Updated measurements of the Higgs boson at 125 GeV in the two photon decay channel

Results are reported from a search for the Standard Model Higgs boson in the two photon channel in the mass range $110 < m_H < 150$ GeV, using the full dataset recorded by the CMS experiment at the LHC from pp collisions at centre-of-mass energies of 7 and 8 TeV. The most sensitive, MVA, analysis observes an excess of events at a mass of 125 GeV, with a local significance of 3.2$\sigma$ (standard deviations), where a local significance of 4.2$\sigma$ is expected from a standard model Higgs boson. The best-fit signal strength, $\sigma/\sigma_{SM}$, is $0.78\pm 0.27$ at $m_H = 125$ GeV, and the mass is fitted to be $125.4 \pm 0.5(stat.) \pm 0.6(syst.)$. The cut-based analysis observes a corresponding excess with a local significance of 3.9$\sigma$ (3.5$\sigma$ expected), and $\sigma/\sigma_{SM} = 1.11 \pm 0.31$ at $m_H = 124.5$ GeV. All measurements are compatible among themselves and with a Higgs boson with a mass of 125.4 GeV.