Performance of L1 CSC TriggerPerformance of L1 CSC Trigger(and strange geometrical effects)(and strange geometrical effects)

D. AcostaUniversity of Florida

PRS/Mu Meeting, July 2, 2002 Darin Acosta2

Eta Eta = 1.6 Region= 1.6 RegionAs reported by Hannes, a large number of high quality

muons reported by L1 CSC trigger originate from PT1 sample Contribute ~1 kHz to L1 rate

1 1.2 1.4 1.6 1.8 2 2.2 2.40

5

10

15

20

25

30

htempNent = 63 Mean = 1.671RMS = 0.3191

abs(Etac[0]) {Ncsc>0&&Qualc[0]>2&&Ptc[0]>10} htempNent = 63 Mean = 1.671RMS = 0.3191 50Kevt

PRS/Mu Meeting, July 2, 2002 Darin Acosta3

ηη Distribution of ME SegmentsDistribution of ME Segments

55 60 65 70 75 80 85 90 95 1000

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htempEntries 5937Mean 76.73RMS 11.34

stubeta[0] {nstub>0&&station[0]==1&&Cscid[0]<3} htempEntries 5937Mean 76.73RMS 11.34

25 30 35 40 45 50 55 600

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40

60

80

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160

180

htempEntries 3920Mean 41.49RMS 9.393

stubeta[0] {nstub>0&&station[0]==1&&Cscid[0]<6&&Cscid[0]>2} htempEntries 3920Mean 41.49RMS 9.393

ME1/1

ME1/2ME1/1 and ME 1/2 overlap in ηsomewhat: 1.5875–1.6625

Creates ambiguity as to which station to use in PT assignment

Also region of detector cracks

PRS/Mu Meeting, July 2, 2002 Darin Acosta4

ηη Distribution after Boundary CreationDistribution after Boundary Creation

55 60 65 70 75 80 85 90 950

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htempEntries 5937

Mean 76.76

RMS 11.3

stubeta[0] {nstub>0&&station[0]==1&&Cscid[0]<3} htempEntries 5937

Mean 76.76

RMS 11.3

25 30 35 40 45 50 550

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htempEntries 3920

Mean 41.42

RMS 9.279

stubeta[0] {nstub>0&&station[0]==1&&Cscid[0]>2&&Cscid[0]<6} htempEntries 3920

Mean 41.42

RMS 9.279

ME1/1

ME1/2

undfl

ovflw

One way to solve ambiguity is to define the η bins so that there is no overlap (even though there is). Define an upper η bin for the ME1/2 chamber and a lower η bin for the ME1/1 chamber (overflow and underflow bins). The deviation from the true η is only 2 bins (0.025 units), which does not affect the L1 CSC Track-Finder efficiency.

Avoids adding more memory chips on board

PRS/Mu Meeting, July 2, 2002 Darin Acosta5

1/P1/PTT ResolutionResolution

-1 -0.5 0 0.5 10

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hPtResEntries 310Mean -0.07004RMS 0.3146

/ ndf 2χ 54.32 / 37Prob 0.03293Constant 1.544± 15.63 Mean 0.01664± -0.0325 Sigma 0.01923± 0.2495

Ptgen/Pt-1 hPtResEntries 310Mean -0.07004RMS 0.3146

/ ndf 2χ 54.32 / 37Prob 0.03293Constant 1.544± 15.63 Mean 0.01664± -0.0325 Sigma 0.01923± 0.2495

-1 -0.5 0 0.5 10

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10

15

20

25

hPtResNent = 310 Mean = -0.008793RMS = 0.2597Chi2 / ndf = 34.3 / 34Prob = 0.4533

1.637 ±Constant = 19.75 0.01439 ±Mean = -0.01955

0.01258 ±Sigma = 0.2169

Ptgen/Pt-1 hPtResNent = 310 Mean = -0.008793RMS = 0.2597Chi2 / ndf = 34.3 / 34Prob = 0.4533

1.637 ±Constant = 19.75 0.01439 ±Mean = -0.01955

0.01258 ±Sigma = 0.2169

Before:PT often overestimated when wrong ME1 chamber was assumed

(less bending between ME1/2 and ME2, so looks like high pTif you assume ME1/1 to ME2)

After:With clean η boundary, tail removed and PTresolution improved

PRS/Mu Meeting, July 2, 2002 Darin Acosta6

PT1 CandidatesPT1 Candidates

1 1.2 1.4 1.6 1.8 20

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htempNent = 53 Mean = 1.544RMS = 0.216

abs(tracketavalue[0]) {ntrack>0&&trackquality[0]>2&&ptvalue[0]>10} htempNent = 53 Mean = 1.544RMS = 0.216

1 1.2 1.4 1.6 1.8 20

1

2

3

4

5

6

htempNent = 13 Mean = 1.235RMS = 0.3243

abs(tracketavalue[0]) {ntrack>0&&trackquality[0]>2&&ptvalue[0]>10} htempNent = 13 Mean = 1.235RMS = 0.3243

Before

After:low PT muons removed !

PRS/Mu Meeting, July 2, 2002 Darin Acosta7

Why ?Why ?A little strange that we see a large impact from this effect now, because the ambiguity has been there all along in previous productions

More punch-through in latest production ?Larger cracks in geometry ?

PRS/Mu Meeting, July 2, 2002 Darin Acosta8

0 1 2 3 4 5 60

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htempNent = 37 Mean = 3.412RMS = 1.564

abs(trackphivalue[0]) {ntrack>0&&trackquality[0]>2&&ptvalue[0]>10&&tracketavalue[0]>=1.6&&tracketavalue[0]<1.7} htempNent = 37 Mean = 3.412RMS = 1.564

0 1 2 3 4 5 60

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htempNent = 53 Mean = 3.41RMS = 1.546

abs(trackphivalue[0]) {ntrack>0&&trackquality[0]>2&&ptvalue[0]>10&&tracketavalue[0]>-1.7&&tracketavalue[0]<=-1.6} htempNent = 53 Mean = 3.41RMS = 1.546

Why spikes in φ for the η=1.6 triggers before fix? Or why the asymmetry for that matter ?

Not aligned on any sector boundary

About 1/3 are associated with generated muons with PT ~ 3 GeV (lower limit of ntuple)

About 2/3 of these CSC triggers have RPC confirmation

+η Endcap

+η Endcap

φφ Distribution of Distribution of ηη=1.6 Triggers=1.6 Triggers

PRS/Mu Meeting, July 2, 2002 Darin Acosta9

Distribution of RPC TriggersDistribution of RPC Triggers

0 1 2 3 4 5 60

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8

htempEntries 68Mean 2.858RMS 1.711

Phir[0] {Nrpc>0&&Ptr[0]>5&&(Etar[0])>=1.5&&(Etar[0])<1.7} htempEntries 68Mean 2.858RMS 1.711

0 1 2 3 4 5 60

1

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5

htempEntries 64Mean 2.993RMS 1.831

Phir[0] {Nrpc>0&&Ptr[0]>5&&(Etar[0])<=-1.5&&(Etar[0])>-1.7} htempEntries 64Mean 2.993RMS 1.831

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.20

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htempEntries 467Mean 1.344RMS 0.5665

abs(Etar[0]) {Nrpc>0&&Ptr[0]>5} htempEntries 467Mean 1.344RMS 0.5665

Maximum triggers for η=1.6

φ Distribution shows spikes

PRS/Mu Meeting, July 2, 2002 Darin Acosta10

Correlation with E/Gamma ?Correlation with E/Gamma ?Chris Seez:

“We deliberately remove trigger tower 18 (1.479 < eta < 1.566)from our fiducial region for precision e/gamma work. This region is strongly shadowed by tracker cables exiting through the barrel/endcap 'corner' (at eta~=1.479). On the high side of the corner there are a number of "missing" crystals - but the location of these small "holes" in the material is/should be 4-fold symmetric (each quadrant of theendcap is identical).”

Possible correlation, or just accidental coincidence ?

Anyway, latest CSC simulation removes low pT triggers (but need to keep an eye on this region if punch-through is large)

Barrel-Endcap crack & tracker cables

η

Trig. Tower 18

PRS/Mu Meeting, July 2, 2002 Darin Acosta11

Other Changes to L1 CSC SimulationOther Changes to L1 CSC SimulationThe addition of the η boundary for the CSC trigger is implemented in the head of the L1CSCTrigger and L1CSCTrackFinder packages

The ORCA_6_1_1 tagged release is several months old

Many other changes have been made to these packages to bring them up-to-date with prototypes currently being built and tested

New anode trigger logic New Sector Receiver look-up table schemeAdditional features in Sector Processor logic

But a few more changes to the default settings need to go in before general release

Also to L1DTTrackFinder because of an interface change

PRS/Mu Meeting, July 2, 2002 Darin Acosta12

CSC Efficiency with Latest CodeCSC Efficiency with Latest Code

Pt (GeV/c)0 20 40 60 80 100

Eff

icie

ncy

0

0.2

0.4

0.6

0.8

1

hEffPt0Entries 27

Mean 51.66

RMS 28.03

Efficiency vs. Pt hEffPt0Entries 27

Mean 51.66

RMS 28.03

1 1.2 1.4 1.6 1.8 2 2.2 2.40

0.2

0.4

0.6

0.8

1

Efficiency vs. Eta

Basically, as good as it ever has been

Need to check for fake di-muon triggers, however