Difference: AmnonHarelCLsInDCR (10 vs. 11)

Revision 112010-10-07 - AmnonHarel

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META TOPICPARENT name="AmnonHarelDijetCentralityRatio"
-- AmnonHarel - 12-Sep-2010
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  • Found a bug that greatly reduced the shift uncertainty in all results, and another that reduced the absolute JES in the results sent to the statistic board during CWR. The three leading uncertainties were unaffected by these bugs, so the results barely change. It is only due to the finicky nature of CLs limits in the regime we're at, that these tiny effects must be resolved.
  • Better understanding of the low LLR tails, described in the next section
  • Now using the CMS LPC batch system - generating obscene amounts of pseudo-datasets has never been easier smile
Added:
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  • Decided on the stopping conditions.
    • lambda value excluded / allowed at 2 sigma level
    • CLs value (i.e. the confidence level of the exclusion) is known at 0.5% accuracy
      • note that this condition is neccesary - without it at the key lambda value, where the exclusion truly is 95%, only a large statistical fluctuation will yield 2 sigma separation between the true CLs level and the desired 5%. Furthermore, closure tests of frequentist methods often show inaccuracies at the 1% level.
 

What drives the low LLR tails?

The earlier results:
  • the nuisance parameters in the tails are as one would expect from their correlations with LLR in the bulk. They are only mildly effected.
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3.40 30000 179 0.0060 0.1191 -3.41 -1.79 -4.86 13 0.0276 0.0079
3.60 244084 455 0.0019 0.0373 -3.50 -1.64 -4.00 120 0.0373 0.0035
3.80 92098 187 0.0020 0.0406 -3.01 -1.43 -3.66 23 0.0321 0.0068
Changed:
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4.00 402210 155 0.0004 0.0077 -3.53 -1.69 -3.57 125 0.0481 0.0044
4.05 323618 --- --- --- --- -1.65 -3.41 133 0.0627 0.0056
4.10 139028 45 0.0003 0.0065 -3.27 -1.62 -3.27 43 0.0491 0.0077
4.15 152000 19 0.0001 0.0025 -3.34 -1.63 -3.18 49 0.0530 0.0079
4.20 111028 3 0.0000 0.0006 -3.32 -1.55 -3.03 42 0.0690 0.0113
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4.00 472238 164 0.0003 0.0069 -3.56 -1.69 -3.57 151 0.0489 0.0041
4.05 413663 12 0.0000 0.0006 -3.83 -1.66 -3.41 156 0.0566 0.0047
4.10 209056 49 0.0002 0.0047 -3.32 -1.62 -3.27 71 0.0551 0.0068
4.15 218000 30 0.0001 0.0028 -3.32 -1.64 -3.18 77 0.0572 0.0068
4.20 181056 4 0.0000 0.0005 -3.34 -1.55 -3.03 71 0.0701 0.0088
 
5.00 25000 --- --- --- --- -1.08 -1.49 48 0.2426 0.0418

Conclusions

Going over the crucial lambda values one by one:
  • Though the separation at lambda=3.6TeV is low enough that it is almost power-constrained away, this lambda value is clearly excluded.
  • 3.8TeV is excluded
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  • A CLs crucial value exists at 4.0TeV. It is probably above the data so that 4.0 is excluded. Generating more PDSs...
  • 4.05TeV?
  • A CLs crucial value exists at 4.1TeV. excluded?
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  • The CLs at 4.0TeV is known to an accuracy of 0.5%, and at that accuracy it is below 5%, so that 4.0TeV is excluded
  • The CLs at 4.05TeV is known to an accuracy of 0.5%, and at that accuracy it is above 5%, so that 4.05TeV is not excluded
  • A CLs critical value exists at 4.1TeV. excluded?
 
  • 4.15TeV?
Changed:
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  • 4.2TeV?
  • If a crucial CLs value exists at 5TeV, the data value is well above it and 5TeV can not be excluded.
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  • A critical CLs value probably exists for 4.2TeV, but it is above the data (at 2 sigma of MC statistics), so 4.2TeV is not excluded.
  • If a critical CLs value exists at 5TeV, the data value is well above it and 5TeV can not be excluded.
 

Updated results during CWR

Generated an obscene amount of additional PDSs...
 
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