may 26th, 2005russell betts - uic1 studies of qcd matter at the large hadron collider russell betts...

May 26th, 2005 Russell Betts - UIC 1

Studies of QCD Matter at the Studies of QCD Matter at the Large Hadron ColliderLarge Hadron Collider

Russell BettsRussell Betts

UICUIC


Experimental Study of Ultra-Relativistic Experimental Study of Ultra-Relativistic Nucleus Nucleus CollisionsNucleus Nucleus Collisions

BNL AGS (1986)

sNN 5 GeV/u

O+O, Si+Si, Au+Au

CERN SPS (1986)

sNN 20 GeV/u

O+A, Pb+Pb

BNL RHIC (2000)

sNN 200 GeV/u

Au+Au, d+Au, Cu+Cu


What Do Multiplicities Teach Us?What Do Multiplicities Teach Us?Time Evolution of CollisionsTime Evolution of Collisions

0 fm/c

2 fm/c

7 fm/c

>7 fm/c

Parton DistributionsNuclear GeometryNuclear Shadowing

Parton Production& Reinteraction

Chemical Freezeout &Quark Recombination

Jet FragmentationFunctions

Hadron RescatteringThermal Freezeout &

Hadron Decays

QCD Matter


Energy Dependence of Particle Energy Dependence of Particle ProductionProduction

Models prior to RHIC dN/d Lower than Most Expectations

Scales with Npart (not Ncoll)

NTot ~ 8000

+

Average Transverse Energy

Energy density ~5 GeV fm–3 (Nucleon ~ 0.3 GeV fm–3)

Partonic Degrees of Freedom


Exploring the Phase DiagramExploring the Phase Diagram

Lattice QCD

T and B from Thermal Model Fits to Particle Ratios

•AGS T=125 MeV B= 540 MeV

•SPS T=170 MeV B = 270 MeV

•RHIC T=170 MeV B = 27 MeV

Tcrit~ 150 MeV


Results for Collective (Elliptic) FlowResults for Collective (Elliptic) Flow

Reaction plane

x

z

y

Hydrodynamic Limit of Flow at RHIC

Strongly Interacting Fluid

sQGP

wQGP


High pHigh pTT Suppression (Medium Effect) Suppression (Medium Effect)

pp

AuAubinaryAuAuAA Yield

NYieldR

/

Suppression of High pT Particles Relative to pp

Reference

Absorption of Away-Side Jet

STAR


Gluon Saturation EffectsGluon Saturation Effects

Small x & Large ALarge occupation number

Coherent state

Saturation momentum Qs (x)

Suppression at Forward

Rapidity (Small x) –

Evidence for Gluon

Saturation – Color Glass

Condensate

x

Brahms

d+Au


Summary of RHIC ResultsSummary of RHIC Results

The Matter is Surprisingly Strongly (Re)Interacting Slow Growth of Multiplicity with Energy ( NOT Ncoll*pp) Chemical Equilibrium of Hadronic Species Very Large “Flow” – Hydrodynamic Limit Strong Suppression of Particles with Relatively High pT

(Not in Cold Matter of d+Au) Saturation Effects at Small x

Much Still to Do: Quarkonium Studies – Color Screening Particle Correlations vs Collision Geometry Modification of Fragmentation Functions Etc etc etc ……………………

Rare Probes Need Increased L or sqrt(s)

RHIC II (New Detectors) ($$$$) or LHC


CERN Large Hadron ColliderCERN Large Hadron Collider√sNN

(TeV)L0

(cm-2s-1)

<L>/L0

(%)Run time(s/year)

geom

(b)

14.0 1034* 107 0.07

5.5 1027 70-50 106 * * 7.7

pp

Pb+Pb


A New Viewpoint for QCD Matter at LHCA New Viewpoint for QCD Matter at LHC

•Factor 30 Higher sqrt(s) Factor 30 Higher sqrt(s) than RHICthan RHIC

•Initial state dominated by Initial state dominated by low-x components. low-x components.

•Abundant production of Abundant production of variety of perturbatively variety of perturbatively produced high pproduced high pT T particles particles for detailed studiesfor detailed studies

•Higher initial energy Higher initial energy density state with longer density state with longer time in QGP phasetime in QGP phase

•Access to new regions of xAccess to new regions of x

J/J/

ZZ00


CMS at the LHCCMS at the LHC


The CMS Central RegionThe CMS Central Region

MUON BARREL

CALORIMETERS

Silicon MicrostripsPixels

ECAL Scintillating PbWO4 crystals

Cathode Strip Chambers (CSC)Resistive Plate Chambers (RPC)

Drift Tube Chambers (DT)

Resistive Plate Chambers (RPC)

SUPERCONDUCTINGCOIL

IRON YOKE

TRACKER

MUONENDCAPS

Total weight : 12,500 tOverall diameter : 14.6 mOverall length : 21.6 mMagnetic field : 4 Tesla

HCAL

Plastic scintillator/brasssandwich


CMS Detector (Augmented)CMS Detector (Augmented)

CASTORCASTOR

T2T2

Collar Collar shieldingshielding

Forward DetectorsForward Detectors

(5.32 < < 6.86)

TOTEMTOTEM

ZDCZDC

(5.32 < < 6.86)

(z = 140 m)

BeamsBeams

EMEM

HADHAD


Particle Detection in CMSParticle Detection in CMS


CMS – Above and Below GroundCMS – Above and Below Ground


SX5 and UXCSX5 and UXC

CMS caverns inaugurated Feb. 1st 2005

250,000 m3 material removed

Main cavern dimensions: 53m x 27m x 24m

Modular design can be fully assembled and tested in surface hall (SX5), then lowered into experimental cavern (UX5) within 4 months

Frank Wilczek


Pixels Barrel: 3 layers Forward: 2 layers 100x150 m2 pixels

Microstrips Barrel: 10 layers (single- and double-sided) Forward: 9 layers 1 GeV central track ~ 15 hits

Overall 210 m2 of silicon || < 2.4

2.4 m

48M pixels

5.4 m

Silicon Inner TrackerSilicon Inner Tracker

10M strips


Si Strip ModulesSi Strip Modules


Tracker Inner Barrel AssemblyTracker Inner Barrel Assembly


ECAL (PbWO4 - APD Readout)ECAL (PbWO4 - APD Readout)


ECAL AssemblyECAL Assembly

Dee

138 Supercrystals

36 Supermodules

4 Dees


HCALHCAL


HCALHCAL

HF in Bat. 186.Start ‘burn-in’ of both HF in mid-2005First elements to be lowered into UX

Shells for HE readout boxes installed.HB source calibrated by May-2005HE- by Aug 2005, HE+ by Nov 2005


Muon SystemMuon System


Barrel Muon SystemBarrel Muon System

AACHEN(MB1) 59/70 end in SeptCIEMAT(MB2) 54/70 end in Sept

LEGNARO(MB3) 56/70 end in DecTORINO(MB4) 6/40 end in Apr. 06

Yoke wheel YB+2:

34 chambers installed


Endcap Muon SystemEndcap Muon System


Status and ScheduleStatus and Schedule

Civil Engineering: USC delivered Aug 04, UXC delivered Feb 05. Civil Engineering is off the Critical Path

Magnet: All 5 coil modules are at CERN. Swivelling in June 2005. End electrical tests by end-05.

HCAL, Muons : Construction on schedule and well advanced.

TO WATCH:

ECAL: Crystals production, contracts ready to be placed with two vendors. Need to generate float in ‘ready for installation’ (rfi) milestone.

TRACKER: Rate of assembly of modules, schedule and integration. Need to generate float in rfi.

CMS* initial detector will be ready and closed for beam on 1 July 2007.

*ECAL Endcaps and Pixels will be installed during Winter 2007 shutdown in time for physics run in 2008. Heavy Ions in 2008


Heavy Ion Physics with CMSHeavy Ion Physics with CMS

Adana-Turkey, Athens, Basel, CERN, Demokritos, Dubna, Ioannina, Kent State, KFKI Budapest, Kiev, LANL, Lyon, MIT, Moscow, Mumbai, N. Zealand, Ohio, Protvino, PSI, Rice, Sofia, Strasbourg, Tbilisi,

UC Davis, UIC, U. Iowa, U Kansas, Warsaw, Yerevan


Detector CoverageDetector Coverage

Large Range of Hermetic Coverage

in , x and Q2

Unique Forward Capability

Abundant High pT Probes, Jets, J/, , Z0


Tracker in HI EnvironmentTracker in HI Environment

TrackerECAL

Central Pb+Pb Event dN/d=5000

(HIJING+OSCAR+IGUANA)

>50,000 Charged Particles –

BUT Pixels are <2% Occupied

(Key to Successful Tracking)


Preliminary

•Pixels have High Granularity, Located near Interaction Region (r1 = 4 cm)

•Use Summed Pulse Height Measurement in Reconstructed Clusters to Remove

Hits from Background Sources (Secondaries, Looping Tracks)

•Can Measure Very Low pT Particles

Charged Multiplicity: dNCharged Multiplicity: dNchch/d/d a la PHOBOS a la PHOBOS

Single layer hit counting in innermost pixel barrel layer

cosh dependence of SumADC

Chadd Smith


Track ReconstructionTrack ReconstructionpT resolution (pT/pT) impact parameter

|| < 0.7

efficiency and fakesHIJING + GEANT + ORCA – C. Roland

Track finder based on Kalman filteringTrack finder based on Kalman filteringmethodmethod

Algorithms exist for primary vertex finding,Algorithms exist for primary vertex finding,seed generation, track propagation, seed generation, track propagation, trajectory smoothing, and regional trackingtrajectory smoothing, and regional tracking

High reconstruction efficiency and low fakeHigh reconstruction efficiency and low fakerate even at high track densityrate even at high track density


100 GeV Jet + Pb+Pb Event 100 GeV Jet + Pb+Pb Event

EM+Hadronic Energy

Hijing + 100 GeV Jet Pair


HIJING (generator level, acceptance of HF and CASTOR) - C.Teplov

Global Physics from CalorimeterGlobal Physics from Calorimeter

HF

ET

CASTOR

Etot

Impact Parameter Correlation

with Calorimeter

Flow from Azimuthal Asymmetry

<Day 1 Measurement

sQGP or wQGP ??


Jet ReconstructionJet Reconstruction

-Resolution

Measured Energy

-Resolution

Efficiency, Purity

Energy resolution

Sliding Jet Cone Algorithm Used for Background SubtractionSliding Jet Cone Algorithm Used for Background SubtractionEnergy Resolution for 100 GeV Jets is Energy Resolution for 100 GeV Jets is 16% 16%

PYTHIA (100 GeV jet) + HIJING (PbPb, dN/d=5000) +

full GEANT- I. Vardanyan, O.Kodolova


Jet FragmentationJet FragmentationLongitudinal momentum fraction z along

the thrust axis of a jet: pT relative to thrust axis:

Using ECAL clusters~0 in CMS

Fragmentation function for 100 GeV Jets embedded in dN/dy ~5000 events. Use charged particles and electromagnetic clusters

C. Roland

P.Yepes


Balancing Balancing or Z or Z00 vs Jets vs Jets

Channel Barrel+endcap

Jet+jet 4.3 x 106

+jet 3.0 x 103

Z->+- + jet, ETet>50 GeV 4x102

# E

ven

ts/4

GeV

ET/0-ET

Jet (GeV)

<E>=8 GeV<E>=4 GeV<E>=0 GeV

Background

Isol. 0+jet

Estimated Event Samples in 1 month Pb+Pb at 1027cm-2s-1

, Z0

jet


J/ family

= 60 MeV

Quarkonia in CMSQuarkonia in CMS

Pb+Pb Kr+Kr Ar+Ar

L 1027 7×1028 1030

J/ 28.7k 470k 2200k

´ 0.8k 12k 57k

22.6k 320k 1400k

´ 12.4k 180k 770k

´´ 7k 100k 440k

Yield/monthYield/month(with 50% duty factor)(with 50% duty factor)


Data Acquisition and TriggerData Acquisition and Trigger

Two-level DAQ/Trigger architectureL1: Low-level hardware trigger

Muon track segmentsCalorimetric towersNo tracker infoOutput rate = few-10 kHz

HLT: online farmReplaces traditional L2, L3, etc.Refit muon and calorimeter information,

and add tracker infoOutput rate = 50 Hz

Data rateapprox. 2-5 MB/event (vs. 1 MB for pp) 100-200 MB/second written to tape

Typical CMS

L1

HLT


Main Types of Trigger Required by Physics multiplicity/centrality:”min-bias”, “central-only” high pT probes: muons, jets, photons, quarkonia etc.

High Occupancy but Low Luminosity many low level trigger objects may be present, but less isolated than in p+p.

Level 1 may be difficult for high pT particles L1 in AA has larger backgrounds than in pp due to underlying event we can read most of the events up to High Level Trigger and do partial

High Level Trigger can do a better job than L1 !High Level Trigger can do a better job than L1 !

High Level Trigger (HLT) High Level Trigger (HLT)


Illustration Of Online Farm Power: Low pIllustration Of Online Farm Power: Low pTT J/J/ψψ

Detection of low pT J/ψ requires efficient selection of low momentum, forward going muons. Simple hardware L1 dimuon trigger is not sufficient

L1 trigger Two 60 HzL2 trigger None 60 HzL3 trigger None 60 Hz

J/ψ pT >3 GeV/c

L1 trigger Single ~2 kHz

L2 trigger Re-fit 70 Hz

L3 trigger Match tracker

<40 Hz

J/ψ pT>1 GeV/c

Without online farm (HLT) With online farm (HLT)

See CMS Analysis Note 2004/02

Online farm

pT

Online farmImprovement

Acceptance x2.5


CASTOR Coverage Near Hermetic coverage (out to |η|<7 with CASTOR) Physics

Centrality Nuclear PDFs - particularly gluon distributions Momentum fractions x ~ 10-6 – 10-7 at scales of a few GeV2 in pp Diffractive processes (10-20% of total cross section at high energies) Limiting Fragmentation Peripheral and Ultra-Peripheral collisions DCC, Centauros, Strangelets ……

ZDC

(5.32 < η < 6.71)

(5.32 < η < 6.86)

Forward Detectors: CASTOR and TOTEMForward Detectors: CASTOR and TOTEM

(z = 140 m)


CASTOR Prototype and TestsCASTOR Prototype and Tests

http://cms.doc.cern.ch/castor/


100 cm of space available (9.6 x 12.5 x 100 cm)

Quartz fiber/tungsten plates

EM section segmented horizontally,HAD section longitudinally

Luminosity detector in 2nd 10 cm

Improves resolution at large b

Readout through HF electronics – signals available for L1 trigger

b2R ~ 15 fm

Zero Degree Calorimetry for CMSZero Degree Calorimetry for CMS

Beam pipe splits~140 m from IR

Beams

Spectators

Spectators

Participant Region

HADHAD

EMEM

LumLum


ZDC SimulationsZDC Simulations

1 TeV Neutron hits ZDC

Megan Lehnherr, Michael Murray, Chadd Smith

+

Daniel Elvira, Boaz Klima

Early product of FNAL LHC Physics Center


People and InstitutionsPeople and Institutions

Russia: Moscow State University, Dubna France: Lyon Georgia: Tbilisi Hungary: KFKI Budapest India: Mumbai New Zealand: Auckland Greece: Athens, Demokritos, Ioannina USA NP: Rice, UC Davis, Kent State, LANL, MIT, Ohio, UIC,

U Iowa, U Kansas Turkey, Adana In general: increased interest due to developments at RHIC

and our progress in evaluation of capabilities

Presently ~15-20 people involved directly in studies/discussions etc.

Expect to grow to ~100 by the time LHC starts, ~50 from the US, including PostDocs and Graduate Students


US Funding Progress (US Funding Progress (II))

Slow Negotiations with DoE Nuclear Physics RHIC is large piece of nuclear physics budget Daily difficulties with supporting the program, competing needs of different

experiments, HI vs spin pp program etc – even before FY06 budget !! BUT: there is a need to plan for the future:

RHIC luminosity upgrades Detector upgrades, possible new detectors LHC proposals: ALICE, ATLAS, CMS

2004 NSAC was asked to form a sub-committee to evaluate whole relativistic heavy ion program.

Recommendation #2 – “The LHC will open up a new regime in relativistic heavy-ion physics with significant opportunities for new discoveries. The Subcommittee recommends that:

Participation in the LHC should become a new component of the US Heavy Ion program

This participation should receive comparable investment priority with each of the two near term upgrade programs for the two large RHIC detectors”


US Funding Progress (US Funding Progress (IIII))US DoE Nuclear Physics Request

People and equipment for High Level Trigger farms ($3.9M)Construction of ZDC ~$0.4MPermission to participate in the program (~30 PhD+15 GS by 2007)Later M&O with main “service” contribution going towards DAQ/HLT/Computing

The FY06 BudgetNP –8.4%. RHIC small experiments terminated. Running threatened.NSAC Panel to revisit Long Range Plan – June Report?

But they didn’t say NO !Michael Murray (U Kansas) gets NSF Career Award to prototype CMS ZDCsNP groups allowed to reprogram operating funds to underwrite CMS activities.

We are optimistic and believe that CMS offers the BEST possibilities for exciting heavy ion physics with the LHC


Summary and OutlookSummary and Outlook

LHC will Extend Energy Range - in Particular High pT Reach - of HI Physics to Provide a New

Window on QCD Matter

CMS Detector offers Superb Capabilities

Full calorimeter coverage Superior momentum resolution due to 4T magnetic field High mass resolution for quarkonia Centrality, multiplicity, spectra, energy flow to very low pT

No modification to detector hardware New High Level Trigger (HLT) algorithms for HI Zero Degree Calorimeter, CASTOR and TOTEM provide unique

access to forward physics


Capital BudgetsCapital Budgets

YEAR Engineers DAQ Equip. DAQ Engineers ZDC Equip. ZDC Total

FY05 275 300 0 0 575

FY06 300 770 20 210 1300

FY07 290 1240 0 170 1700

FY08 230 470 0 0 700

FY09 0 0 0 0 0

FY10 0 0 0 0 0

Total 1095 2780 20 380 4275

Online Farm and ZDC Capital Equipment costs in k$Online Farm and ZDC Capital Equipment costs in k$

Software Professionals (2)

Infrastructure and Processors (1/4 of On-Line Farm)

ZDC Engineering

Prototyping, Testing

Construction and Installation


Operating BudgetsOperating Budgets

YEAR PhDs Cat A Cat B Travel Computing Total

FY05 5 18 0 19 50 87

FY06 10 55 0 38 100 193

FY07 20 154 5 75 350 584

FY08 30 276 5 113 350 744

FY09 30 306 30 113 350 798

FY10 30 321 5 113 350 789

Maintenance and Operation Costs in k$Maintenance and Operation Costs in k$

Cat A – Yearly Running Costs (per PhD) – Fixed by CMS

Cat B – Maintenance and Repair – NB Not for DAQ/HLT

Travel – Incremental to Current Operating Budgets of Groups

Computing – Processors and Storage for HI Data Analysis

CMS Virtual Control Room and Physics Analysis Center at FNAL

may 26th, 2005russell betts - uic1 studies of qcd matter at the large hadron collider russell betts...

Documents

cmsrussell betts uiccms

mevrussell betts uicresults

groundrussell betts

mev mb

lowx components

studies of qcd matter

rhic resultsthe matter

particle ratiosags t