Color evaporation and elastic [ípsilon] photoproduction at DESY HERA

The diffractive photoproduction of vector mesons is usually described by considering the two-gluon (Pomeron) exchange, the nondiagonal parton distributions, and the contribution of the real part to the cross section. In this Brief Report we analyze the diffractive photoproduction of the Y at DESY HE...

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Bibliographic Details
Authors: Gay Ducati, Maria Beatriz, Goncalves, Victor Paulo Barros, Mariotto, Cristiano Brenner
Format: article
Status:Published version
Publication Date:2002
Country:Brasil
Institution:Universidade Federal do Rio Grande do Sul (UFRGS)
Repository:Repositório Institucional da UFRGS
Language:English
OAI Identifier:oai:www.lume.ufrgs.br:10183/104011
Online Access:http://hdl.handle.net/10183/104011
Access Level:Open access
Keyword:Modelo de cor
Interações elétron-próton
Fotoproducao de mesons
Interações foton-próton
Pomerons
Description
Summary:The diffractive photoproduction of vector mesons is usually described by considering the two-gluon (Pomeron) exchange, the nondiagonal parton distributions, and the contribution of the real part to the cross section. In this Brief Report we analyze the diffractive photoproduction of the Y at DESY HERA using an alternative model, the color evaporation model (CEM), where the cross section is simply determined by the boson-gluon cross section and an assumption for the production of the colorless state. We verify that, as in the J/Ψ case, the HERA data for this process can be well described by the CEM. Moreover, we propose the analysis of the ratio R=σY /σJ/Ψ to discriminate between the different approaches.