Search for CP Violation in Neutral D Meson Cabibbo-suppressed Three-body Decays

TL;DR

This study searches for CP violation in specific neutral D meson three-body decays using a large dataset, finding no evidence of CP violation, consistent with Standard Model predictions and constraining new physics models.

Contribution

First comprehensive search for CP violation in D0 decays to pi pi pi0 and K K pi0 with both model-independent and model-dependent analyses.

Findings

No evidence of CP violation found in the studied decays.

Results align with Standard Model predictions.

Constraints placed on models beyond the Standard Model.

Abstract

Using 385 fb^-1 of e^+e^- collision data collected at center-of-mass energies around 10.6 GeV, we search for time-integrated CP violation in the singly Cabibbo-suppressed decays D0/D0bar --> pi^- pi^+ pi^0 and D0/D0bar --> K^- K^+ pi^0. Our model-independent and model-dependent analyses show no evidence of CP violation in these decays. The intermediate amplitudes include well-defined flavor states [e.g., rho(770)^+- pi^-+, K*(892)^+- K^-+] and CP-odd eigenstates [e.g., rho(770)^0 pi^0, phi(1020) pi^0]. With the null results of the previous analyses for CP-even eigenstates D0/D0bar --> K^+ K^- and D0/D0bar --> pi^+ pi^-, we conclude that any CP violation in the singly Cabibbo-suppressed charm decays occurs at a rate which is not larger than a few percent. These results are in accord with the Standard Model predictions, and provide constraints on some models beyond the Standard Model.