RawHits in Pixel/SCT Kohei Yorita The University of Chicago FTK Meeting on Feb. 21 st 2007

2 Pixel Detector Drawing <- X-Y view of Pixel Each line corresponds to a module. Layer 1 : 22 Modules Layer 2 : 38 Modules Layer 3 : 52 Modules In each module, #Row increases as Black->Red->Green->Blue “counterclockwise” in phi. Z-X view of Pixel -> 13 Modules in Z : (EtaModule) In each module, #Column increases as Black->Red->Green->Blue->Yellow Less hits in high eta due to MC track generation (|eta|<1.0) Numbering looks consistent in all module. One module x y x z

3 More on Pixel module (just to be sure) Row# Column# yx phiz In Each module, index is Row (phi): (328) Column (z) : (144) Both Row & Column numbers are monotonically increasing ! 8 Row points (row#= ) look like dead channel (no hits.). Why ? Same plot but all modules in layer1

4 # of Entry : Strange spikes ? > Left (row): 0 entry (hole) in middle 8 points (#row: ). instead, 4x2 spikes (~double entry) before/after the gap. > Right (column) : 9 spikes (~ higher by 40%) -> These should be due to the gaps between FE chips that have to be fully covered in readout. #Row #Column 4 x 4

5 “Ganged” Pixel (Row) & “Longed” Pixel (Column) Row (phi) : Two-fold ambiguity remains. Column(z) : Continuous but 9 points give higher occupancy -> less resolution. column row 8chips In the region between different FE chips, Pixels are either - Longer(600um) for column (z) direction -> Total 9 edges that have x1.5 longer pixel. - Ganged for row (phi) direction. (8cells) -> 4points x each side (before/after gap).

6 SCT Detector Drawing <- X-Y view of SCT Each line corresponds to a module. Layer 1 : 32 Modules Layer 2 : 40 Modules Layer 3 : 48 Modules Layer 4 : 56 Modules In each module, #strip increases as Black->Red->Green->Blue->Yellow->.. “counterclockwise” in phi. 768 strip In r-phi plane, Each strip has same Z=Z(center) In stereo plane Each strip has different Z ~2.4mm (=tan(0.04)x60mm) z Black : r-phi Red : Stereo z (mm)

7 A Module in SCT (Layer1) Side 1 (r-phi)Side 0 (z) -> Strip Number (0-767) increases monotonically. -> Z-coordinate is different between side 1 and side 0 due to 40 mrad rotation. -> Even though two submodules are glued in one module, 6x6->6x12(z), those readouts are treated as if there is no physical gap. (the same readout) Strip# yx phiz Strip# yx phiz 768 strip 1 readout

8 But Be Careful !!! Side0/Side1 definition is different in different layers Radius (mm)OrientationSide=0Side=1 Layer1300Phi/uStereor-phi Layer2373Phi/vr-phiStereo Layer3447Phi/uStereor-phi Layer4520Phi/vr-phiStereo u(v) corresponds to +40mrad(-40mrad) stereo angle -> Have to be careful in coding (choice of side e.t.c.).

9 Comparisons between SP & RawHits Using ~100K single muon training data sample. -> In principle event by event comparison is possible. Pixel0hit1hit2hits>3hits SP~1%~87%~10%~2% Raw~1%~45%~40%~14% SCT0hit1hit2hits>3hits SP~2%~93%~4%~1% Raw~1% ~88%~10%

10 Picking up events with ==2hits/layer in Pixel SPRaw * Not in use In rawhits, two hits are always in the same module. -> In a module, most of them are adjacent in phi(60%) and eta(40%). Module Difference Module Difference Row/column Difference Row/column Difference

11 Picking up events with ==2hits/layer in SCT SP : ~70% of the events (with two hits) are in different modules. RawHits: two hits corresponds to r-phi and stereo side in one module. SPRaw * Not in use Module Difference Module Difference Side/Strip Difference Side/Strip Difference

12 What’s happening in cross points between side0 and side1 ? ….. i i i-1 i-2 i+2 i+1 i-N+1 i-N i+N i+N-1 12cm N = sin(40mrad)x768 = > So expect ~60 cross points between r-phi and stereo plane.

13 Finding “Sector” > Running pattgen with “sector mode”. > Track finding efficiency SPRawHits Pixel(111)62%11% Pixel(111) +SCT(0111) 47%0% Pixel(111) +SCT(0111) Only r-phi -7.6% Number of track found by pattgen : SP : 30284x1.814=54945 Raw : 6146x1.416= /54945=16% -> Next step is how to choose it. 104 sector survive Only 1 sector survive

14 What’s done so far & To do > Numbering & data quality check : almost done -> basically monotonous function but we need to be careful for handling of gaps (pixel) and side definition (SCT) > Modified codes for rawhit input : done Just to include flag “S” (rawhits). Now rawhits are readable for pattgen/corrgen/ftksim > Removed stereo hit in SCT (for now) : done > Should make criteria to choose layers (1D or 2D). > First Try : Random pick-up routine for each pixel layer if hits are nearby (easy-check), then averaging… > Generate constants > And more to follow (I need to know what can be done and can not be done... Still learning.