Combined search for the Higgs boson with the D0 experiment

TL;DR

This paper combines multiple search channels from the D0 experiment to search for the Higgs boson, excluding certain mass ranges and observing a mild excess around 125 GeV.

Contribution

It presents a combined analysis of Higgs searches at D0, including interpretations for models with extra fermion generations and suppressed couplings.

Findings

Excluded Higgs mass ranges at 95% C.L.

Observed a 2-sigma excess near 125 GeV.

Enhanced sensitivity through combined channels.

Abstract

We perform a combination of searches for standard model Higgs boson production in $p\bar{p}$ collisions recorded by the D0 detector at the Fermilab Tevatron Collider at a center of mass energy of $\sqrt{s}=1.96$ 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 $90\leq M_H \leq 200$ 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 two standard deviations, consistent with the presence of a standard model Higgs boson of mass 125 GeV.