Cabibbo-suppressed decays BβD(β)Kβ using a 10.4 fbβ1 data
sample accumulated at the Ξ₯(4S) resonance with the Belle detector at
the KEKB e+eβ storage ring. The high-momentum particle identification
system of Belle is used to isolate signals for BβD0Kβ, D+Kβ,
Dβ0Kβ and Dβ+Kβ from the BβD(β)Οβ decay processes which
have much larger branching fractions. We report ratios of Cabibbo-suppressed to
Cabibbo-favored branching fractions of: B(BββD0Kβ)/B(BββD0Οβ)=0.079Β±0.009Β±0.006; B(B0ΛβD+Kβ)/B(B0ΛβD+Οβ)=0.068Β±0.015Β±0.007; B(BββDβ0Kβ)/B(BββDβ0Οβ)=0.078Β±0.019Β±0.009; and
B(BΛ0βDβ+Kβ)/B(BΛ0βDβ+Οβ)=0.074Β±0.015Β±0.006. The first error is statistical and the second is systematic.
These are the first reported observations of the BβD+Kβ, Dβ0Kβ and
Dβ+Kβ decay processes.Comment: LaTeX, 12 pages, 2 figure