Tagpid  ThreeDseparationplot (compare)

# ThreeDseparationplot

part of the DircPlayground

## 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:

1. Momentum Dependence

Plot Number of sigma in dependence of momentum p:

• Number of sigma:

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

• "sigma" = 0.01 is the resolution of a single photon track
• "sigma/sqrt(nph)" gives the resolution of a track with
• nph = 16 is a typical number of produced photons
• Kaon = 493.68 MeV
• pionn = 139.57
• refractiv index n=1.47

## 2. Angle Dependence

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

http://www.gae.ucm.es/~emma/tesina/node4.html

## Pathlength:

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

Pathlength of a partice in the radiator of the barrel:

## Number of measured Cherenkov photons:

Detected Cherenkov photons:

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

Number of sigma in dependence of momentum p (500-5000MeV/c) and angle theta:

Number of sigma in dependence of momentum p (2000-4000MeV/c) and angle theta:

## Example on the treatment on the Phase Space Plots

On the Example pbar p to phi phi: phi it is shown which numbers fraction of kaon produced kaons 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 and the lower threshold (of the Kaon detection) of the Cherenkov detector and last but not least all the kaon kaons over the limit of numbers of sigma separation beeing 4. The latter conditions shows that is done 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 two track resolutions the Barel DIRC. "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.

Cut momentum and theta angle:

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

IAttachmentActionSizeDateWhoComment
gifFull.gifmanage 6.9 K 06 Dec 2007 - 16:21GeorgSchepers Number of sigma in depndence of momentum and theta angle
gif jpeg l.gif goodtrackresolution.jpeg manage1.9 30.5 K 06 Dec 2007 14 Jan 2008 - 16:18 16:47 GeorgSchepersPathlength of a partice traqck resulution 10 mrad in the radiator of the barrel
gifnphotonp.gif l.gif manage4.0 1.9 K 06 Dec 2007 - 16:13 16:18 GeorgSchepersNumber Pathlength of measured Cherenkov photons a partice in the radiator of the barrel
gifnphotonsdetected_plot.gif nphotonp.gif manage16.1 4.0 K 07 06 Dec 2007 - 17:35 16:13 GeorgSchepersDetected Number of measured Cherenkov photons
gifnsigma.gif nphotonsdetected_plot.gif manage2.5 16.1 K 06 07 Dec 2007 - 16:12 17:35 GeorgSchepersNumber of sigma Detected Cherenkov photons
gifnsigma_p_plot.gif nsigma.gif manage3.4 2.5 K 07 06 Dec 2007 - 17:38 16:12 GeorgSchepersNumber of sigma in dependence of momentum p
gifnsigma_p_theta_2000-4000.gif nsigma_p_plot.gif manage21.2 3.4 K 07 Dec 2007 - 17:40 17:38 GeorgSchepersNumber of sigma in dependence of momentum p (2000-4000MeV/c) and angle theta
gifnsigma_p_theta_500-5000.gif nsigma_p_theta_2000-4000.gif manage21.9 21.2 K 07 Dec 2007 - 17:39 17:40 GeorgSchepersNumber of sigma in dependence of momentum p (500-5000MeV/c) (2000-4000MeV/c) and angle theta
gifpathlength_thetapsi_plot.gif nsigma_p_theta_500-5000.gif manage12.9 21.9 K 07 Dec 2007 - 14:27 17:39 GeorgSchepersPathlength Number of sigma in dependence of momentum p (500-5000MeV/c) and angle theta
jpeg gif pbarptophiphi_cutns.jpeg pathlength_thetapsi_plot.gif manage48.8 12.9 K 11 07 Dec 2007 - 13:56 14:27 GeorgSchepersCut Pathlength momentum and theta angle and number of sigma larger 4
jpegpbarptophiphi_cutptheta.jpeg pbarptophiphi_cutns.jpeg manage52.1 48.8 K 11 Dec 2007 - 13:55 13:56 GeorgSchepersCut momentum and theta angle and number of sigma larger 4
jpegppbartophiphi.jpeg pbarptophiphi_cutptheta.jpeg manage63.8 52.1 K 11 Dec 2007 - 13:54 13:55 GeorgScheperspbar p to phi phi Cut momentum and theta angle
gif jpeg psi.gif ppbartophiphi.jpeg manage2.8 63.8 K 06 11 Dec 2007 - 16:20 13:54 GeorgSchepersAngle psi pbar p to phi phi
gifseparationpower.gif psi.gif manage3.4 2.8 K 29 Nov 06 Dec 2007 - 16:17 16:20 GeorgSchepersSeparation power Angle psi versus momentum
gifseparationpower.gifmanage 3.4 K 29 Nov 2007 - 16:17GeorgSchepers Separation power versus momentum

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