Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract:We present an improved calculation of B → light pseudoscalar formfactors from light-cone sum rules, including one-loop radiative corrections to twist-2 and twist-3 contributions, and leading order twist-4 corrections. The total theoretical uncertainty of our results at zero momentum transfer is 10 to 13% and can be improved, at least in part, by reducing the uncertainty of hadronic input parameters, in particular those describing the twist-2 distribution amplitudes of the π, K and η. We present our results in a way which details the dependence of the formfactors on these parameters and facilitates the incorporation of future updates of their values from e.g. lattice calculations.

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.

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Abstract:We calculate the main observables in B u,d → (ρ, ω, K * )γ and B s → (K * , φ)γ decays, i.e. branching ratios and CP and isospin asymmetries. We include QCD factorisation results and also the dominant contributions beyond QCD factorisation, namely longdistance photon emission and soft-gluon emission from quark loops. All contributions beyond QCD factorisation are estimated from light-cone sum rules. We devise in particular a method for calculating soft-gluon emission, building on earlier ideas developed for analogous contributions in non-leptonic decays. Our results are relevant for new-physics searches at the B factories, the LHC and a future super-flavour factory. Using current experimental data, we also extract |V td /V ts | and the angle γ of the unitarity triangle. We give detailed tables of theoretical uncertainties of the relevant quantities which facilitates future determinations of these CKM parameters from updated experimental results.

Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. We present an improved calculation of B ! light vector form factors from light-cone sum rules, including one-loop radiative corrections to twist-2 and twist-3 contributions, and leading order twist-4 corrections. The total theoretical uncertainty of our results at zero momentum transfer is typically 10% and can be improved, at least in part, by reducing the uncertainty of hadronic input parameters. We present our results in a way which details the dependence of the form factors on these parameters and facilitates the incorporation of future updates of their values from, e.g., lattice calculations. We also give simple and easy-to-implement parametrizations of the q 2 dependence of the form factors which are valid in the full kinematical regime of q 2 .

We present an improved calculation of B → light pseudoscalar formfactors from light-cone sum rules, including one-loop radiative corrections to twist-2 and twist-3 contributions, and leading order twist-4 corrections. The total theoretical uncertainty of our results at zero momentum transfer is 10 to 13% and can be improved, at least in part, by reducing the uncertainty of hadronic input parameters, in particular those describing the twist-2 distribution amplitudes of the π, K and η. We present our results in a way which details the dependence of the formfactors on these parameters and facilitates the incorporation of future updates of their values from e.g. lattice calculations.

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We generalise the Jacob-Wick helicity formalism, which applies to sequential decays, to effective field theories of rare decays of the type B → K J K (→ Kπ)¯ 1 2 . This is achieved by reinterpreting local interaction verticesbΓ µ 1 ..µn s¯ Γ µ 1 ..µn as a coherent sum of 1 → 2 processes mediated by particles whose spin ranges between zero and n. We illustrate the framework by deriving the full angular distributions forB →K 1¯ 2 andB →K * (→Kπ) 1¯ 2 for the complete dimension-six effective Hamiltonian for non-equal lepton masses. Amplitudes and decay rates are expressed in terms of Wigner rotation matrices, leading naturally to the method of moments in various forms. We discuss how higher-spin operators and QED corrections alter the standard angular distribution used throughout the literature, potentially leading to differences between the method of moments and the likelihood fits. We propose to diagnose these effects by assessing higher angular moments. These could be relevant in investigating the nature of the current LHCb anomalies in R K = B(B → Kµ + µ − )/B(B → Ke + e − ) as well as angular observables in B → K * µ + µ − .