Improving the phenomenology of Kl3 form factors with analyticity and unitarity

Abbas, Gauhar and Ananthanarayan, B and Caprini, Irinel and Imsong, Sentitemsu I (2010) Improving the phenomenology of Kl3 form factors with analyticity and unitarity. In: Physical Review D - Particles, Fields, Gravitation and Cosmology, 82 (9).

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Abstract

The shape of the vector and scalar K-l3 form factors is investigated by exploiting analyticity and unitarity in a model-independent formalism. The method uses as input dispersion relations for certain correlators computed in perturbative QCD in the deep Euclidean region, soft-meson theorems, and experimental information on the phase and modulus of the form factors along the elastic part of the unitarity cut. We derive constraints on the coefficients of the parameterizations valid in the semileptonic range and on the truncation error. The method also predicts low-energy domains in the complex t plane where zeros of the form factors are excluded. The results are useful for K-l3 data analyses and provide theoretical underpinning for recent phenomenological dispersive representations for the form factors.

Item Type:	Journal Article
Publication:	Physical Review D - Particles, Fields, Gravitation and Cosmology
Publisher:	The American Physical Society
Additional Information:	Copyright of this article belongs to The American Physical Society.
Department/Centre:	Division of Physical & Mathematical Sciences > Centre for High Energy Physics
Date Deposited:	13 Dec 2010 09:54
Last Modified:	22 Feb 2012 06:33
URI:	http://eprints.iisc.ac.in/id/eprint/34443

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