strong re-scattering is large, and it connects U- \& V-spin symmetries. Drawing diagrams often does not mean we understand the underlying dynamics. We have to probe the decays of beauty \& charm baryons. I discuss the `strategies' more than the `tactics'.