Test Beam 2003 Some Preliminary Results CMS Week Sep-2003
Trigger “quality” for normal incidence TRAC0 resolution (position and angle) for different angles Outlook Trigger (BTI & TRACO) information from the output of TSS-TSM is checked using tracks obtained from chamber TDC hits ( Trigger Configuration: SET STD-DEF)
Selection of “good” events By cutting on 2 No trigger for some “good” events HLT correspond to “good” hit times Most of LLT correspond with delta rays TSS-TSM: BTI Trigger quality vs Meantimers Taking out -rays (by cutting on 2 ) NO BTI trigger events are concentrated mainly near Ibeams but still ~0.65% out of Ibeams. Trigger on Correct BX Tracks with hits in the 4 layers Meantimers from SL
TSS-TSM: BTI Trigger quality vs track fit quality (I) Fitted track “quality” redefined: If track of N-hits has 2 > 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)
TSS-TSM: BTI Trigger quality vs track fit quality (II) TSS-TSM: BTI Trigger quality vs track fit quality (II) Total Trigger efficiency: 0.08 HLT: 0.12 LLT: 5.14 0.12 Total Trigger efficiency: 0.03 HLT: 0.04 LLT: 1.01 0.03 Trigger on Correct BX A) Multi-hitB) Single - hit
Selection of “good” events on SL PHI2 based on: Hits on 4 layers Good fitted track (cut on 2 ) Selection of Events on SL PHI2 High Trigger Quality “expected”
TSS-TSM: TRACO quality vs Meantimers HL triggers correspond mostly with delta rays There is a small fraction of events with “good MT” and no HH trigger Previous events selected on SL phi2 and track with hits in 4 layers on SL phi1 HH = 89.2 % HL = 7.5 % HH = 89.2 % HL = 7.5 % Triggers on Correct BX
Selection of “good” events on SL PHI2 AND SLPHI1 Hits on 4 layers Good fitted track (cut on 2 ) HL 1.7% Ho,Hi0.9% LL,Lo,Li 0.1% NO TRACO0.3% Statistics for “good” events on both SLs HH97% No correlations for “no HH” with respect to MT values
No HH events No correlations for missing TRACO events with respect to chamber position.
Dependence of TSS-TSM: TRACO Trigger quality with fit qualities (I) Again fitted track “quality” redefined 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) HH HL No trigger
Dependence of TSS-TSM: TRACO Trigger quality with fit qualities (I) Trigger on Correct BX A) Multi-hit B) Single - hit Quality of reconstructed Track & x & x + 4 Total Trig. Eff 0.67 Qual expect 0.88 Qual expect 0.88 A) Multi-hit Quality of reconstructed Track & x & x + 4 Total Trig. Eff 0.13 Qual expect 0.15 Qual expect 0.15 B) Single - hit 4 + 4
A first look at 2- Trigger Selection of 2- 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 & HH Quality of the second muon Quality of first TRACO muon HHHH,HL,LL Total Trig. Eff. for 2 nd muon 0.50 Qual expect 1.46
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 2 < 0.6 & Tracks with hits in 4 layers on SL PHI2 with 2 < 0.6 TRACO: HH triggers on correct BX
TRACO PHI coordenate correlated with chamber position Trigger Position = 1.06 x Chamber + offset Different offsets for different regions (TRACO’s) TRACO vs Chamber positions
TRACO: Position resolution for different angles TRACO resolution in position similar for all angles: ~ mm Different region of cells on SL PHI2
Angle Reconstruction Angle Reconstruction Traco–Chamber angle = 1 mrad =-4 mrad =-1 mrad = 3 mrad = 7 mrad = 3 mrad Angle resolution ~ deg (~ 5-7 mrad)
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: ~ mm ~ mrad are in good agreement with the “theoretical” expectations