Difference between revisions of "DV MollerTrackRecon"

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From a GEMC run WITH the Solenoid ced is used to obtain the information from the eg12_rec.ev file.   
 
From a GEMC run WITH the Solenoid ced is used to obtain the information from the eg12_rec.ev file.   
  
    [[File:Event29.png]]
+
      [[File:Event29.png]]
  
  
 
We take the phi angle from the Simulated Event momentum as the initial phi angle.  The obtain the final phi angle, we can look at the final position of the electron with in the drift chambers.  Examining the position from Timer Based Tracking, we can see that after rotations about first the y-axis, then the z-axis transforms from the detector frame of reference to the lab frame of reference.  This shows that the final position within the drift chambers is equal to the eTBTracking position.  Normalizing the position with respect to the vertex location for the even, we can use the angle phi that this position makes with respect to origin to compare to the original phi from the momentum term to see if phi has shifted.
 
We take the phi angle from the Simulated Event momentum as the initial phi angle.  The obtain the final phi angle, we can look at the final position of the electron with in the drift chambers.  Examining the position from Timer Based Tracking, we can see that after rotations about first the y-axis, then the z-axis transforms from the detector frame of reference to the lab frame of reference.  This shows that the final position within the drift chambers is equal to the eTBTracking position.  Normalizing the position with respect to the vertex location for the even, we can use the angle phi that this position makes with respect to origin to compare to the original phi from the momentum term to see if phi has shifted.
  
[[File:Detector_position.png]]
+
      [[File:Detector_position.png]]
  
 
=[[File:EulerAngles.png]]=
 
=[[File:EulerAngles.png]]=

Revision as of 20:35, 22 October 2015

Moller events WITH Solenoid

LUND file with Moller events (with origin of coordinates occurring at each event)

2       1       1       1       1       0       0.000563654     3.53715 0       6.2002
1 -1 1 11 0 0 0.69 -2.4999 10993.7998 10993.80 0.000511 0 0 0
2 -1 1 11 0 0 -0.69 2.4999 6.5852 7.08 0.000511 0 0 0


From a GEMC run WITH the Solenoid ced is used to obtain the information from the eg12_rec.ev file.

      Event29.png


We take the phi angle from the Simulated Event momentum as the initial phi angle. The obtain the final phi angle, we can look at the final position of the electron with in the drift chambers. Examining the position from Timer Based Tracking, we can see that after rotations about first the y-axis, then the z-axis transforms from the detector frame of reference to the lab frame of reference. This shows that the final position within the drift chambers is equal to the eTBTracking position. Normalizing the position with respect to the vertex location for the even, we can use the angle phi that this position makes with respect to origin to compare to the original phi from the momentum term to see if phi has shifted.

     Detector position.png

EulerAngles.png

Transformation Matrix

[math]\left( \begin{array}{ccc} \cos (\theta ) & 0 & -\sin (\theta ) \\ 0 & 1 & 0 \\ \sin (\theta ) & 0 & \cos (\theta ) \\ \end{array} \right).\left( \begin{array}{c} x \\ y \\ z \\ \end{array} \right)[/math]


[math]=\left( \begin{array}{c} x \cos (\theta )-z \sin (\theta ) \\ y \\ z \cos (\theta )+x \sin (\theta ) \\ \end{array} \right)[/math]



For event #29, in sector 3, the location of the first interaction is given by

Conversions.png


Converting -25 degrees to radians, [math]\theta =-0.436332[/math]


[math]\left( \begin{array}{ccc} \cos (\theta ) & 0 & -\sin (\theta ) \\ 0 & 1 & 0 \\ \sin (\theta ) & 0 & \cos (\theta ) \\ \end{array} \right).\left( \begin{array}{c} -15.76 \\ 0 \\ 237.43 \\ \end{array} \right)[/math]

[math]=\left( \begin{array}{c} 86.0588 \\ 0. \\ 221.845 \\ \end{array} \right)[/math]

Finding [math]\phi =\frac{120\ 2 \pi }{360};[/math] since "sector -1" =3-1=2*60=120 degrees

[math]\left( \begin{array}{ccc} \cos (\phi ) & -\sin (\phi ) & 0 \\ \sin (\phi ) & \cos (\phi ) & 0 \\ 0 & 0 & 1 \\ \end{array} \right).\left( \begin{array}{c} 86.0588 \\ 0. \\ 221.845 \\ \end{array} \right)[/math]

[math]\left( \begin{array}{c} -43.0294 \\ 74.5291 \\ 221.845 \\ \end{array} \right)[/math]

Phi shifts

Phi shift line.png

Collecting the Phi shifts as discussed above, for both with and without the Solenoid, and writing to separate data files, a root macro is written to plot the phi shifts.

Phi shifts.png

The large shifts in phi occur for two reasons: Small Energy, and large angles in theta as shown in this sample of phi angles greater than 25°

Reason.png

DV_RunGroupC_Moller#Moller_Track_Reconstruction