Probing Quantum Entanglement in τ ^{^} +τ ⁻ Pairs via the Channel ππ at STCF

Quantum entanglement and Bell-inequality violation in [Formula: see text] pairs provide a sensitive probe of quantum correlations in high-energy interactions. We present a feasibility study of [Formula: see text] at the proposed Super Tau-Charm Facility (STCF) based on full Monte Carlo simulation at [Formula: see text][Formula: see text]GeV, focusing on the [Formula: see text] channel ([Formula: see text]), which offers the maximal spin-analyzing power [Formula: see text] and the simplest final-state topology for validating the quantum-tomography framework. We establish a consistency chain from the tree-level QED prediction through truth-level and detector-level reconstruction, yielding a reconstructed concurrence of [Formula: see text] with the good-solution approach. A complementary full-simulation study of the [Formula: see text] channel is also briefly reported. These results demonstrate that the STCF can provide a competitive platform for precision studies of quantum correlations in [Formula: see text]-lepton pairs.