Measurement of jets produced in association with W and Z bosons with the CMS detector

We present several measurements of vector boson production in association with jets in pp collisions at 7~TeV center-of-mass energy at the LHC, based on 36~${\rm pb^{-1}}$ of data recorded by the CMS detector in 2010. We discuss results for the normalized inclusive rates of jets $\sigma(\mathrm{V} +\ge n~{\mathrm{jets}})/\sigma(\mathrm{V})$, where V represents either a W or a Z; the ratio of W to Z cross sections; and a test of Berends--Giele scaling. In addition, we present studies of the production of vector bosons in association with heavy quark (b, c) jets which provide information on the b-quark and s-quark densities in the proton at LHC energies. Furthermore, we discuss a first measurement of the polarization of W bosons with large transverse momenta in pp collisions, where the W boson recoils against several energetic jets.