CMS Search Plans and Sensitivity to New Physics using Dijets

We present an update to CMS plans to search for physics beyond the standard model using dijets. We study jet cleanup, jet response versus $\eta$, optimization of $|\eta|$ cuts, and the dijet mass resolution. Estimates are presented for both the QCD background and signals of new physics with a focus on the integrated luminosities 10 pb$^{-1}$, 100 pb$^{-1}$, and 1 fb$^{-1}$ expected early in LHC running. The inclusive cross section as a function of jet $p_T$ is a first simple measure of QCD dijets which is sensitive to a 3 TeV contact interaction with only 10 pb$^{-1}$. With the dijet mass distribution we expect to be able to observe dijet resonances with large cross sections, such as a 2 TeV excited quark which produces a convincing signal with only 100 pb$^{-1}$. With the dijet ratio, a simple angular measurement, we expect to be able to discover a contact interaction scale $\Lambda^+$ of 4, 7 and 10 TeV for integrated luminosities of 10 pb$^{-1}$, 100 pb$^{-1}$, and 1 fb$^{-1}$ respectively. Using the dijet ratio we can discover or confirm a dijet resonance, and eventually measure its spin. With 100 pb$^{-1}$ a 2 TeV resonance with the production rate of an excited quark produces a convincing signal in the dijet ratio.