Recent Results From CLEO on D0-D0Bar Mixing, CP Violation in D0 Decays, and D*+ Width

TL;DR

This paper reports on recent CLEO results searching for CP violation and mixing in D0 meson decays, finding no significant CP asymmetry, measuring wrong-sign decay rates, and providing new measurements of mixing parameters and D*+ width.

Contribution

The paper provides the first measurement of the wrong-sign D0 decay rate and new limits on CP violation and mixing parameters in D0 decays, with precise width measurement of D*+.

Findings

No evidence of CP asymmetry in five decay modes.

First measurement of wrong-sign D0 decay rate.

Measurement of the D*+ width as 96 ± 4 ± 22 keV.

Abstract

We present preliminary results of several analyses searching for the effects of CP violation and mixing in the decay of $D^0$ mesons. We find no evidence of CP asymmetry in five different two-body decay modes of the $D^0$ to pairs of light pseudo-scalar mesons: $A_{CP}(K^+ K^-) = (+0.05 \pm 2.18 \pm 0.84)% $, $A_{CP}(\pi^+ \pi^-) = (+2.0 \pm 3.2 \pm 0.8)% $, $A_{CP}(K^0_{\rm S} \pi^0) = (+0.1 \pm 1.3)%$, $A_{CP}(\pi^0 \pi^0) = (+0.1 \pm 4.8)%$, and $A_{CP}(K^0_{\rm S} K^0_{\rm S}) = (-23 \pm 19)%$. We present the first measurement of the rate of wrong-sign $D^0 \to K^+ \pi^- \pi^0$ decay: $R = 0.0043^{+0.0011}_{-0.0010} \pm 0.0007$. We also describe a measurement of the mixing parameter $y_{CP}= {\Delta\Gamma\over 2 \Gamma}$ by searching for a lifetime difference between the CP neutral $K^{-}\pi^{+}$ final state and the CP even $K^+K^-$ and $\pi^+\pi^-$ final states. Under the assumption that CP is conserved we find $y_{CP} = -0.011 \pm 0.025 \pm 0.014$. Finally, we present our measurement of the \dstarp width: $96 \pm 4 \pm 22$~k$e$V.