Unbinned model-independent measurements with coherent admixtures of multibody neutral D meson decays

Various studies of Standard Model parameters involve measuring the properties of a coherent admixture of $$ and $$ states. A typical example is the determination of the Unitarity Triangle angle $$ in the decays $$ , $$ . A model-independent approach to perform this measurement is proposed that has superior statistical sensitivity than the well-established method involving binning of the $$ decay phase space. The technique employs Fourier analysis of the complex phase difference between $$ and $$ decay amplitudes and can easily be generalised to other similar measurements, such as studies of charm mixing or determination of the angle $$ from $$ decays.