Study of track & charge reconstruction for high energy electrons using geometry UPGR12
All plots on this page are produced for a single electron events with pT of 20 GeV/c.
- Input one-electron events.
Generated electrons have fixed pT and zVertex of -30, 0, or +30 cm,and flat eta and phi distribution. Sample of high pT electrons thrown from different zVertex location over eta range [1,2] are shown here:
- Assumptions about resolution of detectors. Positions of GEANT hits were smeared with resolution...
| detector || assumed resolution || weight of the point || Remarks
| FST,FGT || 60 mu m in X,Y |
10 mu in Z
| W=1/(60mu m)^2 || 4 disks
| TPC || 1 mm along arc |
1 mm in Z
| W=1/(1mm)^2 || drop padrow #1, #13 |
drop hits at |Z|>197 cm
| vertex || 200 mu m in X,Y,Z || W=1/(200 mu m)^2 || added as a hit
- # of available hits from FST,FGT, and TPC as function of pseudrapidity (X-Axis)
and assumed Z-vertex position ( red=- 3cm, green=0, blue= +30 cm)
| detector || # of hits vs eta
| FST ||
| FGT ||
| TPC ||
| all+ |
5 hits limit to find the helix is marked by the red line
- Chi2/DOF for Circle fit vs. eta, separate for 3 Z-vertex locations.
Note, DOF changes w/ eta (see above) so the shape of chi2/DOF changes as well.
- Quality of the reco 3D tracks (fit of circle+line) can be measured as a difference of the reco direction of primary track at the vertex vs. Geant direction. I choose angles: theta & phi, in radians.
- Track reco efficiency is defined as the ratio of geant electrons to # of reco tracks w/
* nFitP>=5, including vertex as a hit
* delPhi<3 mrad
* delTheta <3 mrad
Note, at the Endcap SMD plane (Z~300cm) 3 mrad translate to 1cm displacement of reco track vs. projected ideal helix.
- Charge reco efficiency requires additional the sign of the reco track is correct. No cut on reco pT is imposed.
| Pt=20 GeV/c|| Pt=40 GeV/c
Used macro pl3Z.C