Improved Unitarity Bounds for B -> Pi Decays

Abstract

We obtain model independent bounds for the form factors which arise in semileptonic B -> Pi decays. To this end we derive a theoretical restriction for possible combinations of the value of the form factor and its derivatives at the endpoint region. These restrictions are then used as an input in a - slightly modified - general formalism, which has already been deduced and applied in earlier publications. Our results can be used to set constraints on the form factors which have to be obeyed by all model dependent parametrizations.

20 pages, 10 Postscript figures, uses espf. Minor modifications, two references added and aknowledgements changed. The complete paper, including figures, is also available via anonymous ftp at ftp://ttpux2.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints

References in corpus (4)

• Precision Corrections to Dispersive Bounds on Form Factors
• Analyticity, Shapes of Semileptonic Form Factors, and B to pi l nu
• The Scalar $B\to \pi$ and $D\to \pi$ Form Factors in QCD
• The Phenomenology of Inclusive Heavy-to-Light Sum Rules

Cited by in corpus (6)

• Lattice QCD calculation of form factors describing the rare decays $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$ and $B_s\to \varphi {\ell }^{+}{\ell }^{-}$
• Study of the q^2-Dependence of B --> pi ell nu and B --> rho(omega)ell nu Decay and Extraction of |V_ub|
• Extrapolation and unitarity bounds for the $B\to \pi$ form factor
• A model independent determination of $|V_{ub}|$ using the global $q^2$ dependence of the dispersive bounds on the $B\to \pi l\nu$ form factors
• Ward Identities, B-> ρForm Factors and |V_ub|
• Determination of |Vub|