1. Status of DT Local Trigger Commissioning
C. Battilana, F.R. Cavallo, S. Marcellini
YB0, YB+1 and YB+2 fully analyzed and already updated on the
commissioning web page
New computation of trigger efficiency to avoid bias due to
geometrical effects
Discussion and classification of problems
CMS week Dec. 07

2. Local Trigger Efficiency Definition
We want to compute efficiency in MB2:
We require a reconstructed track segment
In MB2 with > 6 hits in ± 40 degrees around
the perpendicular direction.
We also require another trigger and
another track segment in any another
barrel station of the same sector
If these conditions occur, we check if there
is a trigger at any BX in MB2.
This definition avoid biases which happen
in cases when only one station is crossed,
for which trigger effic. is by definition
100 %
CMS week Dec. 07

3. Technical trigger: a trigger in at least one station, with a “almost” HanyTheta
configuration. “Almost” means that the trigger occurs with HanyTheta, but also Low Triggers are released if the chamber is not triggering
CMS week Dec. 07

4. Overview of the Results
YB0
314
12611
269
17319
12819
13475
349
21643
480
18947
166
15361
YB+1
17562
17588
17613
17846
17596
16517
17501
17547
14668
15134
14345
YB+2
18311
22341
24173
23033
18024
23282
25393
Green OK
Red
Low efficiency in all stations.
Purple
Low efficiency only in MB4
Black
OK but maybe a specific hardware problem
Light blue
Other different inefficiency problems
Bold italic underlined (any color)
changed during the test
CMS week Dec. 07

5. Case: OK Efficiency Occupancy MB1 Position  MB2 MB3 MB4 Angle 
CMS week Dec. 07
Angle 

6. HH+HL Phi effic. vs angle
Case: OK
Phi effic. vs angle
Theta effic. vs angle
MB4 has only
correlated
triggers
HH+HL Phi effic. vs angle
H-Theta effic. vs angle
CMS week Dec. 07

7. Case: OK (this is a Sector 4, where MB4 is big and splitted in two parts)
Phi effic. vs position
Theta effic. vs position
HH+HL Phi effic. vs position
H-Theta effic. vs position
Dead cell
CMS week Dec. 07

8. Case: OK Best Quality has most entries, and it
Phi Triggers
Theta Triggers
BX 
Best Quality has most entries, and it
also defines the “correct BX”
CMS week Dec. 07
Trigger quality 

9. Case: Low efficiency in all stations
Occupancy
MB1
Position 
MB2
MB3
MB4
CMS week Dec. 07
Angle 

10. Case: Low efficiency in all stations
Phi effic. vs position
Theta effic. vs position
HH+HL Phi effic. vs position
H-Theta effic. vs position
All efficiencies scaled by about 20 %
CMS week Dec. 07

11. Case: Low efficiency in all stations
Phi Triggers
Theta Triggers
BX 
Plots look normal,
except Theta
triggers in MB4
CMS week Dec. 07
Trigger quality 

12. Case: Low efficiency in all stations
Explanations:
Several cases of doubled events, for what concerns trigger information,
as well as swapped trigger primitives between MB1-MB3 and MB2-MB4
(this explains those events with theta trigger primitives in MB4, which are
actually coming from MB2.
Also events with no triggers at all, usually in bunches, related to very noisy
events.
For all these events there is no matching between TDC-tracks and
trigger primitives.
We checked that in runs catalogued as OK, with good efficiency, such
bad events are not present, or are just very rare.
These events should not occur with the final DAQ and electronics read-out,
and are peculiar of the system used for the test.
CMS week Dec. 07

13. Case: Low Efficiency Only in MB4
Occupancy
MB1
Position 
MB2
MB3
MB4
CMS week Dec. 07
Angle 

14. Case: Low Efficiency Only in MB4
Phi effic. vs angle
Theta effic. vs angle
HH+HL Phi effic. vs angle
H-Theta effic. vs angle
CMS week Dec. 07

15. Case: Low Efficiency Only in MB4
Phi Triggers
Theta Triggers
BX 
Nothing strange in the
trigger quality
CMS week Dec. 07
Trigger quality 

16. Case: Low Efficiency Only in MB4
Explanations:
In run 25393, YB+2, S10, together with the MB4 inefficiency, there are frequent cases with HH quality triggers in MB4, and no TDC track in that station. It might be a sign of bad data.
In runs 269 (YB0, S3) and 349 (YB0 S7) and (YB0 S10) no strange behaviour is observed, except the MB4 inefficiency. Pierluigi and Cristina suggest it might be a wrong shift (positive instead of negative) wrongly assigned in the configurations.
CMS week Dec. 07

17. Case: OK but maybe a specific hardware problem (YB+1, Sector 2)
The Theta occupancy plot is OK
BUT
H-Theta BTIs are not releases
(but L Theta trigger efficiency is 100 %)
CMS week Dec. 07

18. Case: Other different inefficiency problems (S11 YB+1)
Phi effic. vs angle
Theta effic. vs angle
HH+HL Phi effic. vs angle
H-Theta effic. vs angle
Only H-Theta efficiency is Low.
CMS week Dec. 07

19. Case: Other different inefficiency problems (S12 YB+1)
Phi effic. vs position
Theta effic. vs position
HH+HL Phi effic. vs position
H-Theta effic. vs position
H-Theta effic. Low and
different from station to
station
HH+HL Phi efficiency is low
CMS week Dec. 07

20. Case: Other different inefficiency problems (S12 YB+1)
Phi Triggers
Theta Triggers
BX 
Theta Quality peaked at Low trigger
Phi Quality peaked at HL instead of HH
CMS week Dec. 07
Trigger quality 

21. Case: Similar to YB-1, Sector 1 ?
Some gas problem was observed
in this case
CMS week Dec. 07

22. Case: Similar to YB-1, Sector 1 ?
CMS week Dec. 07

23. Conclusions In general the trigger performs correctly.
Several cases of low efficiency seem related to DAQ performances and should not occur in the final system (it can be checked in GREN data)
A small number of sector with strange behaviour, which should be checked more carefully
CMS week Dec. 07