Measurement of $CP$ asymmetries in $D^{\pm }\to \hat{I}{\cdot }^{\prime }\ddot{I}{€}^{\pm }$ and $D_s^{\pm }\to \hat{I}{\cdot }^{\prime }\ddot{I}{€}^{\pm }$ decays

Abstract

A search for $CP$ violation in $D^{\pm }\to \hat{I}{\cdot }^{\prime }\ddot{I}{€}^{\pm }$ and $D_s^{\pm }\to \hat{I}{\cdot }^{\prime }\ddot{I}{€}^{\pm }$ decays is performed using proton-proton collision data, corresponding to an integrated luminosity of $3$ fb${}^{-1}$, recorded by the LHCb experiment at centre-of-mass energies of $7$ and $8$ TeV. The measured $CP$-violating charge asymmetries are $A_{CP}(D^{\pm }\to \hat{I}{\cdot }^{\prime }\ddot{I}{€}^{\pm })=(-0.61\pm 0.72\pm 0.53\pm 0.12)\%$ and $A_{CP}(D_s^{\pm }\to \hat{I}{\cdot }^{\prime }\ddot{I}{€}^{\pm })=(-0.82\pm 0.36\pm 0.22\pm 0.27)\%$, where the first uncertainties are statistical, the second systematic, and the third are the uncertainties on the $A_{CP}(D^{\pm }\to K_S^0\ddot{I}{€}^{\pm })$ and $A_{CP}(D_s^{\pm }\to \ddot{I}•\ddot{I}{€}^{\pm })$ measurements used for calibration. The results represent the most precise measurements of these asymmetries to date.

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-2016-041.html