# Search for $CP$ Violation in ${D}_{s}^{+}\to {K}_{S}^{0}{\pi }^{+}$, ${D}^{+}\to {K}_{S}^{0}{K}^{+}$, and ${D}^{+}\to \varphi {\pi }^{+}$ Decays

28 May 2019

Abstract: A search for charge-parity ($CP$) violation in Cabibbo-suppressed ${D}_{s}^{+}\to {K}_{S}^{0}{\pi }^{+}$, ${D}^{+}\to {K}_{S}^{0}{K}^{+}$, and ${D}^{+}\to \varphi {\pi }^{+}$ decays is reported using proton-proton collision data, corresponding to an integrated luminosity of $3.8\text{}\text{}{\mathrm{fb}}^{-1}$, collected at a center-of-mass energy of 13 TeV with the LHCb detector. High-yield samples of kinematically and topologically similar Cabibbo-favored ${D}_{\left(s\right)}^{+}$ decays are analyzed to subtract nuisance asymmetries due to production and detection effects, including those induced by $CP$ violation in the neutral kaon system. The results are ${A}_{CP}\left({D}_{s}^{+}\to {K}_{S}^{0}{\pi }^{+}\right)=\left(1.3±1.9±0.5\right)×{10}^{-3},\phantom{\rule{0ex}{0ex}}{A}_{CP}\left({D}^{+}\to {K}_{S}^{0}{K}^{+}\right)=\left(-0.09±0.65±0.48\right)×{10}^{-3},\phantom{\rule{0ex}{0ex}}{A}_{CP}\left({D}^{+}\to \varphi {\pi }^{+}\right)=\left(0.05±0.42±0.29\right)×{10}^{-3},$where the first uncertainties are statistical and the second systematic. They are the most precise measurements of these quantities to date, and are consistent with $CP$ symmetry. A combination with previous LHCb measurements, based on data collected at 7 and 8 TeV, is also reported.

Published in: Physical Review Letters 122 (2019)