1. Status of Tracking Development Masashi Kaneta Dept. of Phys., Tohoku Univ.

2. Source Code

3. Deference Class related tracking –DCTrack, PTrack, PVertex, PVertex3D, ParicleAnalysis…. Some difference was found in codes I used –I replaced with Futatsukawa’s version DCTrack PTrack ParticleAnalysis to check –There are the other classes related tracking but not checked yet Effect of the change –extrapolation of track to inside/outside of CDC –difference will be shown from the next page 2010_09 run data is used (run 4755)

4. Example 1 (before) There are a jump in z direction Fitting by Spline Function in DCTrack Compute by Runge-Kutta method in PTrack

5. Example 1 (after)

6. Example 2 (before) There are a jump in z direction

7. Example 2 (after)

8. Difference Number of DCTrack Number of PTrack Number of PVertex

9. Difference Vertex distribution (x, y) Vertex x distribution

10. Difference

11. Extrapolation to Inside After reflecting Futatsukawa’s code –smooth connection of trajectories of spline and RK It is time to extrapolate the trajectory to inside –compute distance between trajectory to hit wire

12. Distance between Trajectory to Hit Wire Before Layer 1 After Layer 8

13. Distance between Trajectory to Hit Wire Before Layer 9 After Layer 18

14. Summary A problem was fixed –Non-smoothness between spline and RK was It was due to independent version of NKS2 lib! –It should be under a central control Use CVS The repository is /NKS2+/dev/analyzer/src Status of tracking development –Residual between DC hit wire and track trajectory show a peak around zero –It wider than VDC cell size –Tracks stay at a nearby place It is helpful to choose VDC hit group for tracking