Search for SM Higgs decaying to two photons at CMS

A search for a Higgs boson decaying into two photons in proton-proton collisions at a centre-of-mass energies of 7~TeV and 8~TeV is reported. The data analysed correspond to an integrated luminosity of 5.1 fb$^{-1}$, recorded in 2011 at $\sqrt{s}=7$ TeV and of 5.3 fb$^{-1}$, recorded in 2012 at $\sqrt{s}=8$ TeV by the CMS experiment at the LHC. The Higgs boson mass range explored is 110--150 GeV. Limits are set on the cross section of the Standard Model Higgs boson decaying to two photons. An excess of events above the expected background is observed for a Higgs boson mass hypothesis of 125~GeV, with a local significance of 4.1$\sigma$. The global significance of observing such an excess anywhere in the search range is estimated to be 3.2$\sigma$. This result constitutes evidence for the existence of a new state that decays into two photons. A fit to this signal gives a mass of $125.1 \pm 0.4 (\rm stat) \pm 0.6 (syst)$~GeV. The decay to two photons indicates that the new particle is a boson with spin different from one.