Model independent bounds on the modulus of the pion form factor on the unitarity cut below the omega pi threshold

Ananthanarayan, B and Caprini, I and Das, Diganta and Imsong, Sentitemsu I (2012) Model independent bounds on the modulus of the pion form factor on the unitarity cut below the omega pi threshold. In: EUROPEAN PHYSICAL JOURNAL C, 72 (10).

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Abstract

We calculate upper and lower bounds on the modulus of the pion electromagnetic form factor on the unitarity cut below the omega pi inelastic threshold, using as input the phase in the elastic region known via the Fermi-Watson theorem from the pi pi P-wave phase shift, and a suitably weighted integral of the modulus squared above the inelastic threshold. The normalization at t = 0, the pion charge radius and experimental values at spacelike momenta are used as additional input information. The bounds are model independent, in the sense that they do not rely on specific parametrizations and do not require assumptions on the phase of the form factor above the inelastic threshold. The results provide nontrivial consistency checks on the recent experimental data on the modulus available below the omega pi threshold from e(+)e(-) annihilation and tau-decay experiments. In particular, at low energies the calculated bounds offer a more precise description of the modulus than the experimental data.

Item Type:	Journal Article
Publication:	EUROPEAN PHYSICAL JOURNAL C
Publisher:	SPRINGER
Additional Information:	Copyright for this article belongs to SPRINGER, NEW YORK,
Department/Centre:	Division of Physical & Mathematical Sciences > Centre for High Energy Physics
Date Deposited:	15 Dec 2012 04:55
Last Modified:	15 Dec 2012 04:55
URI:	http://eprints.iisc.ac.in/id/eprint/45558

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