First observation of quantum correlations in $e^{+}{e}^{-}\to XD\bar{D}$ and $C$-even constrained $D\bar{D}$ pairs

Abstract

The study of meson pairs produced with quantum correlations gives direct access to parameters that are challenging to measure in other systems. In this Letter, the existence of quantum correlations due to charge-conjugation symmetry $C$ are demonstrated in $D\bar{D}$ pairs produced through the processes $e^{+}{e}^{-}\to D\bar{D}$, $e^{+}{e}^{-}\to D^{\ast }\bar{D}$, and $e^{+}{e}^{-}\to D^{\ast }{\bar{D}}^{\ast }$, where the lack of charge superscripts refers to an admixture of neutral-charm-meson particle and antiparticle states, using $7.13{\text{ fb}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected by the BESIII experiment between center-of-mass energies of $4.13-4.23\text{ GeV}$. Processes with either $C$-even or $C$-odd constraints are identified and separated. A procedure is presented that harnesses the entangled production process to enable measurements of $D^0$-meson hadronic parameters. This study provides the first confirmation of quantum correlations in $e^{+}{e}^{-}\to XD\bar{D}$ processes and the first observation of a $C$-even constrained $D\bar{D}$ system. The procedure is applied to measure ${\delta }_{K\pi }^D$, the strong phase between the $D^0\to K^{-}{\pi }^{+}$ and ${\bar{D}}^0\to K^{-}{\pi }^{+}$ decay amplitudes, which results in the determination of ${\delta }_{K\pi }^D={\left(192.8_{-12.4-2.4}^{+11.0+1.9}\right)}^{\circ }$. The potential for measurements of other hadronic decay parameters and charm mixing with these and future datasets is also discussed.

References in corpus (18)

• Design and Construction of the BESIII Detector
• The Precision Monte Carlo Event Generator KK For Two-Fermion Final States In e+e- Collisions
• STCF Conceptual Design Report: Volume 1 -- Physics & Detector
• Measurement of Charm Production Cross Sections in e+e- Annihilation at Energies between 3.97 and 4.26 GeV
• D^0-\bar{D}^0 Mixing and CP Violation in Neutral D-meson Decays
• Time-Independent Measurements of D0-D0bar Mixing and Relative Strong Phases Using Quantum Correlations
• Model-independent determination of the relative strong-phase difference between $D^0$ and ${\bar{D}}^0\to K_{S,L}^0{\pi }^{+}{\pi }^{-}$ and its impact on the measurement of the CKM angle $\gamma /{\varphi }_3$
• Charm mixing in the model-independent analysis of correlated D0-D0bar decays
• Observation of the mass difference between neutral charm-meson eigenstates
• Determination of the D0 -> K+pi- Relative Strong Phase Using Quantum-Correlated Measurements in e+e- -> D0 D0bar at CLEO
• Measurement of the $D\to K^{-}{\pi }^{+}$ strong phase difference in $\psi (3770)\to D^0\overline{D}{}^0$
• Determination of strong-phase parameters in $D\to K_{S,L}^0{\pi }^{+}{\pi }^{-}$
• Measurement of the CKM angle $\gamma$ in $B^{\pm }\to D{K}^{\pm }$ and $B^{\pm }\to D{\pi }^{\pm }$ decays with $D\to K_{\mathrm{S}}^0{h}^{+}{h}^{-}$
• Improved measurement of the strong-phase difference ${\delta }_D^{K\pi }$ in quantum-correlated $D\bar{D}$ decays
• Measurement of the $D\to K^{-}{\pi }^{+}{\pi }^{+}{\pi }^{-}$ and $D\to K^{-}{\pi }^{+}{\pi }^0$ coherence factors and average strong-phase differences in quantum-correlated $D\bar{D}$ decays
• Mixing and CP-violation in charm
• Novel correlated $D^0\overline{D}{}^0$ systems for $c/b$ physics and tests of $T/CPT$
• A novel measurement of the strong-phase difference between $D^0\to K^{-}{\pi }^{+}$ and ${\bar{D}}^0\to K^{-}{\pi }^{+}$ decays using $C$-even and $C$-odd quantum-correlated $D\bar{D}$ pairs

Cited by in corpus (1)

• A novel measurement of the strong-phase difference between $D^0\to K^{-}{\pi }^{+}$ and ${\bar{D}}^0\to K^{-}{\pi }^{+}$ decays using $C$-even and $C$-odd quantum-correlated $D\bar{D}$ pairs