106 research outputs found
Combination of CDF and D0 results on the W boson mass and width
The results based on 1992–95 data (Run 1) from the CDF and D0 experiments on the measurements of the W boson mass and width are presented, along with the combined results. We report a Tevatron collider average MW=80.456±0.059  GeV. We also report the Tevatron collider average of the directly measured W boson width ΓW=2.115±0.105  GeV. We describe a new joint analysis of the direct W mass and width measurements. Assuming the validity of the standard model, we combine the directly measured W boson width with the width extracted from the ratio of W and Z boson leptonic partial cross sections. This combined result for the Tevatron is ΓW=2.135±0.050  GeV. Finally, we use the measurements of the direct total W width and the leptonic branching ratio to extract the leptonic partial width Γ(W→eν)=224±13  MeV
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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