The QCD/SM working group: A Summary report

This report documents the results obtained by the Working Group on Quantum Chromodynamicsand the Standard Model for the Workshop ''Physics at TeV Colliders,'' Les Houches, France, 26 May - 6 June 2003. After a Monte Guide description, the first contributions report on progress in describing multiple interactions, important for the LHC, and underlying events. An announcement of a Monte Carlo database, under construction, is then followed by a number of contributions improving parton showerdescriptions. Subsequently, a large number of contributions address resummationsin various forms, after which follow studies of QCD effects in pion pair, top quarkpair and photon pair plus jet production. After a study of electroweak corrections to hadronic precision observables, the report ends by presenting recent progress in methods to compute finite order corrections at one-loop with many legs, and at two-loop.