Measurement of branching fraction ratios and $CP$ asymmetries in $B^{\pm} \to D_{CP} K^{\pm}$

We report results on the decay

B^{-} \to D_{CP} K^{-}

and its charge conjugate using a data sample of

85.4 \times 10^{6}

B \bar{B}

pairs recorded at the

Υ (4 S)

resonance with the Belle detector at the KEKB asymmetric

e^{+} e^{-}

storage ring. Ratios of branching fractions of Cabibbo-suppressed to Cabibbo-favored processes are determined to be

B {(B}^{-} \to D^{0} K^{-}) / B {(B}^{-} \to D^{0} π^{-}) = 0.077 \pm 0.005 (stat) \pm 0.006 (syst),

B {(B}^{-} \to D_{1} K^{-}) / B {(B}^{-} \to D_{1} π^{-}) = 0.093 \pm 0.018 (stat) \pm 0.008 (syst)

and

B {(B}^{-} \to D_{2} K^{-}) / B {(B}^{-} \to D_{2} π^{-}) = 0.108 \pm 0.019 (stat) \pm 0.007 (syst)

where the indices 1 and 2 represent the

C P = + 1

and

C P = - 1

eigenstates of the

D^{0} - D^{0}

system, respectively. We find the partial-rate charge asymmetries for

B^{-} \to D_{CP} K^{-}

to be

A_{1} = 0.06 \pm 0.19 (stat) \pm 0.04 (syst)

and

A_{2} = - 0.19 \pm 0.17 (stat) \pm 0.05 (syst) .

This publication has 11 references indexed in Scilit:

Measurement of branching fraction ratios andCPasymmetries inB±→DCPK±