Measurement of CP asymmetry in D 0 → K - K + and D 0 → π - πdecays


Creative Commons License

Aaij R., Adeva B., Adinolfi M., Affolder A., Ajaltouni Z., Albrecht J., ...More

Journal of High Energy Physics, vol.2014, no.7, 2014 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 2014 Issue: 7
  • Publication Date: 2014
  • Doi Number: 10.1007/jhep07(2014)041
  • Journal Name: Journal of High Energy Physics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: CP violation, Charm physics, Flavor physics, Hadron-Hadron Scattering
  • Open Archive Collection: AVESIS Open Access Collection
  • Manisa Celal Bayar University Affiliated: Yes

Abstract

Time-integrated CP asymmetries in D 0 decays to the final states K - K + and π - π + are measured using proton-proton collisions corresponding to 3fb-1 of integrated luminosity collected at centre-of-mass energies of 7 TeV and 8 TeV. The D 0 mesons are produced in semileptonic b-hadron decays, where the charge of the accompanying muon is used to determine the initial flavour of the charm meson. The difference in CP asymmetries between the two final states is measured to be Δ ACP = ACP (K- K +) ACP (π- π+) = (+ 0.14 ± 0.16 (stat) ± 0.08 (syst)) %. A measurement of A CP (K - K +) is obtained assuming negligible CP violation in charm mixing and in Cabibbo-favoured D decays. It is found to be ACP (K- K+) = (- 0.06 ± 0.15 (stat) ± 0.10 (syst)) %, where the correlation coefficient between ΔA CP and A CP (K - K +) is ρ = 0.28. By combining these results, the CP asymmetry in the D 0 → π - π + channel is A CP (π - π +) = (-0.20 ± 0.19 (stat) ± 0.10 (syst))%. [Figure not available: see fulltext.] © 2014 The Author(s).