Combined SM Higgs Limits at the Tevatron

TL;DR

This paper combines results from CDF and DØ experiments at the Tevatron to set improved limits on the Standard Model Higgs boson production, excluding certain mass ranges with increased sensitivity from new channels and data.

Contribution

It provides the most comprehensive Tevatron Higgs search by incorporating new channels, reanalyzing previous data, and using updated theoretical models to improve exclusion limits.

Findings

Excluded Higgs mass range 160-170 GeV/c^2 at 95% CL.

Achieved upper limits on Higgs production factor of 2.5 at 115 GeV/c^2.

Analyzed up to 4.2 fb^-1 of data from each experiment.

Abstract

We combine results from CDF and DO on direct searches for a standard model (SM) Higgs boson (H) in pbar-p collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV. Compared to the previous Higgs Tevatron combination, more data and new channels (WH to tau nu b bbar, VH to tau tau b bbar/jj tau tau, VH to jj b bbar, t tbar H to t tbar b bbar) have been added. Most previously used channels have been reanalyzed to gain sensitivity. We use the latest parton distribution functions and gg to H theoretical cross sections when comparing our limits to the SM predictions. With 2.0-3.6fb^-1 of data analyzed at CDF, and 0.9-4.2fb^-1 at DO, the 95% C.L. upper limits on Higgs boson production are a factor of 2.5 (0.86) times the SM cross section for a Higgs boson mass of mH=115 (165) GeV/c^2. Based on simulation, the corresponding median expected upper limits are 2.4 (1.1). The mass range excluded at 95% C.L. for a SM Higgs has been extended to 160<mH<170 GeV/c^2.