Measurement of γCP in D⁰-D̅⁰ Oscillation using Quantum Correlations in e⁺e⁻ → D⁰-D̅⁰ at √s = 3.773 GeV
We report a measurement of the parameter (γCP) in D⁰-D̅⁰ oscillations performed by taking advantage of quantum coherence between pairs of D⁰-D̅⁰ mesons produced in e⁺e⁻ annihilations near threshold. In this work, doubly-tagged D⁰-D̅⁰ events, where one D decays to a CP eigenstate and the other D decays in a semileptonic mode, are reconstructed using a data sample of 2.92 fb⁻¹ collected with the BESIII detector at the center-of-mass energy of √s = 3.773 GeV. We obtain (γCP) = (-2.0 ±1.3 ± 0.7)%, where the first uncertainty is statistical and the second is systematic. This result is compatible with the current world average.