1. 1 CC update –  momentum resolution Software news: –Converted code to read Sue’s ntuples. Allows use of Chris’s analysis framework (including event display) –Using ntuple files generated by Chris (Feb ’04) This talk: –Compare PID results using new ntuples to that presented at previous phone meeting –Look at SR muon momentum resolution D. A. Petyt April 2004

2. 2 Reco. efficiency – new ntuple Reconstructed event must contain at least 1 track CC NC 0<y<0.25 0.25<y<0.5 0.5<y<0.75 0.75<y<1.0

3. 3 Reco. effic. – old ntuple Track finding efficiency much higher for NC in old file. Why?

4. 4 Reco  selection effic - new

5. 5 Reco  selection effic - old

6. 6 PID performance These curves combine both reconstruction and selection efficiencies, although the effect of the trigger is not accounted for NEW file seems somewhat better at higher E NEW OLD

7. 7 SR muon momentum resolution Contained events - range Truth Reconstructed Truth (10% smearing) Resolution function shows small (2%) negative bias and long +/- tails. Momentum resolution ~7%.

8. 8 Track hits Tracking failure in v-z view reco truth

9. 9 Select clean tracks: low y events only Apply cuts: mc_y 20; trk_end radius>40cm Truth Reconstructed Tails are reduced (high-side tail eliminated) and resolution improved, but bias is still present

10. 10 Demux failure in v-z view (low-side tail)

11. 11 Tracking stops prematurely (-ve bias)

12. 12 Tracking stops prematurely (-ve bias)

13. 13 Contained events – q/p Truth Q/P Range Right-side plot: q/p momentum resolution. High-side tail (muon momentum overestimated) is more prominent

14. 14 q/p thrown off by multiple scattering?

15. 15 Disappearing muon?

16. 16 Disappearing muon – x,y,z projections

17. 17 Range/momentum comparison Momentum from range biased low wrt. momentum from curvature

18. 18 Resolution – range vs q/p Multiple scattering? In general, range measurement preferred over q/p for contained tracks.

19. 19 Partially-contained events Truth Reconstructed    

20. 20 All events Truth Reconstructed Use range measurement for contained tracks, q/p for partially-contained.

21. 21 Summary & conclusions Looked at SR muon momentum resolution for clean CEV/PCE tracks : –Obtained resolutions of ~6% for contained tracks, ~12% for partially-contained –Range measurement is biased low (~2%). I think this is probably due to the track finder stopping prematurely at the end of tracks (either because of excessive scattering or high p.h. hits) –Low-side tail evident for CEV/PCE – demux and tracking errors contribute to this. –Would be useful if someone could look at some of the rogue events in detail and see where/how the reconstruction is failing Observed large differences in reconstruction efficiencies (especially for NC) between two reconstruction passes of the same MC file –My hunch is that this is caused by different JobModule configurations – needs looking into.