1. Approved Plots from CMS Cosmic Runs (mostly CRUZET, some earlier)
13-October-2008

2. MTCC Goals: Magnet Test and Cosmic Challenge Summer/Autumn 2006
Test a “vertical slice” of all aspects of final CMS on the surface
Commission the CMS magnet
Measure the magnet field map
ECAL
Magnet
HCAL
Tracker
Muon chambers
barrel & endcap 2
Cosmic Results

3. Golden MTCC event HCAL HCAL ECAL Tracker
Run 2605 / Event 3981 / B=3.8 T / , 22h Muon traversing DT, RPC, HCAL, ECAL, Tracker
Cosmic Results

4. Cosmic Muon Measurements
Behavior of detectors in the magnetic field was verified using MC and physical observables
 B=0
 B=4T
CMS NOTE-2008/016
Momentum Distribution (4T)
Cosmic muon charge ratio measurement from MTCC 4
Cosmic Results

5. ... Field map B = 0 ∆ Measured during MTCC ‘06
3.8T map
Measured during MTCC ‘06
Finite element calculation of field in entire detector volume performed (at 2, 3, 3.5, 3.8, 4 T)
Field map with 12-fold phi-symmetry provided for physics
Analysis of field mapper data:
Calibration corrections of order 10-4 in gain and offset derived, to produce field model that agrees better than 5*10-5 with measurements and with Gauss' law in tracker volume (note: original calibration ~5*10-4 !) [PhD thesis V.Maroussov, Purdue University, May 2008.]
δBz (T)
...
B = 0
R (m) ∆
Z (m)
Cosmic Results

6. Global Runs
Subdetector and trigger considered separately - 19 items, each equally weighted - box size represents approx. fraction included (25%, 50%, 75%, 100%)
With exception of some parts of RPC, all CMS detector and trigger system ready for LHC
ALL CMS with exception of ½ RPCE
% CMS
Reached scale of ’06 Magnet Test & Cosmic Challenge
Muon Tracks in Si-Strip Tracker
Final DAQ hardware, final services
Start of full week exercises (CRUZET 1)
First  coincidence of 2 subsystems
Upgrade to final DAQ software architecture
First cosmic muon triggers underground
Cosmic Results 6

7. Fraction of CMS Systems in Global Runs
Pixel system and ECAL endcaps installed
Muon
Cabling complete, final power & cooling become available
Cooling ready for Strip Tracker
Cosmic Results

8. “Integrated (cosmics) luminosity”
Events collected by CMS in global runs during 2008
Cruzet4
September 10
Cruzet3
Cruzet2
Cruzet1
DAYS after March 31, 2008
Cosmic Results

9. DT Cosmic Muon Movie
Cosmic Results

10. CRUZET: Cosmic Muon Coincidence
HCAL
ECAL
DT and RPC
Cosmic Results

11. CRUZET: showering muon
Energy: ~290 GeV
Cosmic Results

12. Tag & Probe with cosmics
TOF-compensated cosmic trigger: di-muon-like signal in DT
Probe muon trigger and reconstruction
Probability to find at least one segment at the probe side
“X-ray” image of the shaft using cosmic rays
z (at surface) [cm]
x (at surface) [cm]
BOTTOM
TOP
Cosmic rays extrapolated to the surface (80m) 
Cable chimney
Soft muons absorbed
linear scale
Not read-out
 [deg] 12 12
Cosmic Results

13. CRUZET ECAL Barrel Occupancy
Cosmic signal is reconstructed as cluster in 5x5 region with seed crystal(s) above a threshold (~100 MeV)
2M events selected from 13.6M logged events (15% of muon triggers)
61K crystals, O(100) events/crystal in top-bottom regions
Supermodules intentionally left susceptible to noise for diagnosis
Masked trigger tower
EB+
HV problem caught by prompt analysis team
EB-
TOP
BOTTOM 13
Cosmic Results

14. ECAL  in detector units (DT triggered events)  in detector units
Reconstructed clusters matching muon tracks
(DT triggered events)
3x3 energy deposit for cosmic muons – confirms absolute energy scale to few %
Cluster Energy [GeV]
Trigger acceptance
Trigger acceptance
GeV/cm
Track-cluster association
m trigger: 290 GeV cluster!
e/ trigger tested by triggering on m.i.p. signal
synchronized to muon & HCAL triggers 14
I. Mikulec 14
Cosmic Results

15. CRUZET3 Global Tracks: Tracker + Drift Tubes
Global Run Jul08
Muon System
Tracker
ECAL
HCAL
Tracker
Prerequisites:
infrastructure, -trigger, DAQ integration,
r/o synchronization,
muon calibration, reconstruction/tracking, etc. ... 15 15
Cosmic Results

16. CRUZET3: Global Tracks Di-muon Trigger: Muon signals traced through
Muon System
Di-muon Trigger:
Drift-Tube coinc. in top+bottom, each  2 station segments
Muon signals traced through
muon system
Tracker TOB+TIB
ECAL
HCAL
Global track fit
Data being used for alignment
ECAL
Tracker
HCAL 16 16
Cosmic Results

17. CRUZET4: Endcap ECAL
Cosmic Results

18. CRUZET4: ECAL Endcap
Cosmic Results

19. CRUZET4: Endcap ECAL DT Barrel ECAL Endcap ECAL HCAL
End of Aug08 – Endcap ECAL part of Global Runs DT
Barrel ECAL
Endcap ECAL
HCAL 19
Cosmic Results

20. Tracker/Pixel Pixel Aug08: all parts of Tracker integrated
First cosmic tracks with Pixels
Pixel 20
Cosmic Results

21. Testing the muon High-Level Trigger
Routinely running High-Level-Trigger menu (+ dedicated cosmic muon trigger path)‏
Global fit with “L3” tracker track, seeded from “L2” muon track, seeded from “L1” trigger candidate: 0T
Run 58733, event
Cosmic Results

22. Standard MuonID sequence (Cruzet III)‏
Part of the standard muon ID
90k events with tracker track (B off)‏
Tracker tracks are extrapolated outward and matched to
Muon segments
Calorimeter deposits
No. of matched segments
Calorimeter only! 0T
Muon compatibility
Δx between track extrapolation
and muon segment in station 1 (cm)‏
Cosmic Results

23. Cosmic Shower Events:
0.02% rate of events with >100 segments in ~10M cosmic events at 0T
Event-by-event spread in phi compatible with multiple scattering → all events compatible with ~parallel muon shower
Cosmic Results

24. Muon multiplicity
Analyzed events spanning 5 orders of magnitude in muon multiplicity !
illustrates versatility and robustness of detector and software
Run 50908
event
541 segments
...
...
...
Cosmic / Beam Halo
O(1) muon
Cosmic Shower
O(10-100) muons
Beam “splash” event
O(105) muons
Analysis using: tracks segments hits
cosmic charge ratio shower origin shower energy and shape
Cosmic Results

25. Dedicated muon reconstruction
Navigation + seeding optimized for cosmic and beam halo muons
not pointing at IP, traversing whole CMS
using default propagator + Kalman Filter fit, updated to work both with B on and off
CMS Note -2008/001
3.1 GeV 25
6.2 GeV 3T
38.1GeV
8.1 GeV
12.6GeV
Cosmic Results

26. Cosmic-Muon Momentum Spectra
Short run at 3T
Measuring the momentum:
Using centrally RECOed data from run 60302:
Muon system Only
Tracker only
Momentum (GeV/c)‏
Momentum (GeV/c)‏
Cosmic Results