Measurement of CP Violation in D0 Meson Decays at the CMS Experiment

Abstract The paper describes the search results for CP violation in the D 0 → $$K_{S}^{0}K_{S}^{0}$$ decay. The analysis was performed using the proton–proton collision data with centre-of-mass energy of $$\sqrt s $$ = 13 TeV, recorded by the CMS experiment at the Large Hadron Collider. The analyzed data sample contains about 10 10 events associated with production of charm hadrons, which allows performing precise measurements. The measured CP violation parameter is A CP ( D 0 → $$K_{S}^{0}K_{S}^{0}$$ ) = (6.2 ± 3.1 (stat.) ± 0.2 (syst.) ± 0.8 ( A CP ( D 0 → $$K_{S}^{0}$$ π + π − ))%, where the last uncertainty is due to the uncertainty in the reference channel asymmetry A CP ( D 0 → $$K_{S}^{0}$$ π + π − ). The obtained results are consistent with no CP violation in the studied decay. This analysis is the first measurement of CP violation in charm sector at the CMS experiment.