Observation of B+ → c0K+

Using a sample of 31.3 X 10 6 BB pairs collected with the Belle detector at the Y(4S) resonance, we make the first observation of the charged B meson decay to Χ c 0 and a charged kaon. The measured branching fraction is B(B + → Χ c 0 K + ) = (6.0 + 2 . 1 - 1 . 8 ′ 1.1) X 10 - 4 , where the first error is statistical, and the second is systematic.