Combination of the Limits on Higgs Production at CDF
Weiming Yao1), Yoshiaki Kusakabe2), Tatsuya Masubuchi3), Jason Nielsen1), Anyes Taffard4)
1)LBNL, 2)Waseda, 3)Tsukuba, 4)UIUC
Weiming Yao1), Yoshiaki Kusakabe2), Tatsuya Masubuchi3), Jason Nielsen1), Anyes Taffard4)
1)LBNL, 2)Waseda, 3)Tsukuba, 4)UIUC
Contents
1) Abstract
2) Documentation
3) Input Distributions
4) Systematics
5) NNLO Cross Section
6) Bayesian Framework
7) Posterior Probability
8) Pseudo Experiment
9) Effect of the Correlation
10) Combination Result
1) Abstract
2) Documentation
3) Input Distributions
4) Systematics
5) NNLO Cross Section
6) Bayesian Framework
7) Posterior Probability
8) Pseudo Experiment
9) Effect of the Correlation
10) Combination Result
1) Abstract
This analysis is a combination of several searches for Standard Model Higgs boson production at CDF. The searches were performed in a data sample with up to 695 pb-1 of integrated luminosity collected in pp collisions at sqrt{s}=1.96 TeV. The channels considered are WH-> lνbb, ZH-> νν bb, and gg-> H -> W+W-. We have calculated combined upper limits on the ratio of Higgs cross section times the branching ratio to its Standard Model prediction (R95) for Higgs mass hypotheses between 110 and 200 GeV/c2. The results are in good agreement with the expectations obtained from background-only pseudo-experiments. The combined limit is still an order of magnitude higher than the Standard Model prediction, but it will be greatly improved once the results are updated with 1 fb-1 of data in late summer 2006.
This analysis is a combination of several searches for Standard Model Higgs boson production at CDF. The searches were performed in a data sample with up to 695 pb-1 of integrated luminosity collected in pp collisions at sqrt{s}=1.96 TeV. The channels considered are WH-> lνbb, ZH-> νν bb, and gg-> H -> W+W-. We have calculated combined upper limits on the ratio of Higgs cross section times the branching ratio to its Standard Model prediction (R95) for Higgs mass hypotheses between 110 and 200 GeV/c2. The results are in good agreement with the expectations obtained from background-only pseudo-experiments. The combined limit is still an order of magnitude higher than the Standard Model prediction, but it will be greatly improved once the results are updated with 1 fb-1 of data in late summer 2006.
2) Documentation
| 0. Public Note | cdf-8326 | This Site |
| 1. Run1 Higgs Combined Limit | cdf-4985 | |
| 2. WH -> lνbb w/ 695pb-1 | cdf-8240 | website |
| 3. ZH -> ννbb w/ 289pb-1 | cdf-7983 | website |
| 4. gg -> H -> WW* -> llνν w/ 360pb-1 | cdf-7893 | website |
3) Input Distributions
2. ZH -> llbb : Dijet Mass Distribution 3. WW -> llνν: Dijet Mass Distribution
* Event selection in WW analysis depends on higgs mass. The delta phi distributions are different for each higgs mass. (See WW public website)
1. WH -> lνbb : Dijet Mass Distribution
Single Tag w/ NN tag Double Tag
2. ZH -> llbb : Dijet Mass Distribution 3. WW -> llνν: Dijet Mass Distribution
* Event selection in WW analysis depends on higgs mass. The delta phi distributions are different for each higgs mass. (See WW public website)
4) Systematic Unvertaities
*Positive values mean 100% correlation between channels
*Negative values mean uncorrelated between the channels
*Positive values mean 100% correlation between channels
*Negative values mean uncorrelated between the channels
5) Cross Section and Branching Ratio
* NNLO cross section and branching ratio
* Cross Section is from TeV4LHC Higgs working group
* Branching ratio is from John Conway's Calculation with HDECAY
* NNLO cross section and branching ratio
* Cross Section is from TeV4LHC Higgs working group
* Branching ratio is from John Conway's Calculation with HDECAY
6) Bayesian Framework
7) Posterior Probability
- Posterior probability distributions for each higgs mass as a function of (σ BR)95%/(σ BR)SM
- Posterior probability distributions for each higgs mass as a function of (σ BR)95%/(σ BR)SM
8) Pseudo Experiment
- Pseudo Experiments of combined results of (σ BR)95%/(σ BR)SM to see if the observed limit is reasonable enough
- Pseudo Experiments of combined results of (σ BR)95%/(σ BR)SM to see if the observed limit is reasonable enough
9) Effect of the Correlation (Cross Check)
- The output of the limit calculation when all of the correlated uncertainties are
treated as uncorrelated uncertainties to see the effect of the correlation treatment
- In accordance with those numbers, the effect of the correlation treatment is less than 5%.
- The output of the limit calculation when all of the correlated uncertainties are
treated as uncorrelated uncertainties to see the effect of the correlation treatment
- In accordance with those numbers, the effect of the correlation treatment is less than 5%.
10) Result of the Limit Combination
Last Update on June 23, 2006 by Yoshiaki Kusakabe