Search for $CP$ violation using $T$-odd correlations in $D^0\to K^{+}{K}^{-}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ decays

Abstract

A search for $CP$ violation using $T$-odd correlations is performed using the four-body $D^0\to K^{+}{K}^{-}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ decay, selected from semileptonic $B$ decays. The data sample corresponds to integrated luminosities of $1.0{\text{fb}}^{-1}$ and $2.0{\text{fb}}^{-1}$ recorded at the centre-of-mass energies of 7 TeV and 8 TeV, respectively. The $CP$-violating asymmetry $a_{CP}^{T\text{-odd}}$ is measured to be $(0.18\pm 0.29\text{(stat)}\pm 0.04\text{(syst)})\%$. Searches for $CP$ violation in different regions of phase space of the four-body decay, and as a function of the $D^0$ decay time, are also presented. No significant deviation from the $CP$ conservation hypothesis is found.

23 pages including author list, 5 figures