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

2. 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. 3 Information for K-CMS LHC experiment http://public.web.cern.ch http://public.web.cern.ch http://cms.cern.ch http://cms.cern.ch http//www.cms-kr.org http://cms.cern.ch Physics & High Technology 2008.05

4. 4 Overview CERN & LHC CMS Detector Korea- CMS Experiment Group Particle Physics Theory Particle Physics Theory Life at CERN

5. 5 CERN & LHC

6. 6 CERN Member States

7. 7 CERN CMS Experiment

8. 8 CERN Site LHC CERN Site (Meyrin) SPS

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

10. 10 Collisions at the Large Hadron Collider Bunch Crossing 4x10 7 Hz 7x10 12 eV Beam Energy 10 34 cm -2 s -1 Luminosity 2835Bunches/Beam 10 11 Protons/Bunch 7 TeV Proton colliding beams Proton Collisions 10 9 Hz Parton Collisions New Particle Production 10 5 Hz (Higgs, SUSY,....) p p H µ + µ - µ + µ - Z Z pp e - e     q q q q  1 - g ~ ~  2 0 ~ q ~  1 0 ~ 7.5 m (25 ns)

11. - Injection test very successful

12. LHC timeline 12 1984 Workshop on a Large Hadron Collider in the LEP tunnel, Lausanne 1987 Rubbia “Long-Range Planning Committee” recommends Large Hadron Collider as the right choice for CERN’s future 1990 ECFA LHC Workshop, Aachen 1992General Meeting on LHC Physics and Detectors, Evian les Bains 1993Letters of Intent (ATLAS and CMS selected by LHCC) 1994 Technical Proposals Approved 1996Approval to move to Construction (ceiling of 475 MCHF) 1998 Memorandum of Understanding for Construction Signed 1998 Construction Begins (after approval of Technical Design Reports) 2000LEP closes, LHC installation starts 2004Last experimental cavern (CMS) completed 2008 LHC and experiments ready for first beam (Sep.10) LHC inauguration Ceremony (Oct. 21) p + p collisions (?)

13. 13 The CMS Collaboration

14. 14 CMS Detector

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

16. 16 CMS Detector

17. 17 Transverse View of CMS

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

19. 19 Standing in the coil – at 100K!

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

21. 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. 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. 23 Energy Measurement - Calorimeters 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

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

25. 25 Particle interactions in detectors

26. 26 Puzzle

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

28. 28 Korea-CMS Experiment Group

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

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

31. 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(KSNU11.60 Total 1,409.50 MWon

32. 32 Research Fund for 2007: 800MW SKKU: 565MW - Stipends - Travel expenses - Computers & Material expenses - Center operational expenses - Overhead CERN: 235MW - Staying expenses: Ph.D 4000CHF/M, Students 2500CHF/M (1CHF = 800W) - Computers & Material expenses - Apartment rent, car rent

33. 33 Korea-CMS group members(60 persons) Team-1 Lepton(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-2 RPC group - 교수 : 박성근 ( 팀장 )( 고대 ), 이준택 ( 건대 ), 홍성종 ( 가천의대 ) - 연구원 : 이경세, 장현자, 자밀 - 기술자 : 정영군, 손광재, 강민호 - 대학원생 : 안성환, 김태정, 임정구 Team-3 DAQ & 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-4 Heavy 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. 34 Korea-CMS group operation Web site for K-CMS group K-CMS group workshop: 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. 35 Particle Physics Theory

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

37. 37 The Standard Model Where is Gravity? M e ~ 0.5 MeV M ~ 0 M t ~ 175,000 MeV! M  = 0 M Z ~ 100,000 MeV Why ?

38. 38 Unification of fundamental forces

39. 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. 40 If M H ZZ --> 4e or 4  Fully active crystals are the best resolution possible needed for 2 photon decays of the Higgs.

41. 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, e ~ 1/m e. Thus  increases as M decreases,  (0) = 1/137,  (M Z ) = 1/128.

42. 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 10 16 GeV

43. 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. 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. 45 Life at CERN

46. 46 14/09/07Claire Timlin - Festival of Science

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

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

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

50. 50 Claire Timlin - Festival of Science5014/09/07

51. 51 A Week in the Life of an Experimental Particle Physics Student Model making: –Modelling the interactions of particles using computer programs –Figuring out why the results look like they do –Preparing to analyse data from LHC Meetings: –Presenting methods and results –Lots of lively discussion! Researching fields of interest 14/09/07Claire Timlin - Festival of Science