Pion form factor from a contact interaction
Abstract
In a Poincare'-covariant vector-boson-exchange theory, the pion possesses components of pseudovector origin, which materially influence its observable properties. For a range of such quantities, we explore the consequences of a momentum-independent interaction, regularised in a symmetry-preserving manner. The contact interaction, whilst capable of describing pion static properties, produces a form factor whose: evolution for Q2>0.17GeV2 disagrees markedly with experiment; and asymptotic power-law behaviour conflicts strongly with perturbative-QCD.
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