Measurement of indirect CP-violating asymmetries in $D^0\to K^+K^-$ and $D^0\to ��^+��^-$ decays at CDF
説明
We report a measurement of the indirect CP-violating asymmetries ($A_��$) between effective lifetimes of anticharm and charm mesons reconstructed in $D^0\to K^+ K^-$ and $D^0\to ��^+��^-$ decays. We use the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab experiment and corresponding to $9.7$~fb$^{-1}$ of integrated luminosity. The strong-interaction decay $D^{*+}\to D^0��^+$ is used to identify the meson at production as $D^0$ or $\overline{D}^0$. We statistically subtract $D^0$ and $\overline{D}^0$ mesons originating from $b$-hadron decays and measure the yield asymmetry between anticharm and charm decays as a function of decay time. We measure $A_��(K^+K^-) = (-0.19 \pm 0.15 (stat) \pm 0.04 (syst))\%$ and $A_��(��^+��^-)= (-0.01 \pm 0.18 (stat) \pm 0.03 (syst))\%$. The results are consistent with the hypothesis of CP symmetry and their combination yields $A_��= (-0.12 \pm 0.12)\%$.
8 pages, 3 figures, version published by Phys. Rev. D