Total scattering in RICH

Total scattering was calculated using the formula:

Total scattering angle as a function of polar angle and momenta.

Total scattering angle as a function of momenta for different polar angles.

Dependance of the deflection angle on the polar angle.

Small Angle Scattering devided in all RICH components

Dependance of the length of the radiator on the emmision angle:

Small angle scattering in RICH radiator as a function of polar angle and momenta.

Small angle scattering as a function of momentum and emmision angle:

Dependance of the particle trajectory length in the RICH radiator on the polar angle.

Momentum dependance of the small scattering angle for different emmision angles:

Scattering angle in RICH radiator as a function of momenta for different polar angles.	Scattering angle in RICH radiator as a function of momenta for polar angle Theta = 50deg.

Scattering angle in RICH mirror substrate material SIGRADUR as a function of momenta for mean deflection angle 22.25deg

Scattering in Aluminium.	Scattering in MgF2.

Scattering in CFK

Area difference between these two cuts is:

Conversion / Signal from PLUTO simulation

I have compared the 1D distribution for (theta_rich - theta_RK) (in phi it looks similar) for electrons comming from conversion and the electrons comming from all other sources. the conversion signal I have chosen according to the following condition: "pid.genInfo1==7001 || pid.genInfo1==17001 || pid.genInfo1==52001", the "real" signal is negation of the previous condition. the determination of the mean and sigma of the distribution was done with the "standard" 2-gaussian fit for momentum bins (0,150>; (150,350> and (350,1000>

in the picture "compareSim.png" you can see mean and sigma of the delta_theta distributions for the 3 momenta bins. the upper two pictures are done for electrons and positrons separately (red color "real" signal, blue conversion signal). in the lowest picture the comparision between electrons and positrons for the "real" signal is done.

as one can see, the differences in the simulation are only minor. the yields for signal and conversion are comparable (almost 1:1) for momenta (0,150>, it drops to 2:1 for momenta (350,1000> (see thetaNeg.jpg)

The sigma of the delta_theta distributions for negative tracks is:

• Signal: 0.96, 0.74, 0.54
• Conversion: 1.01, 0.81, 0.62

The sigma of the delta_theta distributions for positive tracks is:

• Signal: 1.18, 0.79, 0.60
• Conversion: 1.12, 0.88, 0.60

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in phi are the distributions much more narrower:

The sigma of the delta_phi distributions for negative tracks is:

• Signal: 0.55, 0.47, 0.47
• Conversion: 0.40, 0.53, 0.56

The sigma of the delta_phi distributions for positive tracks is:

• Signal: 0.57, 0.49, 0.50
• Conversion: 0.46, 0.51, 0.40

At this point i have to add, that i set following limits for the fit parameters: for signal is sigma in the range (0.4; 2.0) and for the background (2.0; infinity), which you can see in the fits not very well describing the distributions. in the most cases, the background had sigma of 2.0 in few cases just a touch higher than 2.0! (not a very good model :-(...), since for experimental data this limits worked very well, i decided not to introduce new limits for the fits.

I hope, the selection of the conversion was done properly (according to the documentation i hope i have not overseen something...)

• Comparision delta theta (RICH - MDC) distribution of signal and conversion leptons:
  

• Phi correlation for positive leptons (signal left, conversion right):
  

• Theta correlation for positive leptons (signal left, conversion right):
  

I	Attachment	Action	Size	Date	Who	Comment
png txt	ScatteringRadiatorAll.png scattering50.txt	manage	14.5 3.3 K	05 12 Jun 2007 - 08:31 12:32	MartinJurkovic	Scatteing Total scattering and scattering in radiator for different Theta as a function of momenta at polar angle 50deg
png txt	compareSim.png theta2length.txt	manage	22.6 1.3 K	29 May 12 Jun 2007 - 09:21 12:31	MartinJurkovic	Comparision delta Path length theta (RICH - MDC) distribution of signal and conversion leptons deflection angle as a function of polar angle
jpg	phiPos.jpg	manage	112.7 K	29 May 2007 - 09:24	MartinJurkovic	Phi correlation for positive leptons (signal left, conversion right)
png	scatteringCFK.png	manage	7.3 K	05 Jun 2007 - 08:25	MartinJurkovic	scattering CFK
png	scatteringRadiator.png	manage	26.1 K	05 Jun 2007 - 08:27	MartinJurkovic	3D scattering radiator
png	scatteringRadiator50.png	manage	9.9 K	05 Jun 2007 - 08:50	MartinJurkovic	scattering radiator @ 50deg
png	scatteringTotal.png	manage	28.7 K	12 Jun 2007 - 09:26	MartinJurkovic	Total scattering angle as a function of polar angle and momenta
png	scatteringTotalSlice.png	manage	17.7 K	12 Jun 2007 - 09:27	MartinJurkovic	Scattering angle as a function of momenta for different polar angles
jpg	thetaPos.jpg	manage	118.5 K	29 May 2007 - 09:26	MartinJurkovic	Theta correlation for positive leptons (signal left, conversion right)