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Quarks and the Cosmos

Ian Shipsey(*) (*) one of 15 astrophysicists

& particle physicists at Purdue University

A lecture to thePresident’s CouncilPurdue University

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Unfinished business from the 20th Century

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Quarks and the Cosmos

Inner Space / Outer Space

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Inner Space: Atoms

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Inner Space: quarks & electrons

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Atomic Nucleus

electron1

radius of nucleus1.000

one billionth of a nanometer

0.1 nanometer

1 meter10000.000.000.

The size of atoms, quarks and electrons

Quarks aresimilar insize to electrons

Most of an atom is empty space

1 atomic radius

100,000

one millionth of a nanometer

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Question for the class

Proton electric charge = +1

Neutron electric charge = 0

u

u

d d

u

d

What are the charges of up and down quarks?

up = +2/3 down = +1/3

up = +2/3 down = -1/3

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Inner space: The four forces

Lets quarkschange identity(d u)

(Nobel prize2004)

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The periodic table of the elementary particles

+ anti-matter(antiparticles for each quark & lepton)

1897-2002

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Patterns (symmetry) predict missing particles

Missing particlethe 6th quark

Moremissing particles:GravitonHiggsSUSY

Top quarkfound in 1995

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Unification of the Forces

Electricity

MagnetismElectromagnetism 1864

Electromagnetism

WeakElectroweak 1979

-1982

Electromagnetism

Weak

Strong

Grand unified force?

Requires Higgs

Requires photon

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Grand Unified Force Reqiures SUSY

Supersymmetry=SUSYSUSY normal+ SUSYDecay chain ends in lightest SUSY particlewhich is stable

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SUSY particles are a leading candidate for dark matter

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Dis

tanc

e

Velocity

Expansion of the Universe

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Expansion of the Universe

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Dis

tanc

e

Velocity

AB

Question for the class

Graph shows distance compared to velocity for dots on a rubberband. The white solid line is from two slides ago. What do lines A and B correspond to?

B faster stretchingA slower stretching

B slower stretchingA faster stretching

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Dis

tanc

e

Velocity

Fast

er s

tretc

hingSlo

wer

stre

tchi

ng

Dis

tanc

e

Amount of Stretch

Deceleratingexpansion

Acceleratingexpansion

Longago

Now

Con

stan

tex

pans

ion

What would a change in the expansion rate look like?

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0.10.01 1

1

0.1

0.01

0.001

0.0001

0.00001

Rel

ativ

e In

tens

ity o

f Li

ght

Rel

ativ

e D

ista

nce

Fa

r

Amount of stretchRedshift (z)

Ne

ar

Lo

wH

igh

Acceleratingexpansion

Deceleratingexpansion

Expansion of the Universe is accelerating

Discovery of the year1998

Confirmation & refinements 1999-2004.Major new satellite JDEM planned

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Quantum Uncertainity & “empty” space

Nothing is something!

TIM

E

SPACE

Disappearance

Appearance

Particle

Antiparticle

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Galaxiesborn

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PrimordialSoup

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Particle Physics

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INNER SPACE- THE QUANTUM

PARTICLE ACCELERATOR =TIME MACHINE= TELESCOPE

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2E mcEnergy of the beams new particles

of the primordialsoup

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LHC:27 km (18 mile circumference, 100 m underground)

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Particle Physics

Primordial Soup0.000 000 000 004 seconds AB3,000,000,000,000,000°

CONDENSED in 50 Earth masses in matter one 50 Earth masses in antimatter can + extra mountain of matterHOT per 10 billion years of total serving energy output of the sunINGREDIENTSIn every spoonful every type of elementary particle

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Particle Physics

Primordial SoupKNOWN INGREDIENTS:56% QUARKS 16% GLUONS16% ELECTRON-LIKE PARTICLES9% W’s AND Z’s 5% NEUTRINOS2% PHOTONSPROBABLE INGREDIENTS:2% GRAVITONS 1% HIGGS

SECRET INGREDIENTS: DARK MATTER, DARK ENERGY, EXTRA DIMENSIONS

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How do we see the soup particles?The Eyes of a Insect:

1 billion collisions/second1,000 particles every 25 nanoseconds

Need highly granular detectors thattake pictures quickly, and canmanipulate the resulting data on board and store it before shipping to a farm of CPUs

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The Eyes of a Piece of Silicon:

The length of each side of the square is about the thickness of a piece of paper. Each eye is called a pixel

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The largest Silicon camera ever built at a

University was built at Purdue in 1999.

We are building a more advanced version of this detector for the LHC

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CMS at LHC

21 m

16m36 Nations159 Institutions1940 scientists(including7 Purdue Professors)

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Discovery of the Higgs or SUSY or... in 2008?

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Summary

The LHC is under construction and will take data in 2008

Many other particle physics and astronomy scientific instruments on Earth, deep below ground and in outer space are coming online soon

Particle physicists & astrophysicists are poised to taste the primordial soup , to answer some of the great questions of the 21st CenturyWhat is dark matter? What is dark energy? Is there only one force?Our notion of space and time may be radically altered.We may understand how the universe was born and how it will end

Reading assignment: Scientific American September 2004 issueMany research opportunities for undergraduates: Learn more about our exciting research programs at: http://www.physics.purdue.edu

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Acknowledgements

This talk has drawn heavily on images obtained from CERN, NASA and Scientific American, and excellent talks given by Rocky Kolb, Lawrence Krauss, Gerard `t Hooft, Michael Turner and Jim Virdee.

Original artwork was preparedby Steven Lichti (Purdue).Daniela Bortoletto and Francesca Shipsey are thanked for their love and support.