The Mini-bang : Search for the Quark Gluon Plasma

Virtual Journey from the Big-Bang to the Mini-Bang.

Prof. Claude PruneauWayne State University

MDAPT Meeting at Wayne State University, March 20, 2002

The Night Sky

• The Stars• And the

wanderers• The planets

• What else ?

Mosaic of 51 wide-angle photographs. Made over a three year period from locations in California (USA), South Africa, and Germany, the individual pictures were digitized and stitched together to create an apparently seamless 360 by 180 degree view.

Virgo Cluster

IncreasingRed ShiftWith IncreasingDistance

Doppler Effect

Doppler Effect of light from moving Stars

The further apart galaxies are, the faster they move away from one another.

Expanding UniverseExpanding UniverseExpanding Universe

Measurements of Hubble Expansion:• Hubble Constant : 70 km/sec/mpc (10%)• Galaxies appear to be moving 160,000 miles per hour

faster for every 3.3 million light-years away from Earth.

Wendy Freedman et al.(Carnegie Observatories), HST Key Project Team, and NASA

Fornax cluster barred spiral galaxy NGC1365

HST Picture: Identification of 50 Cepheids variable stars

Big Bang Model

A broadly accepted theory for the origin and evolution of our universe.

It postulates that 12 to 14 billion years ago, the portion of the universe we can see today was only a few millimeters across. It has since expanded from this hot dense state into the vast and much cooler cosmos we currently inhabit.

In the beginning, there was a Big Bang, a colossal explosion from which everything in the Universe sprung out.

Experimental Evidence of the Big Bang

Expansion of the universe Edwin Hubble's 1929 observation that galaxies were generally

receding from us provided the first clue that the Big Bang theory might be right.

Abundance of the light elements H, He, Li The Big Bang theory predicts that these light elements should have

been fused from protons and neutrons in the first few minutes after the Big Bang.

The cosmic microwave background (CMB) radiation The early universe should have been very hot. The cosmic

microwave background radiation is the remnant heat leftover from the Big Bang.

99.97% of the radiant energy of the Universe was released within the first year after the Big Bang itself and now permeate space in the form of a thermal 3 K radiation field.

Cosmic Microwave Background

COBE CMB Measurement

• CMB spectrum is that of a nearly perfect blackbody with a temperature of 2.725 +/- 0.002 K.

• Observation matches predictions of the hot Big Bang theory extraordinarily well.

• Deviation from perfect black body spectrum less than 0.03 %• Nearly all of the radiant energy of the Universe was released within the

first year after the Big Bang.

How did we get from there… … to here?

Tim

e

What is Matter Made Of?

Fire Water Earth Air… that is, according

to the Greeks!

Mendeleev’s Periodic Table of Elements

What is Matter Made Of?

An atom contains a nucleus...

…which contains

protons and neutrons...

…which contain up and down quarks.

Elementary Particles

… and gluons are the guards...

Set the Quarks Free !!!

How? Create a Quark-Gluon Plasma !

Quarks are confined (hadrons)...

Quarks Flavors and Families

light and abundant heavier, rare very heavy,

very rare

What is a Quark-Gluon Plasma?

Phase Transitions

ICEICE WATERWATER STEAMSTEAM

Add heatAdd heat

Add heatAdd heat

Quark Gluon Plasma is another phase of matter!Quark Gluon Plasma is another phase of matter!

Phases of Water

Pressure

How to Create a Quark-Gluon Plasma

How to create a Quark-Gluon Plasma

Quark Gluon Plasma

QuarksQuarksQuarksQuarks

Quark-GluonQuark-GluonPlasmaPlasma

Quark-GluonQuark-GluonPlasmaPlasma

RHIC CollisionRHIC CollisionRHIC CollisionRHIC Collision

KeyKeyKeyKey

GluonsGluonsGluonsGluons

RHIC: Relativistic Heavy Ion Collider

Brookhaven Brookhaven National Laboratory, National Laboratory, Long Island, NYLong Island, NY

Brookhaven Brookhaven National Laboratory, National Laboratory, Long Island, NYLong Island, NY

Long Island

Long Island

New YorkCity

New YorkCity

The RHIC Complex

1. Tandem Van de Graaff

2. Heavy Ion Transfer Line

3. Booster

4. Alternating Gradient Synchrotron (AGS)

5. AGS-to-RHIC Transfer Line

6. RHIC ring

1. Tandem Van de Graaff

2. Heavy Ion Transfer Line

3. Booster

4. Alternating Gradient Synchrotron (AGS)

5. AGS-to-RHIC Transfer Line

6. RHIC ring

11

33 44

66

22

55

Inside the RHIC Ring

• Underground tunnel• Super-conducting

magnets cooled by liquid helium (@ 4.5 K)

• 1740 Magnets• 2.4 Mile circumference

• Underground tunnel• Super-conducting

magnets cooled by liquid helium (@ 4.5 K)

• 1740 Magnets• 2.4 Mile circumference

RHIC Beam Collisions

•Gold nuclei

•Traveling at near light speed

• 99.995 % actually…

•Hit head-on

•Crash through each other

•Release shower of particles

•Gold nuclei

•Traveling at near light speed

• 99.995 % actually…

•Hit head-on

•Crash through each other

•Release shower of particles

RHIC Beam Collisions

Approach Collision Particle ShowerApproach Collision Particle ShowerApproach Collision Particle ShowerApproach Collision Particle Shower

Collision time ~ 10-22 seconds

Actual RHIC Collisions

Each collision

produces thousands of

particles!

Each collision

produces thousands of

particles!

Collision measured in the Star Detector

Measuring RHIC Collisions

Four complementary experiments

Who’s Involved in RHIC?

People from around the worldPeople from around the world

The STAR Experiment

Star Experiment (Construction)

Faculty :

Rene Bellwied

Tom Cormier

Sean Gavin

Claude Pruneau

Sergei Voloshin

Students:

Maria Castro

Alex Stolpovsky

David Bower

Saumitra Chowdhury

Mohamed Abdel-Aziz

Vishist Mandapaka

5 recent graduates

WSU Relativistic Heavy Ion Group

Wayne State Contribution to STAR/RHIC

Silicon Vertex Tracker (SVT) Electromagnetic Calorimeter (EMC)

Charged particles produced in a Single Au + Au collision at an energy of 130 A GeV (25.6 TeV)

STAR TPC

Pad readout

2×12 super-sectors

60 cm

127 cm

190 cm

Outer sector6.2 × 19.5 mm2 pad

3940 pads

Inner sector2.85 × 11.5 mm2 pad

1750 pads

JT: 48The Berkeley Lab

STARPixel Pad Readout

Readout arranged like the face of a clock - 5,690 pixels per sector

Momentum Measurement

+B=0.5 T

Collision Vertex

Trajectory is a helix in 3D; a circle in the transverse plane

qBRmvp

Radius: R

Multiplicity

dNh-/d|=0 = 280120

dNch/d|=0 = 567 138

38% pp52% SPS

Multiplicity dominated by GeometryRelatively flat in (1.)Centrality Consistent with other experiments GeVsNN 130

Transverse SpectraSTAR Preliminary

Power Law:

A (1+pt /p0) - n

<pt>=0.5080.012GeV/c (top 5%), increases from pp, SPS

<pt> Scaling

2

/

)3.0(3.0

R

ddNs

ps

sp

ch

ppTpp

AAAAT

Saturation model:J. Schaffner-Blielich, et al. nucl-th/0108048D. Kharzeev, et al. hep-ph/0111315

Proton, Anti-proton

Small PID range Finite Baryon Stopping Low net baryon density High total baryon

production

p/p ratio

RHIC:1/3 from transport2/3 proton from production (how?)(AGS: 10-4; SPS: 1/10)Small centrality dependenceSmall effect of p absorption?

NA44

STAR

Antinuclei

Ed3NA

d3PBA E

d3 NN

d3 p

A

VB

A

Pp

1, 2

1 fm

R(deuteron ) R(source)

Results Very high temperature achieved Collective/hydrodynamic flow Saturation of strange particle

production. Modification of matter properties. Accumulating evidence that a

“new” phase of matter is produced in Au+Au collisions.

Conclusions A virtual journey from our solar system

outward towards to distant galaxies and backward in time to the big bang.

QGP existed for a time of 1 micro-second after the big-bang.

Production of QGP studied at BNL in high energy gold on gold collisions.

Exciting results and preliminary evidence of a new form of matter.

RHIC Web Pages

rhic15.physics.wayne.eduwww.rhic.bnl.gov www.star.bnl.gov

rhic15.physics.wayne.eduwww.rhic.bnl.gov www.star.bnl.gov