Peter Speckmayer, LCD weekly 1

Late shower start in HCAL stack

Peter Speckmayer

6/29/2010

Peter Speckmayer, LCD weekly 2

Late shower start

• History:– once upon a time... • we had a layer numbering problem. • HCAL stack layer number were reversed (first

layerhighest number)• sometimes incorrect reversing of layer numbers

– shortenes artificially the HCAL (some layers not taken into account)

– has been fixed then• change in geometryconverter layers start with No. 0

6/29/2010

Peter Speckmayer, LCD weekly 3

Late shower start 2

• Detected similar problem again– not related to old (and fixed) bug– but same symptoms

6/29/2010

Peter Speckmayer, LCD weekly 4

late start/ example

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Peter Speckmayer, LCD weekly 5

late start/ example

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Peter Speckmayer, LCD weekly 6

late start/ example

6/29/2010

Peter Speckmayer, LCD weekly 7

Tracking region

• compact.xml: <!-- tracking region --> <constant name="tracking_region_radius" value="126.5*cm"/> <constant name="tracking_region_zmax" value="100.*cm"/>

Define layers of HCAL (material, thickness), define number of layers, define center of HCAL HCAL center differs for different set ups

• lcdd: <constant name="tracking_region_zmax" value="1000.0" /> <constant name="world_x" value="50000.0" /> <position name="HCAL_position" x="0.0" y="0.0" z="4000.0" unit="mm" /> <position name="HCAL_layerType0_slice0_position" x="0.0" y="0.0" z="-3.75" unit="mm" /> <position name="HCAL_layerType0_slice1_position" x="0.0" y="0.0" z="3.75" unit="mm" /> <position name="HCAL_layerType0_slice2_position" x="0.0" y="0.0" z="7.5" unit="mm" /> <position name="HCAL_layer0_position" x="0.0" y="0.0" z="-3491.25" unit="mm" />

Tracking region reaches into Calorimeter no calorimeter hits from impinging particle while in tracking region but calorimeter hits from back-scattered particles

6/29/2010

Peter Speckmayer, LCD weekly 8

Tracking region

• solution so far:– reduce tracking region to 1 cm in z– re-submitted all simulations with corrected tracking

region• next step: reconstruction, creating ROOT-trees• then: training of neural net• this time: want to go down to 3 lambda (up to now: 6

lambda)

• wait for detailed explanation about tracking region

6/29/2010

Peter Speckmayer, LCD weekly 9

After shortening of tracking region

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Peter Speckmayer, LCD weekly 106/29/2010

Peter Speckmayer, LCD weekly 11

Wrong/correct samples

wrong (material, thickness)• W-steel 20• Steel-W 20• Steel 20, 10• W 20

correct (material, thickness)• W-steel 15, 10• Steel-W 15, 10• steel 30, 25, 15• W 05, 10, 15

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Peter Speckmayer, LCD weekly 12

Summary

• some HCAL stacks wrong• problem found• re-simulate ALL stacks (on the grid)– reconstruct down to 3 lambda

6/29/2010