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B-tagging Efficiency

B-tagging Efficiency. Monica Dunford April 24 th , 2007. Cuts and Jet Selection. Using WHbb and WHuu samples with 3mm Pixel and 5mm SCT FTKsim banks (incomplete training) For all samples, the following are applied -1.0 < Cot(  ) < 1.0 -0.3 < curvature(GeV -1 ) < 0.3

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B-tagging Efficiency

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  1. B-tagging Efficiency Monica Dunford April 24th, 2007

  2. Cuts and Jet Selection • Using WHbb and WHuu samples with 3mm Pixel and 5mm SCT FTKsim banks (incomplete training) • For all samples, the following are applied • -1.0 < Cot() < 1.0 • -0.3 < curvature(GeV-1) < 0.3 • No cuts on truth track association • Associate FTK tracks jets using the Cone 0.4 algorithm • Require r = (2+2) < 0.4 • Jet Pt > 20 GeV and jet abs()< 1.0 • Require at least two or more tracks associated with each jet

  3. B-tagging Efficiency • Method 1: Two or more tracks above with d0 > X • Method 2: Two or more tracks above with d0/ > X • Method 3: d0/ Likelihood ratio Likelihood ratio: Acceptance Cut: L2 Trigger uses a 2D selection with d0 and z0

  4. Likelihood Ratio Distribution iPat FTK

  5. FTK B-tagging Efficiency • FTK B-tagging efficiency for three different methods • Not entirely sure why the d0/ method is worse than d0 method

  6. Compared to the L2 results A. Coccaro’s March T&P talk • Note the difference in ordinate scale 2D algorithm used Black - L2 Green - EF Red - offline

  7. Problems with L2 Output • Re-ran L2 algorithm on WH samples • Multiple problems • Bug in Athena, 2D algorithm results are not stored correctly to ntuples • z0 results look bizarre (see next slide) • EF algorithm results are bogus (see next, next slide)

  8. L2 z0 Likelihood Ratio Distr. • Not sure what this distribution should look like, but there is little discrimination power here

  9. EF d0 Algorithm Results • Clearly just something wrong here

  10. Comparing Efficiencies • FTK is on par with L2 d0 algorithm (but not entirely sure that L2 values results are correct)

  11. Summary and Next Steps • Calculate efficiency using • 2D (d0 and z0) methods • Offline Algorithm • Use L1 ROI instead of Cone 4 jets • Fix L2/EF Athena ntuple issues to obtain reasonable output

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