Branching ratios of decays in perturbative QCD approachC.-D. Lü1, 2 and K. Ukai3
1 CCAST (World Laboratory), P.O. Box 8730, Beijing 100080, P.R. China
2 Theory Division, Institute of High Energy Physics, CAS, P.O. Box 918(4), Beijing 100039, China
3 Physics Department, Nagoya University, Nagoya 464-8602, Japan
(Received: 29 November 2002 / Revised version: 16 January 2003 / Published online: 31 March 2003 )
The rare decays and can occur only via annihilation type diagrams in the standard model. We calculate these decays in the perturbative QCD approach. We found that the calculated branching ratio of agreed with the data which had been observed in the KEK and SLAC B factories. The decay has a very small branching ratio at , due to the suppression from the CKM matrix elements |Vub* Vcd|.
© Società Italiana di Fisica, Springer-Verlag 2003