Measurement of forward $W$ and $Z$ boson production in association with   jets in proton-proton collisions at $\sqrt{s}=8$ TeV
  The production of $W$ and $Z$ bosons in association with jets is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 $\pm$ 0.02 fb$^{-1}$. The $W$ boson is identified using its decay to a muon and a neutrino, while the $Z$ boson is identified through its decay to a muon pair. Total cross-sections are measured and combined into charge ratios, asymmetries, and ratios of $W+$jet and $Z$+jet production cross-sections. Differential measurements are also performed as a function of both boson and jet kinematic variables. All results are in agreement with Standard Model predictions. 
LHCb collaboration: R. Aaij, C. Abell\'an Beteta, B. Adeva, M.   Adinolfi, Z. Ajaltouni, S. Akar, J. Albrecht, F. Alessio, M...
hep-ex