Model-independent measurement of mixing parameters in D⁰→K_S⁰π⁺π⁻ decays

The first model-independent measurement of the charm mixing parameters in the decay D⁰→K_S⁰π⁺π⁻ is reported, using a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 1.0 fb⁻¹ at a centre-of-mass energy of 7 TeV. The measured values are x=(−0.86±0.53±0.17)×10⁻², y=(+0.03±0.46±0.13)×10⁻², where the first uncertainties are statistical and include small contributions due to the external input for the strong phase measured by the CLEO collaboration, and the second uncertainties are systematic.