phenix @ rhic r.k. choudhury barc. relativistic heavy ion collider at brookhaven national laboratory...

PHENIX @ RHIC

R.K. CHOUDHURY

BARC

Relativistic Heavy Ion Collider at

Brookhaven National Laboratory (BNL), USA

World’s First Heavy Ion Collider became operational in 2000

PHENIX, STAR, PHOBOS & BRAHMS

Relativistic Heavy Ion Collider @ BNL

Facts about RHIC

Tunnel: 3.66 m wide under the ground Circumference: 3.84 km Au Beam @200GeV/n speed: 99.995 % of c 1000’s of collisions per second 1000’s of particles produced per collision T ~ 1012 K >> T (centre of the sun) 107 K Spin polarized proton beam upto 500GeV/n

PHENIX: Pioneering High Energy Nuclear Interaction eXperiment. PHENIX is designed specifically to measure direct probes of the

collisions such as electrons, muons, phtons and hadrons.

12 Countries, 58 Institutions, 480 participants: Country: Brazil, China, France, Germany, Hungary, India, Israel,

Japan, Korea Russia, Sweden, USA

International Aspect of PHENIXInternational Aspect of PHENIX

PRIMARY MOTIVATION(Physics Driven)

1. Study of Quark Gluon Plasma(To create a mini universe in the

laboratory what might have existed a few micro seconds after the big

bang)

2. To understand the origin of

Proton Spin

To map out the QCD phase diagram

What happens when two Au ions collide heads on ?What happens when two Au ions collide heads on ?

What happens inside a Detector ?What happens inside a Detector ?

Off Line Analysis BeginsOff Line Analysis Begins

Pattern RecognitionPattern Recognition

BARC CONTRIBUTION

Fabrication of Muon Tracking Stations

Simulation and Reconstruction Software

PHENIX RUN STATISTICS

Run 01 2000 Au+Au @ 65 GeV/n for 5 weeks Run 02 2001 Au+Au @ 100 GeV/n for 16

weeks Run 03 2003 d+Au @ 100 GeV/n for 10

weeks Run 04 2004 Au+Au @ 100 GeV/n for 12

weeks Run 05 2005 Cu+Cu @ 100 GeV/n for 8 weeks Pol. p+p @ 100 GeV/n for 9 weeksRun 06 pol. p+p at 100 GeV/n for 14 weeks

Results from PHENIX (HI runs)

-- Charged particle Multiplicities (stopping) -- Transverse Energy ( ~ 5 GeV/fm3) -- Particle Yield Ratios, energy spectra (thermalisation)

-- Elliptic Flow (v2 scales with eccentricity: high collectivity)

-- Two particle correlations -- Non-statistical Fluctuations -- Suppression of particle production at high pT

-- Jet suppression -- Heavy flavour production (open charm,J/psi) -- Large (anti)baryon to pion ratio at intermediate

pT

1. Heavy flavour cross section:

-->Calculable with QCD also include effects such as Shadowing

-->Measure the cross section in pp, pPb and then extrapolate to Pb-Pb

2. Cold matter effects:

--> Nuclear absorption and Comover scattering, e.g.

J/psi + N --> D + D bar+ X

3. Energy loss in the medium:

4. Quarkonium suppression in QGP:

When screening radius rD < rQQbar, at T > TD

5. Quarkonium Enhancement at LHC:

No. of Q Qbar pairs produced at LHC is large. Possibility of recombination

Heavy Flavour Physics

PHENIX - J/ Suppresion system size dependence

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

PHENIX - J/ Suppresion comparison to theory

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

- too much suppression -

PHENIX - J/ Suppresion comparison to theory

Implementing regeneration: much better agreement with the data

Suppressed high pSuppressed high pTT hadroproduction in hadroproduction in

Au+Au Au+Au Au+Au 0 X (peripheral) Au+Au 0 X

(central)

Peripheral data agree well with Strong suppression in

p+p (data & pQCD) plus Ncoll-scaling central Au+Au collisions

Suppressed high pSuppressed high pTT hadroproduction hadroproduction

Discovery ofhigh p

T

suppression(one of most significant

results @ RHIC so far)

Ncoll

scaling

(“hard” production)

x5 suppression

Npart

scaling (surface emission)

RAA

<< 1: well below pQCD (collinear factorization) expectations for

hard scattering cross-sections

ppN

AuAuR

binaryAA

Evidence in Favor of QGPJet Tomography

Jet Quenching Data

A Strong Collective Behavior: FLOW

Definition of flow?

Φ: azimuthal angle relative to reaction plane.f (Φ): azimuthal distribution of particles.Make Fourier expansion of f (Φ).1st Fourier coefficient v1 = directed flow2nd Fourier coefficient v2 = elliptic flow vn = <cos (nΦ)>, n = 1,2,…

Central collision: vn=0, n = 1,2,… But one can have a radial flow.

Elliptic Flow for only non-central collisions.

Elliptic Flow & Hydro. Calcs.

Has PHENIX found the Quark Gluon Plasma ?

It is too early to say for sure, but the observation of jet suppression, indication of a very strong amount of flow etc. are very promising.

The collected observations of all of the four RHIC experiments are consistent with a state of matter that has the properties of a perfect fluid comprised of quarks and gluons. fluid comprised of quarks and gluons.

Future Upgrades at RHIC

RHIC Upgrade: Electron beam cooling x10 Luminosity, longer store time

PHENIX Upgrade: Si Vertex Tracking Nose Cone Calorimeter High pT Aerogel Cerenkov Detector

Large Hadron Collider

CMS Detector

Scanned picture of BEL and CEERI Scanned picture of BEL and CEERI Detectors ( Prototype)Detectors ( Prototype)

Detector Micromodule

Si Preshower detector in Endcap ECAL

THANK YOU

1. Heavy flavour cross section:

-->Calculable with QCD also include effects such as Shadowing

-->Measure the cross section in pp, pPb and then extrapolate to Pb-Pb

2. Cold matter effects:

--> Nuclear absorption and Comover scattering, e.g.

J/psi + N --> D + D bar+ X

3. Energy loss in the medium:

4. Quarkonium suppression in QGP:

When screening radius rD < rQQbar, at T > TD

5. Quarkonium Enhancement at LHC:

No. of Q Qbar pairs produced at LHC is large. Possibility of recombination

Heavy Flavour Physics

PHENIX - J/ Suppresion system size dependence

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

PHENIX - J/ Suppresion comparison to theory

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

- too much suppression -

PHENIX - J/ Suppresion comparison to theory

Implementing regeneration: much better agreement with the data

Suppressed high pSuppressed high pTT hadroproduction in hadroproduction in

Au+Au Au+Au Au+Au 0 X (peripheral) Au+Au 0 X

(central)

Peripheral data agree well with Strong suppression in

p+p (data & pQCD) plus Ncoll-scaling central Au+Au collisions

Suppressed high pSuppressed high pTT hadroproduction hadroproduction

Discovery ofhigh p

T

suppression(one of most significant

results @ RHIC so far)

Ncoll

scaling

(“hard” production)

x5 suppression

Npart

scaling (surface emission)

RAA

<< 1: well below pQCD (collinear factorization) expectations for

hard scattering cross-sections

ppN

AuAuR

binaryAA

Definition of flow?Φ: azimuthal angle relative to reaction plane.f (Φ): azimuthal distribution of particles.Make Fourier expansion of f (Φ).1st Fourier coefficient v1 = directed flow2nd Fourier coefficient v2 = elliptic flow vn = <cos (nΦ)>, n = 1,2,…

Central collision: vn=0, n = 1,2,… But one can have a radial flow.

This talk: only non-central collisions.

Elliptic Flow & Hydro. Calcs.