ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2006, vol. 74, p. -
Observation of B+→Ξ̄c0Λc+ and evidence for B0→Ξ̄c-Λc+
We report the first observation of the decay B+→Ξ̄c0Λc+ with a significance of 8.7σ and evidence for the decay B0→Ξ̄c-Λc+ with a significance of 3.8σ. The product B(B+→Ξ̄c0Λc+)×B(Ξ̄c0→Ξ̄+π-) is measured to be (4.8-0.9+1.0±1.1±1.2)×10-5, and B(B0→Ξ̄c-Λc+)×B(Ξ̄c-→Ξ̄+π- π-) is measured to be (9.3-2.8+3.7±1.9±2.4)×10-5. The errors are statistical, systematic and the error of the Λc+→pK-π+ branching fraction, respectively. The decay B+→Ξ̄c0Λc+ is the first example of a two-body exclusive B+ decay into two charmed baryons. The data used for this analysis was accumulated at the Υ(4S) resonance, using the Belle detector at the e+e- asymmetric-energy collider KEKB. The integrated luminosity of the data sample is equal to 357fb-1, corresponding to 386×106 BB̄ pairs. © 2006 The American Physical Society.