|V_td/V_ts| from QCD Sum Rules on the Light-Cone

Abstract

The dominant theoretical uncertainty in extracting $|V_{td}/V_{ts}|$ from the ratio of branching ratios $R_{\rho /\omega }\equiv \bar{\mathcal{B}}(B\to (\rho ,\omega )\gamma )/\bar{\mathcal{B}}(B\to K^{\ast }\gamma )$ is given by the ratio of form factors ${\xi }_{\rho }\equiv T_1^{B\to K^{\ast }}(0)/T_1^{B\to \rho }(0)$. We find ${\xi }_{\rho }=1.17\pm 0.09$ from QCD sum rules on the light-cone. Using QCD factorisation for the branching ratios, including the most dominant power-suppressed effects beyond QCD factorisation, and the current experimental results for $R_{\rho /\omega }$, this translates into $|V_{td}/V_{ts}{|}_{\mathrm{BaBar}}=0.199_{-0.025}^{+0.023}(\exp )\pm 0.014(\mathrm{th})$, which corresponds to ${\gamma }_{\mathrm{BaBar}}=(61.0_{-16.0}^{+13.5}(\mathrm{th}){}_{-9.3}^{+8.9}(\mathrm{th}))$, and $|V_{td}/V_{ts}{|}_{\mathrm{Belle}}=0.207_{-0.033}^{+0.028}(\exp {)}_{-0.015}^{+0.014}(\mathrm{th})$, ${\gamma }_{\mathrm{Belle}}=(65.7_{-20.7}^{+17.3}(\exp {)}_{-9.2}^{+8.9}(\mathrm{th}){)}^{\circ }$.

Talk given at CKM06

References in corpus (1)

• Exclusive Radiative Decays of B Mesons in QCD Factorization

Cited by in corpus (1)

• Constraints on New Physics from gamma and |V_ub|