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Título:
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Local two-photon couplings and the J=0 fixed pole in real and virtual Compton scattering
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Autores:
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Llanes Estrada, Felipe José ;
Brodsky, Stanley J ;
Szczepaniak, Adam P
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Tipo de documento:
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texto impreso
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Editorial:
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Americal Physical Society, 2009-02
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Dimensiones:
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application/pdf
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Nota general:
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info:eu-repo/semantics/openAccess
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Idiomas:
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Palabras clave:
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Estado = Publicado
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Materia = Ciencias: Física
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Tipo = Artículo
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Resumen:
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The local coupling of two photons to the fundamental quark currents of a hadron gives an energy-independent contribution to the Compton amplitude proportional to the charge squared of the struck quark, a contribution which has no analog in hadron scattering reactions. We show that this local contribution has a real phase and is universal, giving the same contribution for real or virtual Compton scattering for any photon virtuality and skewness at fixed momentum transfer squared t. The t dependence of this J=0 fixed Regge pole is parameterized by a yet unmeasured even charge conjugation form factor of the target nucleon. The t=0 limit gives an important constraint on the dependence of the nucleon mass on the quark mass through the Weisberger relation. We discuss how this 1/x form factor can be extracted from high-energy deeply virtual Compton scattering and examine predictions given by models of the H generalized parton distribution.
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En línea:
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https://eprints.ucm.es/id/eprint/22788/1/Llanes-Estrada_FJ20libre.pdf
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