Procedure for the LHC Higgs boson search combination in Summer 2011
This page contains approved plots and results as they appear in ATL-PHYS-PUB-2011-011
. Only the note contains all the relevant information and should thus be consulted if one of the plots is used. Please contact the HSG Documentation manager if you find any errors on this page.
A Note on Image Types
The original images were in the PDF format and converted to EPS format. Please report any outstanding missed artifacts in the EPS files to the Higgs working group documentation manager. In any case, the PDF files will probably have the highest quality.
Figures
Figure 1: Test statistic distributions for ensembles of pseudo-data generated for
signal+background and
background-only hypotheses. See the text for definitions of the test statistic and methodology of generating pseudo-data.
Figure 2: (Left) An example of differential distribution of possible limits on

for the
background-only hypothesis (

= 1,

= 1, no systematic errors). (Right) Cumulative probability distribution of the plot on the left with 2.5%, 16%, 50%, 84%, and 97.5% quantiles (horizontal lines) defining the median expected limit as well as the ±1σ (68%) and ±2σ (95%) bands for the expected value of

for the
background-only hypothesis.
Figure 3: Distribution

of the test statistic

as obtained by generating pseudo-data (toys) for the
background-only hypotheses.
Figure 4: An illustration of a hypothetical scan of the test statistic

vs

for some data. Up-crossings for a given threshold value

are shown with blue points.
Figure 5: Expected detector resolutions for reconstructing two photons

(blue dotted) and four muons

(blue dashed) as well as the intrinsic Higgs half-width

(red) as a function of the Higgs mass

. The chosen size of mass steps for the Higgs search analyses is shown in green.
Figure 6: (Left) Log-normal distributions with

= 1.10, 1.20, 1.33 and 1.50. (right) Gamma distribution with the number of events in a control sample

= 100, 25, 9 and 4.
Figure 7: local p-value scan vs

. This plot does not correspond to any MC or data analysis. To help guide the eye, the n-sigma significance levels are highlighted with colour bands.
Figure 8: CL
S scan vs

. The solid line shows the observed values of (1 - CL
S) . The green/yellow bands indicate ±1σ and ±2σ intervals for the expected values under the
background-only hypothesis. The median expectation is shown with the dashed line.
Figure 9: 95% C.L. limits

on the Higgs boson production cross section strength modifier

(

) vs Higgs boson mass

. This plot does not correspond to any MC or data analysis. The solid line shows the observed limit. The green/yellow bands indicate ±1σ and ±2σ intervals for the expected limits under the
background-only hypothesis. The median expectation is shown with the dashed line.
Figure 10: Correlations of PDF-associated errors between different backgrounds.
Figure 11: Correlations of PDF-associated errors between different SM Higgs production mechanisms as well as between Higgs production modes and different backgrounds.
Major updates:
--
CalebLampen - 27-Jan-2011
Responsible: CalebLeeParnellLampenExCern