Implications of unitarity and analyticity for the D pi form factors

Ananthanarayan, B and Caprini, I and Imsong, Sentitemsu I (2011) Implications of unitarity and analyticity for the D pi form factors. In: European Physical Journal A (EPJ A), The - Hadrons and Nuclei, 47 (11).

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Abstract

We consider the vector and scalar form factors of the charm-changing current responsible for the semileptonic decay D -> pi/nu. Using as input dispersion relations and unitarity for the moments of suitable heavy-light correlators evaluated with Operator Product Expansions, including O(alpha(2)(s)) terms in perturbative QCD, we constrain the shape parameters of the form factors and find exclusion regions for zeros on the real axis and in the complex plane. For the scalar form factor, a low-energy theorem and phase information on the unitarity cut are also implemented to further constrain the shape parameters. We finally propose new analytic expressions for the D pi form factors, derive constraints on the relevant coefficients from unitarity and analyticity, and briefly discuss the usefulness of the new parametrizations for describing semileptonic data.

Item Type:	Journal Article
Publication:	European Physical Journal A (EPJ A), The - Hadrons and Nuclei
Publisher:	Springer
Additional Information:	Copyright of this article belongs to Springer.
Department/Centre:	Division of Physical & Mathematical Sciences > Centre for High Energy Physics
Date Deposited:	30 Jan 2012 09:03
Last Modified:	30 Jan 2012 09:03
URI:	http://eprints.iisc.ac.in/id/eprint/43170

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