Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Why do we need Jet-id ? Because there are noise/fake...

ConvenersOct-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 p14CPS in p14.05T42 (as a byproduct) in d0correct

Jet-id / Fake Jets / T42G. Bernardi for CALGO (thanks to the Top group)



Jet-ID DefinitionsJID: electron removal, 0.05<EMF<0.95, HOTF<10, CHF<0.4, N90>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)



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

Bad Jets

Good Jets



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 multiplicitygreen: bad third jet in dijet event blue: good dijet events

dijet:

dijet_GRL: djT42GRL:

dijet: dijet_GRL:

diT42GRL:

dijet:

dijet_GRL:

djT42GRL:

Bad Jets

Bad Jets

good Jets

Efficiencies for bad/good Jets in 50k dijet sample



Conclusions on jet-id / fake&noise jetsSome 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….



“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.

• pTe > 20 GeV

•MET > 25 GeV

Standard Jets Criteria:• Em Fraction < 0.95• HOTF < 10• f90 < 0.5 or CHf<0.15 •|| < 2.5• PT > 15 GeV

(left: loose elec.sel.right: tight elec. sel.)



Missing ET , W Transverse Mass

P13




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.




Reducing influence of Noise: T42T42: 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

What neighbours means

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



T42 on high energy electrons

Estimators for EM candidates in data, when pT>13 GeV

OK !



T42 on Missing and Scalar ET

WZ skim , p13.06 , W e nu selection (ET > 20 GeV, MET > 25 GeV)

Compared to Pythia MC

No T42

After T42



Run Selection with T42

Define the average shift:

MET-xy = sqrt [ (<MET-x>)2 +(<MET-y>)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 ET > 70 GeV in all files of a run and scalar ET > 80 GeV

Compare Run selection with and without T42 on 55 pb-1 of p14.03 data



Met-xy Shift

P14.03.02

Met-xy Shift

With T42

Scalar ET

P14.03.02

Scalar ET

With T42

T42 is “cleaner”



P14.03Jul-Aug 2003 one entry / good “file”

(about 20 lumi blocks)

Same p14.03 files

but processed with

T42

xy-shift in Missing ET, xy-rms



P14.03Jul-Aug 2003 one entry / good “file”

(about 20 lumi blocks)

Same p14.03 files

but processed with

T42

Scalar and Missing ET (setb,metb)



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)

Conveners Oct-31-2003 G. Bernardi LPNHE - Paris Why do we need Jet-id ? Because there are noise/fake...

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