Event shapes in deep inelastic scattering at HERA

ZEUS collaboration - arXiv preprint hep-ex/0604032, 2006 - arxiv.org
ZEUS collaboration
arXiv preprint hep-ex/0604032, 2006arxiv.org
Mean values and differential distributions of event-shape variables have been studied in
neutral current deep inelastic scattering using an integrated {luminosity} of 82.2 pb $^{-1} $
collected with the ZEUS detector at HERA. The kinematic range was $80< Q^ 2< 20
480\gev^ 2$ and $0.0024< x< 0.6$, where $ Q^ 2$ is the virtuality of the exchanged boson
and $ x $ is the Bjorken variable. The data are compared with a model based on a
combination of next-to-leading-order QCD calculations with next-to-leading-logarithm …
Mean values and differential distributions of event-shape variables have been studied in neutral current deep inelastic scattering using an integrated {luminosity} of 82.2 pb collected with the ZEUS detector at HERA. The kinematic range was $80 < Q^2 < 20 480\gev^2$ and , where is the virtuality of the exchanged boson and is the Bjorken variable. The data are compared with a model based on a combination of next-to-leading-order QCD calculations with next-to-leading-logarithm corrections and the Dokshitzer-Webber non-perturbative power corrections. The power-correction method provides a reasonable description of the data for all event-shape variables studied. Nevertheless, the lack of consistency of the determination of and of the non-perturbative parameter of the model, $\albar$, suggests the importance of higher-order processes that are not yet included in the model.
arxiv.org