ALICE-USA Collaboration, Physics and Approach

John Harris (Yale) DOE Panel Review of ALICE-USA, May 23-24, 2007

ALICE-USA Collaboration, Physics and Approach

LHC

Alice

Dedicated “general purpose”Heavy Ion experiment at LHC


ALICE-USA CollaborationALICE-USA Author List (2009) - 44 (+ new) PHDs + 15 graduate students

Cal. Poly, San Luis Obispo (NSF) – J. Klay, postdocCreighton U. – M. Cherney, Y. Gorbunov, B. Rizzo (gs), J. SegerU. Houston - L. Pinsky, A. Empl, B.W. Mayes II, C. Delgenio (gs), D. Minthaka (gs),

graduate studentKent State U. – S. Margetis, D. Keane, W. Zhang, postdoc, graduate studentLBNL – P. Jacobs, S. Klein, G. Odyniec, J. Putschke, H.G. Ritter, TJM Symons, M. van LeeuwenLLNL – R. Soltz, A. Glenn, J. NewbyMichigan State U. – G. Westfall, + TBDORNL – T. Awes, P. Stankus, D. Silvermyer, G. Young, postdocPurdue U. - R.P. Scharenberg, B.K. Srivastava, and grad student(s)U. Tennessee – S. Sorensen, K. Read, postdoc, grad. studentU. Texas – C. Markert, + TBDWayne State U. – T.M. Cormier, R. Bellwied, C.A. Pruneau, S. Voloshin,

A. Pavlinov, + 2 postdocs and 3 grad. studentsYale U. – J.W. Harris, J. Bielcik, J. Bielcikova, H. Caines, M. Heinz,

S. Salur, N. Smirnov, T. Aronsson (gs), and 4 graduate students


Heavy Ion Physics at the LHCLHC 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)


Heavy Ion Physics at the LHCLHC 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

hard /total~ 2% at SPS

50% at RHIC

98% at LHC• “real” jets, large pT processes

• abundance of heavy flavors• probe early times, calculable precision studies!

bb (LHC ) ~ 100 bb (RHIC)

cc (LHC) ~ 10 cc (RHIC)


ALICE Set-upHMPID

Muon Arm

TRD

PHOS

PMD

ITS

TOF

TPCSize: 16 x 26 meters

Weight: 10,000 tons

EMCal


ALICE Detectors & Acceptance

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 magnet10 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

(charged particles)

µ arm

EMCal


Particle Identification in ALICE

Pb-Pb

, K, p: 0.1- 0.15 50 GeV

Topological reconstruction Invariant mass

PID in relativistic rise

Pb-Pb

PID capabilities unique to ALICE!

Global tracking (ITS-TPC-TRD)

dE/dx (low pT + relativ. rise)

TOF, HMPID, PHOS

pT range (PID/stat. limits) in 109 pp or 107 central Pb-Pb

Decay particles: 10 - 15 GeV


ALICE EMCal (Cormier Presentation)

10+1/2+1/2=11 super-modules8 SM from US3 SM from France, Italy

Lead-scintillator sampling calorimeter = 1.4, =110o

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 pT ~ 30 GeV

Approved by LHCC 9/28/06

Allows Jet Measurements/Triggering with ALICE


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:

104 / year in minbias Pb+Pb:

inclusive jets: ET ~ 200 GeV

dijets: ET ~ 170 GeV

: pT ~ 75 GeV

inclusive : pT ~ 45 GeV

inclusive e: pT ~ 30 GeVP.Jacobs


Synopsis of ALICE Physics Measurements

Soft Probes – “ala RHIC” • ALICE – important soft physics measurements ala RHIC (+ extended PID)• Expansion dynamics different from RHIC (note - timescales, densities)• Day 1 physics + ….. (unexpected…)

Heavy Quarks• Displaced vertices (Do K- +) from TPC/ITS (charm and beauty)• Electrons in Transition Radiation Detector (TRD)

Quarkonia (forward muon arm)• J/, , ’ (excellent), ’’(2-3 yrs), ’ (very difficult!)

Jet Quenching & Medium Response• Leading particles to intermediate pT (range of intermediate pT at LHC?)• Away-side in TPC (with extended PID)

trigger on leading 0 trigger on / measure jets6x increased acceptance for ’s

compared to PHOS

measure e with pe > 10 GeV (where TRD…)


ALICE Collaboration~ 1000 Members (~ 500 M&O PhDs) 63% CERN States ~ 8% expected US

~ 30 Countries

~ 100 Institutes

~ 150 M CHF capital (+ L3 magnet)

0

200

400

600

800

1000

1200

1990 1992 1994 1996 1998 2000 2002 2004

ALICE Collaboration statistics

LoI

MoU

TP

TRD


ALICE-USAALICE-USA Collaboration

40 - 50 Ph.D. physicists and 15 graduate students by 2009

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

• Ensure the EMCal is constructed, operational in ALICE; extract EMCal physics

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 to construct 3)

• CERN LHC Committee approved EMCal for installation in ALICE in Oct. 2006

• Passed CDs-0,1 Reviews of DOE


Scientific Focus of ALICE-USA

Primary Scientific Goal

“Investigate QCD matter and measure its properties at high at the LHC”

Primary Focus – Utilize Hard Parton Scattering (& measure Eparton)

• 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

pT

Investigate energy propagation in medium to determine medium properties


Jet Yields per LHC Year & Jet Trigger Enhancements

Jet yield in 20 GeV bin

Large gains due to jet trigger

Large variation in statistical reach for different reference systems


Jet Trigger Enhancements vs Reference System

Jet triggerIncludes acceptance, efficiency, dead time, energy resolution

Complete systematic study requires all reference systems.

L1 jet “patch” trigger

x = 0.4 x 0.4

Also e, cluster trigger enhancement

factors 10 – 100 for Pb-Pb to p-p


Medium Modification of Fragmentation from Jets

Fragmentation along jet axis: z = phadron / p parton

Introduce = ln(Ejet / phadron) ~ ln (1/z):

jet directionz

N. Borghini, U. Wiedemannhep-ph/0506218

# particles with low z increases

# particles with high z deceases

z/1ln

pThadron~2 GeV


ALICE-USA Manpower

ALICE-USA Collaboration Manpower Estimates

from 10 DOE-supported research institutions:

Creighton , Houston, Kent State, LBNL, LLNL, Oak Ridge, Purdue,

Tennessee,

Wayne State, and Yale

FTEs estimate for:EMCal detector support, trigger, computing, simulations & analysis, and papers

(anticipate additional manpower from Texas, MSU)


ALICE-USA Common Fund & M&O Fees to CERN

FY07

Common Fund = 5 DOE-supported institutions * CHF 45K = CHF 225K

• CHF 225K (* 0.80) = $180K

M&O = 18 DOE collaborators * CHF 14K = CHF 252K (*0.80) = $202K

FY08

Common Fund = 5 new DOE-supported institutions * CHF 45K = CHF 225K

• CHF 225K (* 0.80) = $180K

M&O = 35 DOE collaborators * CHF 14K = CHF 490K (*0.80) = $392K

FY09

M&O = 40-50 DOE collaborators * CHF 14K = CHF 560-700K (*0.80) = $448-560K

Note - FY07, 08, 09 Common Fund payments total = $360K could be spread over three years amounting to

$120K per year for each of FY07, 08, 09.


ALICE-USA Computing (Soltz Presentation)

ALICE-USA Computing Resources

Requires DOE investment in NERSC/PDSF cluster

(half of projected ALICE-USA computing resources)

Additional resources from

LLNL Livermore Computing (LC)

Ohio Supercomputing Center at the Ohio State Univeristy (OSC/OSU)

Texas Learning Center at University of Houston. (TLC/UH)


Summary of ALICE-USA Request

Request overall DOE support for:

research and participation in ALICE of 10 institutions under review

construction of the US EMCal ($13.3 M)

computing in ALICE

Cost of support from DOE Heavy Ion Research:

redirection of effort from RHIC to ALICE : $2.7M in 2007 $3.8M in 2009

new support: $0.69M in 2007 $1.48M in 2009 (+ 1FTE includes computing)

plus $0.36M one-time fee for 2007-2009

one-time: $0.36M - CERN institutional fees (can be spread over 2007 – 2009)

annual: $0.20M in 2007 increasing to $0.45M in 2009 for CERN M&O fees

$0.05M starting in 2009 in CERN detector fees

$0.18 in 2007 to $0.4M in 2009 for sppl. travel to participate in experiment & install

EMCal

$0.23M annually in new research support

computing: $0.08M in 2007 increasing to ~ 0.35M +1 FTE in 2009 estimated for computing

hardware


Concluding RemarksSignificant new high pT heavy ion physics at LHC

ALICE - versatile, general purpose heavy ion detector at LHCwill contribute significantly to understanding of HI physics

ALICE-USA and EMCal add significant physics to ALICE & LHCmeasure and trigger on jets, photons, pi-zerosheavy quark jet tagstriggered jets response of medium

ALICE-USA seeks DOE support to participate in ALICEconstruct EMCalextract exciting, fundamental physics

ALICE-USA Collaboration, Physics and Approach

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