LB RunGroupC Vertex

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Vertex Reconstruction studies

Inclusive electron GEMC 2.4 & Coatjava 2.4

LB_GEMC2.4CJ2.4_Vertex



Summary

Set all histogram ranges to -6,6 cm  and bin sizes of 0.1 cm

Point target X,Y,Z=0 cm

Below are examples of the reconstruction for several line targets as seen in the CED


We should change it to +30,150,210, and 330 degrees so the electron is not going in between two drift chambers but rather into the center, keep 90 and 270.


6cm Z Target, No Rotation 6cm Z Target, 270 Degree Rotation 6cm Z Target, 90 Degree Rotation 2cm Y Target, 30 Degree Rotation 2cm Y Target, 180 Degree Rotation 2cm X Target, 90 Degree Rotation 2cm X Target, 270 Degree Rotation
Ced ZRaster 0DegRot.png 6cm ZTarg 270DegRot CED.png Ced ZRaster 90DegRot.png 2cm YRaster 30DegRot ced.png Ced YRaster 180DegRot.png Ced XRaster 90DegRot.png Ced XRaster 270DegRot.png



The histograms below are using a 6 GeV electron fired at an angles of 25 degrees in theta and 0 degrees in phi.

No Rastering
Vx Difference NoRaster VxDifference sol.png
Vy Difference NoRaster VyDifference sol.png
Vz Difference NoRaster VzDifference sol.png
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

NoRaster Vx YDifference.png

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. A 6 GeV electron was fired at angles of 25 degrees in theta and 0 degrees in phi.

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 1cm XRaster VxDifference sol 75k.png 1cm YRaster VxDifference sol.png 2cm ZRaster VxDifference sol.png 3cm ZRaster VxDifference sol.png
Vy Difference 1cm XRaster VyDifference sol.png YRaster Eventy.png 2cm ZRaster VyDifference sol.png 3cm ZRaster VyDifference sol.png
Vz Difference 1cm XRaster VzDifference sol.png 1cm YRaster VzDifference sol.png 2cm ZRaster VzDifference.png 3cm ZRaster VZDifference sol 75k.png
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

VertREC_9-22-16_table_3ltZgt-3

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

VertREC_9-22-16_table_3ltZgt-3_1gtRlt-1

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. The generated electrons were shot at 25 degrees in theta and 0 degrees in phi at an energy of 6GeV.

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 Y,X=0,Z=0. The electrons were fired with an energy of 6 GeV at 25 degrees in theta at 0 degrees in phi.

2cm YLineTarg 0 Degree Rotation 09/23/16

Below are the histograms for a 2cm target along the Y axis, X = 0 Z = 0. The electrons were fired with an energy of 6 GeV at 25 degrees in theta and 180 degrees in phi.

2cm YLineTarg 180 Degree Rotation 09/23/16

Below are the Histograms for a 2cm long target in the X Direction with a 6GeV electron fired at 25 degrees in theta and 90 degrees in phi

GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x 90DegRot.png GenPart.y 90DegRot.png GenPart.z 90DegRot.png Event.x 90DegRot.png Event.y 90DegRot.png Event.z 90DegRot.png


Interval Resolution (cm) Vx Difference *** Interval Resolution (cm) Vx Difference
[-1.0,-0.9] 0.1341 +/- 0.0140 VxDiff--1.0,-0.9-.png *** [0.9,1.0] 0.01572 +/- 0.0002 VxDiff-0.9,1.0-.png
[-0.9,-0.8] 0.1304 +/- 0.0051 VxDiff--0.9,-0.8-.png *** [0.8,0.9] 0.01844 +/- 0.00031 VxDiff-0.8,0.9-.png
[-0.8,-0.7] 0.1182 +/- 0.0036 VxDiff--0.8,-0.7-.png *** [0.7,0.8] 0.01722 +/- 0.0028 VxDiff-0.7,0.8-.png
[-0.7,-0.6] 0.09062 +/- 0.0031 VxDiff--0.7,-0.6-.png *** [0.6,0.7] 0.02386 +/- 0.00088 VxDiff-0.6,0.7-.png
[-0.6,-0.5] 0.06816 +/- 0.00191 VxDiff--0.6,-0.5-.png *** [0.5,0.6] 0.024 +/- 0.001 VxDiff-0.5,0.6-.png
[-0.5,-0.4] n/a VxDiff--0.5,-0.4-.png *** [0.4,0.5] 0.04406 +/- 0.00182 VxDiff-0.4,0.5-.png
[-0.4,-0.3] 0.0635 +/- 0.0013 VxDiff--0.4,-0.3-.png *** [0.3,0.4] 0.04517 +/- 0.00118 VxDiff-0.3,0.4-.png
[-0.3,-0.2] 0.0618 +/- 0.0012 VxDiff--0.3,-0.2-.png *** [0.2,0.3] 0.04722 +/- 0.00107 VxDiff-0.2,0.3-.png
[-0.2,-0.1] 0.07473 +/- 0.00178 VxDiff--0.2,-0.1-.png *** [0.1,0.2] 0.05667 +/- 0.00106 VxDiff-0.1,0.2-.png
[-0.1,0.0] 0.08787 +/- 0.00132 VxDiff--0.1,0.0-.png *** [0.0,0.1] 0.08356 +/- 0.00159 VxDiff-0.0,0.1-.png


Below are the Vx Differences using a 2cm target in X with incident 6 GeV electrons at 25 degrees in theta and 270 degrees in phi


GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x 270DegRot.png GenPart.y 270DegRot.png GenPart.z 270DegRot.png Event.x 270DegRot.png Event.y 270DegRot.png Event.z 270DegRot.png


Interval Resolution (cm) Vx Difference *** Interval Resolution (cm) Vx Difference
[-1.0,-0.9] 0.01571 +/- 0.0002 VxDiff--1.0,-0.9- 270Deg.png *** [0.9,1.0] 0.1257 +/- 0.0100 VxDiff-0.9,1.0- 270Deg.png
[-0.9,-0.8] 0.0163 +/- 0.0003 VxDiff--0.9,-0.8- 270Deg.png *** [0.8,0.9] 0.112 +/- 0.004 VxDiff-0.8,0.9- 270Deg.png
[-0.8,-0.7] 0.01821 +/- 0.0003 VxDiff--0.8,-0.7- 270Deg.png *** [0.7,0.8] 0.1162 +/- 0.0034 VxDiff-0.7,0.8- 270Deg.png
[-0.7,-0.6] 0.03065 +/- .000163 VxDiff--0.7,-0.6- 270Deg.png *** [0.6,0.7] 0.08958 +/- 0.00316 VxDiff-0.6,0.7- 270Deg.png
[-0.6,-0.5] 0.02109 +/- 0.00217 VxDiff--0.6,-0.5- 270Deg.png *** [0.5,0.6] 0.07347 +/- 0.00210 VxDiff-0.5,0.6- 270Deg.png
[-0.5,-0.4] 0.03772 +/- 0.00133 VxDiff--0.5,-0.4- 270Deg.png *** [0.4,0.5] 0.07271 +/- 0.00159 VxDiff-0.4,0.5- 270Deg.png
[-0.4,-0.3] 0.04817 +/- 0.00125 VxDiff--0.4,-0.3- 270Deg.png *** [0.3,0.4] 0.06196 +/- 0.00146 VxDiff-0.3,0.4- 270Deg.png
[-0.3,-0.2] 0.05154 +/- 0.00113 VxDiff--0.3,-0.2- 270Deg.png *** [0.2,0.3] 0.06087 +/- 0.00114 VxDiff-0.2,0.3- 270Deg.png
[-0.2,-0.1] 0.05677 +/- 0.00106 VxDiff--0.2,-0.1- 270Deg.png *** [0.1,0.2] 0.07298 +/- 0.00149 VxDiff-0.1,0.2- 270Deg.png
[-0.1,0.0] 0.08348 +/- 0.00144 VxDiff--0.1,0.0- 270Deg.png *** [0.0,0.1] 0.09017 +/- 0.00128 VxDiff-0.0,0.1- 270Deg.png




Below are the histograms for a 6cm target in the Z direction using a 6 GeV electron fired at 25 degrees in theta and 0 degrees in phi.


GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x 6cmZTarg NoRot.png GenPart.y 6cmZTarg NoRot.png GenPart.z 6cmZTarg NoRot.png Event.x 6cmZTarg NoRot.png Event.y 6cmZTarg NoRot.png Event.z 6cmZTarg NoRot.png


Interval Resolution (cm) Vz Difference *** Interval Resolution (cm) Vz Difference
[-3.0,-2.5] 0.1427 +/- 0.0009 VzDiff--3.0,-2.5- NoRot.png *** [2.5,3.0] 0.1467 +/- 0.0008 VzDiff-2.5,3.0- NoRot.png
[-2.5,-2.0] 0.1412 +/- 0.0008 VzDiff--2.5,-2.0- NoRot.png *** [2.0,2.5] 0.1419 +/- 0.0009 VzDiff-2.0,2.5- NoRot.png
[-2.0,-1.5] 0.1365 +/- 0.0007 VzDiff--2.0,-1.5- NoRot.png *** [1.5,2.0] 0.1372 +/- 0.0008 VzDiff-1.5,2.0- NoRot.png
[-1.5,-1.0] 0.1439 +/- 0.0008 VzDiff--1.5,-1.0- NoRot.png *** [1.0,1.5] 0.1394 +/- 0.0008 VzDiff-1.0,1.5- NoRot.png
[-1.0,-0.5] 0.1429 +/- 0.0008 VzDiff--1.0,-0.5- NoRot.png *** [0.5,1.0] 0.1584 +/- 0.0010 VzDiff-0.5,1.0- NoRot.png
[-0.5,0.0] 0.1332 +/- 0.0007 VzDiff--0.5,0.0- NoRot.png *** [0.0,0.5] 0.1378 +/- 0.0009 VzDiff-0.0,0.5- NoRot.png



Below are the histograms for a 6cm target in the Z direction using a 6 GeV electron fired at 25 degrees in theta and 90 degrees in phi.


GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x 90DegRot 6cmZTarg.png GenPart.y 90DegRot 6cmZTarg.png GenPart.z 90DegRot 6cmZTarg.png Event.x 90DegRot 6cmZTarg.png Event.y 90DegRot 6cmZTarg.png Event.z 90DegRot 6cmZTarg.png


Interval Resolution (cm) Vz Difference *** Interval Resolution (cm) Vz Difference
[-3.0,-2.5] 0.1192 +/- 0.0005 VzDiff--3.0,-2.5- 90DegRot.png *** [2.5,3.0] 0.1211 +/- 0.0005 VzDiff-2.5,3.0- 90DegRot.png
[-2.5,-2.0] 0.1205 +/- 0.0005 VzDiff--2.5,-2.0- 90DegRot.png *** [2.0,2.5] 0.1251 +/- 0.0005 VzDiff-2.0,2.5- 90DegRot.png
[-2.0,-1.5] 0.122 +/- 0.001 VzDiff--2.0,-1.5- 90DegRot.png *** [1.5,2.0] 0.1312 +/- 0.0006 VzDiff-1.5,2.0- 90DegRot.png
[-1.5,-1.0] 0.1249 +/- 0.0006 VzDiff--1.5,-1.0- 90DegRot.png *** [1.0,1.5] 0.1233 +/- 0.0005 VzDiff-1.0,1.5- 90DegRot.png
[-1.0,-0.5] 0.1278 +/- 0.0006 VzDiff--1.0,-0.5- 90DegRot.png *** [0.5,1.0] 0.1254 +/- 0.0005 VzDiff-0.5,1.0- 90DegRot.png
[-0.5,0.0] 0.1289 +/- 0.0006 VzDiff--0.5,.0.0- 90DegRot.png *** [0.0,0.5] 0.1237 +/- 0.0005 VzDiff-0.0,0.5- 90DegRot.png



Below are the histograms for a 6 GeV electron fired at angles 25 degrees in theta and 270 degrees in phi. The target was 6cm in the Z direction.

GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x 6cm ZTarg 270DegRot.png GenPart.y 6cm ZTarg 270DegRot.png GenPart.z 6cm ZTarg 270DegRot.png Event.x 6cm ZTarg 270Rot.png Event.y 6cm ZTarg 270DegRot.png Event.z 6cm ZTarg 270DegRot.png


Interval Resolution (cm) Vz Difference *** Interval Resolution (cm) Vz Difference
[-3.0,-2.5] 0.1171 +/- 0.0008 VzDiff--3.0,-2.5- 270DegRot.png *** [2.5,3.0] 0.1186 +/- 0.0008 VzDiff-2.5,3.0- 270DegRot.png
[-2.5,-2.0] 0.1162 +/- 0.0008 VzDiff--2.5,-2.0- 270DegRot.png *** [2.0,2.5] 0.1226 +/- 0.0009 VzDiff-2.0,2.5- 270DegRot.png
[-2.0,-1.5] 0.1207 +/- 0.0009 VzDiff--2.0,-1.5- 270DegRot.png *** [1.5,2.0] 0.1317 +/- 0.0010 VzDiff-1.5,2.0- 270DegRot.png
[-1.5,-1.0] 0.1294 +/- 0.0010 VzDiff--1.5,-1.0- 270DegRot.png *** [1.0,1.5] 0.1239 +/- 0.0009 VzDiff-1.0,1.5- 270DegRot.png
[-1.0,-0.5] 0.131 +/- 0.001 VzDiff--1.0,-0.5- 270DegRot.png *** [0.5,1.0] 0.1256 +/- 0.0009 VzDiff-0.5,1.0- 270DegRot.png
[-0.5,0.0] 0.131 +/- 0.001 VzDiff--0.5,0.0- 270DegRot.png *** [0.0,0.5] 0.1261 +/- 0.0010 VzDiff-0.0,0.5- 270DegRot.png



Below are the histograms for a 6 GeV electron fired at 25 degrees in theta and 0 degrees in phi. The target is 2cm long on the Y axis.

GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x Local Vert.png GenPart.y Local Vert.png GenPart.z Local Vert.png Event.x Local Vert.png Event.y Local Vert.png Event.z Local Vert.png


Interval Resolution (cm) Vy Difference *** Interval Resolution (cm) Vy Difference
[-1.0,-0.9] 0.09406 +/- 0.00128 VyDiff--1.0,-0.9-.png *** [0.9,1.0] 0.1001 +/- 0.0016 VyDiff-0.9,1.0-.png
[-0.9,-0.8] 0.0868 +/- 0.0013 VyDiff--0.9,-0.8-.png *** [0.8,0.9] 0.1221 +/- 0.0018 VyDiff-0.8,0.9-.png
[-0.8,-0.7] 0.08961 +/- 0.00128 VyDiff--0.8,-0.7-.png *** [0.7,0.8] 0.1144 +/- 0.0017 VyDiff-0.7,0.8-.png
[-0.7,-0.6] 0.09853 +/- 0.00148 VyDiff--0.7,-0.6-.png *** [0.6,0.7] 0.169 +/- 0.003 VyDiff-0.6,0.7-.png
[-0.6,-0.5] 0.1038 +/- 0.0016 VyDiff--0.6,-0.5-.png *** [0.5,0.6] 0.171 +/- 0.003 VyDiff-0.5,0.6-.png
[-0.5,-0.4] 0.1202 +/- 0.0018 VyDiff--0.5,-0.4-.png *** [0.4,0.5] 0.1105 +/- 0.0016 VyDiff-0.4,0.5-.png
[-0.4,-0.3] 0.1755 +/- 0.0026 VyDiff--0.4,-0.3-.png *** [0.3,0.4] 0.09508 +/- 0.00137 VyDiff-0.3,0.4-.png
[-0.3,-0.2] 0.1847 +/- 0.0028 VyDiff--0.3,-0.2-.png *** [0.2,0.3] 0.09065 +/- 0.0140 VyDiff-0.2,0.3-.png
[-0.2,-0.1] 0.1255 +/- 0.0019 VyDiff--0.2,-0.1-.png *** [0.1,0.2] 0.093002 +/- 0.0013 VyDiff-0.1,0.2-.png
[-0.1,0.0] 0.09663 +/- 0.00160 VyDiff--0.1,0.0-.png *** [0.0,0.1] 0.09008 +/- 0.0012 VyDiff-0.0,0.1-.png


Below are the histograms for a 2cm target along the Y axis, X = 0 Z = 0. The electrons were fired with an energy of 6 GeV at 25 degrees in theta and 30 degrees in phi.

GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x 2cmYTarg 30DegRot.png GenPart.y 2cmYTarg 30DegRot.png GenPart.z 2cmYTarg 30DegRot.png Event.x 2cmYTarg 30DegRot.png Event.y 2cmYTarg 30DegRot.png Event.z 2cmYTarg 30DegRot.png


Interval Resolution (cm) Vy Difference *** Interval Resolution (cm) Vy Difference
[-1.0,-0.9] 0.069 +/- 0.002 VyDiff--1.0,-0.9- 30DegRot.png *** [0.9,1.0] 0.04936 +/- 0.00068 VyDiff-0.9,1.0- 30DegRot.png
[-0.9,-0.8] 0.08185 +/- 0.00218 VyDiff--0.9,-0.8- 30DegRot.png *** [0.8,0.9] 0.05797 +/- 0.00094 VyDiff-0.8,0.9- 30DegRot.png
[-0.8,-0.7] 0.08764 +/- 0.00212 VyDiff--0.8,-0.7- 30DegRot.png *** [0.7,0.8] 0.05896 +/- 0.00086 VyDiff-0.7,0.8- 30DegRot.png
[-0.7,-0.6] 0.09158 +/- 0.00258 VyDiff--0.7,-0.6- 30DegRot.png *** [0.6,0.7] 0.05895 +/- 0.00091 VyDiff-0.6,0.7- 30DegRot.png
[-0.6,-0.5] 0.07913 +/- 0.00166 VyDiff--0.6,-0.5- 30DegRot.png *** [0.5,0.6] 0.05943 +/- 0.00096 VyDiff-0.5,0.6- 30DegRot.png
[-0.5,-0.4] 0.0774 +/- 0.0014 VyDiff--0.5,-0.4- 30DegRot.png *** [0.4,0.5] 0.06227 +/- 0.00118 VyDiff-0.4,0.5- 30DegRot.png
[-0.4,-0.3] 0.07978 +/- 0.00157 VyDiff--0.4,-0.3- 30DegRot.png *** [0.3,0.4] 0.08115 +/- 0.00186 VyDiff-0.3,0.4- 30DegRot.png
[-0.3,-0.2] 0.08193 +/- 0.00235 VyDiff--0.3,-0.2- 30DegRot.png *** [0.2,0.3] 0.01028 +/- 0.0029 VyDiff-0.2,0.3- 30DegRot.png
[-0.2,-0.1] 0.1812 +/- 0.0025 VyDiff--0.2,-0.1- 30DegRot.png *** [0.1,0.2] 0.136 +/- 0.003 VyDiff-0.1,0.2- 30DegRot.png
[-0.1,0.0] 0.1503 +/- 0.0021 VyDiff--0.1,0.0- 30DegRot.png *** [0.0,0.1] 0.2052 +/- 0.0033 VyDiff-0.0,0.1- 30DegRot.png



Below are the histograms for a 2cm Y target with an incident electron energy of 6 GeV. The angles were theta = 25 degrees and phi = 210 degrees


GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x YTarg 210DegRot.png GenPart.y YTarg 210DegRot.png GenPart.z YTarg 210DegRot.png Event.x YTarg 210DegRot.png Event.y YTarg 210DegRot.png Event.z YTarg 210DegRot.png


Interval Resolution (cm) Vy Difference *** Interval Resolution (cm) Vy Difference
[-1.0,-0.9] 0.04815 +/- 0.00067 VyDiff--1.0,-0.9- YTarg 210DegRot.png *** [0.9,1.0] 0.07184 +/- 0.00181 VyDiff-0.9,1.0- YTarg 210DegRot.png
[-0.9,-0.8] 0.05734 +/- 0.00091 VyDiff--0.9,-0.8- YTarg 210DegRot.png *** [0.8,0.9] 0.08837 +/- 0.00268 VyDiff-0.8,0.9- YTarg 210DegRot.png
[-0.8,-0.7] 0.05873 +/- 0.00085 VyDiff--0.8,-0.7- YTarg 210DegRot.png *** [0.7,0.8] 0.0982 +/- 0.0024 VyDiff-0.7,0.8- YTarg 210DegRot.png
[-0.7,-0.6] 0.05868 +/- 0.00089 VyDiff--0.7,-0.6- YTarg 210DegRot.png *** [0.6,0.7] 0.09622 +/- 0.00305 VyDiff-0.6,0.7- YTarg 210DegRot.png
[-0.6,-0.5] 0.05962 +/- 0.00098 VyDiff--0.6,-0.5- YTarg 210DegRot.png *** [0.5,0.6] 0.08028 +/- 0.00156 VyDiff-0.5,0.6- YTarg 210DegRot.png
[-0.5,-0.4] 0.0645 +/- 0.0014 VyDiff--0.5,-0.4- YTarg 210DegRot.png *** [0.4,0.5] 0.07917 +/- 0.00163 VyDiff-0.4,0.5- YTarg 210DegRot.png
[-0.4,-0.3] 0.0861 +/- 0.0020 VyDiff--0.4,-0.3- YTarg 210DegRot.png *** [0.3,0.4] 0.08056 +/- 0.00159 VyDiff-0.3,0.4- YTarg 210DegRot.png
[-0.3,-0.2] 0.1003 +/- 0.0024 VyDiff--0.3,-0.2- YTarg 210DegRot.png *** [0.2,0.3] 0.08939 +/- 0.00201 VyDiff-0.2,0.3- YTarg 210DegRot.png
[-0.2,-0.1] 0.1305 +/- 0.0024 VyDiff--0.2,-0.1- YTarg 210DegRot.png *** [0.1,0.2] 0.186 +/- 0.003 VyDiff-0.1,0.2- YTarg 210DegRot.png
[-0.1,0.0] 0.2042 +/- 0.0033 VyDiff--0.1,0.0- YTarg 210DegRot.png *** [0.0,0.1] 0.1476 +/- 0.0021 VyDiff-0.0,0.1- YTarg 210DegRot.png


Localized Vertex Resolution Investigation of 2 Dimensional Targets

The histograms below were created using a 6 GeV electron fired at 25 degrees in theta and 30 degrees in phi. To make the cuts I simply made circles of increasing radius centered at the origin. I used 0.1cm increments to make the 10 histograms for each vertex position.

Below are the Vx and Vy Differences for a 2cm XY target, Z=0.

GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x XYTarg 30DegRot.png GenPart.y XYTarg 30DegRot.png GenPart.z XYTarg 30DegRot.png Event.x XYTarg 30DegRot.png Event.y XYTarg 30DegRot.png Event.z XYTarg 30DegRot.png


Radius (cm) Resolution (cm) Vx Difference *** Radius (cm) Resolution (cm) Vx Difference
0.1 0.2309 +/- 0.0091 VxDiff R=0.1 XYTarg 30DegRot.png *** 0.6 0.259 +/- 0.001 VxDiff R=0.6 XYTarg 30DegRot.png
0.2 0.235 +/- 0.004 VxDiff R=0.2 XYTarg 30DegRot.png *** 0.7 0.2769 +/- 0.0014 VxDiff R=0.7 XYTarg 30DegRot.png
0.3 0.2242 +/- 0.0028 VxDiff R=0.3 XYTarg 30.png *** 0.8 0.2927 +/- 0.0013 VxDiff R=0.8 XYTarg 30DegRot.png
0.4 0.2272 +/- 0.0020 VxDiff R=0.4 XYTarg 30DegRot.png *** 0.9 0.3074 +/- 0.0013 VxDiff R=0.9 XYTarg 30DegRot.png
0.5 0.2422 +/- 0.0016 VxDiff R=0.5 XYTarg 30DegRot.png *** 1.0 0.3237 +/- 0.0014 VxDiff R=1.0 XYTarg 30DegRot.png


Radius (cm) Resolution (cm) VyDifference *** Radius (cm) Resolution (cm) Vy Difference
0.1 0.162 +/- 0.006 VyDiff R=0.1 XYTarg 30DegRot.png *** 0.6 0.1733 +/- 0.0020 VyDiff R=0.6 XYTarg 30DegRot.png
0.2 0.1798 +/- 0.0031 VyDiff R=0.2 XYTarg 30DegRot.png *** 0.7 0.1661 +/- 0.0017 VyDiff R=0.7 XYTarg 30DegRot.png
0.3 0.1947 +/- 0.0028 VyDiff R=0.3 XYTarg 30DegRot.png *** 0.8 0.1615 +/- 0.0015 VyDiff R=0.8 XYTarg 30DegRot.png
0.4 0.1959 +/- 0.0033 VyDiff R=0.4 XYTarg 30DegRot.png *** 0.9 0.1578 +/- 0.0013 VyDiff R=0.9 XYTarg 30DegRot.png
0.5 0.1861 +/- 0.0027 VyDiff R=0.5 XYTarg 30DegRot.png *** 1.0 0.4832 +/- 0.0035 VyDiff R=1.0 XYTarg 30DegRot.png


Below are the Vy and Vz differences for a 2cm target in Y and Z, X=0. The electrons were fired with an energy of 6 GeV and angles of 25 degrees in theta and 30 degrees in phi.


GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x 2cmYZTarg 30DegRot.png GenPart.y 2cmYZTarg 30DegRot.png GenPart.z 2cmYZTarg 30DegRot.png Event.x 2cmYZTarg 30DegRot.png Event.y 2cmYZTarg 30DegRot.png Event.z 2cmYZTarg 30DegRot.png


Radius (cm) Resolution (cm) Vy Difference *** Radius (cm) Resolution (cm) Vy Difference
0.1 0.1722 +/- 0.0065 VyDiff R=0.1 YZTarg 30DegRot.png *** 0.6 0.1806 +/- 0.0017 VyDiff R=0.6 YZTarg 30DegRot.png
0.2 0.1773 +/- 0.0037 VyDiff R=0.2 YZTarg 30DegRot.png *** 0.7 0.1868 +/- 0.0015 VyDiff R=0.7 YZTarg 30DegRot.png
0.3 0.1781 +/- 0.0031 VyDiff R=0.3 YZTarg 30DegRot.png *** 0.8 0.1974 +/- 0.0014 VyDiff R=0.8 YZTarg 30DegRot.png
0.4 0.1734 +/- 0.0024 VyDiff R=0.4 YZTarg 30DegRot.png *** 0.9 0.2028 +/- 0.0013 VyDiff R=0.9 YZTarg 30DegRot.png
0.5 0.1764 +/- 0.0020 VyDiff R=0.5 YZTarg 30DegRot.png *** 1.0 0.221 +/- 0.001 VyDiff R=1.0 YZTarg 30DegRot.png


Radius (cm) Resolution (cm) Vz Difference *** Radius (cm) Resolution (cm) Vz Difference
0.1 0.07095 +/- 0.00239 VzDiff R=0.1 YZTarg 30DegRot.png *** 0.6 0.261 +/- 0.001 VzDiff R=0.6 YZTarg 30DegRot.png
0.2 0.1063 +/- 0.0015 VzDiff R=0.2 YZTarg 30DegRot.png *** 0.7 0.2874 +/- 0.0010 VzDiff R=0.7 YZTarg 30DegRot.png
0.3 0.146 +/- 0.001 VzDiff R=0.3 YZTarg 30DegRot.png *** 0.8 0.3232 +/- 0.0011 VzDiff R=0.8 YZTarg 30DegRot.png
0.4 0.1833 +/- 0.0012 VzDiff R=0.4 YZTarg 30DegRot.png *** 0.9 0.3528 +/- 0.0010 VzDiff R=0.9 YZTarg 30DegRot.png
0.5 0.2222 +/- 0.0012 VzDiff R=0.5 YZTarg 30DegRot.png *** 1.0 0.3847 +/- 0.0010 VzDiff R=1.0 YZTarg 30DegRot.png


Below are the Vx and Vz differences for a 2cm XZ target, Y = 0. The electrons were fired with an energy of 6 GeV at angles theta = 25 degrees and phi = 30 degrees.


GenPart.x GenPart.y GenPart.z Event.x Event.y Event.z
GenPart.x 2cmXZTarg 30DegRot.png GenPart.y 2cmXZTarg 30DegRot.png GenPart.z 2cmXZTarg 30DegRot.png Event.x 2cmXZTarg 30DegRot.png Event.y 2cmXZTarg 30DegRot.png Event.z 2cmXZTarg 30DegRot.png


Radius (cm) Resolution (cm) Vz Difference *** Radius (cm) Resolution (cm) Vz Difference
0.1 0.06193 +/- 0.00199 VzDiff R=0.1 XZTarg 30DegRot.png *** 0.6 0.2495 +/- 0.0012 VzDiff R=0.6 XZTarg 30DegRot.png
0.2 0.1059 +/- 0.0015 VzDiff R=0.2 XZTarg 30DegRot.png *** 0.7 0.2862 +/- 0.0011 VzDiff R=0.7 XZTarg 30DegRot.png
0.3 0.1412 +/- 0.0013 VzDiff R=0.3 XZTarg 30DegRot.png *** 0.8 0.3172 +/- 0.001 VzDiff R=0.8 XZTarg 30DegRot.png
0.4 0.1704 +/- 0.0012 VzDiff R=0.4 XZTarg 30DegRot.png *** 0.9 0.3512 +/- 0.0012 VzDiff R=0.9 XZTarg 30DegRot.png
0.5 0.2183 +/- 0.0013 VzDiff R=0.5 XZTarg 30DegRot.png *** 1.0 0.4066 +/- 0.0013 VzDiff R=1.0 XZTarg 30DegRot.png



Radius (cm) Resolution (cm) Vx Difference *** Radius (cm) Resolution (cm) Vx Difference
0.1 0.2125 +/- 0.0090 VxDiff R=0.1 XZTarg 30DegRot.png *** 0.6 0.2365 +/- 0.0016 VxDiff R=0.6 XZTarg 30DegRot.png
0.2 0.2392 +/- 0.0044 VxDiff R=0.2 XZTarg 30DegRot.png *** 0.7 0.2307 +/- 0.0013 VxDiff R=0.7 XZTarg 30DegRot.png
0.3 0.251 +/- 0.003 VxDiff R=0.3 XZTarg 30DegRot.png *** 0.8 0.2251 +/- 0.0012 VxDiff R=0.8 XZTarg 30DegRot.png
0.4 0.2494 +/- 0.0023 VxDiff R=0.4 XZTarg 30DegRot.png *** 0.9 0.222 +/- 0.001 VxDiff R=0.9 XZTarg 30DegRot.png
0.5 0.2439 +/- 0.0019 VxDiff R=0.5 XZTarg 30DegRot.png *** 1.0 0.2193 +/- 0.0010 VxDiff R=1.0 XZTarg 30DegRot.png



Localized Vertex Resolution of 3 Dimensional targets

For the plots below, a 6 GeV electron was fired at angles 25 degrees in theta and 30 degrees in phi. The target has an XY radius of 1cm and a length in the Z direction of 6cm. Setting GenPart.z = 0cm, the resolution was investigated as a function of the target's XY radius along with a table for the values.

In this section, concentric rings with a thickness of 0.1cm were created within the target. For example these plots would include a ring centered at x=y=z=0 and include all GenPart.x and GenPart.y from (0.0 cm, 0.1 cm), then another ring would include all Genpart.x and GenPart.y events from (0.1 cm, 0.2 cm) and so on until we reach the edge of the target.

AnnularRad vs Sigma z=0.png

clas12->Draw("Event.z >> (100,-5,5)","sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)<0.95 && sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)>0.85");

R (cm) 0.05 +/- 0.05 0.15 +/- 0.05 0.25 +/- 0.05 0.35 +/- 0.05 0.45 +/- 0.05 0.55 +/- 0.05 0.65 +/- 0.05 0.75 +/- 0.05 0.85 +/- 0.05 0.95 +/- 0.05
Width (cm) 0.05094 +/- 0.0019 0.07812 +/- 0.0018 0.3688 +/- 0.0063 0.5231 +/- 0.0077 0.718 +/- 0.012 0.7987 +/- 0.0092 0.8709 +/- 0.0085 1.038 +/- 0.01 1.183 +/- 0.012 1.296 +/- 0.013


For the next set of plots, the GEMC simulations had the same energy and angles as above. To construct scatter plots, similar annular cuts in the radius were made (similar to above), but this time the thickness of each ring was 0.2 cm (to ensure enough events were present). In addition, the target will become extended in Z. Cuts were made in Z by restricting GenPart.z to be within a range of certain values. Each "washer" shape has a thickness of 0.5 cm in the Z direction. Histograms were created using the following command line as an example

clas12->Draw("GenPart.z - Event.z >> (100,-5,5)","sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)<0.2 && sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)>0.0 && GenPart.z > 0.0 && GenPart.z < 0.5");


Below is a plot and a table for the Radius vs. Sigma of GenPart.z - Event.z for several cuts in Z. For the plot each Radius is centered at the point plotted with a width of +/- 0.1 cm.

Radius vs sigma pos half.png

Z = (0.0 cm, 0.5 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1548 +/- 0.0106 0.1825 +/- 0.0086 0.2167 +/- 0.0078 0.26 +/- 0.01 0.2774 +/- 0.0075
*******************************************
Z = (0.5 cm, 1.0 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1672 +/- 0.0109 0.1636 +/- 0.0064 0.2277 +/- 0.0075 0.3203 +/- 0.0107 0.3287 +/- 0.0082
*******************************************
Z = (1.0 cm, 1.5 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1282 +/- 0.0068 0.1551 +/- 0.0042 0.1842 +/- 0.0052 0.2172 +/- 0.0069 0.2587 +/- 0.0072
*******************************************
Z = (1.5 cm, 2.0 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1264 +/- 0.0071 0.1558 +/- 0.0042 0.1795 +/- 0.0043 0.2034 +/- 0.0049 0.2391 +/- 0.0055
*******************************************
Z = (2.0 cm, 2.5 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1723 +/- 0.0120 0.1519 +/- 0.0038 0.1896 +/- 0.0048 0.2033 +/- 0.0043 0.2361 +/- 0.0048
*******************************************
Z = (2.5 cm, 3.0 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1273 +/- 0.0054 0.1665 +/- 0.0057 0.1936 +/- 0.0041 0.2143 +/- 0.0042 0.2337 +/- 0.0050


Here is where the problem of a bimodal distribution become relevant as seen below in the histogram.

GenPart.z - Event.z bimodal example.png

For now I will simply fit the larger peak to hopefully get rid of the muddling of the resolution, but this must be noted and investigated further later.

Below is the plot and the table for the negative half of the target.

Radius vs sigma neg half.png


Z = (-0.5 cm, 0.0 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1666 +/- 0.0128 0.1722 +/- 0.0078 0.1983 +/- 0.0067 0.2193 +/- 0.0060 0.2554 +/- 0.0068
*******************************************
Z = (-1.0 cm, -0.5 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1435 +/- 0.0069 0.1708 +/- 0.0068 0.2008 +/- 0.0069 0.2094 +/- 0.0058 0.2544 +/- 0.0065
*******************************************
Z = (-1.5 cm, -1.0 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1418 +/- 0.0073 0.1551 +/- 0.0047 0.2342 +/- 0.0092 0.2286 +/- 0.0066 0.2459 +/- 0.0066
*******************************************
Z = (-2.0 cm, -1.5 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1562 +/- 0.0091 0.1628 +/- 0.0045 0.2115 +/- 0.0076 0.2061 +/- 0.0056 0.2335 +/- 0.0077
*******************************************
Z = (-2.5 cm, -2.0 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1312 +/- 0.0059 0.1517 +/- 0.0040 0.2061 +/- 0.0049 0.257 +/- 0.008 0.2484 +/- 0.005
*******************************************
Z = (-3.0 cm, -2.5 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1339 +/- 0.0065 0.1539 +/- 0.0038 0.202 +/- 0.004 0.2537 +/- 0.0061 0.2517 +/- 0.0062


It would seem that the bimodal distribution is having an effect on the results. It is counterintuitive that the resolution would get better the farther away from zero the events are. To begin investigating this, I made a Radius vs. Sigma plot for several values of Z. Here are some sample command lines in ROOT to get the width of the Gaussian peak.


clas12->Draw("Event.z >> (100,-5,5)","sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)<1.0 && sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)>0.8 && GenPart.z = 0");

clas12->Draw("GenPart.z - Event.z >> (100,-5,5)","sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)<0.6 && sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)>0.4 && GenPart.z > 0.1 && GenPart.z < 0.5");

clas12->Draw("GenPart.z - Event.z >> (100,-5,5)","sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)<0.6 && sqrt(GenPart.x*GenPart.x+GenPart.y*GenPart.y)>0.4 && GenPart.z > 0.5 && GenPart.z < 1.0");



Radius vs Sigma Bimodal Investigation.png


Z = 0.0 cm
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.2873 +/- 0.0035 0.3457 +/- 0.0026 0.4045 +/- 0.0026 0.4466 +/- 0.0026 0.5359 +/- 0.0033
*******************************************
Z = (0.1 cm, 0.5 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.141 +/- 0.010 0.1651 +/- 0.0086 0.1991 +/- 0.0082 0.2572 +/- 0.0093 0.2676 +/- 0.0081
*******************************************
Z = (0.5 cm, 1.0 cm)
R (cm) 0.1 0.3 0.5 0.7 0.9
Sigma (cm) 0.1672 +/- 0.0109 0.1636 +/- 0.0064 0.2277 +/- 0.0075 0.3203 +/- 0.0107 0.3287 +/- 0.0082


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

EG12#Vertex_Studies