Angular correlations in three-jet events in ep collisions at HERA

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMThree-jet production in deep inelastic ep scattering and photoproduction was investigated with the ZEUS detector at HERA using an integrated luminosity of up to 127pb-1. Measurements of differential cross sections are presented as functions of angular correlations between the three jets in the final state and the proton-beam direction. These correlations provide a stringent test of perturbative QCD and show sensitivity to the contributions from different color configurations. Fixed-order perturbative calculations assuming the values of the color factors CF, CA, and TF as derived from a variety of gauge groups were compared to the measurements to study the underlying gauge group symmetry. The measured angular correlations in the deep inelastic ep scattering and photoproduction regimes are consistent with the admixture of color configurations as predicted by SU(3) and disfavour other symmetry groups, such as SU(N) in the limit of large NThis work was supported by the U.S. Department of Energy, the Italian National Institute for Nuclear Physics (INFN), the German Federal Ministry for Education and Research (BMBF) under Contract No. H09PDF, No. 05h09GUF, and the SFB 676 of the Deutsche Forschungsgemeinschaft (DFG); DESY, Germany; the Science and Technology Facilities Council, United Kingdom; an FRGS grant from the Malaysian government; Presidential grant N-4142.2010.2 for Leading Scientific Schools, by the Russian Ministry of Education and Science through its grant for Scientific Research on High Energy Physics and under Contract No. 02.740.11.0244; the Netherlands Foundation for Research on Matter (FOM); the Israel Science Foundation; the Max Planck Institute for Physics, Munich, Germany; MEIN research grant No. 1 P03B 04529 (2005–2008), Poland; Warsaw University, Poland; the Russian Foundation for Basic Research, Grant 11-02- 91345-DFG_a; the Polish Ministry of Science and Higher Education as a scientific project No. DPN/N188/DESY/ 2009 and its grants for Scientific Research; the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) and its grants for Scientific Research; the Korean Ministry of Education and Korea Science and Engineering Foundation; FNRS and its associated funds (IISN and FRIA) and by an Inter-University Attraction Poles Programme subsidized by the Belgian Federal Science Policy Office; the Spanish Ministry of Education and Science through funds provided by CICYT; the Natural Sciences and Engineering Research Council of Canada (NSERC); and the U.S. National Science Foundatio