Scaling Violations and Determination of αs from Jet Production in γp Interactions at HERA
Differential cross sections for jet photoproduction in the reaction ep → e jet X have been measured with the ZEUS detector at HERA using 82.2 pb-1 of integrated luminosity. Inclusive jet cross sections are presented as a function of the jet transverse energy, ETjet, for jets with ETjet > 17 GeV and pseudorapidity -1 <ηjet <2.5, in the γp centre-of-mass-energy range 142 < Wγp < 293 GeV. Scaled jet invariant cross sections are presented as a function of the dimensionless variable xT ≡ 2ETjet/Wγp for (Wγp) = 180 and 255 GeV. Next-to-leading-order QCD calculations give a good description of the measured differential cross sections in both magnitude and shape. The ratio of scaled jet invariant cross sections at the two (Wγp) values shows clear non-scaling behaviour. A value for the strong coupling constant of αs(MZ) = 0.1224 ± 0.0001 (stat.)-0.0019+0.0022(exp.)-0.0042+0.0054(th.) has been extracted from a QCD analysis of the measured dσ/dETjet. The variation of αs with ETjet is in good agreement with the running of αs as predicted by QCD. © 2003 Published by Elsevier Science B.V.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Chekanov, S.; Krakauer, D.; Loizides, J. H.; Magill, S.; Musgrave, B.; Repond, J.; Yoshida, R.; Mattingly, Margarita C. K.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cara Romeo, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; de Pasquale, S.; Giusti, P.; Iacobucci, G.; Margotti, A.; Nania, R.; Palmonari, F.; Pesci, A.; Sartorelli, G.; Zichichi, A.; Aghuzumtsyan, G.; and Bartsch, D., "Scaling Violations and Determination of αs from Jet Production in γp Interactions at HERA" (2003). Faculty Publications. 2207.