On a CP Anisotropy Measurement in the Dalitz Plot

TL;DR

This paper introduces a novel, model-independent method using Dalitz plots to detect local CP asymmetries in three-body meson decays, applicable to B and D mesons with varying expected effects.

Contribution

It proposes a new observable inspired by astronomy to map CP asymmetries locally in Dalitz plots, enhancing sensitivity and model independence.

Findings

Applicable to B decays with large CP effects

Effective for D decays with small effects and low background

Provides a new tool for CP symmetry analysis

Abstract

We describe a novel use of the Dalitz plot to probe CP symmetry in three-body modes of $B$ and $D$ mesons. It is based on an observable inspired by astronomers' practice, namely the significance in the difference between corresponding Dalitz plot bins. It provides a model independent mapping of local CP asymmetries. We illustrate the method for probing CP symmetry in the complementary cases of B decays, where sizable or even large effects can be expected, yet have to be differentiated against leading Standard Model contributions, and $D$ decays, where one cannot count on sizable effects, yet has to deal with much less Standard Model background.