MCEEP simulation

I am still working on the MCEEP simulation, trying to simulate ee'd and ee'p cross-sections. Since I do not understand MCEEP I first need to reconstruct ep-elastic cross section. This is what I am working at the moment.

My MCEEP script has a following form:

200000				           								   #n_event
4,4,4,4,4,4                                for default ranges
938.27,1,0.0                               m_eject,z_eject,em_bound
2425.5,0.,0.,2320.0,12.5,0.,500.,-75.0,0.  kinematics
4.5,-4.5,80.0,-60                          momentum acceptances
'R','R',60.,120.,1200.,1500.                  nominal solid angles
0.3061,0.47,1.                           luminosity,time,spec_fac
45.,2.2,2.2                                for singles only
1.,1.,0.000765,4,2                         targ: a,z,dens,targ_mod,eloss_mod
-0.2, 0.2                                  targ: cell start/end
1.109,1.100                                drift to aperture - nom. sld. ang.
0.8,0.,0.,0.,0.                            beam: pol, vert, disp, df, tof_win
0.,0.,0.,0.,0.                             beam: FWHM   in cm,cm,mr,mr,%
0.,0.,0.,0.,0.                             beam: offset in cm,cm,mr,mr,%
'R',0.0040,0.0040                          beam: raster shape, X size, Y size
'E',T,2,-90.,0.,0.,0.                     ELECTRON ARM
'HRS','E',T,T,T,T,T
'HRI','E'
'P',T,0,-90.,0.,0.,0.                     HADRON ARM
1                                          # global cuts
5,-0.1, 0.1
0 					   #specific cuts
21                                          # plots
'NTU',1,24,2,4,5,6,8,10,12,13,14,15,22,23,24,26,45,46,47,62,64,66,72,73,74,76,'He3QEResults.ntu'
'P1D',1,-0.3,0.3,100,1.,0.,0,5,'He3QEResults_ReacZ.top'
'P1D',1,0.,300.,200,1.,0.,0,15,'He3QEResults_omega.top'
'P1D',1,0.,0.5,200,1.,0.,0,19,'He3QEResults_Q2.top'
'P2D',1,0.,300,0,0.5,50,50,1.,1.,0.,0.,0,15,19,'He3QEResults_omegaQ2.top'
'P1D',1,0.1,50.,200,1.,0.,0,24,'He3QEResults_ExEn.top'
'P1D',1,0.1,50.1,201,1.,0.,0,34,'He3QEResults_MissEn.top'
'P1D',1,0.,300.,200,1.,0.,0,26,'He3QEResults_MissMom.top'
'P1D',1,-300.,300.,200,1.,0.,0,36,'He3QEResults_MissMom_x.top'
'P1D',1,-300.,300.,200,1.,0.,0,37,'He3QEResults_MissMom_y.top'
'P1D',1,-300.,300.,200,1.,0.,0,38,'He3QEResults_MissMom_z.top'
'P1D',1,-1.7,1.7,200,1.,0.,0,48,'He3QEResults_MissMomTheta.top'
'P1D',1,-2.0,2.0,200,1.,0.,0,49,'He3QEResults_MissMomPhi.top'
'P1D',1,-0.5,0.5,200,1.,0.,0,17,'He3QEResults_Thetaq.top'
'P1D',1,-1.8,0.0,200,1.,0.,0,18,'He3QEResults_Phiq.top'
'P1D',1,200,900,200,1.,0.,0,12,'He3QEResults_pBB.top'
'P1D',1,-0.5,0.5,200,1.,0.,0,8,'He3QEResults_ThetaBB.top'
'P1D',1,-1.5,-1.0,200,1.,0.,0,10,'He3QEResults_PhiBB.top'
'P1D',1,0,0.4,200,1.,0.,0,22,'He3QEResults_thPQ.top'
'P1D',1,200,900,200,1.,0.,0,16,'He3QEResults_qvec.top'
'P1D',1,-0.5,0.5,200,1.,0.,0,72,'He3QEResults_ThetaTg.top'

Comments:  H(e,e'p) with JLAB Hall A HRS
           10 uA on

I am running this script with following flags:

 Enter input file prefix (.inp) > He3QE
 Elast (E), Bnd State (B), Contin (C), Acceptance (A)?  E
 Radiate? 1,2,3
 0=No  
 1=Yes 
 2=Yes & multiphoton correction 
 3=full angular dist. (ep elastic ONLY) 
 NOTE:  Cross sections will be additionally 
        differential in the photon energy. 
 Cutoff energy in MeV (RET for 1 MeV default) >  1 (and others)

 Proton Elastic --------------- 10
 Deuteron Elastic ------------- 20
 Tritium Elastic -------------- 30
 3He Elastic ------------------ 40
 4He Elastic ------------------ 50
 12C Elastic ------------------ 60
 Miha Accept. for ep elas. ---- 91

 Enter Option> 10
 Enforce hadron-arm accept. tests? (Y/N)> Y,N

The simulated histograms are then compared to the real data. I concentrated on run #3265 from the ee'd experiment. To analyze real data I perform only cuts on target and cut on trigger type. The obtained histograms are then ready for the comparison. No additional scripts (my own script) is being used for this comparison, so that I do not distort the histograms.


Block: RawDecode

Block: Decode
TriggerT3 (DL.evtypebits&8) == 8
CoincT5  (DL.evtypebits&32) == 32
CoincT6  (DL.evtypebits&64) == 64

Decode_master   TriggerT3

Block: Physics

TargetSizeCut  ReactPt_L.z > -0.10 && ReactPt_L.z < 0.10

Physics_master  TargetSizeCut

Progress from last week:

1.) I removed a factor 2 from the density, considering now the molecular density of H2 instead of atomic density. This is consistent with Peter Monaghan scripts.

2.) There is a problem with energy-losses calculation. The material thicknesses are not precise. I modified some parameters to agree better. However, the Target balloon is still missing. This is important but not crucial!

3.) I realized that reconstructed CS does not agree with the simulated CS with flags (0,1,2). However, it ~agrees with 3. type of radiative losses. This is the full angular model, that was added to version 3.9 of MCEEP. The comparison was done for #3265. Why are these differences so large?

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4.) Spent a lot of time trying to understand, how the radiative effects are considered. At the moment I ~understand model 2 (peaking approximation). I still have some doubts about some factors 2, but I understand the idea. However, I still need understand model 3, which gives only 1/2 of the rates.

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5.) Tried to analyze other runs. WE HAVE ONLY LIMITED STATISTICS (please see Meeting #44 - Hydrogen data). I looked at run #2814. Now, the picture is flipped. Now models 1,2 agree with the data, while model 3 gives only 1/2 of the statistics. Need to look at more data and try to find some consistency. In the analysis I did consider DT and PRESCALE FACTORS.

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If I smear the L.gold.p variable for 3MeV with a Gaussian function, I get more realistic MissMass plot:

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6.) I developed my script, that uses MCEEP only to calculate kinematics and radiative corrections (using model 91), and calculates the CS outside MCEEP - in a root script. Plots show, that this kind approach works OK!

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Last modified: 01/09/13