Search for a Higgs-like boson decaying to two photons in proton antiproton collisions at center of mass energy of 1.96 TeV

Abstract

We present a search for the Standard Model (SM) Higgs boson decaying to two photons using the 9.6 fb-1 of proton antiproton collisions at center of mass energy of 1.96 TeV collected by the D0 detector at the Tevatron from July 2002 to September 2011. The data corresponds to the complete data-set in the RunII period of the Tevatron. This thesis employs a multivariate technique, boosted decision trees, to optimize the discrimination of signal from background. No significant excess of data above theoretical prediction is observed, so limits on the ratio of the production cross section times the branching ratio to the SM value are set at 95% confidence level as a function of hypothetical Higgs boson mass. The expected and observed limits on this ratio are 8.7 and 12.8 respectively at 125 GeV. We also interpret the data in the fermiophobic Higgs model. The result has reached a sensitivity of 114 GeV, and we set a lower limit on the fermiophobic Higgs mass of MHf 113 GeV.