r10  14 Jan 2008  16:06  GeorgSchepers  r9  14 Jan 2008  14:31  GeorgSchepers  

ThreeDseparationplot 
ThreeDseparationplot 

part of the DircPlayground 
part of the DircPlayground 

Calculation of the Separationpower in dependence of momentum and angle 
Calculation of the Separationpower in dependence of momentum and angle 

The dependence of N(sigma) from the momentum p and the angle theta is calculated and displayed with Mathematia: 
The dependence of N(sigma) from the momentum p and the angle theta is calculated and displayed with Mathematia: 

1. Momentum Dependence 
1. Momentum Dependence 

Plot Number of sigma in dependence of momentum p: 
Plot Number of sigma in dependence of momentum p: 




The plot represents the Numbers of sigmas two particles are separated depending on the mometum with 
The plot represents the Numbers of sigmas two particles are separated depending on the mometum with 




2. Angle Dependence 
2. Angle Dependence 

The number of produced photons denpends on the pathlength in the radiator which depends again on the incident angle. 
The number of produced photons denpends on the pathlength in the radiator which depends again on the incident angle. 

Pathlength: 
Pathlength: 

(see PathLength, Aida Galoyan))with: Angle psi: 
(see PathLength, Aida Galoyan))with: Angle psi: 

Pathlength of a partice in the radiator of the barrel: 
Pathlength of a partice in the radiator of the barrel: 

Number of measured Cherenkov photons: 
Number of measured Cherenkov photons: 

Detected Cherenkov photons: 
Detected Cherenkov photons: 

Number of sigma in dependence of momentum and theta angle: 
Number of sigma in dependence of momentum and theta angle: 

Number of sigma in dependence of momentum p (5005000MeV/c) and angle theta: 
Number of sigma in dependence of momentum p (5005000MeV/c) and angle theta: 

Number of sigma in dependence of momentum p (20004000MeV/c) and angle theta: 
Number of sigma in dependence of momentum p (20004000MeV/c) and angle theta: 

Example on the treatment on the Phase Space Plots 
Example on the treatment on the Phase Space Plots 

On the Example pbar p to phi phi it is shown which fraction of produced kaons can be separated from pions with the help of the Barrel Dirc. First one sees all the kaons produced, secondly the kaons in the solid angle and the lower threshold (of the Kaon detection) of the Cherenkov detector and last but not least all the kaons over the limit of numbers of sigma separation beeing 4. The latter conditions is done for the two track resolutions "sigma" (track) = 10 mrad and 30 mrad. It shows that we loose with a bad track resolution for higher monenta a not minor amount of kaons (meaning having a not sufficient resolution to separate them from pions) in the angular region of the Barel DIRC. Remark: The calculations are peliminary and the separation limit arbitrary. 
On the Example pbar p to phi phi: is shown which numbers of kaon can be separated from the pions with the help of the Barrel Dirc. First one sees all the kaons produced, secondly the kaons in the solid angle of the detector and last but not least the kaon over the limit of numbers of sigma separation beeing 4. The latter conditions shows that we loose for higher monenta a not minor amount of kaons (meaning having a not sufficient resolution to separate them from pions) in the angular region of the Barel DIRC. 

Cut momentum and theta angle: 
Cut momentum and theta angle: 

Cut momentum and theta angle and number of sigma larger 4: 
Cut momentum and theta angle and number of sigma larger 4: 

With a track resulution of 10 mrad: 

With a track resolution of 30 mrad: 

 GeorgSchepers  29 Nov 2007 
 GeorgSchepers  29 Nov 2007 




r10  14 Jan 2008  16:06  GeorgSchepers  r9  14 Jan 2008  14:31  GeorgSchepers  