1. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 ALICE-USA LHC Alice Dedicated “general purpose” Heavy Ion experiment at LHC

2. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 ALICE Collaboration ~ 1000 Members (63% - CERN States) ~ 30 Countries ~ 100 Institutes ~ 150 M CHF capital (+ ‘free’ magnet)

3. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 ALICE Set-up HMPID Muon Arm TRD PHOS PMD ITS TOF TPC Size: 16 x 26 meters Weight: 10,000 tons EMCal

4. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 ALICE Detectors & Acceptance (charged particles) µ arm central barrel -0.9 <  < 0.9  = 2  tracking, PID (TPC/ITS/ToF) single arm RICH (HMPID) single arm e.m. cal (PHOS) jet calorimeter (proposed EMCal) forward muon arm 2.4 <  < 4 absorber, 3 T-m dipole magnet 10 tracking + 4 trigger chambers multiplicity detectors -5.4 <  < 3 including photon counting in PMD trigger & timing detectors 6 Zero Degree Calorimeters T0: ring of quartz window PMT's V0: ring of scint. Paddles

5. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007

6. Heavy Ion Physics at the LHC LHC Heavy Ions – guided by pQCD predictions expectations (detector simulations) based on RHIC extrapolations and theory lesson from RHIC – guided by theory + versatility + “expect the unexpected” Soft Physics at LHC – smooth extrapolation from SPS  RHIC  LHC? expansion will be different (v 2, HBT, T chem & T kin, strange/charm particles & resonances) 1 event : 5000  C(q inv ) q inv (GeV/c)

7. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 Heavy Ion Physics at the LHC LHC Heavy Ions – guided by pQCD predictions expectations (detector simulations) based on RHIC extrapolations and theory lesson from RHIC – “expect the unexpected” Soft Physics at LHC – smooth extrapolation from SPS  RHIC  LHC? expansion will be different (v 2, HBT, T chem & T kin, strange/charm particles & resonances) Hard Probes at LHC – significant increase in hard cross sections   hard /  total  ~ 2% at SPS 50% at RHIC 98% at LHC “real” jets, large p T processes abundance of heavy flavors probe early times, calculable  precision studies!  bb (LHC ) ~ 100  bb (RHIC)  cc (LHC) ~ 10  cc (RHIC)

8. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 ALICE Physics Measurements Hard Probes – Jet Quenching Jets,  pi-zeros, leading particles to large p T Hard Probes – Heavy Quarks Displaced vertices (D o  K -  +) from TPC/ITS Electrons in Transition Radiation Detector (TRD) Hard Probes – Quarkonia J/ , ,  ’ (excellent),  ’’(2-3 yrs),  ’ (NO WAY…) Soft Probes – “ala RHIC” Expansion dynamics different from RHIC due to timescales, densities All soft physics measurements as at RHIC so far (+ extended PID) Day 1 physics +

9. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 ALICE-USA ALICE-USA Collaboration 12 DOE-supported research institutions: Creighton, Houston, Kent State, LBNL, LLNL, Michigan State, Oak Ridge, Purdue, Tennessee, Texas, Wayne State, and Yale ALICE-USA Primary Focus Investigate medium modification of partonic energy loss – “jet quenching” Investigate response of medium to large energy depositions ALICE-USA Equip. Proposal to DOE for Major Fraction of ALICE EMCal Construct 8 of 11 super-modules of EMCal for ALICE Italy and France proposing to construct 3 CERN LHC Committee approved EMCal for installation in ALICE Passed CDs-0,1 Reviews of DOE

10. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 Scientific Focus of ALICE-USA Primary Scientific Goal “Investigate QCD matter and measure its properties at high  at the LHC” Primary Focus – Utilize Initial Hard Parton Scattering High energy jets, photons and heavy flavors  requires EMCal and triggering Exploit large kinematic range of jets at LHC Measure jet structure & medium-induced jet modification Investigate energy loss mechanism with quark-tagged jets (heavy flavor decays) gluon jets (light hadron leading)  – jet coincidences Low energy particles correlated with trigger or quenched jet  requires ALICE acceptance, robust tracking, & PID to low/high p T Investigate energy propagation in medium to determine medium properties

11. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 ALICE EMCal 10+1/2+1/2=11 super-modules 8 SM from US 3 SM from France, Italy Lead-scintillator sampling calorimeter  = 1.4,  =110 o Shashlik geometry, APD photosensor ~13K towers (  x  ~ 0.014 x 0.014) Energy resolution  15%/√E + 2% over-takes tracking above 30 GeV  o /  discrimination to p T ~ 30 GeV Approved by LHCC 9/28/06 Allows Jet Measurements with ALICE

12. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 Capabilities of ALICE Extended by EMCal EMCal improves detector capabilities: - Fast trigger ~10 -100 enhancement of jets - Improves jet reconstruction (plus TPC) - Good   discrimination increases coverage - Good electron/hadron discrimination EMCal extends the physics of ALICE: 10 4 / year in minbias Pb+Pb: inclusive jets: E T ~ 200 GeV dijets: E T ~ 170 GeV   : p T ~ 75 GeV inclusive  : p T ~ 45 GeV inclusive e: p T ~ 30 GeV Thanks – P.Jacobs

13. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 ALICE Performance for Jets E T = 100 GeV, R = 0.4 EM (TPC+EMCal) (TPC) (TPC – like RHIC)

14. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 Medium Modification of Fragmentation from Jets Fragmentation along jet axis: z = p hadron / p parton Introduce  = ln(E jet / p hadron ) ~ ln (1/z): jet direction z N. Borghini, U. Wiedemann hep-ph/0506218 # particles with low z increases # particles with high z deceases p T hadron ~2 GeV Black line = radiative E-loss Dashed line = flat = “opaque” What about collisional E-loss?

15. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 ALICE-USA Manpower ALICE-USA Collaboration Manpower Estimates from 12 DOE-supported research institutions: Creighton, Houston, Kent State, LBNL, LLNL, Michigan State, Oak Ridge, Purdue, Tennessee, Texas, Wayne State, and Yale FTEs estimate for: EMCal detector support, trigger, computing, simulations & analysis, and papers

16. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 Summary and Purpose Much to understand and significant high p T physics at upgraded RHIC (& detectors) luminosity at LHC ALICE - versatile, general purpose heavy ion detector at LHC will contribute significantly to understanding of HI physics ALICE-USA and EMCal add significant physics to ALICE measure and trigger on jets, photons, pi-zeros heavy quark jet tags triggered jets  response of medium ALICE-USA seeks community & DOE support to participate in ALICE construct EMCal extract exciting, fundamental physics

17. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 Back-up Slides

18. John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007 Particle reconstruction and identification capabilities: unique to ALICE Global tracking (ITS-TPC-TRD) + dE/dx (low p T + relativ. rise), TOF, HMPID, PHOS, … Invariant mass, topological reconstruction Acceptance / efficiency / reconstruction rate (  ) / contamination p T range (PID or stat. limits) for 10 7 central Pb-Pb and 10 9 min. bias pp Identified particle spectra Pb-Pb Mid-rapidity PID in the relativistic rise p K  Pb-Pb p T (GeV/c) For ~ 20 particle species for -1 < y < +1 and -4 < y < +2.5 , K, p: 0.1- 0.15 to 50 GeV Weak or strong decaying particles: to 10-15 GeV