Rapidity distributions are presented for events containing either a Z boson or a photon with a single jet in proton-proton collisions produced at the CERN LHC. The data, collected with the CMS detector at root s = 7 TeV, correspond to an integrated luminosity of 5.0 fb(-1). The individual rapidity distributions of the boson and the jet are consistent within 5% with expectations from perturbative QCD. However, QCD predictions for the sum and the difference in rapidities of the two final-state objects show discrepancies with CMS data. In particular, next-to-leading-order QCD calculations, and two common Monte Carlo event generators using different methods to match matrix-element partons with parton showers, appear inconsistent with the data as well as with each other.
Rapidity distributions in exclusive Z plus jet and gamma plus jet events in pp collisions at root s=7 TeV
BISELLO, DARIO;CARLIN, ROBERTO;GALANTI, MARIO;GASPARINI, FABRIZIO;GASPARINI, UGO;GIUBILATO, PIERO;GOZZELINO, ANDREA;MARGONI, MARTINO;MENEGUZZO, ANNA TERESA;PAZZINI, JACOPO;POZZOBON, NICOLA;RONCHESE, PAOLO;SIMONETTO, FRANCO;TOSI, MIA;A. Triossi;ZOTTO, PIERLUIGI;ZUCCHETTA, ALBERTO;ZUMERLE, GIANNI;M. Grassi;ROSSIN, ROBERTO;A. Gaz;M. Zanetti;
2013
Abstract
Rapidity distributions are presented for events containing either a Z boson or a photon with a single jet in proton-proton collisions produced at the CERN LHC. The data, collected with the CMS detector at root s = 7 TeV, correspond to an integrated luminosity of 5.0 fb(-1). The individual rapidity distributions of the boson and the jet are consistent within 5% with expectations from perturbative QCD. However, QCD predictions for the sum and the difference in rapidities of the two final-state objects show discrepancies with CMS data. In particular, next-to-leading-order QCD calculations, and two common Monte Carlo event generators using different methods to match matrix-element partons with parton showers, appear inconsistent with the data as well as with each other.Pubblicazioni consigliate
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