First Observation of the Radiative Decay Λ0b→Λγ

Research output: Contribution to journalArticlepeer-review

  • External authors:
  • Silvia Borghi
  • Christopher Burr
  • Deepanwita Dutta
  • Lucia Grillo
  • Martha Hilton
  • George Lafferty
  • Andrew Mcnab
  • Gediminas Sarpis
  • Mark Williams
  • The LHCb Collaboration


The radiative decay Λ0b→Λγ is observed for the first time using a data sample of proton-proton collisions corresponding to an integrated luminosity of 1.7  fb−1 collected by the LHCb experiment at a center-of-mass energy of 13 TeV. Its branching fraction is measured exploiting the B0→K*0γ decay as a normalization mode and is found to be B(Λ0b→Λγ)=(7.1±1.5±0.6±0.7)×10−6, where the quoted uncertainties are statistical, systematic, and systematic from external inputs, respectively. This is the first observation of a radiative decay of a beauty baryon.

Bibliographical metadata

Original languageEnglish
Article number132002
JournalPhysical Review Letters
Early online date15 Jul 2019
Publication statusPublished - 19 Jul 2019