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 √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. © 2013 CERN. Published by the American Physical Society.
Chatrchyan, S., Khachatryan, V., Sirunyan, A. M., Tumasyan, A., Adam, W., Bergauer, T., … Swanson, J. (2013). Rapidity distributions in exclusive Z+jet and γ+jet events in pp collisions at √s=7 TeV. Physical Review D - Particles, Fields, Gravitation and Cosmology, 88(11). https://doi.org/10.1103/PhysRevD.88.112009