Measurement of strong phase in $D^0\to K\pi$ decay at BESIII

Abstract

Based on 2.92 fb${}^{-1}$ of $e^{+}{e}^{-}$ collision data collected with the BESIII detector at $\sqrt{s}$ = 3.773 GeV, we measured the asymmetry ${\mathcal{A}}_{CP\to K\pi }$ of the branching fractions of $D^{CP\pm }\to K^{-}{\pi }^{+}$ ($D^{CP\pm }$ are the $CP$-odd and $CP$-even eigenstates) to be $(12.77\pm 1.31_{-0.31}^{+0.33})\%$. ${\mathcal{A}}_{CP\to K\pi }$ is used to extract the strong phase difference ${\delta }_{K\pi }$ between the doubly Cabibbo-suppressed process $\overline{D}{}^0\to K^{-}{\pi }^{+}$ and Cabibbo-favored $D^0\to K^{-}{\pi }^{+}$. By taking inputs of other parameters in world measurements, we obtain $\cos {\delta }_{K\pi }=1.03\pm 0.12\pm 0.04\pm 0.01$. This is the most accurate result of $\cos {\delta }_{K\pi }$ to date and can improve the world constrains on the mixing parameters and on $\gamma /{\varphi }_3$ in the CKM matrix.

4 pages, 2 figures, proceedings for the XXXIII international symposium on Physics in Collision (PIC2013), Beijing, P.R. China, 3-7 September 2013

References in corpus (1)

• D^0-D^0bar mixing in Υ(1S) \to D^0 D^0bar decay at Super-B