Realistic tracking

Realistic tracking resolution from Nicolas

  • EPIC
  • tracking evaluated at r =70 cm with all sub detectors
  • with TOF
  • DIRC@EIC, EPIC
  • 3-layer spherical lens with sapphire, r=[62,36]
  • 3 mm pixels HIQ400, CE=95%
  • pions and kaons @ 6 GeV/c; phi = 0 (no field); vertex y-shifted by 0.5*barwidth (to hit middle of the bar)
  • 100 ps time precision
  • geometrical reconstruction with averaged LUT from 15M photons
  • GR with per-PMT and chromatic corrections
  • 20k tracks for pdf generation (per each particle species) (generated with 0.5 mrad track resolution); 5k for determining separation

Tracking resolution:

Interpolated map for polar angle:

Zoomed:

Interpolated map for azimuthal angle:

Zoomed:

Smearing in particle's CS (old way of smearing) vs global CS (new). Particle's CS smearing with theta = 2.2 mrad (results plotted in global CS):

  G4ThreeVector vec(0, 0, 1);
  vec.setTheta(theta);
  vec.setPhi(phi);
  G4ThreeVector vec0 = vec;
  vec.setTheta(G4RandGauss::shoot(theta, fTrackingRes));
  vec.rotate(2 * M_PI * G4UniformRand(), vec0.unit());

Global CS smearing with theta and phi = 2.2 mrad (results are in global CS):

  G4ThreeVector vec(0, 0, 1);
  vec.setTheta(G4RandGauss::shoot(theta, fTrackingRes));
  vec.setPhi(G4RandGauss::shoot(phi, fTrackingRes));

Performance plots for pi/K @ 6 GeV/c:

Photon yield after GR:

Photon yield after TI:

GR:

TI:

Performance plots for pi/e @ 1.2 GeV/c:

Photon yield after GR:

Photon yield after TI:

GR:

TI:

Event display of 2.2 mrad smearing in theta and phi(@ 30 deg):

Event display of 4 mrad smearing in theta and 16 mrad smearing in phi (@ 30 deg):

=> smearing track at the vertex with large resolutions is not representative as it also leads to too much smearing of the hit position on radiator