Next Generation Nuclear Physics

QCD with nuclei as the laboratory

colliders to explore the frontiers of high temperature and high density

QCD lab at BNL

High Temperature limit of QCD: HI collisions at RHIC

High Density limit:electron-ion colliderreach very small x

non-perturbative QCD:large-scale computing resources: QCDOC +…

T>200 MeV

A Unique Evolution

QCD

confinement new phases

low xcolor glass

High T, QCD

p-spinstructure

RHIC RHIC upgrades eRHIC

Discovery Exploration Precision

QCD phase transition at high T

Color charge of gluons self-interaction theory is non-abelian

confinement of quarks in hadrons

at large distance:

+ +…

At high temperature and density: force is screened by produced color-chargesexpect transition to plasma of (free?) quarks and gluons

asymptotic freedom

4 complementary experiments at RHIC

STAR

We have found really surprising stuff!

Pressure built up very rapidly during ion collisions at RHIC large collective flowhydrodynamics works w/low viscosityinteraction large, fast thermalizationviscosity small

huge energy loss in fast quarks

traversing mediumenergy, gluon density largemedium is opaque

3x higher baryon yield than p+p

Kolb, et al

Not the expected ideal gas!!

PHENIX

fast equilibration, flow, opacity – how?

parton cascade using free q,g scattering cross sections doesn’t work! need x50 in medium

Molnar

Lattice QCD shows qqresonant states at T > Tc, also implying high interaction cross sections

Hatsuda, et al.

see something like this in EM plasma!

visc

osit

y

coupling = <PE>/<KE>

S. Ichimaru

strong coupling

do heavy quarks also lose energy and flow?

seems so, but cannot be all by radiating gluons

e± from charm show non-zero flow

thermalization with the light quarks?not so easy to do!

large mass → produced earlysets scale for interaction w/QGP

so…

How do we study the plasma physics of this stuff?

hint:how are electromagnetic (normal) plasmas studied?

Plasma properties studied by plasma physicists

density and opacity seen to be high at RHIC

transport properties of the plasmaelectrical and thermal conductivityhydrodynamic expansion, shock propagation, diffusionwaves in plasma and dispersion relationplasma oscillations and instabilitiesscreening length

radiation (temperature, dynamics, bound states…)blackbody radiation from plasmabremsstrahlungcollisions and recombination in the plasma

So, here’s a plan

1) Upgrade RHIC detectorsrare and/or high background probes of plasmaQGP plasma a “filter” for fragmentation, confinement

2) Increase RHIC luminosity hard probes cross sections small at √s=200 GeVscan beam energy, size in lifetime of a grad student!x40 compared to baseline (x10 by electron cooling)

Add electron accelerator (either ring or linac)reach very high gluon densities - saturation?

probe with DISstudy role of quarks, gluons in nucleon spin structure

reach very low-x, with high luminosity

Detector upgrades to address key measurements

Electromagnetic radiation → plasma temperaturesignal electron

Cherenkov blobs

partner positronneeded for rejection e+

e-

pair opening angle

e+e- pair continuum

background: e+ e -

e+ e -

photon detection byCsI-coated triple GEMs

will be installed in PHENIX in 2007

correlations of ≥ 2 particles from jets traversing QGP-jet correlations; fixes jet energyidentify the fragments for hadronization, charm e-loss

upgrade PID(STAR), coverage(PHENIX) & luminosity!

Jet tomography (jet-jet and -jet) → plasma transport

major upgrades, continued

Heavy flavor (c- and b-production)

D

AuAu D

X

J/B

X

K

ee

add Si vertextrackers to STAR (thinned wafers)PHENIX (strips, pixels)

RHIC (1.5 nb-1) RHIC upgrade (30 nb-1)J/y (y’) 38,000 (1400) 760,000 (28,000) 35 700

•Quarkonia need luminosity!

W-Physics upgrades for q,qbar spin contribution

Forward GEM Tracker

Heavy Flavor Tracker

Inner Silicon Tracker

Forward Silicon Tracker

STAR: Tracking UpgradeR&D ongoing

PHENIX: muon triggerfunded by NSF

R1

R2

R3

RHIC II

FY 2006 FY 2007 FY 2008 FY 2009 FY 2010 FY 2011 FY 2012 FY 2013

RHIC Mid-Term Strategic Plan

LHI

LP4

e Cooling CD-0 CD-1 CD-2 CD-3 CD-4

PHENIX + STAR Data-Taking

Hi Rate DAQ 1000

PIDHBD

TOF

VTX

Forward

FMSMu Trigger Nose Cone Calorimeter

EBIS

Heavy Ion Luminosity

SPIN F.O.M.

e-pair spectrum Open Charm Jet Tomography

Mono-JetU+U

PHENIX STAR

G/G P-V W± prod. and Transversity

PHENIX & STAR VTX upgrades

STAR Integrated Tracking

Scientific Frontiers for eRHIC

Understand nucleon structure and its spin, role of quarks & gluons in the nucleons, issues of confinement, low-x & DVCS…

Determine the role of partons in nuclei to understand confinement in nuclei

Study hadronization in nucleons & in nuclear media

Explore partonic matter under extreme conditions with e-A Large “A” at RHIC : very high gluon densitiesSaturation/Color Glass Condensate

EIC detector

central tracking:high precision, fast Si (inner) triple-GEM (outer)

Collisionsystem

<L>/L0

(%)

107

Run time

(s/year)

L0

(cm-2s-1)

√sNN

(TeV)

1034 * 14.0

pp

70-50 106 ** 7.71027 5.5PbPb

Running parameters:

geom

(b)

0.07

Other collision systems:pA, lighter ions (Sn, Kr, Ar, O) and energies

*Lmax(ALICE) = 1031 ** Lint(ALICE) ~ 0.7 nb-1/year

Further pushing the high T limit:the LHC as a heavy ion collider

ALICE: the dedicated HI experiment

Solenoid magnet 0.5 T

Central tracking system:• ITS •TPC• TRD• TOF

MUON Spectrometer:• absorbers• tracking stations• trigger chambers• dipole

ALICE Tracking

Combined tracking efficiency and momentum resolution

Challenges for TPCs in high luminosity A+A

event pile-uppattern recognition problem gets “interesting”

space chargefield distortion effect upon momentum reconstruction

can the compact TPC ideas be practical and efficient for the huge multiplicities of heavy ion collisions?

Upgrades High T QCD…. QGP Spin Low-x

PHENIX

e+e- heavy jet quarkonia

flavor tomog.

W ΔG/G

Hadron blind detector

Vertex Tracker

Muon Trigger

Forward cal. (NCC)

X

X X O O

O

O O

X

X

O

O

X

STAR

Time of Flight (TOF)

MicroVtx (HFT)

Forward Tracker

Forward Cal (FMS)

DAQ 1000

O X O

X X

O

O X X

X O

O

O O

X

O

RHIC Luminosity O O X X O O O

RHIC Upgrades Overview

X upgrade critical for successO upgrade significantly enhances program

A. Drees 4/4/05

Goal:q andq spin structure of the nucleonUse pp → W+X

Challenges:nb cross section: run pp at 500 GeV

with high luminosity and polarizationReduce MHz interaction rate → few

kHz event rate Unambiguous identification of W+,W

Detector upgrades:PHENIX: high pT single muon

triggerSTAR: tracking upgrade

Spin Structure of the Proton: W physics

d (u)

u ( d)

W

Forward Physics Upgrades: 1<<3

PHENIX: forward calorimeterR&D ongoing

STAR: forward meson calorimeterProposal submitted to NSF

what is a plasma?

4th state of matter (after solid, liquid and gas)

a plasma is:ionized gas which is macroscopically neutral

(not neutral on scale of interparticle distance)exhibits collective effects

interactions among charges of multiple particlesspreads charge out into characteristic (Debye) length, D

multiple particles inside this lengththey screen each other

plasma size > D

Where the QCD plasma physics fits in

high energy density: > 1011 J/m3

P > 1 MbarI > 3 X 1015W/cm2 Fields > 500 Tesla

is QGP a strongly coupled plasma?

Huge gluon density! estimate = <PE>/<KE>

using QCD coupling strength g<PE>=g2/d d ~1/(41/3T)

<KE> ~ 3T ~ g2 (41/3T) / 3Tg2 ~ 4-6 (value runs with T)

for T=200 MeV plasma parameter

quark gluon plasma should be a strongly coupled plasma

how does it compare to interesting EM plasmas?

> 1: strongly coupled, few particles inside Debye radius

more sophisticated

see Markus Thomas hep-ph/0503154

getting the units right… = 2Cg2/4dT

get ~ 1.5 – 5 at T=200 MeVNB: magnetic interaction is ~ comparable to electric

interaction in a relativistic plasmarange from uncertainties in g2 and Casimirs

A (supersymmetric) pseudo-QCD theory can be mapped to a 10-dimensional classical gravity theory on the background of black 3-branes

The calculation can be performed there as the absorption of gravitons by the braneTHE SHEAR VISCOSITY OF STRONGLY COUPLED N=4 SUPERSYMMETRIC YANG-MILLS PLASMA., G.

Policastro, D.T. Son , A.O. Starinets, Phys.Rev.Lett.87:081601,2001 hep-th/0104066

gives = (h/4) S known liquids, even He, are above this!

seems to be a perfect fluid (not quite sci-fi!)

would like tocalculate:

this is hard!

for strongly coupled EM plasmas

kinetic energy distribution (T)measure electrons radiated from plasma

flow properties (turbulent and non)particle transport via laser-induced flourescenceagain study electron radiation from plasmaopacity to hard x-rays (time resolved)

thermalization timephoton absorption & ion spectrum vs. time

plasma oscillations see density fluctuations in electron arrival times

correlations among particlesmeasure radiated particle pairs

crystallization viscosity

M.Miller, QM04

(1/N

trig)d

N/d

()

STAR Preliminary

cGeVp

cGevpassocT

trigT

/42.0

/64

speed of sound via a density wave?

+/-1.23=1.91,4.37 → cs ~ 0.33 (√0.33 in QGP, 0.2 in hadron gas)

PHENIX preliminary

dN

/d(

)

g radiates energykick particles in the plasmaaccelerate them along the jet

Jet tomography

correlations of 2, 3 (more?) particles from jets traversing medium

-jet correlations; fixes jet energygq → q

identify the hadrons: hadronization, charm e-loss

increase PHENIX, STAR calorimeter coverage for

upgrade rate capabilities of data acquisition, analysis2007

increased machine luminosity (2013?)

cross section small, so rate is low

why so many baryons at medium pT?

sensitive probe of hadronizationquark coalescence: good starting point

small production rate → sensitivity to correlations of quarks inside the medium!a tool to probe wakes in the plasma. correlators?

upgrade PID in STAR and PHENIX by ‘09 increased luminosity to allow scanning collision energy,

species (Au+Au, Cu+Cu compare to p+p, d+Au)

jet

par

tner

s p

ertr

igge

r

Npartp+p

all baryons from quarks drawn from the medium

dileptons and photons

pT spectrum of soft * reflects Tinitial

interpretation problem: unfolding time history of the expansionnote: fixing the EOS for hydro is essential!

medium modificationof final vector mesons

decays of bound states?

detector upgrades will reduce decay background and allow measurement of charm background

energy & system size scans require luminosity upgrade

Heavy Quarkonium – a screening probe

map charmonium and bottomonium states to study competition between melting and regeneration

color screening length? Tinitial? upgraded luminosity will allow:

measurement of Y v2 of J/energy scan for J/, screening vs. regeneration

RHIC

counts per yearcomparable to thoseat LHC!

why do we need high luminosity?

QCD analogy to hard x-ray probes in plasma physics?for opacity studies & Thomson scattering-> monoenergetic hard colored probe

achievable via g-jet coincidences, binned in g energy

QCD analogy to probes of screening lengthJ/psi suppression via screening c-cbar bound state?

very confusing at the moment!need more theory and data

QCD analogy to plasma shots with different conditionsscan in energy and system size

measure opacity, elliptic flow, charm, g-jet

Heavy Quarks – open charm

precision measurements to quantify energy loss and v2 as a function of momentumhow opaque IS the medium?relative role of gluon radiation and collisional energy loss

must measure charm yieldto subtract from intermediate mass dilepton continuum

inner tracker upgrades for PHENIX and STAR needed to tag displaced vertex for clean measurement

ready by 2011

what sQGP plasma properties could these yield?

speed of sound via jet modifications quark correlations in the medium

baryon formationmedium modifications of jet fragmentation

propagation of jet-induced shocks constrain radiative vs. collisional energy loss screening length via onium spectroscopy T via radiated dileptons, photons dissipation via energy flow in shocked medium Would like to identify experimental signatures of

viscosityWeibel instability in first 0.6 fm/c

look for the jet on the other sideSTAR PRL 90, 082302 (2003)

Central Au + Au

Peripheral Au + Au

Medium is opaque!

Are back-to-back jets there in d+Au?

Pedestal&flow subtracted

Yes!

no medium ↓

no jet quenching

At RHIC:

CuCu

200 GeV/c

AuAu

200 GeV/c

dAu

200 GeV/c

J/ muon arm

1.2 < |y| < 2.2

mea

sure

d/e

xpec

ted

At RHIC:

CuCu

200 GeV/c

AuAu

200 GeV/c

dAu

200 GeV/c

AuAuee

200 GeV/c

CuCuee

200 GeV/c

J/ muon arm

1.2 < |y| < 2.2

J/ eeCentral arm

-0.35 < y < 0.35

At RHIC:

CuCu

200 GeV/c

AuAu

200 GeV/c

dAu

200 GeV/c

AuAuee

200 GeV/c

CuCu

62 GeV/c

J/ muon arm

1.2 < |y| < 2.2

J/ eeCentral arm

-0.35 < y < 0.35

Factor ~3suppression

in central events

CuCuee

200 GeV/c

At RHIC:

J/ muon arm

1.2 < |y| < 2.2

J/ eeCentral arm

-0.35 < y < 0.35

Factor ~3suppression

in central events

Data show the same trend within errors for all beams and even at √s=62 GeV

RAA

vs Npart

: PHENIX and NA50

NA50 data normalized at NA50 p+p point.

Suppression similar in the two experiments, although the collision energy is 10 times higher (200GeV in PHENIX & 17GeV in NA50)

What suppression should we expect?

Models that were successful in describing SPS datafail to describe data at RHIC

- too much suppression -

can get better agreement with data

if add formation of “extra” J/ by coalescence of c and anti-c from the plasma

caveat: not necessarily unique or correct explanation!

Possibility of plasma instability → anisotropy

small deBroglie wavelength q,g point sources for g fieldsgluon fields obey Maxwell’s equationsadd initial anisotropy and you’d expect Weibel instability

moving charged particles induce B fieldsB field traps soft particles moving in A directiontrapped particle’s current reinforces trapping B fieldcan get exponential growth

(e.g. causes filamentation of beams) could also happen to gluon fields early in Au+Au collision

timescale short compared to QGP lifetimebut gluon-gluon interactions may cause instability to

saturate → drives system to isotropy & thermalization

The vision of a QCD laboratory

QCD Laboratory at BNLA place to do e-p, e-A, p-A, p-p & A-A collisions &

multiple detectors and Lattice QCD computing facility

explore zero and high temperature QCD at limits of our

knowledge nucleon spin structure in its entirety using hadronic

and leptonic probes

A. Deshpande (SBU/RBRC) & Richard Milner (MIT) the advisors for the eRHIC

B. Jacak (SBU) and John Harris (Yale) for A-A experiments in the next decade

non-perturbative QCD – lattice gauge theory

T/Tc

Karsch, Laermann, Peikert ‘99

/T4

Tc ~ 170 ± 10 MeV (1012 °K)

~ 3 GeV/fm3

required conditions to create quark gluon plasma in lab

~15% from ideal gas of weakly interacting quarks & gluons

42

30Tg

baryons are a real puzzle…

baryons enhanced for pT < 5 GeV/c

RAA

at high pT v2 reflects opacity of medium

v2

STAR

approximately expected level from jet quenching