A determination of the CKM-matrix element ratio |V ts |/|V cb | from the rareB-decaysB→K *+γ andB→X s +γ

Abstract

Implications of the recent CLEO observation [1] of the rare decay modeB→K*+γ having a combined branching ratio BR(B→K*+γ)=(4.5±1.5±0.9)×10−5 and an improved upper limit on the inclusive branching ratio BR(B→Xs+γ) -108 GeV. Within the SM, we show that the resulting experimental upper limit can be interpreted as a corresponding limit on the CKM-matrix element ratio yielding |Vts|/|Vcb| 1.6×10−5 [1,2]. Combining the exclusive and inclusive decay rates, we determine 0.50≤|Vts|/|Vcb|≤1.67 (at 95% C.L.).