Search for higgs boson diphoton decay with CMS at LHC

We have carried out a detailed study of the inclusive search for the Higgs boson in diphoton decay channel with CMS detector at LHC. The analysis is based on full Monte Carlo simulation. Though for the moment we have only simulated data to work with, we have designed an analysis that can determine the background from real data. This largely reduces the systematic error and, together with the excellent resolution of the CMS electromagnetic calorimeter, enables a search that would otherwise be very difficult. We have studied both a standard cut-based analysis and more optimized analysis that takes advantage of the wide range of signal/background expectations as function of the possible selection cuts. Since discovery in this channel is expected to take one or more years of LHC running, such optimized analysis should be studied to minimize the time to discovery and to assure that the experiment is competitive in this important measurement.