Combined search for the Higgs boson with the D0 experiment

Abstract

We perform a combination of searches for standard model Higgs boson production in pp-bar collisions recorded by the D0 detector at the Fermilab Tevatron Collider at a center of mass energy of s√=1.96 TeV. The different production and decay channels have been analyzed separately, with integrated luminosities of up to 9.7 fb(−1) and for Higgs boson masses 90≤M(H)≤200 GeV. We combine these final states to achieve optimal sensitivity to the production of the Higgs boson. We also interpret the combination in terms of models with a fourth generation of fermions, and models with suppressed Higgs boson couplings to fermions. The result excludes a standard model Higgs boson at 95% C.L. in the ranges 90<M(H)<101 GeV and 157<M(H)<178 GeV, with an expected exclusion of 155<M(H)<175 GeV. In the range 120<M(H)<145 GeV, the data exhibit an excess over the expected background of up to 2 standard deviations, consistent with the presence of a standard model Higgs boson of mass 125 GeV.