ALICEUSA

1
ALICE-USA
LHC
2
ALICE Collaboration
1000 Members (63 - CERN States) 30
Countries 100 Institutes 150 M CHF capital
( free magnet)
3
ALICE Set-up
TOF
TRD
HMPID
EMCal
ITS
PMD
Muon Arm
PHOS
Size 16 x 26 meters Weight 10,000 tons
TPC
4
ALICE Detectors Acceptance

• central barrel -0.9 lt h lt 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 lt h lt 4
• absorber, 3 T-m dipole magnet10 tracking 4
  trigger chambers
• multiplicity detectors -5.4 lt h lt 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
(No Transcript)
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 (v2, HBT, Tchem
  Tkin,
• strange/charm particles resonances)

7
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!

8
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

9
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
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

11
ALICE EMCal
Approved by LHCC 9/28/06
101/21/211 super-modules 8 SM from US 3 SM
from France, Italy
Allows Jet Measurements with ALICE
Lead-scintillator sampling calorimeter Dh 1.4,
Df110o Shashlik geometry, APD photosensor
13K towers (Dh x Df 0.014 x 0.014) Energy
resolution ? 15/vE 2 over-takes tracking
above 30 GeV po/g discrimination to pT 30 GeV
12
Capabilities of ALICE Extended by EMCal
EMCal improves detector capabilities - Fast
trigger 10 -100 enhancement of jets - Improves
jet reconstruction (plus TPC) - Good g/p0
discrimination increases coverage - Good
electron/hadron discrimination
EMCal extends the physics of ALICE 104 /
year in minbias PbPb 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
13
ALICE Performance for Jets
14
Medium Modification of Fragmentation from Jets
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?
15
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
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
17
Back-up Slides
18
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 lt y lt 1 and -4
lt y lt 2.5
p, K, p 0.1- 0.15 to 50 GeV
Weak or strong decaying particles to 10-15 GeV
Mid-rapidity
PID in the relativistic rise
p
K
p
Pb-Pb
Pb-Pb
pT (GeV/c)