Difference between revisions of "LB RunGroupC Vertex"
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Here is an example of how the cuts were made. Consider the case of a 2cm line target in the Z direction centered at (0,0,0). Closed intervals begin at the end of the target and are 0.1cm long. So the first interval would be [-1.0,-0.9], then the next would be [-0.9, -0.8] and so on until the entire target is covered. The events in the EVENTHB bank were cut so that in any given interval there would be a margin of +/- 1cm to remove any outliers that may cause the histograms to have long tails. | Here is an example of how the cuts were made. Consider the case of a 2cm line target in the Z direction centered at (0,0,0). Closed intervals begin at the end of the target and are 0.1cm long. So the first interval would be [-1.0,-0.9], then the next would be [-0.9, -0.8] and so on until the entire target is covered. The events in the EVENTHB bank were cut so that in any given interval there would be a margin of +/- 1cm to remove any outliers that may cause the histograms to have long tails. | ||
| − | Below are the histograms for the line target in X | + | |
| + | |||
| + | |||
| + | Below are the histograms for the 2cm line target in X | ||
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Revision as of 18:38, 27 July 2016
Vertex Reconstruction studies
Inclusive electron GEMC 2.4 & Coatjava 2.4
Summary
Set all histogram ranges to -6,6 cm and bin sizes of 0.1 cm
Point target X,Y,Z=0 cm
| No Rastering | |
|---|---|
| Vx Difference | 
|
| Vy Difference | 
|
| Vz Difference | 
|
| X Resolution (cm) | 0.2362 +/- 0.0008 |
| Y Resolution(cm) | 0.09809 +/- 0.00033 |
| Z Resolution (cm) | 0.05435 +/- 0.00017 |
These histograms raise some questions. To begin I created a LUND file with 6 GeV incident electrons at 25 degrees in theta and 0 degrees in phi. All of the vertex positions were set to 0. I then ran GEMC 2.4 using the command line ~/src/CLAS/GEMC/source/gemc -USE_GUI=0 -INPUT_GEN_FILE="LUND,No_Raster.LUND" -N=75000 eg12_sol_No_Raster.gcard
which created an output file called eg12_sol_75k_No_Raster.ev. After that the reconstruction command line used was
~/src/CLAS/coatjava-2.4/bin/clas12-reconstruction -i eg12_sol_75k_No_Raster.ev-config GEOM::new=true -config MAG::torus=-1.0 -config MAG::solenoid=1.0 -o eg12_sol_75k_No_Raster_rec.evio -s DCHB:DCTB:EC:FTOF:EB -config DATA::mc=true -config DCTB::useRaster=true
After the reconstruction a root file was created using
~/src/CLAS/evio2root/bin/evio2root eg12_sol_75k_No_Raster_rec.evio eg12_sol_75k_No_Raster_rec.root 75000
A plot was then created to show the X Vertex and Y Vertex Differences
The first question is why is there a shift in the Y Difference. What would make X more centered around 0? The next question is when rastering begins, why do the resolutions in the X Vertices remain unchanged while the resolutions in the Y Vertices change?
Point in 2-D but extended target in 1-D
Two vertex variables are fixed at zero and the third vertex variable is altered
| 2cm X Raster, Y=0,Z=0 | 2 cm Y Raster, X=0,Z=0 | 2 cm Z Raster ,X=0,Y=0 | 6 cm Z Raster ,X=0,Y=0 | |
|---|---|---|---|---|
| Vx Difference |  |
 |
 |
|
| Vy Difference |  |
 |
 |
|
| Vz Difference |  |
 |
 |
|
| X Resolution (cm) | 0.2658 +/- 0.0010 | 0.2531 +/- 0.0009 | 0.2544 +/- 0.0009 | 0.2539 +/- 0.0009 |
| Y Resolution(cm) | 0.1728 +/- 0.0007 | 0.2368 +/- 0.0007 | 0.2644 +/- 0.0007 | 0.6191 +/- 0.0013 |
| Z Resolution (cm) | 0.1792 +/- 0.0006 | 0.1998 +/- 0.0004 | 0.4318 +/- 0.0009 | 1.105 +/- 0.002 |
Extended target -3 < Z < 3 cm
| 1cm X Raster | 1 cm Y Raster | 1 cm X & Y Raster | |
|---|---|---|---|
| X Resolution (cm) | 0.2696 +/- 0.0009 | 0.2588 +/- 0.0009 | 0.2734 +/- 0.0009 |
| Y Resolution (cm) | 0.6234 +/- 0.0014 | 0.6851 +/- 0.0014 | 0.6927 +/- 0.0013 |
| Z Resolution (cm) | 1.136 +/- 0.002 | 1.361 +/- 0.002 | 1.381 +/- 0.003 |
| Generated Vx (cm) |  |
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| Generated Vy (cm) |  |
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| Generated Vz (cm) |  |
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| Reconstructed Vx (cm) |  |
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| Reconstructed Vy (cm) |  |
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| Reconstructed Vz (cm) |  |
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| Vx Difference (cm) |  |
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| Vy Difference (cm) |  |
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| Vz Difference (cm) |  |
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Extended target in Z. Vy shift analysis
All Histograms below were created by simply making the target longer along the Z axis. Each case uses vertex points for X and Y ranging from -1cm to 1cm
| 0.5cm Z Target | 1cm Z Target | 2cm Z Target | 3cm Z Target | 4cm Z Target | 5cm Z Target | |
|---|---|---|---|---|---|---|
| X Resolution (cm) | 0.2705 +/- 0.0010 | 0.2726 +/- 0.0010 | ** | 0.2731 +/- 0.0010 | 0.2702 +/- 0.0009 | 0.2736 +/- 0.0010 |
| Y Resolution (cm) | 0.2041 +/- 0.0010 | 0.2282 +/- 0.0011 | ** | 0.433 +/- 0.002 | 0.5584 +/- 0.0018 | 0.6454 +/- 0.0015 |
| Z Resolution (cm) | 0.28 +/-0.00 | 0.3582 +/- 0.0013 | ** | 0.7927 +/- 0.0023 | 1.034 +/- 0.003 | 1.253 +/-0.003 |
| X Centroid (cm) | 0.0139 +/- 0.001 | 0.0139 +/- 0.00107 | ** | 0.01217 +/- 0.00107 | 0.00991 +/- 0.00104 | 0.009022 +/- 0.00105 |
| Y Centroid (cm) | -0.1893 +/- 0.0011 | -0.2004 +/- 0.0012 | ** | -0.2936 +/- 0.0022 | -0.3648 +/- 0.0027 | -0.3871 +/- 0.0026 |
| Z Centroid (cm) | 0.0928 +/- 0.0014 | 0.06464 +/- 0.0013 | ** | -0.1582 +/- 0.0040 | -0.3016 +/- 0.0053 | -0.486 +/- 0.006 |
| Generated Vx (cm) |  |
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** |  |
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| Generated Vy (cm) |  |
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** |  |
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| Generated Vz (cm) |  |
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** |  |
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| Reconstructed Vx (cm) |  |
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** |  |
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| Reconstructed Vy (cm) |  |
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** |  |
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| Reconstructed Vz (cm) |  |
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** |  |
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| Vx Difference (cm) |  |
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** |  |
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| Vy Difference (cm) |  |
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** |  |
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| Vz Difference (cm) |  |
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** |  |
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|
It would seem that increasing the length of the target in the Z direction has an effect on the resolution of the Y vertex position along with how far the center of the Gaussian peak will shift for the Y vertex differences.
Localized Vertex Resolution Investigation of Line Targets
GEMC was ran to create electrons being produced in a line along certain axes. These include three separate 2cm targets centered at (0,0,0) in the X, Y , and Z directions. The final target is a line along the Z axis centered at (0,0,0) that is 6cm long.
Here is an example of how the cuts were made. Consider the case of a 2cm line target in the Z direction centered at (0,0,0). Closed intervals begin at the end of the target and are 0.1cm long. So the first interval would be [-1.0,-0.9], then the next would be [-0.9, -0.8] and so on until the entire target is covered. The events in the EVENTHB bank were cut so that in any given interval there would be a margin of +/- 1cm to remove any outliers that may cause the histograms to have long tails.
Below are the histograms for the 2cm line target in X
| [-1.0 , -0.9] | [-0.9 , -0.8] | [-0.8 , -0.7] | [-0.7 , -0.6] | [-0.6 , -0.5] | [-0.5 , -0.4] | [-0.4 , -0.3] | |
|---|---|---|---|---|---|---|---|
| Resolution (cm) | 0.2512 +/- 0.0042 | 0.3018 +/- 0.0049 | 0.2873 +/- 0.0049 | 0.2475 +/- 0.0038 | 0.2398 +/- 0.0038 | 0.2203 +/- 0.0035 | 0.2178 +/- 0.0034 |
| Vx Difference |  |
 |
 |
 |
 |
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|
| * | * | * | * | * | * | * | * |
| [-0.3 , -0.2] | [-0.2 , -0.1] | [-0.1 , 0.0] | [0.0 , 0.1] | [0.1 , 0.2] | [0.2 , 0.3] | [0.3 , 0.4] | |
| Resolution (cm) | 0.227 +/- 0.003 | 0.225 +/- 0.003 | 0.2357 +/- 0.0035 | 0.2256 +/- 0.0035 | 0.234 +/- 0.003 | 0.254 +/- 0.004 | 0.3227 +/- 0.0049 |
| Vx Difference |  |
 |
 |
 |
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|
Elastic electron proton GEMC 2.4 & Coatjava 2.4
References
https://clasweb.jlab.org/wiki/index.php/TF_EG12_Vertex#Z_resolution_With_micro-megas