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CMS Experiment at CERN LHC

CMS Experiment at CERN LHC. Young-Il Choi Sungkyunkwan University (Hanyang Univ. 08.9.24 ). Prof. Young-Il Choi (Sungkyunkwan University) EDUCATION: Ph. D. in Physics, (1982-1986) 1986 University of Pittsburgh, Pittsburgh, PA, USA M. S. in Physics, (1980-1982) 1982

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CMS Experiment at CERN LHC

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  1. CMS Experiment at CERN LHC Young-Il Choi Sungkyunkwan University (Hanyang Univ.08.9.24)

  2. Prof. Young-Il Choi (Sungkyunkwan University) EDUCATION: • Ph. D. in Physics, (1982-1986) 1986 University of Pittsburgh, Pittsburgh, PA, USA • M. S. in Physics, (1980-1982) 1982 University of Pittsburgh, Pittsburgh, PA, USA • B. S. in Physics, (1974-1979) 1979 Seoul National University, Seoul, Korea CAREER: • Professor (1997 - ) Sungkyunkwan University • Associate Professor (1992 - 1997) Sungkyunkwan University • Research Scientist (1989 - 1992) Purdue University, IN, USA • Research Associate (1986 - 1989) Purdue University, IN, USA RESEARCH: - CMS Experiment at CERN, Switzerland (2000 – 2007 – ) - RENO Experiment, Korea (2006 – ) • Super Kamiokande Experiment , Japan (2002 - ) • BELLE Experiment at KEK, Japan (1997 - ) • ALEPH Experiment at CERN LEP, Switzerland (1995 - 1997) • EOS-TPC Experiment at LBL HISS, USA (1989 - 1996) • E735(Quark-Gluon Plasma) at FNAL Tevatron, USA (1986 - 1992) • AFS(E808) Experiment at CERN ISR, Switzerland (1982 - 1986)

  3. Information for K-CMS LHC experiment http://public.web.cern.ch http://cms.cern.chhttp//www.cms-kr.org Physics & High Technology2008.05

  4. Overview • CERN & LHC • CMS Detector • Korea-CMS ExperimentGroup • Particle Physics Theory • Life at CERN

  5. CERN & LHC

  6. CERN Member States

  7. CERN CMS Experiment

  8. CERN Site LHC SPS CERN Site (Meyrin)

  9. LHC Detectors General-purpose Higgs SUSY ?? Heavy Ions Quark-gluon plasma LHCf General-purpose Higgs SUSY ?? B-physics CP Violation TOTEM

  10. Collisions at the Large Hadron Collider 7x1012 Beam Energy eV 1034 cm-2 s-1 Luminosity 2835 Bunches/Beam 1011 Protons/Bunch Proton 7.5 m (25 ns) 7 TeV Proton colliding beams Bunch Crossing 4x107Hz Proton Collisions 109 Hz n - e e Parton Collisions q µ + - c 1 µ - ~ q q Z ~ p g H p New Particle Production 105 Hz p p ~ q (Higgs, SUSY, ....) Z + m µ + - q ~ m c 0 µ 2 - c ~ 0 1

  11. Injection test very successful

  12. LHC timeline • Workshop on a Large Hadron Collider in the LEP tunnel, Lausanne • Rubbia “Long-Range Planning Committee” recommends Large Hadron Collider as the right choice for CERN’s future • ECFA LHC Workshop, Aachen 1992 General Meeting on LHC Physics and Detectors, Evian les Bains 1993 Letters of Intent (ATLAS and CMS selected by LHCC) • Technical Proposals Approved 1996 Approval to move to Construction (ceiling of 475 MCHF) • Memorandum of Understanding for Construction Signed 1998 Construction Begins (after approval of Technical Design Reports) 2000 LEP closes, LHC installation starts 2004 Last experimental cavern (CMS) completed • LHC and experiments ready for first beam (Sep.10) LHC inauguration Ceremony (Oct. 21) p + p collisions (?)

  13. The CMS Collaboration

  14. CMS Detector

  15. CMS – Compact Muon Solenoid • Total weight : 12,500 t • Overall diameter : 15 m • Overall length : 21.6 m • Magnetic field : 4 Tesla

  16. CMS Detector

  17. Transverse View of CMS

  18. “Swivelling the coil” Coil is constructed vertically but needs to be horizontal!

  19. Standing in the coil – at 100K!

  20. The “Gothic Cathedrals of the 21st Century” CMS detector 100m underground

  21. Particle Detectors • Cannot directly “see” the collisions/decays • Interaction rate is too high • Lifetimes of particles are too small Even moving at the speed of light, some particles (e.g. Higgs) may only travel a few mm (or less) • Must infer what happened by observing long-lived particles • Need to identify the visible long-lived particles (e, p, π, μ etc) Measure their momenta Energy (speed) • Infer the presence of neutrinos and other invisible particles Conservation laws – measure missing energy

  22. Particle Momentum Measurement • Electrically charged particles moving in a magnetic field curve • Radius of curvature is related to the particle momentum R = p/0.3B • Should not disturb the passage of the particles • Low-mass detectors sensitive to the passage of charged particles • Many layers – join the dots! • E.g. CMS silicon tracker Electron In CMS

  23. Idea is to “stop” the particles and measure energy deposit Particles stop via energy loss processes that produce a “shower” of many charged and neutral particles – pair-production, bremsstrahlung etc. Detector can be to measure either hadrons or electrons/photons Energy Measurement - Calorimeters

  24. The CMS Muon System • The Higgs decay into ZZ to 4 is preferred for Higgs masses > 160 GeV. Coverage to || < 2.5 is required ( > 6 degrees)

  25. Particle interactions in detectors

  26. Puzzle

  27. Answer Make a “cut” on the Transverse momentum Of the tracks: pT>2 GeV

  28. Korea-CMS Experiment Group

  29. Status of Korea-CMS Experiment Group -1994 CMS Ex-Spokesperson Dr. Della Negra contacted Korean groups < Kangnung, KNU, KU, SKKU > -1997 KUS.K. Parkresearch fund(190MW 3yrs) from MoST: KODEL < KNU, KUjoinedCMS experiment > -1999 KU-CERN CMSMoU(Forward RPC detector construction) -2000 KUS.K. Parkresearch fund(410MW5yrs) 13Universities(Kangwon, KNU, Konkuk, KU, Dongshin, Seonam, SNU, Seoul Education, SKKU,Wonkwang, CNU Jeju, Chungbuk) 5Subgroups: Single Gap Production(K.S. Shim), Assemblage(J.T. Rhee), Network(S.B. Kim), Power Supply(Y.I. Choi), Magnet(S.K. Park) < 11Universities joinedCMS experiment > -2002 <KNU, Dongshin, SNU, SKKU, CNU> withdrawed from the KU RPC Construction Project -2003 KNU(SRC)-CERN CMS MoU(0.5MCHFDAQ PC Farm Construction) -2006 MoST-CERNMoU(payed CMSM&O Cat. A for 2005-2007 only) -2007 MoSTKorea-CERN cooperation: organized Korea-CMS experiment group -2008 UoSjoined CMS experiment in June. * CMS requires about 0.2MCHF/institutecontribution to join CMS newly.

  30. [MEST]Korea-CERN Cooperation Project □Organization MEST | --- Steering Committee KICOS | ALICECMSLCG (ALICE, CMS)

  31. 18 Prof.s applied for Korea-CMS research fund(07.3.23) • S.J. Hong(Gacheon-KU) 14.30 MWon • S.K. Oh(Konkuk-KNU) 75.00 • J.T. Lee(Konkuk) 43.10 • *K.N. Kim(KNU) 1,74.60 • D.H. Kim(KNU) 1,01.44 • D.C. Son(KNU) 1,71.64 • S.K. Park(KU) 2,12.92 • K.S. Shim(KU) 1,07.00 • E.I. Won(KU) 86.50 • B.S. Hong(KU) 85.00 • K.K. Joo(SNU) 48.00 • I.K. Parc(UoS-KU) 40.00 • I.T. Yu(SKKU) 30.70 • S.Y. Choi(SKKU) 74.80 • Y.I. Choi(SKKU) 53.30 • J.Y. Kim(CNNU) 53.50 • E.J. Kim(CPNU-KNU) 26.10 • *S.K. Choi(KSNU 11.60 Total 1,409.50 MWon

  32. Research Fund for 2007: 800MW • SKKU: 565MW - Stipends - Travel expenses - Computers & Material expenses - Center operational expenses - Overhead • CERN: 235MW - Staying expenses: Ph.D4000CHF/M, Students2500CHF/M(1CHF = 800W) - Computers & Material expenses - Apartment rent, car rent

  33. Korea-CMS group members(60 persons) • Team-1Lepton(muon) group - 교수: 김동희(경북대), 원은일(고대), 유인태, 최수용(팀장), 최영일(성대) - 연구원: 공대정, 김지은, 김현수, 박차원, 서현관, 서준석, 주경광 - 대학원생: 고정환, 권정택, 김장호, 이종석, 정호연, 아즈말, 미안 • Team-2RPC group - 교수: 박성근(팀장)(고대), 이준택(건대), 홍성종(가천의대) - 연구원: 이경세, 장현자, 자밀 - 기술자: 정영군, 손광재, 강민호 - 대학원생: 안성환, 김태정, 임정구 • Team-3DAQ & Analysis group - 교수: 김귀년(팀장), 손동철(경북대), 오선근(건대), 김재률(전남대) - 연구원: 김경숙, 김진철, 노상률, 이만우, 정진혁, 박향규, 함승우 - 대학원생: 송상현, 안상언, 서지원, 허애영, 유스포브 • Team-4Heavy Ion group - 교수: 김은주(전북대), 박인규(팀장)(서울시립대), 심광숙, 홍병식(고대) - 연구원: 김근범, 박진우, 김유상, Sood Gopika - 대학원생: 김지현, 김현철, 문동호, 심현하, 한가람 * Anyone can join freely.

  34. Korea-CMS groupoperation • Web site for K-CMS group • K-CMS groupworkshop: twice a year • (Mini-) workshops with theorists: twice or more • Annual evaluation for research activity: (evaluate the results quantitatively) => M&O Cat. A. 12 selection (Authorship) => Research Fund

  35. Particle Physics Theory

  36. Leptons Strong Electromagnetic Electric Charge Gluons (8) Photon Tau Tau -1 0 Neutrino Muon Muon -1 0 Neutrino Quarks Atoms Light Electron Electron -1 0 Neutrino Chemistry Mesons Electronics Baryons Nuclei Quarks Weak Gravitational Electric Charge Bosons Graviton ? Bottom Top -1/3 2/3 (W,Z) Strange Charm -1/3 2/3 Neutron decay Down Solar system Up Beta radioactivity -1/3 2/3 Galaxies Neutrino interactions Black holes Burning of the sun each quark: R , B , G 3 colours The particle drawings are simple artistic representations Matter and Force Particles

  37. The Standard Model Me ~ 0.5 MeV Mn ~ 0 Mt ~ 175,000 MeV! Mg = 0 MZ ~ 100,000 MeV Why ? Where is Gravity?

  38. Unification of fundamental forces

  39. Origin of mass and the Higgs mechanism Simplest theory – all particles are massless !! A field pervades the universe Particles interacting with this field acquire mass – stronger the interaction larger the mass The field is a quantum field – the quantum is the Higgs boson Finding the Higgs establishes the presence of the field

  40. If MH < 160 GeV use H --> ZZ --> 4e or 4 Fully active crystals are the best resolution possible needed for 2 photon decays of the Higgs.

  41. Grand Unified Theories • Perhaps the strong and electroweak forces are related. In that case leptons and quarks would make transitions and p would be unstable. The unification mass scale of a GUT must be large enough so that the decay rate for p is < the rate limit set by experiment. • The coupling constants "run" in quantum field theories due to vacuum fluctuations. For example, in EM the e charge is shielded by virtual  fluctuations into e+e- pairs on a distance scale set by, le ~ 1/me. Thus a increases as M decreases, a(0) = 1/137, a(MZ) = 1/128.

  42. SUSY and Evolution of  It is impossible to maintain the big gap between the Higgs mass scale and the GUT mass scale in the presence of quantum radiative corrections. One way to restore the gap is to postulate a relationship between fermions and bosons. Each SM particle has a supersymmetric (SUSY) partner with spin 1/2 difference. If the mass of the SUSY partners is ~ 1 TeV, then the GUT unification is good - at 1016 GeV

  43. Unanswered questions in Particle Physics a. Can gravity be included in a theory with the other three interactions ? b. What is the origin of mass?  LHC c. How many space-time dimensions do we live in ? d. Are the particles fundamental or do they possess structure ? e. Why is the charge on the electron equal and opposite to that on the proton? f. Why are there three generations of quark and lepton ? g. Why is there overwhelmingly more matter than anti-matter in the Universe ? h. Are protons unstable ? i. What is the nature of the dark matter that pervades our galaxy ? j. Are there new states of matter at exceedingly high density and temperature? k. Do the neutrinos have mass, and if so why are they so light ?

  44. What will we find at the LHC? • There is a single fundamental Higgs scalar field. This appears to be incomplete and unsatisfying. • Another layer of the “cosmic onion” is uncovered. Quarks and/or leptons are composites of some new point like entity. This is historically plausible – atoms  nuclei  nucleons  quarks. • There is a deep connection between Lorentz generators and spin generators. Each known SM particle has a “super partner” differing by ½ unit in spin. An extended set of Higgs particles exists and a whole new “SUSY” spectroscopy exists for us to explore. • The weak interactions become strong. Resonances appear in WW and WZ scattering as in  + . A new force manifests itself, leading to a new spectroscopy. • New massive vector bosons, Extra dimensions, Mini black holes, • Dark matter, Quark-gluon plasma state of the early universe • “There are more things in heaven and earth than are dreamt of”

  45. Life at CERN

  46. A PhD in Experimental Particle Physics Claire Timlin Imperial College 14/09/07 Claire Timlin - Festival of Science

  47. What do I do? What did I do before my PhD? Who am I? Introduction Why choose a PhD? Why Experimental Particle Physics? 14/09/07 Claire Timlin - Festival of Science

  48. Atmosphere at CERN Working on the LHC at such an interesting time Enjoying what I do every day – Well almost! Learning many new skills The Best Bits! Living near the Alps! Working with people who are enthusiastic about what they do Contributing to a field of research I care about Working in different countries 14/09/07 Claire Timlin - Festival of Science

  49. The Worst Bits! Job Security: Can be difficult to obtain permanent positions in the field Admin: 6 weeks advance notice required for business trips Pay: Generally not as good as in industry 14/09/07 Claire Timlin - Festival of Science

  50. Some of the Questions we hope to Answer... What is the origin of mass? How many space-time dimensions do we live in? Are the particles fundamental or do they possess structure? Why is there overwhelmingly more matter than anti-matter in the Universe? What is the nature of the dark matter that pervades our galaxy? 14/09/07 Claire Timlin - Festival of Science 50

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