Z Segmentation Update (improving reconstruction of non-prompt tracks with the SiD)

Z Segmentation UpdateZ Segmentation Update(improving reconstruction of non-(improving reconstruction of non-

prompt tracks with the SiD)prompt tracks with the SiD)

Lori Stevens (SLAC/UCSC)Lori Stevens (SLAC/UCSC)

August 21, 2007August 21, 2007

ILC Simulation Reconstruction Meeting

AxialBarrelTrackFinder1 BugAxialBarrelTrackFinder1 Bug

Phi requirement: phi coordinate of all hits Phi requirement: phi coordinate of all hits must be within must be within ππ/2 of each other/2 of each other

Bug in my version of code caused phi Bug in my version of code caused phi requirement to be too restrictiverequirement to be too restrictive

Fixed bug and found improvement in both Fixed bug and found improvement in both efficiency and number of fake tracks when efficiency and number of fake tracks when using z segmentationusing z segmentation

Comparing Z Segmentation Comparing Z Segmentation Before and After Fix Before and After Fix

Sample: pythiaZPolebbbar-0-1000_SLIC_v1r9p3_sidaug05.slcioSample: pythiaZPolebbbar-0-1000_SLIC_v1r9p3_sidaug05.slcio

NoneNone NoneNoneno bugno bug

30cm30cm 30cm30cm no bugno bug

10cm 10cm

10cm10cmno bugno bug

5cm5cm 5cm5cmno bugno bug

1cm1cm 1cm1cmno bugno bug

#MCPs#MCPs 304304 304304 304304 304304 304304 304304 304304 304304 304304 304304

Found Found with 5 hitswith 5 hits 145145 155155 144144 161161 157157 162162 156156 157157 126126 126126

Found Found with 4 hitswith 4 hits 112112 115115 110110 113113 115115 115115 117117 117117 106106 107107

MissedMissed 4747 3434 5050 3030 3232 2727 3131 3030 7272 7171

FakeFake 158158 6565 156156 5555 4848 1717 2222 1010 44 11

Some other studies Some other studies (collisions at 500GeV)(collisions at 500GeV)

panpyuds_nobeam_nobrem-1-500_SLIC_panpyuds_nobeam_nobrem-1-500_SLIC_v2r0p6_sidaug05.slciov2r0p6_sidaug05.slcio



panpyuds_nobeam_nobrem-1-panpyuds_nobeam_nobrem-1-500_SLIC_v2r0p6_sidaug05.slcio500_SLIC_v2r0p6_sidaug05.slcio

No No segmentssegments

30cm 30cm segmentssegments




# MCPs# MCPs 3333 3333 3333 3333 3333

Found Found with 5 hitswith 5 hits 1515 1515 1515 1616 1414


MissedMissed 55 77 33 11 55

FakeFake 5959 6161 3737 3030 1818







# MCPs# MCPs 169169 169169 169169 169169 169169



MissedMissed 2424 1919 2020 1717 3232

FakeFake 262262 255255 161161 128128 5252







# MCPs# MCPs 150150 150150 150150 150150 150150



MissedMissed 3434 3333 2424 2323 3737

FakeFake 252252 239239 157157 100100 5252

Combining the 3 data setsCombining the 3 data sets






# MCPs# MCPs 352352 352352 352352 352352 352352



MissedMissed 6363 5959 4747 4141 7474

FakeFake 573573 555555 355355 258258 122122

ZPole vs. 500GeV collisionsZPole vs. 500GeV collisionspythiaZPolebbbar-0-1000_SLIC_

v1r9p3_sidaug05.slcio, no beam no brem

0

20

40

60

80

100

120

140

160

180

200

0 0.5 1 1.5

Log base 10 of segmentation length (in cm)

N u m

b e r

o f

T r a

c k s

Found 5

Found 4

Missed

Fake

1cm 5cm 10cm 30cm

Combining all three 500GeV data sets

0

100

200

300

400

500

0 0.5 1 1.5

Log base 10 of segmentation length (in cm)

N u m

b e r

o f

T r a

c k s

Found 5

Found 4

Missed

Fake

1cm 5cm 10cm 30cm

ConclusionConclusion

The use 4 hit tracks may depend on the jet The use 4 hit tracks may depend on the jet energyenergy

Will 10cm segmentation make a Will 10cm segmentation make a difference?difference?

Tyler Rice and Chris Meyer are doing a Tyler Rice and Chris Meyer are doing a study using variable segmentation in Dima study using variable segmentation in Dima Onoprienko's Garfield Tracker…this may Onoprienko's Garfield Tracker…this may help find some answershelp find some answers

HelicalTrackFitter improvementsHelicalTrackFitter improvements

Does not currently fit hits in tracker barrelDoes not currently fit hits in tracker barrel

Improving to fit hits in all regionsImproving to fit hits in all regions

Will use various fitting methods such as Will use various fitting methods such as circle fitting, line fitting, 2D hit consistency circle fitting, line fitting, 2D hit consistency checks, and Rich Partridge’s checks, and Rich Partridge’s z segmentation codez segmentation code

Presentation next Friday (8/31/07)Presentation next Friday (8/31/07)

Z Segmentation Update (improving reconstruction of non-prompt tracks with the SiD)

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