Measurement of the Mass Difference Between Neutral Charm-Meson Eigenstates
Measurement of the Mass Difference Between Neutral Charm-Meson Eigenstates
We report a measurement of the mass difference between neutral charm-meson eigenstates using a novel approach that enhances sensitivity to this parameter. We use $2.3\ifmmode\times\else\texttimes\fi{}{10}^{6}$ ${D}^{0}\ensuremath{\rightarrow}{K}_{\mathit{S}}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ decays reconstructed in proton-proton collisions collected by the LHCb experiment in 2011 and 2012. Allowing for $CP$ violation in mixing and in the interference …