Measurement of the charm-mixing parameter $y_{CP}$

Abstract

A measurement of the charm-mixing parameter $y_{CP}$ using $D^0\to K^{+}{K}^{-}$, $D^0\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}$, and $D^0\to K^{-}\ddot{I}{€}^{+}$ decays is reported. The $D^0$ mesons are required to originate from semimuonic decays of $B^{-}$ and ${\overline{B}}^0$ mesons. These decays are partially reconstructed in a data set of proton-proton collisions at center-of-mass energies of 7 and 8 TeV collected with the LHCb experiment and corresponding to an integrated luminosity of 3 fb${}^{-1}$. The $y_{CP}$ parameter is measured to be $(0.57\pm 0.13(stat.)\pm 0.09(syst.))\%$, in agreement with, and as precise as, the current world-average value.

All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2018-038.html