Constraints on B--->pi,K transition form factors from exclusive semileptonic D-meson decays

Abstract

According to the heavy-quark flavour symmetry, the $B\to \pi ,K$ transition form factors could be related to the corresponding ones of D-meson decays near the zero recoil point. With the recent precisely measured exclusive semileptonic decays $D\to \pi \ell \nu$ and $D\to K\ell \nu$, we perform a phenomenological study of $B\to \pi ,K$ transition form factors based on this symmetry. Using BK, BZ and Series Expansion parameterizations of the form factor slope, we extrapolate $B\to \pi ,K$ transition form factors from $q_{max}^2$ to $q^2=0$. It is found that, although being consistent with each other within error bars, the central values of our results for $B\to \pi ,K$ form factors at $q^2=0$, $f_{+}^{B\to \pi ,K}(0)$, are much smaller than predictions of the QCD light-cone sum rules, but are in good agreements with the ones extracted from hadronic B-meson decays within the SCET framework. Moreover, smaller form factors are also favored by the QCD factorization approach for hadronic B-meson decays.

19 pages, no figure, 5 tables

References in corpus (12)

• Form Factors from Light-Cone Sum Rules with B-Meson Distribution Amplitudes
• Study of B --> pi l nu and B --> rho l nu Decays and Determination of |V_ub|
• The B -> pi l nu semileptonic form factor from three-flavor lattice QCD: A model-independent determination of |V(ub)|
• B, Bs -> K form factors: an update of light-cone sum rule results
• Measurement of the q2 dependence of the Hadronic Form Factor in D0 --> K- e+ nu_e decays
• Charmless Two-body $B(B_s)\to VP$ decays In Soft-Collinear-Effective-Theory
• Testing QCD Sum Rules on the Light-Cone in D->(pi,K) l nu Decays
• |V_ub| from UTangles and B->pi l nu
• B- -> pi- pi0/rho- rho0 to NNLO in QCD factorization
• Visualization of semileptonic form factors from lattice QCD
• |Vub| from exclusive semileptonic B to pi decays revisited
• |Vub| from Exclusive Semileptonic B to pi Decays