BURSTNature, Published online: 02 September 2026; doi:10.1038/s41586-026-10818-8
Polarization and quantum entanglement measurements of baryon semileptonic decay greatly enhance single-event sensitivity, and combined with lattice quantum chromodynamics calculations enable determination of the |Vus| element of the Cabibbo–Kobayashi–Maskawa matrix, providing an independent test of the standard model.