Test Beam 2003 Some Preliminary Results

1. Test Beam 2003 Some Preliminary Results CMS Week Sep-2003

2. Outlook Trigger (BTI & TRACO) information from the output of TSS-TSM is checked using tracks obtained from chamber TDC hits • Trigger “quality” for normal incidence • TRAC0 resolution (position and angle) for different angles ( Trigger Configuration: SET STD-DEF)

3. TSS-TSM: BTI Trigger quality vs Meantimers Taking out d-rays (by cutting on c2) NO BTI trigger events are concentrated mainly near Ibeams but still ~0.65% out of Ibeams. Meantimers from SL q Trigger on Correct BX Tracks with hits in the 4 layers No trigger for some “good” events HLT correspond to “good” hit times Most of LLT correspond with delta rays Selection of “good” events By cutting on c2

4. TSS-TSM: BTI Trigger quality vs track fit quality (I) Fitted track “quality” redefined: If track of N-hits has c2 > 2 the ¨worst¨ hit is removed and refitted with N-1 hits. Selection of N´= 4 hit tracks 2 Cases studied depending on the number of hits per cell in track A) At least 1 cell with 2 hits (Multi-hit) B) ONLY 1 hit per cell (Single-hit)

5. TSS-TSM:BTI Trigger quality vs track fit quality (II) A) Multi-hit B) Single - hit Trigger on Correct BX Trigger on Correct BX Total Trigger efficiency: 99.49 0.03 HLT: 98.99  0.04 LLT: 1.010.03 Total Trigger efficiency: 97.56  0.08 HLT: 94.86 0.12 LLT: 5.14 0.12

6. Selection of Events on SL PHI2 Selection of “good” events on SL PHI2 based on: Hits on 4 layers Good fitted track (cut on c2) High Trigger Quality “expected”

7. TSS-TSM: TRACO quality vs Meantimers Triggers on Correct BX HH = 89.2 % HL = 7.5 % Previous events selected on SL phi2 and track with hits in 4 layers on SL phi1 HL triggers correspond mostly with delta rays There is a small fraction of events with “good MT” and no HH trigger

8. Statistics for “good” events on both SLs Selection of “good” events on SL PHI2 AND SLPHI1 Hits on 4 layers Good fitted track (cut on c2) HH 97% HL 1.7% Ho,Hi 0.9% LL,Lo,Li 0.1% NO TRACO 0.3% No correlations for “no HH” with respect to MT values

9. No HH events No correlations for missing TRACO events with respect to chamber position.

10. Dependence of TSS-TSM:TRACO Trigger quality with fit qualities (I) Again fitted track “quality” redefined HH HL No trigger 2 Cases studied depending on the number of hits per cell in track A) At least 1 cell with 2 hits (Multi-hit) B) ONLY 1 hit per cell (Single-hit)

11. Dependence of TSS-TSM:TRACO Trigger quality with fit qualities (I) A) Multi-hit A) Multi-hit Trigger on Correct BX 4 + 4 B) Single - hit B) Single - hit Trigger on Correct BX 4 + 4

12. A first look at 2-m Trigger Selection of 2-m events: 2 fitted tracks 4+4 on chamber && TRACO HH, HL, LL Position of the best track different from TRACO position THEN We look for a second muon on TRACO compatible with the chamber track Quality of the second muon 4 + 4 & HH

13. Reconstruction of tracks TRACO vs Chamber Selection of “golden” tracks on chamber and TRACO: Chamber: Tracks with hits in 4 layers on SL PHI1 with c2 < 0.6 & Tracks with hits in 4 layers on SL PHI2 with c2 < 0.6 TRACO: HH triggers on correct BX

14. TRACO vs Chamber positions TRACO PHI coordenate correlated with chamber position Trigger Position = 1.06 x Chamber + offset Different offsets for different regions (TRACO’s)

15. TRACO: Position resolution for different angles Different region of cells on SL PHI2 TRACO resolution in position similar for all angles: ~0.5-0.6 mm

16. AngleReconstruction Traco–Chamber angle • = 1 mrad • =-4 mrad • =-1 mrad • = 3 mrad • = 7 mrad D= 3 mrad Angle resolution ~0.3-0.4 deg (~ 5-7 mrad)

17. Summary • Preliminary results show a good trigger performance for TRACO and BTI • There is a clear correlation between chamber performance and trigger response (as expected ! ) • Data indicate trigger “intrinsic inefficiencies” (good chamber track but no trigger) lower than 1%. • TRACO track resolution (for HH) at different angles: ~ 0.5-0.6 mm ~ 5 - 7 mrad are in good agreement with the “theoretical” expectations