Prospects for exploring quantum-correlated neutral $D\overline{D}$ decays at STCF

Abstract

We investigate the prospects for determining charm mixing, indirect $C\!P$ violation and hadronic parameters in charm decays with quantum-correlated neutral charm mesons at the proposed Super Tau-Charm Facility. The study is based on time-integrated double tag rates of coherent $D\overline{D}$ pairs produced at $\sqrt{s}=3.773$ and $4.030$ GeV, from $e^{+}e^{-}\to D^{(*)}\overline{D}^{(*)}$ processes. Here, one $D$ is tagged with the quasi flavour-specific decays $D\to K^-\pi^+\pi^+\pi^-$, $K^-\pi^+\pi^0$, and $K^-\pi^+$, while the other $\overline{D}$ is detected with the final states in flavour-specific mode, $C\!P$ eigenstate mode, or self-conjugate mode. The expected sensitivities are evaluated assuming an integrated luminosity of $1~{\rm ab}^{-1}$ at each energy point, demonstrating the capability on precise determination of the charm mixing parameters, the indirect $C\!P$ violation parameters, the strong-phase differences, and the coherence factors. The constraints of the hadronic-parameters provide unique inputs to the CKM angle $\gamma$ fit, while the measurements of charm mixing and indirect $C\!P$ violation parameters are complementary to the time-dependent measurements in the Belle II and LHCb experiments.