  Invariant mass spectra for jets reconstructed using the anti-kt and
Cambridge-Aachen algorithms are studied for different jet "grooming" techniques
in data corresponding to an integrated luminosity of 5 inverse femtobarns,
recorded with the CMS detector in proton-proton collisions at the LHC at a
center-of-mass energy of 7 TeV. Leading-order QCD predictions for inclusive
dijet and W/Z+jet production combined with parton-shower Monte Carlo models are
found to agree overall with the data, and the agreement improves with the
implementation of jet grooming methods used to distinguish merged jets of large
transverse momentum from softer QCD gluon radiation.
