1. The Large Hadron Collider at CERN: Entering a new era in unravelling the mystery of matter, space and time Tsinghua, Beijing April 2009 Felicitas Pauss LHC

2. Tsinghua University Beijing, April 2009 2 Atom Proton Big Bang Radius of Earth Earth to Sun Universe Radius of Galaxies cm Hubble ALMA 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 Physics Super-Microscope LHC

3. Tsinghua University Beijing, April 2009 3 Particle mass Particle mass ? Open Fundamental questions Unification of Forces ? Dark Matter ? Matter-Antimatter Asymmetry? Answers to open questions  LHC at CERN LHC

4. 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. LHC ring: 27 km circumference Will address some of the most fundamental questions in modern physics CMSCMS ALICEALICE LHCbLHCb ATLASATLAS Enter a New Era in Fundamental Science

5. Tsinghua University Beijing, April 2009 5 illuminate a new landscape of physics fundamental questions in modern physics The LHC will illuminate a new landscape of physics, possibly answering some of the most fundamental questions in modern physics, like e.g. The origin of mass Unification of fundamental forces New forms of matter Extra dimensions of spacetime LHC: Exploration of a new energy frontier LHC Proton-proton collisions at E CM = 14 TeV Heavy Ions: Energy/nucleon = 2.76 TeV/u Proton-proton collisions at E CM = 14 TeV Heavy Ions: Lead-lead collisions: Energy/nucleon = 2.76 TeV/u

6. Tsinghua University Beijing, April 2009 6 Future of High-Energy Frontier increasesince May 200146% Overall increase of CERN Users since May 2001: 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 LABORATORY GLOBAL LABORATORY

7. Tsinghua University Beijing, April 2009 7 Chinese Involvement in LHC Experiments LHC 3 Institutes IHEP Beijing Peking Univ. USTC Hefei 55 members 1 Institute Tsinghua University, Beijing 14 members 3 Institutes Inst. of Atomic Energy, Beijing Hua-Zhong Normal Univ., Wuhan Hua-Zhong Univ., Wuhan 7 members 4 Institutes IHEP Beijing Nanjing Univ. Shangdong Univ. USTC Hefei 31 members Chinese Institutes are involved in all 4 LHC experiments Hardware contributions Preparation for physics analysis LCG: Tier-2 at IHEP

8. Tsinghua University Beijing, April 2009 8 Chinese Involvement in LHC Experiments ATLAS China Group, meeting IHEP, May 2005 Chinese muon chambers installed in the ATLAS detector 32 MDT constructed at IHEP 32 MDT constructed at IHEP Muon trigger chambers construction at Shandong Examples

9. Tsinghua University Beijing, April 2009 9 Chinese Involvement in LHC Experiments 1/3 of CSC chamber production at IHEP CSC in CMS RPC’ RPC’s for barrel muon system, Peking University RPC chambers are mounted behind the CSCs CMS infrastructure and cabling and contribution to purchase of crystals from SIC Examples Support carts support carts for endcap disks All support carts for endcap disks were built at Hudong Shipyards

10. Tsinghua University Beijing, April 2009 10 Chinese Involvement in LHC Experiments HV card testing system Construction of the HV card testing system at Tsinghua Testing of all the HV cards at NIKHEF (1850 HV boards) at Tsinghua : Gigabit Ethernet Board (GEB), Construction and testing of Gigabit Ethernet Board (GEB), Optical Receiver Card (ORC) GEB ORC read-outtrigger electronics Contribution to the production and commissioning of the read-out and trigger electronics for the Photon spectrometerPHOS Chinese team participated in the ALICE installation at Point 2 CCNU, Wuhan HUST, Wuhan CIAE, Beijing Examples

11. Tsinghua University Beijing, April 2009 11 Protons, E beam = 7 TeV Beam crossings : 40 Million / sec p p - Collisions : ~ 600 Million / sec Write to disk : ~ 100 / sec, 1-2 Mbyte each Collisions at LHC …. in 2009 Protons, E beam = 7 TeV

12. Tsinghua University Beijing, April 2009 12 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 during first 100 days of operation.. ≈100pb -1 The during first 100 days of operation.. ≈100pb -1 Peak L of 5.10 31 η (overall) = 10% gives 0.5pb -1 /day Peak L of 2.10 32 η (overall) = 10% gives 2.0pb -1 /day During next 100 days of operation ≈ 200pb -1 ? During next 100 days of operation ≈ 200pb -1 ? heavy ion run Towards end of year (2010) heavy ion run The LHC is an unprecedented adventure Imperative to progress with care

13. Tsinghua University Beijing, April 2009 13 Present Status of Experiments 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

14. Tsinghua University Beijing, April 2009 14 Basic processes at LHC g g W/Z W/Z

15. Tsinghua University Beijing, April 2009 15 LHC Physics in 2009/2010 First beams: rediscover SM physics First beams: very early physics - rediscover SM physics Detector synchronization, in-situ alignment and calibration 10 pb -1 10 pb -1 : Standard Model processes measure jet and lepton rates, observe W, Z bosons first lookextraordinary signatures first look at possible extraordinary signatures… Measure Standard Model Processes Measure Standard Model Processes (at 10TeV need ~ 30pb -1 ): ~ 10 4 Z  e+e- (golden Z’s for detector studies (1%)) ~ 10 5 W  e ~ 10 3 ttbar (measure  to 10%) Initial Higgs searches and searches for physics beyond the SM Background for new physics Need to understand very well 30 pb -1 > 200 pb -1 Entering Higgs discovery era and explore large part of SUSY and new resonances at ~ few TeV

16. Tsinghua University Beijing, April 2009 16 L=10 35 LHC discoveries vs. time: we can dream !! “ We are ready for an unforeseen event that may or may not occur” (A. Gore) Update 2009

17. Tsinghua University Beijing, April 2009 17 LHC ring: 27 km circumference CMSCMS ALICEALICE LHCbLHCb ATLASATLAS Very exciting years are ahead of us 谢谢 !