Search for Dijet Resonances in the Dijet Mass Distribution in pp Collisions at sqrt(s)=7 TeV

We present a measurement of the dijet invariant mass spectrum and search for new particles decaying to dijets at CMS in pp collisions at $\sqrt{s}=7$~TeV using data corresponding to an integrated luminosity of $836 \pm 92$~nb$^{-1}$. The dijet mass distribution of the two leading jets is measured and compared to QCD predictions from PYTHIA propagated through the CMS detector simulation. We require the pseudorapidity separation of the two jets to satisfy $\mid \Delta\eta \mid < 1.3$ with each jet inside the region $\mid \eta \mid < 2.5$. The highest observed dijet mass is $1.92$ TeV. We fit the observed dijet mass spectrum with a parameterization, search for dijet resonances, and set upper limits at 95\% Confidence Level (C.L.) on the product of the resonance cross section, branching ratio into dijets, and acceptance. These generic cross section limits are compared with theoretical predictions for the cross section for several models of new particles: string resonances, axigluons, colorons, excited quarks, $E_{6}$ diquarks, Randall-Sundrum gravitons, W' and Z'. We exclude at 95\% C.L. string resonances with mass less than $2.10$ TeV, excited quarks with mass less than $1.14$ TeV, axigluons and colorons with mass less than $1.06$ TeV, and $E_{6}$ diquarks with mass less than $0.58$ TeV.