BESIII Experiment Achieves High-Precision Measurement of Charm Meson Semileptonic Decays and First Constraint on "Scalar Current"
Recently, the BESIII international collaboration utilized the world's largest near-threshold charm meson data sample to perform a combined measurement of four semileptonic decay channels: D⁰→K⁻e⁺νₑ, D⁰→K⁻μ⁺νμ, D⁺→K̄⁰e⁺νₑ, and D⁺→K̄⁰μ⁺νμ. The research team extracted the quark mixing matrix element |Vcs| with a precision better than 0.5%, determined the form factor zero-point value f₊(0) with a precision better than 0.2%, and verified lepton universality in the above processes at the 0.5% precision level. Beyond these precise determinations of Standard Model parameters, what is particularly noteworthy is that this experiment has, for the first time...
2026-09-08
