1. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 1 Near Detector Efficiency

2. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 2 Rehash Examining the efficiency of the Near Detector to record muon hits Efficiency defined as #hit planes expected/#hit planes seen R1.16 was used initially Cuts – Pitt track quality(chi2/ndof<20,|beginU -beginV|<6, pass tracker fit) – Through going spill muon – Fiducial: 0.3m<U<1.8 and -1.8<V<-0.3 for vertex and track end-2 planes

3. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 3 Track Efficiency – How many planes hit for individual tracks Plane Efficiency – record how many tracks traverse plane and how many hits are recorded XXXXXXXXXXXX Vertex End Plane

4. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 4 Initial Results Calorimeter Tracks ( 120 planes ) – Partially Instrumented (PI) was.8883 +/-.0136 – Fully Instrumented (FI) was.8783 +/-.0140 Inefficiency stems from – Tracking – Poisson(PMT)- Landau(Scintillator) nature of light – Other Stuff?

5. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 5 Quick Check Study of the Far Detector put the tracking efficiency at ~.95 (John Marshall) – Extracting the tracking efficiency from overall efficiency yields the inefficiency due to light ● 1-.88/.95=.074 Is the ~7% inefficiency that is not track related solely from light or is it systematic of another problem? – Examine ADC per plane to get idea of light contribution

6. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 6 Top plot shows summed ADC for all spill muon hits (w/o cuts) in May – Landau fit for comparison Bottom shows similar with a 7.4% increase in low ADC counts – Simulates 0% light inefficiency The ~7.4% is not totally light dominated

7. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 7 Monte Carlo Comparison R1.16 High Energy Monte Carlo – PI.9446 +/-.0172 – FI.9485 +/-.0140 MC is 6-7% higher using same method/code Discrepancy is big

8. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 8 MC/Data Discrepancy causes Low level ADC hits in MC, which are not seen in data More MC tracks staying in analysis region of detector – inside volume containing both FI and PI planes Data efficiency being 'pulled' down handful of single tracks with low efficiency Reconstruction not finding hits in data that are part of track

9. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 9 Both MC (top) and Data(bottom) track efficiencies are 'smooth' No peak at low efficiency values

10. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 10 Data(red) MC (blue) MC and Data are similar in ADC level <2% of events fall outside fid very similar to MC

11. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 11 Tracking Removed possible tracking issues – Used all hits in event, regardless of (U,V) position Efficiency increase of ~1% in both MC and Data

12. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 12 Inefficiency not caused by: Low level hits – MC and Data have similar ADC distribution More Data tracks move out of fiducial region – MC and Data have similar hit distribution Handful of tracks with low efficiency in data – No spike in Data track efficiency plots at low efficiency The only bit left is that the reconstruction is not finding or allocating hits to the track

13. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 13 More possible causes 'Dead' bits of Near Detector – Strips or planes that may not respond as effectively as expected Alignment issues – Are muon tracks in Data sneaking through gaps Actual hits are not being included in event

14. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 14 Uniform distribution for both methods Two methods of establishing missing hit position – Neighbour – interpolate missed hit position from adjacent hits – U/V – use hit positions in next similar plane ● ex. Missed hit is a U plane, two nearest hit U plane positions are used

15. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 15 Gaps Identified by missing hits near strip edges – Hits congregate near edge more in MC than data – Tracks not 'slipping' through gaps R1.16 Data R1.16 MC

16. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 16 R1.18 R1.18 Data matches R1.16 MC, but not Data R1.16 R1.18MC Track hits All hits

17. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 17 Same set of data (06/2005) with different reconstructions (R1.16, R1.18) have different efficencies Suggests that hits are not being included in events in R1.16, but are in R1.18

18. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 18 Look at same event in R1.16 and R1.18 when efficiencies differ – R1.16 has 69% track efficiency, R1.18 has 94% R1.16 R1.18

19. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 19 End Finished – The culprit of the Near Detector efficiency issue is hits not being included in event ● slicer? – Old code sucks, new code good Outstanding – Missing hit location between MC and Data ● Missing hit location is similar for R1.16 and R1.18 Data, but does not match MC ● I'm not doing this

20. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 20

21. D. Jason Koskinen FNAL Collaboration mtg. 10/2005 21