Third Track, Muon Selection

We select J/&psi+track and J/&psi+&mu samples using the cut requirements outlined in Table 2. The resulting mass distrubtions can be seen in Figure 2. Figure 3 shows the reconstructed J/&psi+K^± mass which we use for our relative cross section times brancing ratio measurement. We expect our B_c->J/&psi &mu &nu signal to fall into the 4.0-6.0 GeV/c² three track mass region as can be seen by the reconstructed J/&psi&mu mass for B_c events generated using BGenerator and shown in Figure 4.

Table 2: Summary of the cuts used to create J/&psi+track and J/&psi+&mu samples.

Figure 2: Left: Three track mass for J/&psi+track sample. Right: Three track mass for J/&psi+&mu sample.

Figure 3: Mass fit for B^±->J/&psi K^± events from the J/&psi+track sample.

Figure 4: Reconstructed J/&psi+&mu mass for B_c events generated using BGenerator.