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

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.