Precision measurement of the mass and lifetime of the Ξ- b baryon


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

Physical Review Letters, vol.113, no.24, 2014 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 113 Issue: 24
  • Publication Date: 2014
  • Doi Number: 10.1103/physrevlett.113.242002
  • Journal Name: Physical Review Letters
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Manisa Celal Bayar University Affiliated: Yes

Abstract

We report on measurements of the mass and lifetime of the Ξ- b baryon using about 1800 Ξ- b decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0 fb-1, collected by the LHCb experiment. The decays are reconstructed in the Ξ- b → Ξ0 cπ-, Ξ0 c → pK-K-π+, channel and the mass and lifetime are measured using the Λ0 b → Λ+ Cπ-, mode as a reference. We measure M (Ξ- b) - M(Λ0 b)= 178.36 ± 0.46 ± 0.16 MeV=c2, (τξ- B/τΛ0 b) = 1.089 ± 0.026 ± 0.011, where the uncertainties are statistical and systematic, respectively. These results lead to a factor of 2 better precision on the Ξ- b mass and lifetime compared to previous best measurements, and are consistent with theoretical expectations.