We present B q → ρ, B q → ω, B q → K * , B s → K * and B s → φ form factors from light-cone sum rules (LCSR) at O(α s ) for twist-2 and 3 and O(α 0 s ) for twist-4 with updated hadronic input parameters. Three asymptotic light-cone distribution amplitudes of twist-4 (and 5) are determined, necessary for the form factors to obey the equations of motion. It is argued that the latter constrain the uncertainty of tensor-to-vector form factor ratios thereby improving the prediction of zeros of helicity amplitudes of major importance for B → K * angular observables. We provide easy-to-use fits to the LCSR results, including the full error correlation matrix, in all modes at low q 2 as well as combined fits to LCSR and lattice results covering the entire kinematic range for B q → K * , B s → K * and B s → φ. The error correlation matrix avoids the problem of overestimating the uncertainty in phenomenological applications. Using the new form factors and recent computations of non-factorisable contributions we provide Standard Model predictions for B → K * γ as well as B → K * + − and B s → φµ + µ − at low dilepton invariant mass. Employing our B → (ρ, ω) form factor results we extract the CKM element |V ub | from the semileptonic decays B → (ρ, ω) ν and find good agreement with other exclusive determinations.
The rare decay B → K * (→ Kπ)µ + µ − is regarded as one of the crucial channels for B physics as the polarization of the K * allows a precise angular reconstruction resulting in many observables that offer new important tests of the Standard Model and its extensions. These angular observables can be expressed in terms of CP-conserving and CP-violating quantities which we study in terms of the full form factors calculated from QCD sum rules on the light-cone, including QCD factorization corrections. We investigate all observables in the context of the Standard Model and various New Physics models, in particular the Littlest Higgs model with T-parity and various MSSM scenarios, identifying those observables with small to moderate dependence on hadronic quantities and large impact of New Physics. One important result of our studies is that new CP-violating phases will produce clean signals in CP-violating asymmetries. We also identify a number of correlations between various observables which will allow a clear distinction between different New Physics scenarios. * wolfgang.altmannshofer@ph.tum.de † Patricia.Ball@durham.ac.uk
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