Introduction

This note summarizes the measurement of B_c decays through B_c->J/&psi &mu &nu and estimates the cross-section times branching ratio relative to B^±->J/&psi K^± in pp collisions at √ s = 1.96 TeV with the CDF detector at the Fermilab Tevatron. The measurement uses a sample J/&psi di-muon events that are subsequently matched with a third high quality muon. Our cross-section times branching ratio measurement for B_c->J/&psi &mu &nu improves upon measurements made in CDF Run I.

The CDF detector is described in detail in ¹. The parts of the detector important to this analysis are: the SVX (silicon vertexer), the CMU, CMX and CMP (central muon, central muon extension and central muon upgrade detectors) and the COT (central outer tracker).