We report measurements of charm-mixing parameters based on the decay-time-dependent ratio of D0→K+π− to D0→K−π+ rates. The analysis uses a data sample of proton-proton collisions corresponding to an integrated luminosity of 5.0 fb−1 recorded by the LHCb experiment from 2011 through 2016. Assuming charge-parity (CP) symmetry, the mixing parameters are determined to be x′2=(3.9±2.7)×10−5, y′=(5.28±0.52)×10−3, and RD=(3.454±0.031)×10−3. Without this assumption, the measurement is performed separately for D0 and D⎯⎯⎯⎯0 mesons, yielding a direct CP-violating asymmetry AD=(−0.1±9.1)×10−3, and magnitude of the ratio of mixing parameters 1.00<|q/p|<1.35 at the 68.3% confidence level. All results include statistical and systematic uncertainties and improve significantly upon previous single-measurement determinations. No evidence for CP violation in charm mixing is observed.

Updated determination of D0–D¯0 mixing and CP violation parameters with D0→K+π− decays

Calabrese, R.;Capriotti, L.;Fiorini, M.;Luppi, E.;Minzoni, L.;Pappalardo, L.;Tomassetti, L.;
2018

Abstract

We report measurements of charm-mixing parameters based on the decay-time-dependent ratio of D0→K+π− to D0→K−π+ rates. The analysis uses a data sample of proton-proton collisions corresponding to an integrated luminosity of 5.0 fb−1 recorded by the LHCb experiment from 2011 through 2016. Assuming charge-parity (CP) symmetry, the mixing parameters are determined to be x′2=(3.9±2.7)×10−5, y′=(5.28±0.52)×10−3, and RD=(3.454±0.031)×10−3. Without this assumption, the measurement is performed separately for D0 and D⎯⎯⎯⎯0 mesons, yielding a direct CP-violating asymmetry AD=(−0.1±9.1)×10−3, and magnitude of the ratio of mixing parameters 1.00<|q/p|<1.35 at the 68.3% confidence level. All results include statistical and systematic uncertainties and improve significantly upon previous single-measurement determinations. No evidence for CP violation in charm mixing is observed.
2018
Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Ali, S.; Alkhazov, G.; Alvar...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/2397000
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