Search for a Higgs boson decaying into two photons in the CMS detector

This note describes the search for a Higgs boson decaying into diphotons in pp collisions at the LHC at a center-of-mass energy of 7~TeV. Data-driven methods are used to evaluate the reconstruction and selection performance for the signal, and the background is evaluated from a fit to the data. The analysis is performed on a dataset corresponding to 1.66~fb$^{-1}$ of data recorded in 2011 by the CMS experiment. Limits are set on the cross section of a Standard Model Higgs boson decaying to 2 photons, and on the cross section of a fermiophobic Higgs boson decaying to 2 photons. The expected exclusion limit at 95\% CL is between 2.7 and 4.7 times the Standard Model cross section, and the observed limit fluctuates between about 1.3 and 8 times the Standard Model cross section. For the fermiophobic model, the expected exclusion limit at 95\% CL covers the mass range between 110-116.5~GeV$/c^{2}$, while the data excludes only the mass range 110-112~GeV$/c^{2}$.