Evidence for a new state decaying into two photons in the search for the standard model Higgs boson in pp collisions

A search for a Higgs boson decaying into two photons is described. The analysis is performed using datasets recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energies of 7~TeV and 8~TeV. The datasets correspond to an integrated luminosity of 5.1 and 5.3~fb$^{-1}$, respectively. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. An excess of events above the expected standard model 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 an excess with a local significance $\geq$4.1$\sigma$ anywhere in the search range 110--150~GeV is estimated to be 3.2$\sigma$. This result constitutes evidence for the existence of a new state that decays into two photons.