Download ppt - Christina Markert Physics Workshop UT Austin November 11 2006 1 Christina Markert The ‘Little Bang in the Laboratory’ – Accelorator Physics. Big Bang Quarks

Christina Markert Physics Workshop UT Austin November 11 2006 1

Christina Markert

The ‘Little Bang in the Laboratory’ – Accelorator Physics.

• Big Bang • Quarks and Strong Interaction• Heavy Ion Collisions ‘Little Bang’• Our Heavy Ion Group at UT Austin• Conclusions


Our basic Questions are:

What is matter made of ?

How does matter organize itself & stay together?

How does matter behave?


Space Time Diagram of the Early Universe

The Cosmic Timeline

proton

atommolecule

crystal

quarks

nucleiExpansion:Temperature decreaseDensity decreasesVolume expandsIt takes timeMore structure

Universe is13*109

Years old


What do we know about the smallest building blocks?


Quarks in a Neutron or Proton = Mass

Theory:QuantumChromoDynamics

Quarks are the smallest building blocks of massive matter


Strong color fieldForce grows with separation !!!

Analogies and differences between QED and QCD

to study structure of an atom…

“white” proton

…separate constituents

nucleus

electron

quark

quark-antiquark paircreated from vacuum

“white” proton (baryon)(confined quarks)

“white” 0 (meson)(confined quarks)

Confinement: fundamental & crucial (but not understood!) feature of strong force- colored objects (quarks) have energy in normal vacuum

neutral atom

quarksu,d, (s,c,t,b)

QED Quantum Electro Dynamics

QCD Quantum Chromo Dymanics


Generating a deconfined state

Nuclear Matter(confined)

Hadronic Matter(confined)

Quark Gluon Plasmadeconfined !

Present understanding of Quantum Chromodynamics (QCD)• heating• compression deconfined matter !


Going back in time…


Phase Transitions

ICEICE WATERWATER

Add heatAdd heat

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


Phase Diagram

Pressure

We heat up the system


Create Quark Gluon Plasma

q

qqq

q

q

q q q

q

q

qq

q

qqq

Compress and

Add heat

Compress and

Add heat

HadronsHadrons Quark Gluon Plasma

Quark Gluon Plasma

T = 1,000,000,000,000 K


Phase Diagram of Nuclear Matter

SPS

AGS

RHIC

Tem

pera

ture

~150 MeV

LHC

Center of mass energies:for different acceleratorsAGS: √s ~ 5 GeVSPS : √s ~ 17 GeVRHIC: √s ~ 200 GeV LHC: √s ~ 5500 GeV

q

qqq

q

qq q q

q

q

qq

q

qqq

qq

q

q q

hadrons quarks and gluons hadrons

Pressure


Phase transition of nuclear matter predicted

Gross, Politzer, Wilczek win 2004 Nobel Prize in physics for the theory of asymptotic freedom in strong interaction.

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) was built to measure the phase transition of nuclear matter to an ‘asymptotically free’ partonic state (deconfined) under the condition of maximum particle and energy density. (after Big Bang ?)

Wilczek


What can we do in the laboratory ?

a.) Re-create the conditions as close as possible to the Big Bang, i.e. a condition of maximum density and minimum volume in an expanding macroscopic system.

b.) Measure a phase transition, characterize the new phase, measure the de-excitation of the new phase into ‘ordinary’ matter – ‘do we come out the way we went in ?’

c.) Learn about hadronization how matter is formed

(mechanism how quarks from hadrons protons, neutrons, etc…)


How do we do heavy ion collisions in laboratory ?

• We take an atom (Au)

• We take away the electrons ion

• We accelerate the ion

• We collide the ions and hopefully create the predicted quark gluon plasma in our‘little bang’ (Au+Au)


RHIC BRAHMSPHOBOS

PHENIXSTAR

AGS

TANDEMS

Relativistic Heavy Ion Collider (RHIC)

1 mile

v = 0.99995c

Au+Au @ sNN=200 GeV


STAR experiment at RHIC collider


Study all phases of a heavy ion collision

If the Quark Gluon Plasma was formed, it will only live for 10-23 s !!!!Nuclei are so thin because of velocity = nearly speed of light


Space Time Diagram of the Early Universe

The Cosmic Timeline

proton

atommolecule

crystal

quarks

nucleiExpansion:Temperature decreaseDensity decreasesVolume expandsMore structure

Takes time

atoms 6*105years


Heat and Compress Nuclear Matter

We produce new quark-antiquark pairs:

Producing new matter out of Energy Producing new quarks s,c,t,b which don’t exist in ground state nuclear matter (neutrons+protons)

System expands new particles are produced:Protons (uud) , anti-protons (antimatter)Lambdas (uds)


STAR Experiment at the RHIC Collider


Particle Tracks in the Detector

Head-on Au+Au collision

~1500 charged hadrons (protons,…) and leptons (electrons,..)


a.) Which particles are produced ?b.) How many are produced ?c.) How are they arranged (angle)

d.) What does the theory tell us?

What can we measure ?


Resonance Reconstruction in STAR TPC

Energy loss in TPC dE/dx

momentum [GeV/c]

En

ergy

los

s d

E/d

x

p

K

e

-

p

(1520)

K- p

End view STAR TPC

• Identify decay candidates (p, dedx, E)• Calculate invariant mass

2212

21 ppEEminv


Time of Flight Detector

Our Group at UT Austin


Conclusion

Data show evidence that we created a Quark Gluon Plasma

We have a phase transition proton -> quarks Quark-gluon plasma lasts less than

0.00000000000000000000001 seconds It is very dense and very hot It behaves like a liquid not like a plasma New experiment at larger Collider LHC at

CERN to investigate properties of the ‘Quark Soup’

Data show evidence that we created a Quark Gluon Plasma

We have a phase transition proton -> quarks Quark-gluon plasma lasts less than

0.00000000000000000000001 seconds It is very dense and very hot It behaves like a liquid not like a plasma New experiment at larger Collider LHC at

CERN to investigate properties of the ‘Quark Soup’


The world takes notice !


Questions

1.Can we produce anti matter here on earth ? Yes2.Can we create matter out of energy ? Yes

3.Is the proton the smallest building block of nuclear matter ? No (quark)

4.Can we accelerate particles up to nearly the speed of light ? Yes

5.Can we observe a single quark ? No