Update of Time-Dependent CP Asymmetry Measurements in $b$-->$c\bar{c}s$ Decays

TL;DR

This paper reports updated measurements of time-dependent CP asymmetries in neutral B decays involving charmonium, using a large dataset from the BABAR experiment, providing refined parameters consistent with the Standard Model.

Contribution

The study provides the most recent and precise measurements of CP asymmetry parameters in specific B decay modes, improving upon previous results with a larger dataset.

Findings

Measured CP asymmetry parameters with reduced uncertainties.

Results are consistent with Standard Model predictions.

Enhanced understanding of CP violation in B meson decays.

Abstract

We present updated measurements of time-dependent CP asymmetries in fully reconstructed neutral B decays containing a charmonium meson. The measurements reported here use a data sample of $(465\pm 5)\times 10^6$ $\Upsilon(4S) \to B \bar{B}$ decays collected with the BABAR detector at the PEP-II $B$ factory. The time-dependent CP asymmetry parameters measured from $J/\psi K_S^0$, $J/\psi K_L^0$, $\psi(2S) K_S^0$, $\chi_{c1} K_S^0$, $\eta_c K_S^0$, and $J/\psi K^{*0}$ decays are \begin{eqnarray} C_f &=& 0.026 \pm 0.020(stat) \pm 0.016(syst), S_f &=& 0.691 \pm 0.029(stat) \pm 0.014(syst). \end{eqnarray}