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: 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 and number of sigma larger 4:

-- GeorgSchepers - 29 Nov 2007

Topic attachments
I Attachment Action Size Date Who Comment
gif Full.gif manage 6.9 K 06 Dec 2007 - 16:21 GeorgSchepers Number of sigma in depndence of momentum and theta angle
gif l.gif manage 1.9 K 06 Dec 2007 - 16:18 GeorgSchepers Pathlength of a partice in the radiator of the barrel
gif nphotonp.gif manage 4.0 K 06 Dec 2007 - 16:13 GeorgSchepers Number of measured Cherenkov photons
gif nphotonsdetected_plot.gif manage 16.1 K 07 Dec 2007 - 17:35 GeorgSchepers Detected Cherenkov photons
gif nsigma.gif manage 2.5 K 06 Dec 2007 - 16:12 GeorgSchepers Number of sigma
gif nsigma_p_plot.gif manage 3.4 K 07 Dec 2007 - 17:38 GeorgSchepers Number of sigma in dependence of momentum p
gif nsigma_p_theta_2000-4000.gif manage 21.2 K 07 Dec 2007 - 17:40 GeorgSchepers Number of sigma in dependence of momentum p (2000-4000MeV/c) and angle theta
gif nsigma_p_theta_500-5000.gif manage 21.9 K 07 Dec 2007 - 17:39 GeorgSchepers Number of sigma in dependence of momentum p (500-5000MeV/c) and angle theta
gif pathlength_thetapsi_plot.gif manage 12.9 K 07 Dec 2007 - 14:27 GeorgSchepers Pathlength
jpeg pbarptophiphi_cutns.jpeg manage 48.8 K 11 Dec 2007 - 13:56 GeorgSchepers Cut momentum and theta angle and number of sigma larger 4
jpeg pbarptophiphi_cutptheta.jpeg manage 52.1 K 11 Dec 2007 - 13:55 GeorgSchepers Cut momentum and theta angle
jpeg ppbartophiphi.jpeg manage 63.8 K 11 Dec 2007 - 13:54 GeorgSchepers pbar p to phi phi
gif psi.gif manage 2.8 K 06 Dec 2007 - 16:20 GeorgSchepers Angle psi
gif separationpower.gif manage 3.4 K 29 Nov 2007 - 16:17 GeorgSchepers Separation power versus momentum
This topic: Tagpid > WebHome > TasksandResults > BarrelDirc > DircPlayground > ThreeDseparationplot
Topic revision: revision 9

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