CGC beyond eikonal accuracy: finite width target effects
1 Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, E-15706 Santiago de Compostela, Galicia-Spain
2 CENTRA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa, Portugal
3 European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*) and Fondazione Bruno Kessler, Strada delle Tabarelle 286, I-38123 Villazzano ( TN), Italy
a e-mail: email@example.com
Published online: 21 March 2016
We present a method to systematically include the corrections to the eikonal approximation that are associated with the finite width of the target. The retarded gluon propagator in background field is calculated at next-to-next-to-eikonal (NNE) accuracy by using this method. The corrections to the strict eikonal limit of the gluon propagator are found to be Wilson lines decorated by gradients of the background field of the target. The result is then applied to single inclusive gluon production and to single transverse spin asymmetry for a polarized target in pA collisions.
© Owned by the authors, published by EDP Sciences, 2016
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