Measurement of $y_{CP}$ in $D^0$ meson decays to the $K_S^0K^+K^-$ final state

TL;DR

This paper measures the $D^0$-$ar{D}^0$ mixing parameter $y_{CP}$ using a large data sample of $D^0$ decays to $K_S^0K^+K^-$, employing decay time analysis across invariant mass intervals, and finds results consistent with no mixing.

Contribution

First measurement of $y_{CP}$ in $D^0 o K_S^0K^+K^-$ decays using a novel decay time method.

Findings

Measured $y_{CP} = (+0.11 ext{±}0.61 ext{(stat.)} ext{±} 0.52 ext{(syst.)}) ext{%}$.

Results are consistent with no $D^0$-$ar{D}^0$ mixing.

Utilized a large 673 fb$^{-1}$ data sample from Belle.

Abstract

We present a measurement of the $D^0$-$\overline{D}{}^0$ mixing parameter $y_{CP}$ using a flavor-untagged sample of $D^0\to K_S^0K^+K^-$ decays. The measurement is based on a 673 fb$^{-1}$ data sample recorded with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. Using a method based on measuring the mean decay time for different $K^+K^-$ invariant mass intervals, we find $y_{CP} = (+0.11\pm 0.61 ({\rm stat.})\pm 0.52 (\rm syst.))%$.