A lattice study of the exclusive $B\to K^{\ast }\gamma$ decay amplitude, using the Clover action at $\beta =6.0$

Abstract

We present the results of a numerical calculation of the $B\to K^{\ast }\gamma$ form factors. The results have been obtained by studying the relevant correlation functions at $\beta =6.0$, on an $18^3\times 64$ lattice, using the $\mathrm{O}(\mathrm{a})$-improved fermion action, in the quenched approximation. From the study of the matrix element $<K^{\ast }|\bar{s}{\sigma }_{\mu \nu }b|B>$ we have obtained the form factor $T_1(0)$ which controls the exclusive decay rate. The results are compared with the recent results from CLEO. We also discuss the compatibility between the scaling laws predicted by the Heavy Quark Effective Theory (HQET) and pole dominance, by studying the mass- and $q^2$-dependence of the form factors. From our analysis, it appears that the form factors follow a mass behaviour compatible with the predictions of the HQET and that the $q^2$-dependence of $T_2$ is weaker than would be predicted by pole dominance.

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References in corpus (20)

• Nonperturbative Contributions to the Inclusive Rare Decays $B\to X_s\gamma$ and $B\to X_s{\ell }^{+}{\ell }^{-}$
• Scheme Independence of the Effective Hamiltonian for $b\to s\gamma$ and $b\to sg$ Decays
• Exact Dirac Quantization of All 2-D Dilaton Gravity Theories
• Exclusive Radiative B-Decays in the Light-Cone QCD Sum Rule Approach
• Leading Order QCD Corrections to $b\to s\gamma$ and $b\to sg$ Decays in Three Regularization Schemes
• The Semileptonic Decays $D\to \pi (\rho )e\nu$ and $B\to \pi (\rho )e\nu$ from QCD Sum Rules
• $b\to s\gamma$ AND $b\to sg$: A THEORETICAL REAPPRAISAL
• The b -> s gamma decay revisited
• Semi-leptonic Decays of Heavy Flavours on a Fine Grained Lattice
• Lattice Calculation of D- and B-meson Semileptonic Decays, using the Clover Action at beta=6.0 on APE
• Radiative Rare B Decays into Higher K-Resonances
• On The Dimensional Methods in Rare b Decays
• Uncertainties from Long Range Effects in $B \to K^* γ
• $B \rar K^* \ γ$} from Hybrid Sum Rule
• Critical Analysis of Theoretical Estimates for $B$ to Light Meson Form Factors and the $B\to \psi K(K^{\ast })$ Data
• Radiative $B\to K^{\ast }\gamma$ transition in QCD
• $B\to K^{\ast }+\gamma$ and $B_s\to \varphi +\gamma$ on the Lattice
• $B\to K^{\ast }\gamma$: Penguins on the Lattice
• Dominance of the light-quark condensate in the heavy-to-light exclusive decays
• Geometrical Volume Effects in the Computation of the Slope of the Isgur-Wise Function

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• Phenomenology of Heavy Meson Chiral Lagrangians
• Experimental Tests of Factorization in Charmless Non-Leptonic Two-Body B Decays
• Lattice QCD calculation of form factors describing the rare decays $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$ and $B_s\to \varphi {\ell }^{+}{\ell }^{-}$
• Multichannel one-to-two transition amplitudes in a finite volume
• Rare exclusive semileptonic b -> s transitions in the Standard Model
• Short Distance Coefficients and the Vanishing of the Lepton Asymmetry in $B\to V{\ell }^{+}{\ell }^{-}$
• QCD factorization for B -> PP
• Light Quenched Hadron Spectrum and Decay Constants on different Lattices
• $|V_{ub}|$ from exclusive $B$ and $D$ decays
• Rare B \to K^{(*)} ν\barνDecays at B Factories
• Phenomenological Analysis of B->PP Decays with QCD Factorization
• An estimate of the B-->K*gamma form factor
• Right-handed currents in rare exclusive B -> (K, K*) nu bar{nu} decays
• The $B\to K^{\ast }$ form factors on the lattice
• Nuclear Reactions from Lattice QCD
• Exclusive Decays of $B\to K^{(\ast )}{l}^{+}{l}^{-}$ in the PQCD
• Theoretical Review of B-physics
• B -> K^* gamma from D -> K^* l nu
• Heavy Light Weak Matrix Elements
• Form factors for semi-leptonic B decays
• NRQCD Results on Form Factors