Observation of Bc -> J/ψ π and mass measurement of the Bc meson

This web page summarizes the results for the observation of Bc -> J/ψ π and the mass measurement of the Bc meson, based upon approximately 2.2 fb-1 of data.
The results have been approved as of July 12, 2007. This latest result is an update from previously approved 1.1 fb-1 result and 0.8 fb-1 result that are included in this update.
This result is a separate analysis from earlier work on 0.36 fb-1 data. This work includes that initial 0.36 fb-1 data set and additional data collected but with a different analysis technique.

Using an unbiased selection with requirements chosen on the basis of enhancing the reference decay, Bu -> J/ψ K, we apply those same requirements to the region of interest in J/ψ π. We observe an excess of events attributed to the Bc meson with a significance greater than 8σ. We measure the mass of the Bc meson to be:

Recent lattice QCD calculations predict [1]: Mass(Bc) = 6304 12 +18-0 MeV/c2
[1] I. F. Allison et al., Phys. Rev. Lett. 94, 172001 (2005), hep-lat/0411027

A public note summarizing the analysis can be found here: .ps .pdf
A three page powerpoint summary can be found here: .ppt .pdf.
A web page for the analysis for CDF collaborators only: web page

Below are the eps and gif versions of all blessed figures meant for downloads.