Search for CP violation in $D^0\to\pi^-\pi^+\pi^0$ decays with the energy test

TL;DR

This study searches for CP violation in the decay D^0 to pi^- pi^+ pi^0 using an unbinned, model-independent energy test method on LHCb data, finding no evidence of CP violation.

Contribution

First application of the energy test to D^0 decay CP violation search, providing the most sensitive measurement to date with LHCb data.

Findings

Data consistent with CP symmetry (p-value ~2.6%)

Set the world's best sensitivity to CP violation in this decay

No significant CP violation observed

Abstract

A search for time-integrated CP violation in the Cabibbo-suppressed decay $D^0\to\pi^-\pi^+\pi^0$ is performed using for the first time an unbinned model-independent technique known as the energy test. Using proton-proton collision data, corresponding to an integrated luminosity of 2.0 fb$^{-1}$ collected by the LHCb detector at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV, the world's best sensitivity to CP violation in this decay is obtained. The data are found to be consistent with the hypothesis of CP symmetry with a p-value of (2.6 +/- 0.5)%.