Measurement of sin 2β from BJ/ψKS0 with the CDF detector

Phys. Rev. D 61, 072005 – Published 9 March 2000
T. Affolder et al. (CDF Collaboration)


This paper reports an updated measurement of the standard model CP violation parameter sin 2β using the CDF Detector at Fermilab. The entire run I data sample of 110pb-1 of proton-antiproton collisions at s=1.8TeV is used to identify a signal sample of 400BJ/ψ KS0 events, where J/ψμ+μ- and KS0π+π-. The flavor of the neutral B meson is identified at the time of production by combining information from three tagging algorithms: a same-side tag, a jet-charge tag, and a soft-lepton tag. A maximum likelihood fitting method is used to determine sin 2β=0.79-0.44+0.41(stat+syst). This value of sin 2β is consistent with the standard model prediction, based upon existing measurements, of a large positive CP-violating asymmetry in this decay mode.


  • Received 8 September 1999
  • Published 9 March 2000

© 2000 The American Physical Society

Authors & Affiliations

References (Subscription Required)

Authorization Required




Log In



Article Lookup
Paste a citation or DOI

Enter a citation
  1. Enter a citation to look up or terms to search.

    Ex: "PRL 112 068103", "Phys. Rev. Lett. 112, 068103", "10.1103/PhysRevLett.112.068103"