This webpage summarizes the results for the measurement of R = BR(B^-->D⁰K^-)/BR(B^-->D⁰π^-).
This preliminary result was approved on April 20, 2006.

Abstract

The partial widths of B^-->D⁰_(CP)K^- decays (D⁰->K^-π⁺ and D⁰_CP+->K⁺K^-, π⁺π^-) provide a theoretically clean way of measuring the CKM angle gamma.
We present the measurement of the ratio R = BR(B^-->D⁰K^-)/BR(B^-->D⁰π^-) that is the first step through the gamma angle measurement.
The value of the ratio is:

R = 0.065 ± 0.007 (stat) ± 0.004 (sys)

Description

A complete description of the analysis is available here: note-8242.

Figures

Below the .eps and .gif versions of all figures available for download.

• Generic MC of B^-->D⁰π^-
• generic MC     (gif)
• generic MC zoom     (gif)

• Data sample
• Invariant mass distribution     (gif)

• Mass vs α
• Mass vs α     (gif)

• p_tot distributions for B^-->D⁰π^- and B^-->D⁰K^-
• ptot_BD0pi     (gif)
• ptot_BD0K     (gif)

• p_tot distribution for the physics background: B^-->D^*0π^-
• ptot_BDstrpi     (gif)

• p_tot distribution for the combinatorial background
• ptot_back     (gif)

• (α,p_tot) joint distributions for B^-->D⁰π^- and B^-->D⁰K^-
• alpha_ptot_BD0pi     (gif)
alpha_ptot_BD0pi_fit     (gif)

• alpha_ptot_BD0K     (gif)
alpha_ptot_BD0K_fit     (gif)


• (α,p_tot) joint distributions for the physics background B^-->D^*0π^-
  • alpha_ptot_BDstrpi     (gif)
  alpha_ptot_BDstrpi_fit     (gif)
  

• (α,p_tot) joint distribution for the combinatorial background background
• alpha_ptot_bkg     (gif)
alpha_ptot_bkg_fit     (gif)

• Fit Projections
  • Invariant D⁰π-mass    (gif)
  alpha     (gif)
  ptot     (gif)
  ID     (gif)
  

• PR-PLOT of DCP decays
  • Invariant D_CPπ-mass with D_CP->K K;    (gif)

  • Invariant D_CPπ-mass with D_CP->π π    (gif)