CDF Note 7649      

URL http://www-cdf.fnal.gov

Abstract:

We have performed a search for B_c->J/&psi &mu X in 360 pb^-1 of exclusive J/&psi data from Run II. We have identified and estimated several sources of background in the J/&psi+muon mass window of 4.0-6.0 GeV/c², including decay-in-flight and punch-through of pions, kaons and protons, tri-muons arising from the fragmentation of bb pairs, and fake J/&psi together with a third muon.

• Our J/&psi+muon sample of B_c candidates has 106 events with a background of 46.0± 7.3 events.

• The hypothesis that the observed sample can be accounted for by the background is rejected at the level of 5.2 standard deviations.

• The cross-section times branching ratio for B_c->J/&psi &mu &nu relative to B^±->J/&psi K^± is measured and found to be 0.245± 0.045(stat.)± 0.066(syst.)+0.080-0.032(life.) for the case where the B p_T is greater than 6.0 GeV/c.

Study of B_c->J/&psi &mu X in Run II data

The CDF Collaboration

11 May 2005