# Measurement of CP asymmetry in D0→K−K+ decays

Abstract : A measurement of the time-integrated CP asymmetry in the Cabibbo-suppressed decay D0→K−K+ is performed using pp collision data, corresponding to an integrated luminosity of 3fb−1, collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV. The flavour of the charm meson at production is determined from the charge of the pion in D∗+→D0π+ and D∗−→D0¯π− decays. The time-integrated CP asymmetry ACP(K−K+) is obtained assuming negligible CP violation in charm mixing and in Cabibbo-favoured D0→K−π+, D+→K−π+π+ and D+→K0¯π+ decays used as calibration channels. It is found to be ACP(K−K+)=(0.14±0.15(stat)±0.10(syst))%. A combination of this result with previous LHCb measurements yields ACP(K−K+)=(0.04±0.12(stat)±0.10(syst))%, ACP(π−π+)=(0.07±0.14(stat)±0.11(syst))%. These are the most precise measurements from a single experiment. The result for ACP(K−K+) is the most precise determination of a time-integrated CP asymmetry in the charm sector to date, and neither measurement shows evidence of CP asymmetry.
Type de document :
Article dans une revue
Physics Letters B, Elsevier, 2017, 767, pp. 177-187. 〈10.1016/j.physletb.2017.01.061〉

http://hal.in2p3.fr/in2p3-01390877
Contributeur : Claudine Bombar <>
Soumis le : mercredi 2 novembre 2016 - 15:24:59
Dernière modification le : jeudi 18 janvier 2018 - 01:51:09

### Citation

R. Aaij, L. Beaucourt, M. Chefdeville, D. Decamp, N. Déléage, et al.. Measurement of CP asymmetry in D0→K−K+ decays. Physics Letters B, Elsevier, 2017, 767, pp. 177-187. 〈10.1016/j.physletb.2017.01.061〉. 〈in2p3-01390877〉

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