A measurement of the CP asymmetry difference between Λc + → pK K + and pππ+ decays

The Lhcb Collaboration

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


The difference between the CP asymmetries in the decays Λc + → pKK+ and Λc + → pππ+ is presented. Proton-proton collision data taken at centre-of-mass energies of 7 and 8 TeV collected by the LHCb detector in 2011 and 2012 are used, corresponding to an integrated luminosity of 3 fb−1. The Λc + candidates are reconstructed as part of the Λb 0 → Λc +μX decay chain. In order to maximize the cancellation of production and detection asymmetries in the difference, the final-state kinematic distributions of the two samples are aligned by applying phase-space-dependent weights to the Λc + → pππ+ sample. This alters the definition of the integrated CP asymmetry to ACP wgt(pππ+). Both samples are corrected for reconstruction and selection efficiencies across the five-dimensional Λc + decay phase space. The difference in CP asymmetries is found to be ΔACPwgt=ACP(pK−K+)−ACPwgt(pπ−π+)=(0.30±0.91±0.61)%, where the first uncertainty is statistical and the second is systematic.[Figure not available: see fulltext.].

Original languageEnglish (US)
Article number182
JournalJournal of High Energy Physics
Issue number3
StatePublished - Mar 1 2018


  • CP violation
  • Charm physics
  • Flavor physics
  • Hadron-Hadron scattering (experiments)

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


Dive into the research topics of 'A measurement of the CP asymmetry difference between Λc + → pK K + and pππ+ decays'. Together they form a unique fingerprint.

Cite this