1. Heavy-Ion Program in CMS at the Large Hadron Collider Byungsik Hong Korea University Outline 1. Most Important results from RHIC 2. LHC & CMS 3. Heavy-ion program at LHC 4. Korean contributions to CMS so far 5. Preparation of CMS heavy-ion program in Korea

2. 05-13-2006KIAS Workshop on LHC2 Motivation of HI Collisions Investigating the QCD prediction of a deconfined (& chiral symmetry restored) high-energy-density phase of nuclear matter QGP is thought to have existed ten millionths of second after the Big Bang; creating the primordial matter of universe in the laboratory, Little Bang. High-energy nuclear collisions will compress and heat the heavy nuclei so much that their individual protons and neutrons overlap and lots of pions arise, creating the Quark-Gluon Plasma (QGP)

3. 05-13-2006KIAS Workshop on LHC3 Lattice QCD Phase transition is expected in a strongly interacting matter, but not so close to the Stefan-Boltzmann limit.

4. 05-13-2006KIAS Workshop on LHC4 Relativistic Heavy-Ion Machines Accelerator c.m. Energy (GeV) Status SIS 18 (GSI, Germany) 2A (A=mass number) Running AGS (BNL, USA) 5AFinished SIS 300 (GSI, Germany) 8A Plan to run from ~2014 SPS (CERN, Switzerland) 20AFinish soon RHIC (BNL, USA) 200A Has been run since 2000 LHC (CERN, Switzerland) 5500A Plan to run from ~2007

5. 05-13-2006KIAS Workshop on LHC5 Phases of Nuclear Matter SIS300

6. 05-13-2006KIAS Workshop on LHC6  Brookhaven National Lab. in New York in New York Circumference: 3.83 km First collision: 2000 100A GeV Au+Au(2X10 26 /cm 2 /s) 250 GeV p+p(2X10 32 /cm 2 /s) Relativistic Heavy Ion Collider

7. 05-13-2006KIAS Workshop on LHC7 QGP Probes 1.Expectation –quarks and quarkonium states may respond differently to a plasma compared to ordinary nuclear matter 2.Hard Probes –Formed in initial collisions with high Q 2 –Calculable in pQCD given Parton structure function Hard scattering rate Fragmentation function q q Hadron jet Hadron jet

8. 05-13-2006KIAS Workshop on LHC8 Partonic Energy Loss in QGP Partons are expected to loose energy via gluon radiation in traversing a QGP(jet quenching) Hadrons above p T > 2 GeV expected to be from jet fragmentation Look for a suppression of leading hadrons in that p T region

9. 05-13-2006KIAS Workshop on LHC9 Suppression strong suppression in π 0 : –decreasing with p T –factor 6 at p T > 6 GeV/c similar suppression in charged hadrons –R AA slightly higher at intermediate p T due to protons discrepancies in charged R AA between experiments –Glauber calculations? –NN-reference? better consistency between STAR and PHENIX for central/peripheral! PHENIX, PRL 91, 072301 (2003)

10. 05-13-2006KIAS Workshop on LHC10 Initial vs. Final State Effect Initial state: gluon saturation? CGC? How to discriminate? Turn off final state  d+Au collisions Final state: parton energy loss?

11. 05-13-2006KIAS Workshop on LHC11 Centrality Dependence 1.Dramatically different and opposite centrality evolution of Au+Au experiment from d+Au control one. 2.Jet Suppression is clearly a final state effect. Au + Au Experimentd + Au Control Experiment Preliminary DataFinal Data

12. 05-13-2006KIAS Workshop on LHC12 Jet Correlation trigger Phys Rev Lett 90, 082302

13. 05-13-2006KIAS Workshop on LHC13 Away-Side Jet Correlation at Low p t 1σ syst 2σ syst PHENIX Preliminary

14. 05-13-2006KIAS Workshop on LHC14 Interpretation Near Side Far Side PHENIX Preliminary Discovery of the color shockwave?

15. 05-13-2006KIAS Workshop on LHC15 Elliptic Flow x z y time reaction plane transverse plane (at midrapidity) v 2 0 elliptic flow R N =(1+ v 2 )/(1-v 2 ) v 1 0 sideward flow p x = v 1 p t

16. 05-13-2006KIAS Workshop on LHC16 Anisotropic Flow v 1, v 2, v 4, … Spectators Reaction plane  ~-3  ~3  ~0 v 2 = 15% v 2 = 15%, v 4 =4% v 2 = 7% v 2 = 7%, v 1 =+7% v 2 = 7% v 2 = 7%, v 1 =-7% Isotropic emission Spectators X Y 1 In-plane Out-of-plane 1.5 0.5 η∼0η∼0 η∼3η∼3 η ∼ -3 x z

17. 05-13-2006KIAS Workshop on LHC17 Directed Flow v 1 STAR, PRL92, 062301 (2004) NA49, PRC69, 034903 (2003) M. Belt-Tonjes for PHOBOS (QM04) H. Masui for PHENIX (QM04) 1.Consistent among RHIC Expts. 2.Shape in forward rapidity agree with low energy data by NA49 3.Elongated shape near midrapidity

18. 05-13-2006KIAS Workshop on LHC18 v 2 vs Rapidity M.B. Tonjes for PHOBOS (QM04) v 2 is positive: v 1 and v 2 are in the same plane STAR

19. 05-13-2006KIAS Workshop on LHC19 v 2 vs Transverse Momentum Quark Recombination or Coalescence?

20. 05-13-2006KIAS Workshop on LHC20 Recombination Model B. Hong, C.-R. Ji, and D.-P. Min, Phys. Rev. C 73, 054901 (2006)

21. 05-13-2006KIAS Workshop on LHC21 Summary of Present RHIC Results 1.RHIC collisions produce more particles and energy than ever produced. 2.Fireball is close to the condition for early universe in energy density estimate and antiproton/proton ratio (> 0.6). 3.Jet quenching is observed with high p t single hadrons and jet correlations → rapid formation of QGP 4.Hot and dense matter behaves collectively and consistent with the quark recombination model → formation of the strongly interacting liquidlike QGP with the viscosity near zero 5.Spectra for electron and muons, and their implications for charm production.

22. 05-13-2006KIAS Workshop on LHC22 Future of HI research 1.Establish that the QGP is formed via leptons. 2.Explore the energy and system size dependence for the threshold effect. 3.Spin structure function of partons, especially gluons by polarized proton collisions 4.Future Project –LHC heavy-ion collision (CMS in particular) –CBM/SIS200/GSI heavy-ion collisions for the highest baryon density nuclear matter RHIC

23. 05-13-2006KIAS Workshop on LHC23 What is LHC? 1.Run p-p collisions from 2007 - Find Higgs and Supersymmetry, etc. 2.Run Pb-Pb and other ion collisions from about 2008 - Find QGP and study the detailed properties.

24. 05-13-2006KIAS Workshop on LHC24 Cosmic Timeline Taken from Scientific American (May 06)

25. 05-13-2006KIAS Workshop on LHC25 CMS (Compact Muon Solenoid)

26. 05-13-2006KIAS Workshop on LHC26 Tracking with heavy- ion events  p T /p T (%) |η| < 0.7 Fakes Efficiency (%) dN/dy p T > 1GeV p T > 3GeV p T (GeV)  (cm) Impact parameter resolution  z  r Fakes Efficiency (%) p T (GeV)

27. 05-13-2006KIAS Workshop on LHC27 ZDC @ 140 m CASTOR Lumi monitor Hermetic calorimetry up to |  |<7 plus zero degree neutral energy. T1 and T2 are multiplicity detectors. Physics: Centrality, Low-x, Limiting fragmentation, strangelets, DCC, etc. Forward Detectors

28. 05-13-2006KIAS Workshop on LHC28 E T for 3<|  |<5 Collision Geometry E T (GeV) b (fm) Assume  = 0.1 radians x z y

29. 05-13-2006KIAS Workshop on LHC29 Expected N ch ?

30. 05-13-2006KIAS Workshop on LHC30 Kinematic Range by LHC J/ψ Z0Z0  BRAHMS PHENIX LHC ε ~ 50 GeV/fm 3 Low x High M High P t Jets Quarkonia Photons Z 0, etc. by

31. 05-13-2006KIAS Workshop on LHC31 Abundant Quarkonia  J/ψ Large production cross section → should be enough to observe different melting points of 3  states.

32. 05-13-2006KIAS Workshop on LHC32 Quarkonia and QGP Ref) H. Satz, hep-ph/0512217 larger smaller

33. 05-13-2006KIAS Workshop on LHC33 Quarkonia in CMS J/  family Expect ~24k J/ψ and ~ 18/5/3 k ,  ’,  ’’ for one month with L=10 27 cm -2 s -1 and 50% efficiency σ M = 50 MeV Coverage in central rapidity region -- --+ +-- --+ +

34. 05-13-2006KIAS Workshop on LHC34 Abundant Jet Large jet cross section Full jet reconstruction: jet-jet, jet- , jet-Z 0 correlations Study in medium modifications

35. 05-13-2006KIAS Workshop on LHC35 Fragmentation of 100 GeV Jets Precision tracking out to high momenta will give detailed information on modification of the jet by the medium axis p T jet p T relative to thrust axis Momentum fraction z along thrust axis

36. 05-13-2006KIAS Workshop on LHC36 Forward Region of CMS Korea Italy Korea in CMS Total Area of Endcap RPC ~1,400 m 2

37. 05-13-2006KIAS Workshop on LHC37 Resistive Plate Chamber Final Gas mixture used in all tests 95.5% Freon 3.5% Isobutane 0.3% SF 6 + RH 50% Gap Mechanics

38. 05-13-2006KIAS Workshop on LHC38 History of the Korean RPC 1.Fundamental studies to develop the Endcap RPCs (1997 - ) 1) CERN beam test by using high intensity muon beam and 20 Ci 137 Cs 2) Cosmic muon tests (Korea Univ.) 3) Study of RPC pulses and simulations 4) Long term aging study for linseed oiled RPC 2.Design of double gap RPCs for the Endcap Region (2000 – 2003) 1) Chamber designs 2) Services for HV, LV, gas, electronics on the chamber level 3.Detector manufacturing facilities (2000 – 2003) 1) Gap and chamber production facilities 2) Gaps and chamber testing facilities for the quality controls 4.Mass production of the Endcap RPC (2004 - )

39. 05-13-2006KIAS Workshop on LHC39 Endcap RPC 1. Function : L1 muon triggers 2 wings (RE+, RE-) 4 stations (RE1, RE2, RE3, RE4) Pseudo rapidity covering: 0.9 < η < 2.1(1.6) η segmentations : 10 (6) 2. Total # of RPCs : 756 (432) Total # of FEBs : 2,268 (1,296) Total # of channels : 85,248 (41,472) 3. By September 2006, the gap production in 0.9 < η < 1.6 will be completed for the first operation of the CMS detector.

40. 05-13-2006KIAS Workshop on LHC40 Korean Endcap RPC Characteristics CMS Requirements Test Results Time Resolution< 3 nsec< 1.5 nsec Efficiency> 95 % Rate Capability> 1 kHz/cm 2 Noise Rate< 15 Hz/cm 2 < 10 Hz/cm 2 Plateau Region> 300 V> 400 V Summary of the Performance

41. 05-13-2006KIAS Workshop on LHC41 18 RE1/2s have been installed on CMS in last 2 weeks A RE1/2 is mated to CSC before installation Installation of the very 1 st RE1/2+CSC module 1 st RE1/2 installed on CMS CSC RE1/2

42. 05-13-2006KIAS Workshop on LHC42

43. 05-13-2006KIAS Workshop on LHC43 Participation of the Korean Heavy- Ion Group in CMS 1.Korea University (B. Hong and K.S. Sim) –Important role in the endcap RPC production since 1997 –Preparing the computing facility for MC simulation and data analysis 2.Konkuk University (J.T. Rhee) –Important role in the endcap RPC production since 1997 3.City University of Seoul (I.C. Park) –Will use existing computing facility for MC simulation and data analysis 4.Pusan National University (I.K. Yoo) 5.Yonsei University (J.H. Kang) 6.All major HI institutions in Korea will participate in the CMS Heavy-Ion program. CMS 참여를 결정한 순서

44. 05-13-2006KIAS Workshop on LHC44 Conclusions 1.RHIC has produced a lot of exciting new results on the quark-gluon matter in extreme conditions. 2.We look forward to seeing even more exciting results in heavy-ion collisions at LHC. –New energy frontier: √s ~1.2 PeV for a Pb-Pb collision event 3.Korean Heavy-Ion group has contributed a lot already on the construction of the CMS endcap RPC system. 4.Korean Heavy-Ion group is preparing the computing farm for the CMS MC generation and data analysis. 5.All major institutions will participate in the CMS heavy- ion program.