The Large Hadron Collider at CERN:The Large Hadron Collider at CERN: Entering a new era in unravelling the mystery of Entering a new era in unravelling the mystery of
matter, space and timematter, space and time
Tsinghua, BeijingApril 2009
Felicitas Pauss
LHCLHC
Tsinghua University Beijing, April 2009 2
AtomProton
Big Bang
Radius of Earth
Earth to Sun
Universe
Radius of Galaxies
cmHubbleALMA
VLT
WMAP
Study the structure of the Universe at its most fundamental level: explore the basic physics laws which govern the fundamental building blocks of matter
and the structure of spacetime
Particle PhysicsParticle Physics
Super-MicroscopeSuper-Microscope
LHCLHC
Tsinghua University Beijing, April 2009 3
Particle massParticle mass ?Particle massParticle mass ?
Open Fundamental questionsOpen Fundamental questions
Unification of Forces ?Unification of Forces ?Unification of Forces ?Unification of Forces ?
Dark MatterDark Matter ? ?Dark MatterDark Matter ? ?
Matter-Antimatter Asymmetry?Matter-Antimatter Asymmetry?Matter-Antimatter Asymmetry?Matter-Antimatter Asymmetry?
Answers to open questionsAnswers to open questions LHC at CERNLHC at CERN
LHCLHC
Tsinghua University Beijing, April 2009 4
Start-up of the Large Hadron Collider (LHC), one of the largest and truly global scientific projects ever, is the most exciting turning point in particle physics.
Start-up of the Large Hadron Collider (LHC), one of the largest and truly global scientific projects ever, is the most exciting turning point in particle physics.
LHC ring:27 km circumference
Will address Will address some of the most fundamental some of the most fundamental questions in modern physicsquestions in modern physics
Will address Will address some of the most fundamental some of the most fundamental questions in modern physicsquestions in modern physics
CMSCMSCMSCMS
ALICEALICEALICEALICE
LHCbLHCbLHCbLHCb
ATLASATLASATLASATLAS
Enter a New Era in Fundamental ScienceEnter a New Era in Fundamental Science
Tsinghua University Beijing, April 2009 5
The LHC will illuminate a new illuminate a new landscape of physicslandscape of physics, possibly answering some of the most
fundamental questions in modern fundamental questions in modern physicsphysics, like e.g.
The origin of massUnification of fundamental forces
New forms of matterExtra dimensions of spacetime
LHC: LHC: Exploration of a new energy frontierExploration of a new energy frontier
LHCLHC
Proton-proton collisions at EProton-proton collisions at ECMCM = 14 TeV = 14 TeV
Heavy Ions: Heavy Ions: Lead-lead collisions: Energy/nucleon = 2.76 TeV/uEnergy/nucleon = 2.76 TeV/u
Tsinghua University Beijing, April 2009 6
Future of High-Energy Frontier
Overall increaseincrease of CERN Users since May 2001since May 2001: 46%46% 26% Member States 97% Observer States (India, Israel, Japan, Russia, Turkey, USA)
121% Other States
Due to LHC
CERN became a CERN became a GLOBAL GLOBAL
LABORATORYLABORATORY
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ChineseChinese Involvement in LHC Experiments Involvement in LHC Experiments
LHCLHC
3 InstitutesIHEP BeijingPeking Univ.USTC Hefei
55 members
1 InstituteTsinghua University, Beijing
14 members
3 InstitutesInst. of Atomic Energy, Beijing
Hua-Zhong Normal Univ., WuhanHua-Zhong Univ., Wuhan
7 members
4 InstitutesIHEP BeijingNanjing Univ.
Shangdong Univ.USTC Hefei
31 members
Chinese Institutes are involved in all 4 LHC experiments
Hardware contributionsHardware contributionsPreparation for physics analysisPreparation for physics analysis
LCG: Tier-2 at IHEPLCG: Tier-2 at IHEP
Tsinghua University Beijing, April 2009 8
ChineseChinese Involvement in LHC Experiments Involvement in LHC Experiments
ATLAS China Group, meeting IHEP, May 2005ATLAS China Group, meeting IHEP, May 2005
Chinese muon chambers installed in the Chinese muon chambers installed in the ATLAS detectorATLAS detector
32 MDT constructed at IHEP32 MDT constructed at IHEP
Muon trigger chambers construction Muon trigger chambers construction at Shandongat Shandong
ExamplesExamples
Tsinghua University Beijing, April 2009 9
ChineseChinese Involvement in LHC Experiments Involvement in LHC Experiments
1/3 of CSC chamber production at IHEP1/3 of CSC chamber production at IHEP
CSC in CMSCSC in CMS
RPC’RPC’s for barrel muon system, Peking University
RPC chambers are mounted behind RPC chambers are mounted behind the CSCsthe CSCs
CMS infrastructure and cabling
andcontribution to purchase of
crystals from SIC
ExamplesExamples
Support carts
All support carts support carts for endcap disksfor endcap disks
were built at Hudong Shipyards
Tsinghua University Beijing, April 2009 10
ChineseChinese Involvement in LHC Experiments Involvement in LHC Experiments
Construction of the HV card testing systemHV card testing system at Tsinghua Testing of all the HV cards at NIKHEF (1850 HV boards)
at Tsinghua :Construction and testing of Gigabit Ethernet Board (GEB), Gigabit Ethernet Board (GEB), Optical Receiver Card (ORC)Optical Receiver Card (ORC)GEBGEBORCORC
Contribution to the production and commissioning of the read-read-
outout and trigger electronicstrigger electronics for the Photon spectrometer
PHOSPHOS
Chinese team participated in the Chinese team participated in the ALICE installation at Point 2ALICE installation at Point 2
CCNU, WuhanCCNU, WuhanHUST, WuhanHUST, WuhanCIAE, BeijingCIAE, Beijing
ExamplesExamples
Tsinghua University Beijing, April 2009 11
Protons, Ebeam= 7 TeV
Beam crossings : 40 Million / secp p - Collisions : ~ 600 Million / secWrite to disk : ~ 100 / sec, 1-2 Mbyte each
Collisions at LHC …. in 2009Collisions at LHC …. in 2009
Protons, Ebeam= 7 TeV
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Beam Conditions for Physics Machine protection will be tested with beam (at
0.45 TeV energy levels)
Beam energy limit in 2010: 5 TeV Beam energy limit in 2010: 5 TeV
Estimated integrated luminosity Estimated integrated luminosity The The during first 100 days of operation.. during first 100 days of operation.. ≈≈100pb100pb-1-1
Peak L of 5.1031 η (overall) = 10% gives 0.5pb-1/dayPeak L of 2.1032 η (overall) = 10% gives 2.0pb-1/day
During next 100 days of operationDuring next 100 days of operation ≈ ≈ 200pb200pb-1-1??
Towards end of year (2010) heavy ion runheavy ion run
The LHC is an unprecedented adventureThe LHC is an unprecedented adventureImperative to progress with careImperative to progress with care
Tsinghua University Beijing, April 2009 13
Present Status of ExperimentsUse time in most efficient way:Use time in most efficient way:
Installation of some detector components, some repairs, commissioning using cosmics
Gain operation experience in situ before collisions start
ATLAS: 216 million cosmic events
CMS: 300 million cosmic events
CMS
Tsinghua University Beijing, April 2009 14
Basic processes at LHC
gg
gg
W/ZW/Z
W/ZW/Z
Tsinghua University Beijing, April 2009 15
LHC Physics in 2009/2010LHC Physics in 2009/2010
First beams: First beams: very early physics - rediscover SM physicsrediscover SM physics Detector synchronization, in-situ alignment and calibration
10 pb10 pb-1-1: Standard Model processes measure jet and lepton rates, observe W, Z bosons first lookfirst look at possible extraordinary signaturesextraordinary signatures…
Measure Standard Model ProcessesMeasure Standard Model Processes (at 10TeV need ~ 30pb-1):
~ 104 Z e+e- (golden Z’s for detector studies (1%))
~ 105 W e~ 103 ttbar (measure to 10%)
Initial Higgs searches and searches for physics beyond the SM
Background for new physics
Need to understand very well
30 pb30 pb-1-1
> 200 pb> 200 pb-1-1 Entering Higgs discovery era and explore large part of SUSY and new resonances at ~ few TeV
Tsinghua University Beijing, April 2009 16
L=1035
LHC discoveries vs. time: we can dream !!LHC discoveries vs. time: we can dream !!
“ “ We are ready for an unforeseen event that may or may not occur”We are ready for an unforeseen event that may or may not occur”(A. Gore)
Up
da
te 2
00
9
Tsinghua University Beijing, April 2009 17
LHC ring:27 km circumference
CMSCMSCMSCMS
ALICEALICEALICEALICE
LHCbLHCbLHCbLHCb
ATLASATLASATLASATLAS
Very exciting years are ahead of usVery exciting years are ahead of usVery exciting years are ahead of usVery exciting years are ahead of us
谢谢 !