Constraining the ratio of matrix elements V(td)/V(ts) using radiative penguin B meson going to V(kaon/rho/omega)gamma decays.

摘要

Exclusive radiative penguin B decays, B → ( K*0/K*+) g and B → (rho/o) g , are flavor-changing neutral-current (FCNC) processes. Studies of these decays are of special interest in testing Standard Model (SM) predictions and searching for other beyond-the-SM FCNC interactions. Using 89 x 106 BB pairs from BABAR, we measure the branching fraction ( B ), CP-asymmetry ( A ), and isospin asymmetry (Delta0-) of B → (K*0/K* +) g as follows: BB0 →K*0g =3.92+/-0.20stat. +/-0.24syst., BB+→K *+g =3.87+/-0.28stat. +/-0.26syst. , AB→K*g =-0.013+/-0.36st at.+/-0.10 syst., D0-B→K*g =0.050+/-0.045stat. +/-0.028syst.+/- 0.024&parl0;R+/0&parr0;. The 90% confidence intervals for the CP-asymmetry and the isospin-asymmetry in the B → K* g decay are given as: -0.074A B→K*g0.04 9, -0.046D0-B→K *g0.146. We also search for B → (rho/o) g decays using 211 x 106 BB pairs from BABAR. No evidence for these decays is found. We set the upper limits at 90% confidence level for these decays: BB0 →r0g 0.4x10-6, BB+→ r+g1.8x 10-6, BB0→ wg1.0x10 -6, B&d1; B→r/wg 1.2x10-6. These results are in good agreement with the SM predictions. The branching fractions of these decays are then used to constrain the ratio |Vtd|/|Vts|.