W. Smith, U. Wisconsin, HCP, Nov. 16, 2009. CMS Detector Global Status - 1 CMS Detector Global...

W. Smith, U. Wisconsin, HCP, Nov. 16, 2009. CMS Detector Global Status - 1

CMS Detector Global StatusCMS Detector Global Status

Wesley H. Smith

U. Wisconsin

HCP2009 - Hadron Collider Physics Symposium

Evian, November 16, 2009

Outline:

Testing with Cosmics & Splash Events

Detector & Analysis Performance

Readiness for first collisions


CMS Detector DesignCMS Detector Design

MUON BARREL

CALORIMETERS

PixelsSilicon Microstrips210 m2 of silicon sensors9.6M (Str) & 66M (Pix) channels

ECAL76k scintillating PbWO4 crystals

Cathode Strip Chambers (CSC)Resistive Plate Chambers (RPC)

Drift Tube Chambers (DT)

Resistive Plate Chambers (RPC)

Superconducting Coil, 4 Tesla

Steel YOKE

TRACKER

MUONENDCAPS

HCALPlastic scintillator/brasssandwich

Level-1 Trigger Output• Today: 50 kHz

(eventually100 kHz)• Directly feeds Higher

Level Trigger CPU farm


20082008

Cosmics, Splashes &Circulating Beams


CMS Minus End & ClosureCMS Minus End & Closure


Final Closure(3 Sept. 2008)

Final Closure(3 Sept. 2008)


2008: First Beam through CMS2008: First Beam through CMS

Beam Pickup (ch1) CMS Beam Condition Monitors (ch 3, 4) Point 5 Control Room

CMS Centre Meyrin

Halo Muons in CSCs and HB


Beam Halo Events in CMS EndcapCSC muon chambers

Beam Halo Events in CMS EndcapCSC muon chambers

ME-4ME-3ME-2ME-1

ME+1 ME+2 ME+3 ME+4


Circulating Beam: Beam Halo EventsCirculating Beam: Beam Halo Events

HCAL Endcap: un-captured (lhs) & captured beam (rhs)


CMS Continuous Operation:CRAFT - Cosmics Run at 4 T*CMS Continuous Operation:

CRAFT - Cosmics Run at 4 T*Ran CMS continuously for 6

weeks (Oct – Nov ’08) to gain operational experience, stability of infrastructure.

Collected ~300M cosmic events.

About 400 TB of data distributed widely.

Efficiency ~ 70% (24/7)First analyses of these data

used s/w release intended for 2008 data-taking & LHC grid infrastructure.

Re-reconstruction & analyses with more advanced versions of the release

*operating field of CMS is 3.8T


CRAFT08: Performance Plots(> 20 papers being submitted to JINST)CRAFT08: Performance Plots(> 20 papers being submitted to JINST)

Energy deposited by muonsEnergy deposited by muons

HCALHCAL

ECALECAL

radiativeradiativeionisationionisation

Points- dataPoints- data

totaltotal

10

Muon Chambers Point Resolution

Muon Chambers Point Resolution

Distn of Mean ResidualsDistn of Mean Residuals

Alignment in Inner Tracker Alignment in Inner Tracker

Si TrkrModulesSi Trkr

Modules

BpixModules

BpixModules

TOBx

2.6 um

PXBx

2.6 um


’08-’09 Shutdown – CMS Activities

’08-’09 Shutdown – CMS Activities

After cosmics run (Nov ‘08), detector was opened for maintenance & repair activities, installation of preshower subdetector & CASTOR. • Work progressed according to the schedule laid down in Nov. 2008.

Major Accomplishments:• Removal, repair, and re-insertion of the forward pixel system• Installation and commissioning of the preshower (ES)• Completion of maintenance & (some) repairs of all sub-systems• Completion of the revision of the tracker cooling plant• Understanding of magnetic field in the return iron-yoke• Overpressure protection (new item) – occupy underground control room• Re-commissioning of CMS • Prepared software (CMSSW3) for 2009 data taking, improving stability &

reliability of computing infrastructure• New TOSCA Field Map – agreement of data & MC now better than 2%• Large MC production & analysis exercise at 10 & 7 TeV (“October Exercise”)

CRAFT09:• 40 day global cosmic run July 23 – Sept. 1, 2009

• Mostly continuous with a few planned downtimes


2009 so far2009 so far

Cosmics & Splashes


Cosmic Data Taking: CRAFT09

Cosmic Data Taking: CRAFT09

CRAFT09: 23.7-1.9.09:Collected 300M+ cosmic events with tracking detectors & field on (3.8T).

(160 M with field = 0)

Quality of data from, and performance of, CMS is equal or better than that in CRAFT08

24/7 Data-taking effic’y ~ 80%. Possible to improve, e.g. on weekends e ~ 85-90%.


Barrel Pixel

Endcap Pixel

Tib/TID

TOB

TEC+

TEC-

ECAL barrel

ECAL endcap

Preshower

HCAL barrel

HCALEndcap

HCAL Outer

HF

ZDC

DRIFT tubes

RPC barrel

RPC endcap

CSC

95% 96% 97% 98% 99% 100%

Percent Operational

CRAFT09 PerformanceCRAFT09 Performance

PT Comparison (B-Field): Stand-Alone Muons vs. Tracker Muons

Sub

dete

ctor

s

% Operational


CRAFT09: Tracker availabilityCRAFT09: Tracker availability

Silicon strip : 98.1%•Tracker Outer Barrel: 98.3%•T. Inner Barrel/T. Inner Disks 96.5%•T. EndCap+: 98.8%•T. EndCap-: 99.2%

1 control ring*

1 cooling ring*

*will investigatepossibility of repairin long shutdown

Silicon Pixel: 98.5%• Barrel: 99.1%• Forward: 96.9

CMS preliminaryStrip map : working modules (green), disabled (white), not read-out (red), other (mainly missing HV blue)


CRAFT09 Track finding efficiency for cosmic muons

CRAFT09 Track finding efficiency for cosmic muons

Tag muon with tracks from μ chambers.2 track-finders:

• Combinatorial Track Finder (will be used in collisions)

• Cosmic Track Finder(simple algorithm tailored for single muon tracks provides cross check)

CMS preliminary CMS preliminary


CRAFT09 Tracker hit efficiencyCRAFT09 Tracker hit efficiency

Hit efficiency for Cosmic Muons Efficiency in the various layers of Si tracker• Tracks searched for without considering layer to be investigated.

• Track extrapolated into layer investigated

• Hit searched for inexpected region

• Eff’cy includingfaulty modules*: 98.2%

• Eff’cy excluding knownfaulty modules*: 99.9%

*not including recent lossof 50 modules (0.4%) dueto cooling incident

CMS PreliminaryData for field on & off

*

*

*Excluding known faulty modules


CRAFT09: RPC SignalsCRAFT09: RPC Signals CRAFT09: Barrel and Endcap

RPC fully functional Barrel chamber HV scan: Hit

efficiency as a function of High Voltage

Shown for two thresholds On plateau: efficiency is

independent of threshold: robust settings

CMS preliminary

CMS preliminary

Efficiency at fixed HV(9.3kV) for two different thresholds.Robust operational conditions


CRAFT09 Endcap Muon CSC data: reconstructed y vs x in each station

CRAFT09 Endcap Muon CSC data: reconstructed y vs x in each station

+z endcap

-z endcap

99% of chambers delivered data in CRAFT09 (cf. 96% in CRAFT08)

Borrowed LV supplies for a test -- turned back on laterFrom one run (110508, 11 Aug 2009)

cm

cm


HF jets -jets e

iso ET/HT Multiple

objects

Unused bits

halo

CRAFT09: All Level-1 Trigger algorithms used

CRAFT09: All Level-1 Trigger algorithms used

DT, CSC, RPC muon triggers with cosmic timingAlso used: LHC timing and pointing roads in muon triggerECAL & HCAL based triggers with very low thresholds

Thresholds & cuts adjusted to provide comparable rates

Tested steady long-term running at 80 kHz


L1 trigger performance(CRAFT09)

L1 trigger performance(CRAFT09)

L1 Drift Tube Track Finder Muon candidates• efficiency vs pT

(threshold 10 GeV)

L1 eγ efficiency turn-on curve• Measurement using muon

brems in crystals• Muon triggered events,

requiring muon associated with ECAL e.m. cluster

Super-pointing sample

(LHC-like)

pT from tracker

Effcy. of 1, 5, 10 Gev Thr.

trigger vs.EM

cluster Et


CRAFT09 Data AcquisitionCRAFT09 Data Acquisition

Efficient running with 80 kHz input rate

All systems in, including Preshower detector

> 4700 Filter units applications running

on 672 PCs

Huge muon trigger rate*,DAQ/HLT/SM ok

• ~1 kHz cosmics / calib + 80 kHz randoms• ~15 hours, ~ 4 109 events

*Noise temporarily raised rate – automatic throttling keeps stability


CMS Splash Events Nov. ‘09CMS Splash Events Nov. ‘09• LHC started to deliver beam shots to CMS on

afternoon of Saturday, Nov. 7 • ~every 40 sec in 3 sessions

• CMS collected 1105 splashes• Solenoid at 3.8T• Shielding closed• Silicon tracking systems off (strips & pixels)• Muon systems at reduced HV (CSC, DT, RPC)• Only downstream RPC endcap enabled• Calorimeters on• Trigger on ECAL (central ring)• Silicon preshower detector on NEW• CASTOR (5.1 < |η| < 6.55) calorimeter on NEW• First ZDC (8.5 < |η|) channels on NEW


Beam 2

Splash ‘09 Event DisplaySplash ‘09 Event Display

ECAL energy deposits in red, HCAL energy deposits in blue (light blue for HF and HO)

RPC muon hits are in yellow, and CSC muon hits are in magenta.

Note that CSC wires are also visible.



ECAL energy deposits in red, Preshower in green, HCAL energy deposits in blue (light blue for HF and HO), RPC muon hits are in yellow, and CSC muon hits are in magenta.

Beam 2



ECAL energy deposits in red, HCAL energy deposits in blue (light blue for HF and HO), RPC muon hits are in yellow.


Splash ‘09: ECAL vs. HCAL Observed Energy

Splash ‘09: ECAL vs. HCAL Observed Energy

• 721 Splash events in a wide range of beam intensity

• Response in EndCap+ is lower than EndCap- due to particle losses from material in CMS

Barrel

EndCap+

EndCap-

Millions of muons per event 1000’s of TeV/event!


Bottom

Beam

HCAL Response: single Splash ’09 event

HCAL Response: single Splash ’09 event

• Response in HCAL (HB/HE/HF)• No dead channels

• 6 HF channels (out of 1728) masked in trigger• Includes several saturated towers

HF+HE HB HEHF- | || |


Splash ‘09: HCAL HB TimingSplash ‘09: HCAL HB TimingHCAL reconstructed (Rechit) time for barrel

Left: Apply Splash08 measured η correction for splash vs. collision time-of-flight & cables to Splash09 data

Right: Add ϕ correction for cables measured during first Splash09 data (Sat-Sun) to later (Mon) Splash09 data

η-dep. ToF corr.

HB+HB-μ

1 ns!

ϕ-dep. cable corr.


ECAL Response: 800 Splash ’09 events

ECAL Response: 800 Splash ’09 events

Average energy per crystal in ECAL

White regions are masked channels • 0.9% of total

• one quarter may be recovered.

• Use coarse trigger data to recover all but 0.15%

Energy modulations are combination of energy flow traversing CMS & geometry effects. • e.g. lower energy at large

radii in the ECAL Endcap downstream to the beam direction is due to the ECAL barrel shield.

Average muon fluence is about 5 muons cm-2

CMS 2009 Prelim.

ECAL Endcap - (beam side) ECAL Endcap +

ECAL BarrelECAL Barrel

η=0

Beam

x [crystal index]

Bottom

y [c

ryst

al in

dex

]

η=1.5

ϕη=-1.5

η=-

1.5

η=

-3.0

η=1

.5

η=

3.0


ECAL Preshower Responseto single Splash ’09 event

ECAL Preshower Responseto single Splash ’09 event

Installed Spring ’09•Successfully operated during all Splash ‘09 events

Number of muons per sensor shown

•Flux modulations consistent with energy maps seen in ECAL Endcaps.

•Isolated hot spots are attributed to muon radiation

Sensors cover 37.1 cm2 each →average muon fluence ~ 5 cm-2

LV problem – 50% now fixed

Readout problem (now fixed)CMS 2009 Prelim.

η=-

1.65

η=

-2.6

η=1

.65

η=

2.6


NowNow

Preparing for the 2009/2010 Run


Ready for Collisions:Trigger Menu for 1031cm-2s-1

Ready for Collisions:Trigger Menu for 1031cm-2s-1

Total calculated L1 rate 9 kHz (50 kHz capacity)Muons:

• Unprescaled at pT=9 GeV; L1 single μ thresh. at 7 GeV

• Also unprescaled L1/L2/L3 μ outputat pT=30/11/9 GeV

Electrons:• No isolation requirements at L1• Unprescaled at pT=20 GeV w/no isolation

& at 15 GeV with loose track isolationPhotons:

• No isolation requirements at L1• Unprescaled at pT=25 GeV with no

isolationJets:

• Unprescaled 1-Jet pT=110 GeVMinBias:

• Algorithms use HF-tower ET,HF ET ring sums, Ecal ET, & pixel triplets

• Jet: 18 Hz• MET & HT: 8 Hz• Muon: 37 Hz• Electron: 26 Hz• Photon: 23 Hz• B-Tau: 13 Hz• x-triggers: 11 Hz• MinBias: 8 Hz• Total: 145 Hz

Higher Level Trig. Rates by Object

Planned HLT Rate 300 Hz(600 Hz capacity)<CPU time>/event = 42 ms(100 ms capacity)


Analysis Model in CMSAnalysis Model in CMS

Tier-1

Tier-2 Tier-2 Tier-2

Tier-3 Tier-3 Tier-3Tier-3

Tier-3

Tier-1 Computing Facilities are major repositories of MC & reconstructed data

Tier-2 Computing Facilities are half devoted to simulation half user analysis. Primary resource for analysis

Tier-3

CAF

Tier-3 Computing Facilities are entirely controlled by the providing institution & used for analysis

Tier-0CERN CAF

Tier-1 Tier-1Tier-2

Tier-2 Tier-1

Tier-3

CMS Analysis is performed on a globally distributed collection of computing facilities

Tier-2Tier-2


Computing ReadinessComputing ReadinessMC Production

• Generated 760M full simulation events July-Oct, 2009• For both 7 and 10 TeV analyses

Tier-1 & Tier-2 readiness• Closely monitored: much improvement in Tier-2 readiness• Intensively tested during 2-week “October Exercise” of analysis

• 77 separate analyses w/230 participants, increment of 700K jobs• ~ 2000 data sample subscriptions, 900 TB from Tier-1’s to Tier-2’s

October Exercise4 times average

Different colors for different Tier-2’sReady & Working

Not Ready

Scheduled Downtime

200k/day50 sites


Early Physics ProgramEarly Physics ProgramEarly beam - collisions, up to 10-20 pb-1 @ 7 TeV

• Commission trigger, start “physics commissioning” – “rediscover SM”: • Physics objects; measure jet & lepton rates; observe W, Z,

top &, of course, first look at possible extraordinary signatures…

7 TeV, 10’s of pb-1: measure S.M., start searches• Approx per pb-1: 3000 Wl (l = e,); 300 Zll (l =e, );

5 ttbar +X• Improved understanding of physics objects; jet energy scale

from W j j′; extensive use (& understanding) of b-tagging• Measure/understand backgrounds to SUSY & Higgs

searches• As data accumulates higher, look for excesses from SUSY

& Z′ resonances.


Particle Multiplicities &B physics

Particle Multiplicities &B physics

B+ → J/yK+ with 10 pb-1

B+ → J/yK+ with 10 pb-1

e.g. Exclusive B production with early data:• B+(0) → J/yK+(*0)

cross section & lifetime ratio for 10 pb-1 @ 10 TeV

Charged Hadron Multiplicity in Minimum Bias pp Collisions at 900 GeV and 10 TeV(5k events)

M J/yK+

900 GeV900 GeV

10 TeV10 TeV

10 TeV10 TeV

Analyses have beenredone for 7 TeV –available soon


QCD: Jet MeasurementsQCD: Jet Measurements

Startup inclusive jet measurement using kT & SISCone• Studying other algorithms – present intent to make anti-kT the default

Startup inclusive jet measurement using kT & SISCone• Studying other algorithms – present intent to make anti-kT the default

Inclusive jet cross-section uncertainties (SISCone) for

10 pb-1 data @ 10 TeV

Inclusive jet cross-section uncertainties (SISCone) for

10 pb-1 data @ 10 TeV

Inclusive jet cross-section measurement (kT) for 10 pb-1 data @ 10 TeV

Inclusive jet cross-section measurement (kT) for 10 pb-1 data @ 10 TeV


W, Z s∙BR (10 pb-1, 10 TeV)W, Z s∙BR (10 pb-1, 10 TeV)

syst. uncert: 2.4% + 10% for Ldt syst. uncert: 4.0% + 10% for Ldt;

Z eeZ ee W enW en

Z SelectionET > 20.0 GeVboth e isolated 70 < Me,e < 110 GeV

W SelectionET > 30.0 GeVIsolated e

Use data driven methods e.g. tag and probe method to work out efficiencies from “data”


Conclusions & OutlookConclusions & OutlookCMS closed after 10-month successful

maintenance period & in “data-taking” state• Round-the-clock operation• Magnet is at operational field.• All sub-detectors operating• Took data in 2009 beam splash events

Data analyzed from cosmic & beam-splash running shows an aligned, calibrated detector with trigger & DAQ that is ready for physics• Computing and Software systems have been

exercised to demonstrate readiness for data analysis• Physics planning & tools are ready for beam

We are ready and eager for first collisions!

W. Smith, U. Wisconsin, HCP, Nov. 16, 2009. CMS Detector Global Status - 1 CMS Detector Global...

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