Neutral kaons as decay products and analyzers of heavier flavors

TL;DR

This paper explores how cascade decays involving neutral kaons can be used as precise tools to study heavy flavor hadrons, their CP-violation parameters, and to distinguish decay amplitudes, thereby testing the Standard Model and searching for New Physics.

Contribution

It introduces the use of neutral kaon oscillations in cascade decays as a novel method for detailed heavy hadron analysis and CP-violation studies.

Findings

Kaon oscillations relate eigenstate masses to CP-parities and lifetimes.

Unambiguous separation of decay amplitudes in charmed hadrons.

Discrimination between D-meson mixing effects and interference in decays.

Abstract

Cascade decays of heavy flavor hadrons to states with neutral kaons are discussed as an instrument for detailed studies of the heavy hadron properties. For neutral flavored mesons the well-known kaon oscillations provide a unique experimental possibility of relating lighter/heavier eigenstate masses to (approximate) even/odd eigenstate CP-parities and to longer/shorter eigenstate lifetimes. As a result, they allow to eliminate sign ambiguities of CP-violating parameters and, therefore, to check the Standard Model (or to find New Physics). Specifically for charmed hadrons, both neutral/charged mesons and baryons, the secondary kaon oscillations permit unambiguous separation of Cabibbo-allowed and doubly-suppressed decay amplitudes, including measurement of their relative phases. For neutral $D$-meson decays the kaon oscillations can also discriminate, again unambiguously, between effects of $D$-meson mixing and interference of suppressed/allowed amplitudes. Another problem discussed is the influence of kaon CP-violation on the amplitude structure and on phenomenology of CP-violation in heavy hadron decays.