Jets and Heavy Flavours at LHC with ATLAS and CMS
Anne-Marie Magnan
Imperial College, High Energy Physics
Imperial College London, SW7 2BW, UK
Abstract
QCD processes constitute the dominant source of interactions at the LHC due to their large cross sections relative to other processes. This makes QCD processes an attractive topic for early physics at LHC. The LHC experiments ATLAS and CMS plan to take advantage of large multi-jet samples with and without heavy flavour tagging and vector boson production to test QCD at the TeV scale. Initial comparisons of multi-jet cross section measurements at LHC with those from the Tevatron will demonstrate understanding of the calibration of the CMS detector, the Jet Energy Scale systematics and the trigger. Further in the LHC run measurements of inclusive diject cross sections with heavy flavour tag, which provides the process hard scale, will probe QCD at scales never tested before. Jet production measurements with associated W and Z bosons provide a separate test of QCD in different and complementary channels. The large rapidity coverage of the LHC experiments will enable measurements of the proton PDFs over a wide range of Bjorken-x and Q2. Measurements of these processes are essential to demonstrate understanding of major backgrounds to Higgs and SUSY channels such as those of top-quark production or W+jet/Z+jet for Higgs.