Improved model-independent determination of the strong-phase difference between $D^{0}$ and $\bar{D}^{0}\to K^{0}_{\mathrm{S,L}}K^{+}K^{-}$ decays

TL;DR

This paper reports the most precise measurement of the strong-phase difference between $D^{0}$ and $ar{D}^{0}$ decays to $K^{0}_{S,L}K^{+}K^{-}$, which is crucial for accurately determining the CKM angle $oldsymbol{ extgamma/ extphi_3}$ in $B$ meson decays.

Contribution

The study provides a model-independent, highly precise measurement of the strong-phase difference using quantum-entangled charm meson pairs from BESIII data.

Findings

Most precise strong-phase difference measurement to date.

Data collected from 2.93 fb$^{-1}$ at $oldsymbol{ extpsi(3770)}$.

Improves constraints on CKM angle $oldsymbol{ extgamma/ extphi_3}$.

Abstract

We present a measurement of the strong-phase difference between $D^{0}$ and $\bar{D}^{0}\to K^{0}_{\rm S,L}K^{+}K^{-}$ decays, performed through a study of quantum-entangled pairs of charm mesons. The measurement exploits a data sample equivalent to an integrated luminosity of 2.93~fb$^{-1}$, collected by the BESIII detector in $e^{+}e^{-}$ collisions corresponding to the mass of the $\psi(3770)$ resonance. The strong-phase difference is an essential input to the determination of the Cabibbo-Kobayashi-Maskawa (CKM) angle $\gamma/\phi_3$ through the decay $B^{-}\to DK^{-}$, where $D$ can be either a $D^{0}$ or a $\bar{D}^{0}$ decaying to $K^{0}_{\rm S,L}K^{+}K^{-}$. This is the most precise measurement to date of the strong-phase difference in these decays.