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Alice. Dedicated “general purpose” Heavy Ion experiment at LHC. ALICE-USA. LHC. ALICE Collaboration. ~ 1000 Members (63% - CERN States) ~ 30 Countries ~ 100 Institutes ~ 150 M CHF capital (+ ‘free’ magnet). ALICE Set-up. TOF. TRD. HMPID. EMCal. ITS. PMD. Muon Arm.
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Alice Dedicated “general purpose” Heavy Ion experiment at LHC ALICE-USA LHC 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) John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
ALICE Set-up TOF TRD HMPID EMCal ITS PMD Muon Arm PHOS Size: 16 x 26 meters Weight: 10,000 tons TPC John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
(charged particles) µ arm ALICE Detectors & Acceptance central barrel -0.9 < h < 0.9 • Df = 2p tracking, PID (TPC/ITS/ToF) • single arm RICH (HMPID) • single arm e.m. cal (PHOS) • jet calorimeter (proposed EMCal) forward muon arm 2.4 < h < 4 • absorber, 3 T-m dipole magnet10 tracking + 4 trigger chambers multiplicity detectors -5.4 < h < 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 John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
1 event : 5000 p C(q inv) q inv (GeV/c) 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 (v2, HBT, Tchem & Tkin, • strange/charm particles & resonances) John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
sbb (LHC ) ~ 100 sbb (RHIC) scc (LHC) ~ 10 scc (RHIC) 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 (v2, HBT, Tchem & Tkin, • strange/charm particles & resonances) Hard Probes at LHC – • significant increase in hard cross sections • shard /stotal~ 2% at SPS • 50% at RHIC • 98% at LHC • “real” jets, large pT processes • abundance of heavy flavors • probe early times, calculable precision studies! John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
ALICE Physics Measurements Hard Probes – Jet Quenching • Jets, g , pi-zeros, leading particles to large pT Hard Probes – Heavy Quarks • Displaced vertices (Do K- p+) from TPC/ITS • Electrons in Transition Radiation Detector (TRD) Hard Probes – Quarkonia • J/y, , ’ (excellent),’’(2-3 yrs),y’(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 + 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 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 e 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) • g – jet coincidences • Low energy particles correlated with trigger or quenched jet • requires ALICE acceptance, robust tracking, & PID to low/high pT • Investigate energy propagation in medium to determine medium properties John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
ALICE EMCal Approved by LHCC 9/28/06 • 10+1/2+1/2=11 super-modules • 8 SM from US • 3 SM from France, Italy Allows Jet Measurements with ALICE Lead-scintillator sampling calorimeter Dh = 1.4, Df=110o Shashlik geometry, APD photosensor ~13K towers (DhxDf ~ 0.014 x 0.014) Energy resolution 15%/√E + 2% over-takes tracking above 30 GeV po/g discrimination to pT ~ 30 GeV 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) - Goodg/p0discrimination increases coverage - Good electron/hadron discrimination • EMCal extends the physics of ALICE: • 104 / year in minbias Pb+Pb: • inclusive jets: ET ~ 200 GeV • dijets: ET ~ 170 GeV • p0: pT ~ 75 GeV • inclusive g: pT ~ 45 GeV • inclusive e: pT ~ 30 GeV Thanks – P.Jacobs John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
ALICE Performance for Jets ET = 100 GeV, R = 0.4 EM (TPC+EMCal) (TPC) (TPC – like RHIC) John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
Medium Modification of Fragmentation from Jets jet direction z N. Borghini, U. Wiedemann hep-ph/0506218 # particles with low z increases # particles with high z deceases pThadron~2 GeV Fragmentation along jet axis: z = phadron / p parton Introduce = ln(Ejet / phadron)~ ln (1/z): Black line = radiative E-loss Dashed line = flat = “opaque” What about collisional E-loss? 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 John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
Summary and Purpose Much to understand and significant high pT 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 John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
Back-up Slides John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007
Identified particle spectra Particle reconstruction and identification capabilities: unique to ALICE Global tracking (ITS-TPC-TRD) + dE/dx (low pT + relativ. rise), TOF, HMPID, PHOS, … Invariant mass, topological reconstruction Acceptance / efficiency / reconstruction rate (e) / contamination pT range (PID or stat. limits) for 107 central Pb-Pb and 109 min. bias pp For ~ 20 particle species for -1 < y < +1 and -4 < y < +2.5 p, K, p: 0.1- 0.15 to 50 GeV Weak or strong decaying particles: to 10-15 GeV Mid-rapidity p PID in the relativistic rise K p Pb-Pb Pb-Pb pT (GeV/c) John Harris (Yale) QCD Town Meeting, Rutgers University, 12 – 14 Jan 2007