Title Elastic and inelastic photoproduction of $J/\psi$ mesons at HERAElastic and inelastic photoproduction of $J/\psi$ mesons at HERA Author Aid, S. De Roeck, A. de Wolf, E.A. Van Mechelen, P. [et al.] Faculty/Department Faculty of Sciences. Physics Research group Elementary Particle Physics Publication type article Publication 1996Amsterdam, 1996 Subject Physics Source (journal) Nuclear physics: B. - Amsterdam Volume/pages 472(1996):1/2, p. 3-31 ISSN 0550-3213 0029-5582 ISI A1996UX86300001 Carrier E Target language English (eng) Full text (Publishers DOI) Affiliation University of Antwerp Abstract Results on J/psi production in ep interactions in the Hi experiment at HERA are presented. The J/psi mesons are produced by almost real photons (Q(2) approximate to 0) and detected via their leptonic decays. The data have been taken in 1994 and correspond to an integrated luminosity of 2.7 pb(-1). The yp cross section for elastic J/psi production is observed to increase strongly with the center of mass energy. The cross section for diffractive J/psi production with proton dissociation is found to be of similar magnitude as the elastic cross section. Distributions of transverse momentum and decay angle are studied and found to be in accord with a diffractive production mechanism. For inelastic J/psi production the total yp cross section, the distribution of transverse momenta, and the elasticity of the J/psi are compared to NLO QCD calculations in a colour singlet model and agreement is found. Diffractive psi' production has been observed and a first estimate of the ratio to J/psi production in the HERA energy regime is given. E-info https://repository.uantwerpen.be/docman/iruaauth/b2de15/edb2363.pdf http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1996UX86300001&DestLinkType=RelatedRecords&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1996UX86300001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1996UX86300001&DestLinkType=CitingArticles&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 Handle