A method for model-independent measurement of the CKM angle $\beta$ via time-dependent analysis of the $B^0\to D\pi^+\pi^-$, $D\to K_S^0\pi^+\pi^-$ decays

TL;DR

This paper proposes a novel, model-independent method to measure the CKM angle β using time-dependent analysis of specific B meson decays, aiming for high-precision results with future experimental data.

Contribution

It introduces a new approach for measuring the CKM angle β that does not rely on decay models, enhancing measurement accuracy.

Findings

Method enables measurement of β with about one degree precision.

Applicable to data from Belle II and LHCb experiments.

Improves robustness of CKM angle determination.

Abstract

A new method for model-independent measurement of the CKM angle $\beta$ is proposed, that employs time-dependent analysis of flavour-tagged $B^0\to D\pi^+\pi^-$ decays with $D$ meson decays into CP-specific and~$K_S^0\pi^+\pi^-$ final states. This method can be used to measure the angle $\beta$ with future data from the Belle II and LHCb experiments with the precision level of one degree.