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

TL;DR

This paper introduces a Fourier analysis-based, model-independent method for measuring parameters like the CKM angle gamma using coherent D meson decays, offering improved statistical sensitivity over traditional binning techniques.

Contribution

The paper proposes a novel Fourier analysis approach for model-independent measurements of D meson properties, enhancing statistical sensitivity and generalizability compared to existing methods.

Findings

Demonstrates superior statistical sensitivity over binning methods

Applicable to measurements of CKM angles and charm mixing

Easily generalizable to other decay analyses

Abstract

Various studies of Standard Model parameters involve measuring the properties of a coherent admixture of $D^0$ and $\overline{D}^0$ states. A typical example is the determination of the Unitarity Triangle angle $\gamma$ in the decays $B\to DK$, $D\to K_S^0\pi^+\pi^-$. A model-independent approach to perform this measurement is proposed that has superior statistical sensitivity than the well-established method involving binning of the $D\to K_S^0\pi^+\pi^-$ decay phase space. The technique employs Fourier analysis of the complex phase difference between $D^0$ and $\overline{D}^0$ decay amplitudes and can be easily generalised to other similar measurements, such as studies of charm mixing or determination of the angle $\beta$ from $B^0\to D h^0$ decays.