Search for $CP$ violation in $D^0\rightarrow \pi^-\pi^+\pi^0$ decays at LHCb

TL;DR

This study uses the LHCb experiment's large dataset to search for $CP$ violation in $D^0$ decays to three pions, employing a novel model-independent technique to achieve the world's best sensitivity.

Contribution

It introduces a new model-independent unbinned method for detecting $CP$ violation in charm decays, utilizing an unprecedentedly large data sample for improved sensitivity.

Findings

No significant $CP$ violation observed (p-value ~ 0.026).

Largest dataset used for this decay mode to date.

Method achieves the world's best sensitivity for this search.

Abstract

The LHCb experiment has recorded the world's largest sample of charmed meson decays. This paper presents a study of a $D^0$ meson decaying into a final state containing a neutral pion in LHCb. The search for $CP$ violation exploits a novel model-independent unbinned technique to assign a $p$-value for the no $CP$ violation hypothesis. With a data sample size exceeding that of previous measurements by almost an order of magnitude the world's best sensitivity is obtained. The $p$-value of no CP violation hypothesis given data of $D^0\rightarrow \pi^-\pi^+\pi^0$ decay analysed is found to be $(2.6 \pm 0.5)\times 10^-2$.