photon's angle distribution in EV

Distribution of angles and propagation lengths of photons inside of the expansion volume. The angle in defined as the one between photon direction before entering the lens and long axis of the radiator.

  • DIRC@EIC design; 11 bars; 4x6 MCP-PMT array; 3-layer spherical lens with nlak33
  • 3 mm pixels HIQ400, CE=95%
  • pions and kaons @ 6 GeV/c; phi = 0
  • 0.5 tracking resolution. See track resolution scan for more.
  • 100 ps time precision
  • geometrical reconstruction with averaged LUT from 15M photons
  • GR with per-PMT and chromatic corrections
  • 15k tracks for pdf generation (per each particle species); 10k for determining separation

Accumulated for all polar angles of charged particle: