72 research outputs found
Combined CDF and D0 Upper Limits on Standard Model Higgs Boson Production with up to 8.6 fb-1 of Data
We combine results from CDF and D0 on direct searches for the standard model
(SM) Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at
sqrt{s}=1.96 TeV. Compared to the previous Tevatron Higgs boson search
combination more data have been added, additional channels have been
incorporated, and some previously used channels have been reanalyzed to gain
sensitivity. We use the MSTW08 parton distribution functions and the latest
theoretical cross sections when comparing our limits to the SM predictions.
With up to 8.2 fb-1 of data analyzed at CDF and up to 8.6 fb-1 at D0, the 95%
C.L. our upper limits on Higgs boson production are factors of 1.17, 1.71, and
0.48 times the values of the SM cross section for Higgs bosons of mass m_H=115
GeV/c^2, 140 GeV/c^2, and 165 GeV/c^2, respectively. The corresponding median
upper limits expected in the absence of Higgs boson production are 1.16, 1.16,
and 0.57. There is a small (approx. 1 sigma) excess of data events with respect
to the background estimation in searches for the Higgs boson in the mass range
125<m_H<155 GeV/c^2. We exclude, at the 95% C.L., a new and larger region at
high mass between 156<m_H<177 GeV/c^2, with an expected exclusion region of
148<m_H<180 GeV/c^2.Comment: Sumitted to the EPS 2011 Conferenc
Combined CDF and D0 Upper Limits on Standard Model Higgs-Boson Production with 2.1 - 5.4 fb-1 of Data
We combine results from CDF and D0 on direct searches for a standard model
(SM) Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at
sqrt(s)=1.96 TeV. Compared to the previous Tevatron Higgs search combination
more data have been added and some previously used channels have been
reanalyzed to gain sensitivity. We use the latest parton distribution functions
and gg->H theoretical cross sections when comparing our limits to the SM
predictions. With 2.0-4.8 fb-1 of data analyzed at CDF, and 2.1-5.4 fb-1 at D0,
the 95% C.L. upper limits on Higgs boson production are a factor of 2.70 (0.94)
times the SM cross section for a Higgs boson mass of m_H=115 (165) GeV/c^2. The
corresponding median upper limits expected in the absence of Higgs boson
production are 1.78 (0.89). The mass range excluded at 95% C.L. for a SM Higgs
is 163<m_H<166 GeV/c^2, with an expected exclusion of 159<m_H<168 GeV/c^2.Comment: 30 pages, five figures. Results prepared for the HCP 2009 conference,
November 16-20, in Evian, Franc
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