Measurement of CP-violating and mixing-induced observables in cBs0 →φγ decays

Research output: Contribution to journalArticlepeer-review


  • LHCb Collaboration

Colleges, School and Institutes

External organisations

  • Nikhef National Institute for Subatomic Physics
  • University of Zurich
  • Universidad de Santiago de Compostela
  • University of Bristol
  • University of Michigan
  • LPC
  • Ruprecht-Karls-Universität Heidelberg
  • University of Cincinnati
  • Laboratori Nazionali dell'Infn di Frascati
  • TU Dortmund University, Germany
  • CERN
  • University of Glasgow
  • Universitat de Barcelona
  • Petersburg Nuclear Physics Institute (PNPI)
  • Imperial College London
  • Universidade Federal Do Rio de Janeiro
  • IN2P3
  • Sezione INFN di Firenze
  • Ecole Polytechnique Federale de Lausanne
  • Sezione INFN di Ferrara
  • University of Maryland
  • Institute for High Energy Physics (IHEP)
  • Syracuse University
  • Yandex School of Data Analysis
  • INFN Sezione di Cagliari
  • University of Warwick
  • Laboratoire Leprince-Ringuet
  • Institute of Physics


A time-dependent analysis of the Bs0→φγ decay rate is performed to determine the CP -violating observables Sφγ and Cφγ and the mixing-induced observable 𝒜φγΔ. The measurement is based on a sample of pp collision data recorded with the LHCb detector, corresponding to an integrated luminosity of 3 fb-1 at center-of-mass energies of 7 and 8 TeV. The measured values are Sφγ=0.43±0.30±0.11, Cφγ=0.11±0.29±0.11, and 𝒜φγΔ=-0.67-0.41+0.37±0.17, where the first uncertainty is statistical and the second systematic. This is the first measurement of the observables S and C in radiative Bs0 decays. The results are consistent with the standard model predictions.


Original languageEnglish
Article number081802
Number of pages10
JournalPhysical Review Letters
Issue number8
Publication statusPublished - 23 Aug 2019

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