Search for New Physics in Highly Boosted Z0 Decays to Dimuons in pp Collisions at sqrt(s)=7 TeV

An inclusive search for anomalous production of highly boosted \Zzero~bosons in the dimuon decay channel arising from the decays of new heavy particles has been performed by the CMS Collaboration. The data correspond to an integrated luminosity of \anaLumi~collected with the CMS detector from pp collisions provided by the CERN LHC at \collisionEnergy. The search is optimized for the detection of excited quark production and decay via $q^* \rightarrow q Z^0 \rightarrow q \mu^+ \mu^-$, with no explicit reconstruction of the jet recoiling against a high transverse momentum \Zzero. The results are consistent with background-only expectations. Limits are derived on excited quark production in the plane of compositeness scale versus mass for two scenarios of production and decay: one assuming excited quark transitions via Standard Model gauge bosons only, and one including also novel contact interaction transitions from new strong dynamics. The mass limits at 95\% confidence level with contact interactions are more sensitive than previous searches in scenarios where the coupling to gluons is suppressed relative to the electroweak gauge bosons, ruling out masses below 1.17~TeV in the extreme case when this coupling is zero.