# First measurement of $\boldsymbol{T}$-odd moments in $\boldsymbol{D^{0} \rightarrow K_{S}^{0} \pi^{+} \pi^{-} \pi^{0}}$ decays

## TL;DR

This paper presents the first measurement of T-odd moments in D0 decays to K_S^0 pi+ pi- pi0, finding results consistent with no CP violation, using a large data sample from the Belle experiment.

## Contribution

It provides the first measurement of T-odd moments in this decay mode and explores CP violation sensitivity in different phase space regions.

## Key findings

- Measured CP-violation-sensitive asymmetry consistent with zero.
- Performed phase space analysis showing no evidence of CP violation.
- Utilized a large dataset of 966 fb^{-1} from Belle.

## Abstract

We report the first measurement of the $T$-odd moments in the decay $D^{0} \rightarrow K_{S}^{0} \pi^{+} \pi^{-} \pi^{0}$ from a data sample corresponding to an integrated luminosity of $966\,{\rm fb}^{-1}$ collected by the Belle experiment at the KEKB asymmetric-energy $e^+ e^-$ collider. From these moments we determine the $CP$-violation-sensitive asymmetry $a_{CP}^{T\text{-odd}} = \left[-0.28 \pm 1.38 ~(\rm{stat.}) ^{+0.23}_{-0.76} ~(\rm{syst.})\right] \times 10^{-3}$, which is consistent with no $CP$ violation. In addition, we perform $a_{CP}^{T\text{-odd}}$ measurements in different regions of the $D^{0} \rightarrow K_{S}^{0} \pi^{+} \pi^{-} \pi^{0}$ phase space; these are also consistent with no $CP$ violation.