A. Lai - Readiness of the LHCb experiment for first data

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Readiness of Readiness of

the the LHCb LHCb experiment experiment

for first datafor first dataAdriano LaiAdriano Lai

INFN INFN - - CagliariCagliariOn behalf of the LHCb collaborationOn behalf of the LHCb collaboration

A. Lai - Readiness of the LHCb experiment for first data

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Talk Talk outlineoutline• IntroductionIntroduction

• Some results from experiment commissioning in the Some results from experiment commissioning in the last yearlast year

• Present ActivitiesPresent Activities

• Short term perspective (first beam in 2009)Short term perspective (first beam in 2009)

• ConclusionsConclusions

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NP (?) in CP & b rare NP (?) in CP & b rare decaysdecays

PotentialPotential ChallengesChallengesEffective bb(14 TeV) in LHCb acceptance ~230

b

yearLHCLdt

_

0= 2 fb-1

270 x 109 Bd per year 70 x 109 Bs per year

All b-hadrons species All b-hadrons species producedproduced

Multiplicity per rapidity unity = 30

Background from high inelastic cross section of 80 mb

Branching ratios for B-meson decays relevant for LHCb physics O(10−3 –10−9)

Monte Monte Carlo Carlo

event: event: BBss

J/J/

PerformancePerformance

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Level-0 Hardware TriggerLevel-0 Hardware Triggerhigh-pT m, e, g, hadron candidates

2 kHz2 kHz

Level -0

L0 e,

40 MHz (12 MHz visible interactions) 40 MHz (12 MHz visible interactions)

1 MHz

L0 had

L0

ECAL

Alley

Had.Alle

y

Global reconstruction

30 kHz

HLT1

HLT2

Trigger had e± 0

pT> (GeV) 3.5 1.3 >1.5 2.6 2.3 4.5

MuonAlley

Inclusive selections, +track,

Exclusive selections

Storage: Event size Storage: Event size ~40kB~40kB

High Level TriggerHigh Level Trigger (C++ application)Event Filter Farm with up to 1000 16-core nodes

HLT1:HLT1: Check L0 candidate with more complete info (tracking), add impact parameters and lifetime cuts

HLT2:HLT2: global event reconstruction + selections.

(L0) (HLT) (totalHadronic 50% 80% 40%

Electromagnetic

70 %60% 40%

Muon 90% 80% 70%

Hig

h-L

evel

Hig

h-L

evel

Tri

gg

er

Tri

gg

er

Hard

war

Hard

war

e

e

Tri

gg

er

Tri

gg

er

“software” approach provides increasing processing power ~for free

corrected for acceptance and selection

LHCb triggerLHCb trigger

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Commissioning (2008)Commissioning (2008)COSMICSCOSMICS

““Wrong” detector geometry, but still well Wrong” detector geometry, but still well visible visible in large sub-detectors (Muon, Calo, in large sub-detectors (Muon, Calo, Outer Tracker)Outer Tracker)

Extensive commissioning of basic L0 building Extensive commissioning of basic L0 building blocksblocks

1.8 x 101.8 x 1066 triggers acquired during Summer 2008 triggers acquired during Summer 2008

OR of Calorimeter and Muon triggers (in various OR of Calorimeter and Muon triggers (in various combinations)combinations)

- Nominal Muon trigger Nominal Muon trigger configuration:configuration:

Coincidence of ≥ 1 hit for each muon station in projective geometry (from IP) ~ 0 Hz rate~ 0 Hz rate

- Used Muon trigger Used Muon trigger config:config:

≥ 1 hit in station M3 60 Hz rate60 Hz rate

≥ 1 hit in stations (M4 & M5)

4 Hz rate4 Hz rate

- Calorimeter trigger:Calorimeter trigger:

ECAL & HCAL with high gain (MIP)

10 Hz rate10 Hz rate

M2M2 M3M3 M4M4 M5M5

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Forward tracks

M2

M3

M4

M5

M2

Hit raw Hit raw time (ns)time (ns)

00 5050-50-50

First muon Alignment with cosmicsFirst muon Alignment with cosmicsBackward tracks

Alignment corrections loaded to be aligned on forward tracks

B

F

No No analysis, analysis, no TOF no TOF

correctioncorrectionss

~11 ns

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… After data analysis of events from cosmics

Cleaning of tracks (tracks with only 4

hits)

Detailed TOF correction

Average on smaller detector areas

(not enough statistics on single

channels)

Low stat

Expectations from lab measurements

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Muon detector EfficiencyMuon detector Efficiency

Not corrected for projectivityNot corrected for projectivity

as a as a function of function of the track the track

angleangle

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Commissioning (2008)Commissioning (2008)Particle blasts… the more messy the better…Particle blasts… the more messy the better…

What done during months with cosmics could be (better) done in What done during months with cosmics could be (better) done in a few hours or days with beama few hours or days with beam Only a few opportunities: TED injection tests Only a few opportunities: TED injection tests (August/September 08)(August/September 08)

First LHC beam circulation (10 First LHC beam circulation (10 September 08)September 08)

Splash event from beam 1

(10 September 08)

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TED runsTED runs

LHC Beam 2

SPSTED beam stopperTED beam stopper

Beam 2 dump on injection line Beam 2 dump on injection line beam stopper (TED)beam stopper (TED)

340m before LHCb along 340m before LHCb along beam 2beam 2 8 mrad H and 8 mrad H and 12 mrad V from LHCb beam 12 mrad V from LHCb beam axisaxis

Particles coming from Particles coming from behindbehind the detector and the detector and not not centeredcenteredCentre of shower in upper right quadrantCentre of shower in upper right quadrantHigh flux, centre of blast ~10 particles/cmHigh flux, centre of blast ~10 particles/cm2 2 (x20 than (x20 than nominal !)nominal !)Vertex Locator ~0.1 particles/cmVertex Locator ~0.1 particles/cm22

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TED runs (2)TED runs (2)Trigger by Scintillator Pad Detector (SPD) Trigger by Scintillator Pad Detector (SPD) multiplicity.multiplicity.Readout of consecutive triggers centered on the triggered event (Time Alignment Events)

2 usable LHC injection tests:2 usable LHC injection tests:

August 22nd, 5x109 p per shot (every 48s)Muon, Calo, VELO 700 tracks in VELO

September 5th and 6th, lower flux 2x109 p per shot Muon, Calo, VELO, IT, TT700 tracks in VELO

Useful tests to verify space and time alignment Useful tests to verify space and time alignment within single sub-detectors and among sub-detectorswithin single sub-detectors and among sub-detectors

First opportunity of “good” statistics in small area First opportunity of “good” statistics in small area detectors detectors (VeLo, TT)(VeLo, TT)

SPD

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Pictures from TED Pictures from TED runsruns

VeLo reconstructed tracks, August 22, 2008

MuonMuon~70 candidates per shot~70 candidates per shot

M2

M3

M4

M5

VeLo tracks extrapolated to TT

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TED runs and Alignments : TED runs and Alignments : highlights from space highlights from space

domaindomain

VELO alignment:Module alignment

precision is about 3.4 m for X and Y

translation and 200 rad for Z rotation

~500m

Relative alignment VELO-TT (~1.5m Relative alignment VELO-TT (~1.5m apart)apart)

• Expected Expected uncertainty uncertainty in VELO-TT in VELO-TT

extrapolation:extrapolation: 300 300mm

• Hit residuals observed in TT:Hit residuals observed in TT: 500500m m

• Offsets: Offsets: 150-300 150-300mm

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September, 10September, 10thth 2008 2008

11stst circulating beams (no collisions yet) circulating beams (no collisions yet) Beam 1 in the right direction:Beam 1 in the right direction:Looking for halo and splash eventsLooking for halo and splash events

SplashSplash

Important testbench Important testbench forfor::

• AlignmentsAlignments• Experiment operation Experiment operation (smooth and quick on/off of (smooth and quick on/off of the system)the system)Exciting yet too shortExciting yet too short

• Very good response of Control and DAQ Systems• Use of “physics” Muon trigger (4-fold coincidences)

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Beam 1 on RICH2Beam 1 on RICH2

One event in RICH2 during the beam1 on collimator runs on

September 10th.

Photon blast, occupancy as high as

140k hits, out of roughly 200k pixels

in the active area.

RICH1 stayed off during these runs

(too close to the beam pipe).

Timing inside 25 ns window

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First beam: Calo & First beam: Calo & Muon Muon

5 consecutive time slots acquired per trigger5 consecutive time slots acquired per trigger

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5 consecutive time slots acquired per trigger5 consecutive time slots acquired per trigger

Tracks in the Outer Tracks in the Outer Tracker Tracker

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Back-end testsBack-end tests

Raw-Monte Carlo events Raw-Monte Carlo events injected into the DAQ injected into the DAQ

chain chain as if coming from as if coming from the readout boardsthe readout boards

(@2kHz “preselected (@2kHz “preselected events that will pass the events that will pass the

HLT”)HLT”)

1.9kHz achieved 1.9kHz achieved steadily (limited by MC steadily (limited by MC

injector)injector)

FEST (Full Experiment System Test)FEST (Full Experiment System Test)

Online and offline data monitoring and processingOnline and offline data monitoring and processing

AIMAIM:: get prepared to receive, process get prepared to receive, process and analyze 7 million events in the first and analyze 7 million events in the first

hour of collisionshour of collisions

What we test:What we test:

• Run control (the “injector” Run control (the “injector” emulates a sub-detector);emulates a sub-detector);• Data stream;Data stream;• Dynamic farm node Dynamic farm node balancing;balancing;• Data monitoring;Data monitoring;• Data storage Data storage • Interaction with the GRIDInteraction with the GRID

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2009 Shutdown activities2009 Shutdown activities

Main activities until next July:Main activities until next July:

M1 installation and commissioningM1 installation and commissioningHPD replacement (RICH)HPD replacement (RICH)HV and readout boards modification (ECAL)HV and readout boards modification (ECAL)Fixing of defective channels (MUON)Fixing of defective channels (MUON)

Control System optimizationControl System optimizationFEST weeksFEST weeks

Installation of full–size readout network for a Installation of full–size readout network for a 1 MHz readout1 MHz readout(add 350 nodes to the 200 presently in place)(add 350 nodes to the 200 presently in place)Commissioning 1 MHz readout from April onwardsCommissioning 1 MHz readout from April onwards

Reduce HLT output rate to 2 KHzReduce HLT output rate to 2 KHz Debug, continue to debug and, when Debug, continue to debug and, when finished, start finished, start debugging againdebugging again

Still (always) a lot of work…Still (always) a lot of work…

DetectorDetector

EFF EFF hardwarehardware

HLTHLT

EverythingEverything

System & DAQSystem & DAQ

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LHC schedule LHC schedule 2009/102009/10

What we can expect/hope today:What we can expect/hope today:

Setting-up run

Technical run

450 GeV 450 GeV 2 TeV 2 TeV

2 TeV 2 TeV 4 TeV, 5 pb 4 TeV, 5 pb-1-1 overalloverall

4 TeV 50 ns, 0.5(3) fb4 TeV 50 ns, 0.5(3) fb-1-1 overalloverall

Preliminary phase(~like planned one year

before…)

Physics run

TED runs (August)TED runs (August)450 Gev runs (September)450 Gev runs (September)

October and October and beyondbeyond

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9 x 1010 p/bunch, *=3m L ~2.3 x 1031 (target L)

Few weeks @ 2.3 x 1031, op = 20% 5 pb-1

LHCb plans LHCb plans 2009/102009/10Set-up and Technical phases: Set-up and Technical phases:

ramping from 450 GeV to 4 TeVramping from 450 GeV to 4 TeV

Up to 2 TeV Up to 2 TeV (6-7 weeks (6-7 weeks ?)?)::

1. Refine time and space alignment reaching nominal conditions.

2. VELO open, no LHCb B-field (With LHCb B-field at nominal, VELO may only be closed with ≥2 TeV/beam)

≥≥2 TeV/beam2 TeV/beam (6-7 (6-7 weeks ?):weeks ?):

1. Operation of LHCb magnets2. Closing of VELO

68 colliding bunch pairs out of 15668 colliding bunch pairs out of 156

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LHCb plans 2009/10LHCb plans 2009/10Physics runs @ 4 Physics runs @ 4 TeVTeV50ns bunch scheme: 1173 colliding bunch pairs out of 1333, 50ns bunch scheme: 1173 colliding bunch pairs out of 1333,

4(5?) TeV/beam4(5?) TeV/beam

9 x 109 x 101010 p/bunch, p/bunch, *=10m *=10m LL = ~1.3 x 10 = ~1.3 x 103232

200 days @ 1.3 x 10200 days @ 1.3 x 103232, , opop = 20/30% = 20/30% ~0.3(5) fb ~0.3(5) fb-1-1

Nominal LHCb year should provide 2 fbNominal LHCb year should provide 2 fb-1-1 @ 7 TeV @ 7 TeV ……but significant measurements @ 0.3 fbbut significant measurements @ 0.3 fb-1-1 and lower energy are possible and lower energy are possible

BBss J/ J/) ) BBss

AAFBFB in B in Bdd K* K*

2s measurement competing or better than Tevatron result

BR limit approaches SM value

Statistics ~4 times better than present B-factories

Trigger strategy is adapted to favor inclusive Trigger strategy is adapted to favor inclusive selections of key channels for the first selections of key channels for the first

measurementsmeasurements

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ConclusionConclusion

LHCb is eager to receive the first collisions LHCb is eager to receive the first collisions (we need them!) to conclude commissioning (we need them!) to conclude commissioning

and tune calibrations towards nominal and tune calibrations towards nominal conditions conditions

The experiment is well advanced in The experiment is well advanced in preparing the reception of the first preparing the reception of the first

collisions at moderate luminosity as soon as collisions at moderate luminosity as soon as the LHC will be able to deliver significant the LHC will be able to deliver significant

physics (DAQ, HLT and analysis)physics (DAQ, HLT and analysis)

Our (reacheable!) target Our (reacheable!) target is collecting and is collecting and quickly exploiting 0.3 fbquickly exploiting 0.3 fb-1-1 of physics in the of physics in the

first “year” of runfirst “year” of run

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THANK THANK YOU !YOU !