This web page summarizes the results for the measurement of the ratio of branching fractions between two decay modes, B⁺ → J/psi pi⁺ and B⁺ → J/psi K⁺, based upon 220 pb^-1 of data.
The results have been approved as of August 18, 2005.

We measure:

Br(B⁺ → J/psi pi⁺)/Br(B⁺ → J/psi K⁺) = 4.86 ± 0.82 (stat.) ± 0.15 (syst.) %

A more detailed summary of the results can be found here: ps.

• Figure 1 : Fit projection onto mass distribution (.eps)(.png)
  Mass distribution with fitting functions overlaid. The inset plot shows the magnificant region of the B⁺ → J/psi pi⁺ signal.
  Where the dotted line is the B⁺→J/psi K⁺ signal, the dashed line is the B⁺→J/psi pi⁺ signal and the dotted-dashed line is the background.


• Figure 2 : Fit projection onto alpha distribution (.eps)(.png)
  Alpha distribution with fitting functions overlaid.
  Where the dotted line is the B⁺→J/psi K⁺ signal, the dashed line is the B⁺→J/psi pi⁺ signal and the dotted-dashed line is the background.


• Figure 3 : Templates of the alpha distribution of each signal and background.
  B⁺→J/psi K⁺ signal (.eps)(.png) obtained from the simulation.
  B⁺→J/psi pi⁺ signal (.eps)(.png) obtained from the simulation.
  Background (.eps)(.png) obtainted from the sidebands of data.
  Overlay version (.eps)(.png)