Observation of the Λ b → J/ψ pπ - Decay


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Aaij R., Adeva B., Adinolfi M., Affolder A., Ajaltouni Z., Akar S., ...Daha Fazla

Journal of High Energy Physics, cilt.2014, sa.7, 2014 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 2014 Sayı: 7
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1007/jhep07(2014)103
  • Dergi Adı: Journal of High Energy Physics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: B physics, CP violation, Branching fraction, Flavor physics, Hadron-Hadron Scattering
  • Manisa Celal Bayar Üniversitesi Adresli: Evet

Özet

The first observation of the Cabibbo-suppressed decay Λ b → J/ψpπ is reported using a data sample of proton-proton collisions at 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1. A prominent signal is observed and the branching fraction relative to the decay mode Λ b → J/ψpK is determined to be B (Λb → J / ψp π-/ B Λ b → J / ψp K- = 0.0824 ± 0.0025 stat ± 0.0042 syst. A search for direct CP violation is performed. The difference in the CP asymmetries between these two decays is found to be A CP (Λb → J / ψp π-) - A CP (Λb → J / ψp K-) = + 5.7 ± 2.4 stat ± 1.2 syst %, which is compatible with CP symmetry at the 2.2σ level. [Figure not available: see fulltext.] © 2014 The Author(s).