1. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Why do we need Jet-id ? Because there are noise/fake jets What are the Noise/Fake jets ? 1)Noise jets (partly cured by on-line/off-line Data quality corrections) 2)Fake jets are overcalibrated “jets” (either by picking up noise, or in difficult regions like ICR) What are the handles we have ? Precision readout  estimators like EMF, F90 L1 information  allows confirmation (in p14) Tracking  also better in p14 CPS  in p14.05 T42 (as a byproduct)  in d0correct Jet-id / Fake Jets / T42 G. Bernardi for CALGO (thanks to the Top group)

2. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Jet-ID Definitions JID: electron removal, 0.05 1 JID-f90: JID and ( if f90 < 0.5 or CHF < 0.15 ) L1: JID and ((CC or EC) and L1SET/pT >0.2 or ICD and L1SET/pT >0.1) Track: JID and Sum tracks in 0.5-cone pT / jet pT > 0.05 L1/Track: L1 in CC and EC, Track in ICD L1+Track: L1/Track + Track in CC Perfect jets: L1+Track ( 1) Bad jets : no L1, no Track, JID (-1) Ugly jets: no L1, no Track, JID (-2) Rest: which includes “good” jets (JID-f90) ( 0)

3. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Number of bad/good Jets in 50k dijet sample all erem hotf emf> emf< n90 JID f90 L1 L1&T L1/T or L1t Track coml comt 8118 8108 8105 7951 7938 7937 7738 5310 5089 3851 4557 4967 4849 4337 4810 4570 6544 6535 6533 6488 6480 6479 6347 4438 4224 3290 3839 4166 4034 3674 4052 3862 2797 2790 2789 2753 2731 2730 2725 2552 1896 1516 1789 1882 1830 1659 1860 1794 231 230 229 219 217 217 184 117 125 93 113 124 121 109 121 117 188 187 186 177 175 175 151 97 103 79 94 99 100 90 98 95 95 93 93 89 83 83 82 78 54 39 49 53 52 46 53 51 1499 1463 1462 1453 1431 1431 1401 1311 1394 1249 1338 1374 1388 1255 1374 1368 1138 1111 1110 1102 1085 1085 1063 1007 1058 953 1019 1043 1055 958 1043 1040 1296 1239 1239 1233 1222 1222 1212 1184 1203 1086 1166 1198 1202 1093 1197 1196 dijet: dijet_GRL: djT42GRL: dijet: dijet_GRL: diT42GRL: dijet: dijet_GRL: djT42GRL: black: bad jets from high jet multiplicity green: bad third jet in dijet event blue: good dijet events GRL = good run list applied Bad Jets Good Jets

4. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris all erem hotf emf> emf< n90 JID f90 L1 L1&T L1/T or L1t Track coml comt 100 99.9 99.8 97.9 97.8 97.8 95.3 65.4 62.7 47.4 56.1 61.2 59.7 53.4 59.3 56.3 100 99.9 99.8 99.1 99 99 97 67.8 64.5 50.3 58.7 63.7 61.6 56.1 61.9 59 100 99.7 99.7 98.4 97.6 97.6 97.4 91.2 67.8 54.2 64 67.3 65.4 59.3 66.5 64.1 100 99.6 99.1 94.8 93.9 93.9 79.7 50.6 54.1 40.3 48.9 53.7 52.4 47.2 52.4 50.6 100 99.5 98.9 94.1 93.1 93.1 80.3 51.6 54.8 42 50 52.7 53.2 47.9 52.1 50.5 100 97.9 97.9 93.7 87.4 87.4 86.3 82.1 56.8 41.1 51.6 55.8 54.7 48.4 55.8 53.7 100 97.6 97.5 96.9 95.5 95.5 93.5 87.5 93 83.3 89.3 91.7 92.6 83.7 91.7 91.3 100 97.6 97.5 96.8 95.3 95.3 93.4 88.5 93 83.7 89.5 91.7 92.7 84.2 91.7 91.4 100 95.6 95.6 95.1 94.3 94.3 93.5 91.4 92.8 83.8 90 92.4 92.7 84.3 92.4 92.3 black: bad jets from high jet multiplicity green: bad third jet in dijet event blue: good dijet events dijet: dijet_GRL: djT42GRL: dijet: dijet_GRL: diT42GRL: dijet: dijet_GRL: djT42GRL: Bad Jets good Jets Efficiencies for bad/good Jets in 50k dijet sample

5. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Conclusions on jet-id / fake&noise jets Some properties of the noise jets: " low pT, sit mainly in the ICD and CH " fake high met, large HT and high jet Multiplicity -> the noise is found where we look for interesting physics In p13 LP03 sample only 45 highest ET towers: -> much lower efficiency to find L1 confirmed jets! T42: 50% reduction of bad jets  Use T42 and Use L1 confirmation for Jet-id. Use Tracks to monitor jet-id efficiencies But….

6. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris “tmb-fixed” W sample P13 P13 with TMB fix and T42 Em-id: Em Fraction > 0.90 Isolation < 0.15 Em HM8 < 20 |  | < 1.1, In Fiducial vol. p T e > 20 GeV ME T > 25 GeV Standard Jets Criteria: Em Fraction < 0.95 HOTF < 10 f90 < 0.5 or CHf<0.15 |  | < 2.5 P T > 15 GeV (left: loose elec.sel. right: tight elec. sel.)

7. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Missing E T, W Transverse Mass P13 P13 with TMB fix and T42

8. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Eta of Leading Jet P13 (left: loose elec.sel. right: tight elec. sel.) huge change in the distribution. Coming from the change of ICD Cal_Weight. P13 with TMB fix and T42

9. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Reducing influence of Noise: T42 T42: reject ALL isolated cells below 4 sigmas (and ALL negative energy cells) Select high signal cells (4 sigma) Keep their significant neighbours (2 sigma  Thresholds 2  is 2.5  at the moment  T42.5 Full description is available in DØNotes 4124, 4146 Available in D0Reco in shadow mode Not running yet: We wants to have first a tmbfix w/o T42

10. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris T42 on high energy electrons Estimators for EM candidates in data, when pT>13 GeV OK !

11. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris T42 on Missing and Scalar E T WZ skim, p13.06, W  e nu selection (E T > 20 GeV, MET > 25 GeV) Compared to Pythia MC No T42 After T42

12. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Run Selection with T42 Define the average shift: MET-xy = sqrt [ ( ) 2 +( ) 2 ] RMS-xy = sqrt [ ( RMS-x ) 2 + ( RMS-y ) 2 ] To declare a RUN “GOOD”: 1) Require MET-xy < 6 GeV in all files of a run, and MET-xy < 4 GeV in average 2) Require RMS-xy < 18 GeV in all files of a run and RMS-xy < 16 GeV in average 3) Require scalar E T > 70 GeV in all files of a run and scalar E T > 80 GeV Compare Run selection with and without T42 on 55 pb -1 of p14.03 data

13. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Met-xy Shift P14.03.02 Met-xy Shift With T42 Scalar E T P14.03.02 Scalar E T With T42 T42 is “cleaner”

14. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris P14.03 Jul-Aug 2003 one entry / good “file” (about 20 lumi blocks) Same p14.03 files but processed with T42 xy-shift in Missing E T, xy-rms

15. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris P14.03 Jul-Aug 2003 one entry / good “file” (about 20 lumi blocks) Same p14.03 files but processed with T42 Scalar and Missing E T (setb,metb)

16. Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Summary We are progressing ! The potential of p14 is large after all the fixes. Finalize the jet-id  JES can start Watch ICD behavior Use T42(.5) (prepare T42 for restart)