Difference between revisions of "Recoil proton reconstruction"

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[[Image:p_eta_rec_eff.png | 400px]]
 
[[Image:p_eta_rec_eff.png | 400px]]
 
# Red curve represents efficiency for events where a proton candidate track is found.
 
# Red curve represents efficiency for events where a proton candidate track is found.
−
 
+
# Blue curve corresponds to events with |p_rec - p_gen| < +-3 sigma and
 +
|theta_rec - theta_gen| < +- 3 sigma
  
 
* '''Eta missing mass distribution'''
 
* '''Eta missing mass distribution'''

Revision as of 12:00, 2 October 2011

gamma p -> p eta decays

  • Recoil proton kinematics

P eta kin.png

  1. Proton polar angle versus momentum for generated events (top left)
  2. Momentum distributions for generated and reconstructed protons as a function of the generated momentum (top right)
  3. Polar angle of reconstructed protons as a function of the generated proton momentum (middle left)
  4. Chisq/Ndof for reconstructed protons (middle right)
  5. Ndof distribution (bottom left)
  6. Ndof versus proton momentum (bottom right)


  • Proton momentum residuals

P eta presid no cut.png No cuts P eta presid chi10.png Chisq/Ndof < 10

p(rec) - p(gen) as a function of the genarted proton's momentum.


  • Momentum resolution and reconstruction bias

P eta mom res.png

  1. Reconstruction bias (top). The mean value of residual distributions, < p_rec - p_gen >, as a function of the proton generated momentum, p_gen.
  2. Energy resolution dp/p (bottom).


  • Polar angle of reconstructed protons

P eta theta resid.png P eta theta res.png

  1. Residuals, theta_rec - theta_gen (left plot).
  2. Polar angle resolution (right plot):
< theta_rec - theta_gen >, as a function of the generated proton momentum, p_gen (top)
sigma(theta) in degrees (bottom)


  • Proton reconstruction efficiency

P eta rec eff.png

  1. Red curve represents efficiency for events where a proton candidate track is found.
  2. Blue curve corresponds to events with |p_rec - p_gen| < +-3 sigma and

|theta_rec - theta_gen| < +- 3 sigma

  • Eta missing mass distribution

P eta mis mas.png

  1. Missing masses were computed for different momentum ranges of

generated protons. Reconstructed proton tracks were required to satisfy chi2/ndof < 10. The top left plot represents the missing mass distribution for all reconstructed protons.


gamma p -> p pi0 decays

  • Recoil proton kinematics

P pi kin.png

  1. Proton polar angle versus proton momentum for generated events (top left)
  2. Momentum distributions for generated and reconstructed protons as a function of the p generated momentum (top right)
  3. Polar angle of reconstructed protons as a function of the proton generated momentum (middle left)
  4. Chisq/Ndof for reconstructed protons (middle right)
  5. Ndof distribution (bottom left)
  6. Ndof versus proton momentum (bottom right)


  • Proton momentum and polar angle resolutions

P pi mom res.png

  1. Reconstruction bias (top). The mean value of residuals, < p_rec - p_gen >, as a function of p_gen.
  2. Energy resolution dp/p (bottom). The distribution was fit to the function p1/sqrt(x) + p2

P pi theta res.png

  1. Reconstruction bias (top). The mean value of residuals, < theta_rec - theta_gen >, as a function of theta_gen.
  2. Angular resolution sigma(theta) in degrees (bottom). The distribution was fit to the function p1/x + p2


  • pi0 missing mass distribution

P pi mis mas.png

  1. Missing masses were computed for different momentum ranges of generated protons. Reconstructed proton tracks were required to satisfy chi2/ndof < 10. The top left plot represents the missing mass distribution for all reconstructed protons.


  • Toy MC: pi0 missing mass distributions for various momentum and angular resolutions

P pi mm toy1.png P pi mm toy2.png P pi mm toy3.png


  • Missing mass distributions for pi0 and eta

Comp mis mas.png

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