A/Prof. Anthony G. WilliamsA/Prof. Anthony G. WilliamsCSSMCSSM

Adelaide UniversityAdelaide University

22 November 2001, Melbourne22 November 2001, Melbourne

Probing the Heart of MatterProbing the Heart of Matter

Outline of TalkOutline of Talk

• Introduction and ContextIntroduction and Context• Special Research Centre for the Subatomic Structure of Special Research Centre for the Subatomic Structure of

Matter (Matter (CSSMCSSM))• The Standard Model of Particle PhysicsThe Standard Model of Particle Physics• Quantum Chromodynamics (Quantum Chromodynamics (QQCCDD))• Quarks and Gluons and the Origin of 98% of the Mass of Quarks and Gluons and the Origin of 98% of the Mass of

Tangible Matter Tangible Matter • Lattice Gauge Theory and Lattice Lattice Gauge Theory and Lattice QQCCD D • Orion Supercomputer Orion Supercomputer • Centre for High-Performance Computing and Centre for High-Performance Computing and

Applications (Applications (CHPCACHPCA))• Conclusions and OutlookConclusions and Outlook

Introduction and ContextIntroduction and Context• Strongly interacting matter makes up almost the entire mass of Strongly interacting matter makes up almost the entire mass of

the tangible universe, from the protons and neutrons in the nuclei the tangible universe, from the protons and neutrons in the nuclei of atoms and molecules to neutron stars. of atoms and molecules to neutron stars.

• The strong interaction fuels the sun and stars and determines The strong interaction fuels the sun and stars and determines which nuclei are stable and hence which elements can exist. which nuclei are stable and hence which elements can exist.

• The underlying theory of the strong interaction is called quantum The underlying theory of the strong interaction is called quantum chromodynamics (chromodynamics (QQCCDD) and has quarks (like electrons) and ) and has quarks (like electrons) and gluons (like photons but self-interacting) as its fundamental gluons (like photons but self-interacting) as its fundamental constituents. constituents.

• Quarks and gluons are bound so strongly together that they can Quarks and gluons are bound so strongly together that they can never appear as free particles. This is called never appear as free particles. This is called confinementconfinement..

• When probed at increasingly higher energies the interaction When probed at increasingly higher energies the interaction between them becomes progressively weaker. This is called between them becomes progressively weaker. This is called asymptotic freedomasymptotic freedom..

• The quarks in your body represent only about 2% of your mass The quarks in your body represent only about 2% of your mass with the rest of your mass being generated by the strong with the rest of your mass being generated by the strong interaction itself.interaction itself.

• The world's fastest supercomputers are being used to improve our The world's fastest supercomputers are being used to improve our understanding of the strong interaction and the unusual understanding of the strong interaction and the unusual properties of quarks and gluons.properties of quarks and gluons.

•Strongly interacting matter is Strongly interacting matter is referred to as referred to as hadronichadronic matter and matter and strongly interacting particles are strongly interacting particles are called called hadronshadrons, e.g., protons, , e.g., protons, neutrons, and pions are all hadronsneutrons, and pions are all hadrons

•Hadrons with 1/2 integer spin (e.g., Hadrons with 1/2 integer spin (e.g., 1/2, 3/2, 5/2,…) are fermions and are 1/2, 3/2, 5/2,…) are fermions and are called called baryonsbaryons. Protons and . Protons and neutrons are baryons.neutrons are baryons.

•Hadrons with integer spin (e.g., 0, Hadrons with integer spin (e.g., 0, 1, 2, …) are bosons and are called 1, 2, …) are bosons and are called mesonsmesons. The pion is a meson.. The pion is a meson.

•Nuclei consist of protons and Nuclei consist of protons and neutrons bound together by the neutrons bound together by the strong interaction.strong interaction.

•The elements and hence all of The elements and hence all of chemistry is determined by which chemistry is determined by which nuclei are stable.nuclei are stable.

ConceptsConcepts

BosonBoson = Bose-Einstein = Bose-Einstein statisticsstatistics

FermionFermion = Fermi-Dirac = Fermi-Dirac statisticsstatistics

ScalesScales• Typical atomic size is 10Typical atomic size is 10-10 -10 m = 1 m = 1

AngstromAngstrom• Typical nuclear sizes are 10Typical nuclear sizes are 10-14 -14 m = m =

10 fermi 10 fermi • 1 fermi = 1 fm = 101 fermi = 1 fm = 10-15-15 m m• Proton radius is 0.8 fm,i.e., Proton radius is 0.8 fm,i.e.,

approximately 1 fmapproximately 1 fm• No substructure of electrons or No substructure of electrons or

quarks has ever been observed at quarks has ever been observed at resolutions down to approximately resolutions down to approximately 1/100,000,000 Angstroms = 101/100,000,000 Angstroms = 10-18 -18 m. m.

• At the present time we assume that At the present time we assume that electrons and quarks are elementary electrons and quarks are elementary particles.particles.

Atomic Atomic StructureStructure

• Warning: Warning: Sketch Sketch not to scale!not to scale!

• If the If the protonsprotons and and neutronsneutrons in this in this nucleus are 10cm nucleus are 10cm across thenacross then

• thethe nucleus nucleus is is about 100cm about 100cm across,across,

• the the electronselectrons and and quarksquarks are less are less than 0.1mm across,than 0.1mm across,

• and the and the atomatom is is 10km across!10km across!

Fundamental ForcesFundamental Forces

There are four fundamental forces which are believed to give rise to all There are four fundamental forces which are believed to give rise to all observed physical phenomena.observed physical phenomena.

• Gravity:Gravity: holds us to the earth, binds stars, solar systems, galaxies, etc. holds us to the earth, binds stars, solar systems, galaxies, etc.• Electromagnetic: Electromagnetic: e.m. radiation, chemistry hence biology, touch, e.m. radiation, chemistry hence biology, touch,

electronics, etc.electronics, etc.• Weak: Weak: radioactivity, neutrino physics of supernovae, etc.radioactivity, neutrino physics of supernovae, etc.• Strong: Strong: all familiar matter, nuclear energy, powers sun and stars, etc.all familiar matter, nuclear energy, powers sun and stars, etc.

Special Research Centre for the Subatomic Special Research Centre for the Subatomic Structure of Matter (Structure of Matter (CSSMCSSM))

• TheThe CSSM CSSM is a Special Research Centre of the Australian Research Council is a Special Research Centre of the Australian Research Council (ARC)(ARC)funded for nine years (since 1997) to carry out theoretical research in funded for nine years (since 1997) to carry out theoretical research in subatomic physics.subatomic physics.

• Mission:Mission:

- - Make major advances in the understanding of the structure of hadronic matterMake major advances in the understanding of the structure of hadronic matter-- Cross fertilization enhances opportunities for breakthroughs in understanding Cross fertilization enhances opportunities for breakthroughs in understanding

-- Pursue lattice, models, phenomenology, and strong links to experimental results Pursue lattice, models, phenomenology, and strong links to experimental results

-- Develop strong international links, exchanges Develop strong international links, exchanges• Personnel:Personnel:

-- High level postgraduate and postdoctoral training High level postgraduate and postdoctoral training

-- Interact with best researchers in a stimulating atmosphere Interact with best researchers in a stimulating atmosphere

• Service:Service:- LANL Archive for Australia- LANL Archive for Australia- Workshop program (support external students and affiliate staff) - Workshop program (support external students and affiliate staff) - Stimulate school students to science (brochures, school visits) - Stimulate school students to science (brochures, school visits) - Physics Guru, Public Lectures, Newspapers, radio, Television- Physics Guru, Public Lectures, Newspapers, radio, Television

CSSM: Current Academic CSSM: Current Academic StaffStaff

• Professor Anthony Thomas (Director)Professor Anthony Thomas (Director)• A/Prof. Anthony Williams (Deputy Director)A/Prof. Anthony Williams (Deputy Director)• Dr. P. Coddington Dr. P. Coddington • Dr. Alex Kalloniatis (Australian Research Fellow)Dr. Alex Kalloniatis (Australian Research Fellow)• Dr. Derek LeinweberDr. Derek Leinweber• Dr. Andreas Schreiber (Australian Research Fellow)Dr. Andreas Schreiber (Australian Research Fellow)• Dr. Ingo BojakDr. Ingo Bojak• Dr. Xin-Heng GuoDr. Xin-Heng Guo• Dr. Ayse KizilersüDr. Ayse Kizilersü• Dr. Vadim GuzeyDr. Vadim Guzey• Dr. Martin Oettel (joint appointment Alexander von Humbolt Dr. Martin Oettel (joint appointment Alexander von Humbolt

Stiftung/Foundation & CSSM)Stiftung/Foundation & CSSM)• Dr. Jianbo ZhangDr. Jianbo Zhang

Postgraduate StudentsPostgraduate Students• Sundance Bilson-Thompson (Ph.D.). Sundance Bilson-Thompson (Ph.D.).

Supervisors: D.B. Leinweber & A.G. Supervisors: D.B. Leinweber & A.G. WilliamsWilliams

• Francois Bissey (Ph.D.). Cotutelle Francois Bissey (Ph.D.). Cotutelle (U. Blaise Pascal) & A.W. Thomas.(U. Blaise Pascal) & A.W. Thomas.

• Frederic Bonnet (Ph.D.). Frederic Bonnet (Ph.D.). Supervisors: D.B. Leinweber & A.G. Supervisors: D.B. Leinweber & A.G. Williams.Williams.

• Patrick Bowman (Ph.D.). Patrick Bowman (Ph.D.). Supervisors: D.B. Leinweber & A.G. Supervisors: D.B. Leinweber & A.G. Williams; Williams; position at Florida State Univposition at Florida State Univ..

• Shane Braendler (Ph.D.). Shane Braendler (Ph.D.). Supervisor: A.W. ThomasSupervisor: A.W. Thomas

• Will Detmold (Ph.D.). Supervisors: Will Detmold (Ph.D.). Supervisors: A. Bender & A.W. ThomasA. Bender & A.W. Thomas

• Emily Hackett-Jones (M.Sc.). Emily Hackett-Jones (M.Sc.). Supervisors: D.B. Leinweber & Supervisors: D.B. Leinweber & A.W. Thomas A.W. Thomas

• Waseem Kamleh (Ph.D.). Waseem Kamleh (Ph.D.). Supervisor: A.G. WilliamsSupervisor: A.G. Williams

• Daniel Kusterer (M.Sc. Baden-Daniel Kusterer (M.Sc. Baden-Wuerttemberg/S.A. Exchange Wuerttemberg/S.A. Exchange Program) - Supervisor: D.B. Program) - Supervisor: D.B. LeinweberLeinweber

• Olivier Leitner (Ph.D.). Olivier Leitner (Ph.D.). Cotutelle (U. Cotutelle (U. Blaise Pascal) & A.W. ThomasBlaise Pascal) & A.W. Thomas

• Tom Sizer (Ph.D.). Supervisor: Tom Sizer (Ph.D.). Supervisor: A.G. WilliamsA.G. Williams

• Stewart Wright (Ph.D.). Stewart Wright (Ph.D.). Supervisors: D.B. Leinweber & A.W. Supervisors: D.B. Leinweber & A.W. Thomas;Thomas;position at Liverpool, UKposition at Liverpool, UK..

• Ross Young (Ph.D.). Supervisors: Ross Young (Ph.D.). Supervisors: D.B. Leinweber & A.W. ThomasD.B. Leinweber & A.W. Thomas

• James Zanotti (Ph.D.). Supervisors: James Zanotti (Ph.D.). Supervisors: D.B. Leinweber & A.G. WilliamsD.B. Leinweber & A.G. Williams

International Collaborative AgreementsInternational Collaborative Agreements

Abdus Salam International Centre for Theoretical Physics - ItalyAbdus Salam International Centre for Theoretical Physics - Italy

Argonne National Laboratory - USAArgonne National Laboratory - USA

Bonn University - GermanyBonn University - Germany

Chinese Academy of Sciences (Beijing) - ChinaChinese Academy of Sciences (Beijing) - China

Commissariat à l'Energie Atomique - FranceCommissariat à l'Energie Atomique - France

European Centre for Theoretical Studies in Nuclear Physics and Related European Centre for Theoretical Studies in Nuclear Physics and Related

Areas (Trento) - EuropeAreas (Trento) - Europe

Indiana University (Bloomington) - USAIndiana University (Bloomington) - USA

Institute for Nuclear Theory, University of Washington (Seattle) - USAInstitute for Nuclear Theory, University of Washington (Seattle) - USA

Instituto De Fisica Teòrica (IFT-UNESP) - BrazilInstituto De Fisica Teòrica (IFT-UNESP) - Brazil

Joint Institute for Nuclear Research (JINR - Dubna) - RussiaJoint Institute for Nuclear Research (JINR - Dubna) - Russia

Jülich (FZ) - GermanyJülich (FZ) - Germany

International Collaborative International Collaborative Agreements (cont.)Agreements (cont.)

MESON (Medium Energy Science Open Network) involving IUCF MESON (Medium Energy Science Open Network) involving IUCF

Indiana; Yonsei, Korea; RCNP Osaka; KVI Groningen; IMP Lanzhou; Indiana; Yonsei, Korea; RCNP Osaka; KVI Groningen; IMP Lanzhou;

TSL Uppsala; NAC Cape Town; SAHA Calcutta; FZ Jülich; CIAE BeijingTSL Uppsala; NAC Cape Town; SAHA Calcutta; FZ Jülich; CIAE Beijing

Osaka University - JapanOsaka University - Japan

Computational Science and Information Technology (CSIT, Florida) - Computational Science and Information Technology (CSIT, Florida) -

USAUSA

Svedberg Laboratory - SwedenSvedberg Laboratory - Sweden

Thomas Jefferson National Accelerator Facility (Newport News) - USAThomas Jefferson National Accelerator Facility (Newport News) - USA

Technical University of Munich - GermanyTechnical University of Munich - Germany

TRIUMF (Vancouver) - CanadaTRIUMF (Vancouver) - Canada

Université Blaise Pascal - FranceUniversité Blaise Pascal - France

University of Tübingen - GermanyUniversity of Tübingen - Germany

CSSM Workshops/Conferences CSSM Workshops/Conferences 20002000

• 3rd International Symposium on Symmetries in Subatomic 3rd International Symposium on Symmetries in Subatomic Physics - MarchPhysics - MarchTotal Number of Participants: 85Total Number of Participants: 85Overseas Participants: 45Overseas Participants: 45Interstate Participants: 12Interstate Participants: 12Local Participants: 28Local Participants: 28

• International Conference on Quark Nuclear Physics - International Conference on Quark Nuclear Physics - FebruaryFebruaryTotal Number of Participants: 109Total Number of Participants: 109Overseas Participants: 75Overseas Participants: 75Interstate Participants: 1Interstate Participants: 1Local Participants: 33Local Participants: 33

• HallD Workshop - FebruaryHallD Workshop - FebruaryTotal Number of Participants: 45Total Number of Participants: 45Overseas Participants: 24Overseas Participants: 24Interstate Participants: NilInterstate Participants: NilLocal Participants: 21Local Participants: 21

CSSM Workshops/Conferences CSSM Workshops/Conferences 20012001

• Lattice Hadron Physics Workshop - JulyLattice Hadron Physics Workshop - JulyTotal Number of Participants: 42Total Number of Participants: 42Overseas Participants: 26Overseas Participants: 26Interstate Participants: 1Interstate Participants: 1Local Participants: 15Local Participants: 15

• Hamiltonian Lattice Gauge Theories Workshop - AprilHamiltonian Lattice Gauge Theories Workshop - AprilTTotal Number of Participants: 19otal Number of Participants: 19Overseas Participants: NilOverseas Participants: NilInterstate Participants: 4Interstate Participants: 4Local Participants: 15Local Participants: 15

• Leptonic Scattering Workshop - MarchLeptonic Scattering Workshop - MarchTotal Number of Participants: 64Total Number of Participants: 64Overseas Participants: 35Overseas Participants: 35Local Participants: 29Local Participants: 29

Visitor Program 2001Visitor Program 2001• Dr. P. Bowman, Florida, USADr. P. Bowman, Florida, USA• Dr. A. Chian, Sao Paolo, BrazilDr. A. Chian, Sao Paolo, Brazil• Dr. M. Chaichian, HelsinkiDr. M. Chaichian, Helsinki• Dr. G. Dunne, ConnecticutDr. G. Dunne, Connecticut• Dr. Y. Hoshino, Kushiro, JapanDr. Y. Hoshino, Kushiro, Japan• Dr. C.-S. Huang, Beijing, ChinaDr. C.-S. Huang, Beijing, China• Prof. A. Ioannides, RIKEN, Prof. A. Ioannides, RIKEN,

JapanJapan• Dr. S. Krewald, Jueilich, Dr. S. Krewald, Jueilich,

GermanyGermany• Dr. R. Landau, Oregon, USADr. R. Landau, Oregon, USA• Dr. D. Lu, Zhejiang, ChinaDr. D. Lu, Zhejiang, China• Prof. W.-X. Ma, Beijing, ChinaProf. W.-X. Ma, Beijing, China

• Dr. K. Maltman, York, CanadaDr. K. Maltman, York, Canada• Dr. S. Sharpe, Seattle, USADr. S. Sharpe, Seattle, USA• Dr. A. Signal, Massey, NZDr. A. Signal, Massey, NZ• Dr. D. Sinclair, Argonne, USADr. D. Sinclair, Argonne, USA• Prof. J. Speth, Juelich, GermanyProf. J. Speth, Juelich, Germany• Dr. P. Tandy, Ohio, USADr. P. Tandy, Ohio, USA• Dr. G. Valencia, Iowa, USADr. G. Valencia, Iowa, USA• Prof. M. Veltman, UtrechtProf. M. Veltman, Utrecht• Dr. J. Vergados, Ionnina, GreeceDr. J. Vergados, Ionnina, Greece• Dr. L. von Smekal, ErlangenDr. L. von Smekal, Erlangen• Dr. M. Weyrauch, Bundesanstalt, Dr. M. Weyrauch, Bundesanstalt,

GermanyGermany

Future WorkshopsFuture Workshops

• Joint Workshop with JHF, March 2002Joint Workshop with JHF, March 2002

• The Structure of the Nucleon (Joint with ECT* in The Structure of the Nucleon (Joint with ECT* in Trento), September 2002Trento), September 2002

• NUPP Summer School, February 2003NUPP Summer School, February 2003

• 2nd Lattice Workshop, Cairns, June/July(?) 20032nd Lattice Workshop, Cairns, June/July(?) 2003

The Standard ModelThe Standard ModelLet us review some Let us review some aspects of the aspects of the standard model standard model briefly before briefly before beginning to focus beginning to focus on on QQCCD D itself.itself.

The Standard Model: FermionsThe Standard Model: Fermions• In addition to In addition to

the 6 known the 6 known flavors of flavors of quarks they quarks they come in 3 come in 3 “colours”: “colours”: redred,, blueblue,, andand greengreen

• ““Lepton” comes Lepton” comes from the Greek from the Greek for small massfor small mass

• Leptons do not Leptons do not carry color carry color charge, i.e., charge, i.e., they do not feel they do not feel the strong the strong forceforce

The Standard Model: BosonsThe Standard Model: Bosons

• The very massive WThe very massive W--, W, W++, and Z, and Z00 bosons mediate the weak bosons mediate the weak interaction, which as a result is very short rangeinteraction, which as a result is very short range

• The massless photon mediates the long-range e.m. The massless photon mediates the long-range e.m. interactionsinteractions

• Gluons carry Gluons carry ccoolloorr and mediate the strong interaction and mediate the strong interaction

The Standard Model: ForcesThe Standard Model: Forces

• Gravitons are thought to mediate the gravitational Gravitons are thought to mediate the gravitational force but have not yet been seenforce but have not yet been seen

• Gravitational waves are to gravitons what e.m. Gravitational waves are to gravitons what e.m. radiation is to photonsradiation is to photons

• Above we see the relative strengths and relative Above we see the relative strengths and relative ranges of the four fundamental forcesranges of the four fundamental forces

Standard ModelStandard Model: Sample : Sample ProcessesProcesses

Standard model processes and interactions:Standard model processes and interactions:• neutron beta decay (neutrons are neutron beta decay (neutrons are onlyonly stable in nuclei stable in nuclei which is just as which is just as

well!well!) ) - imagine the universe if this was not so ...- imagine the universe if this was not so ...• electron-positron annihilation to meson-antimeson pairelectron-positron annihilation to meson-antimeson pair• proton-proton collision producing two Zproton-proton collision producing two Z00 bosons and other hadrons bosons and other hadrons

Early Early UniverUniver

sese• Free quarks Free quarks

and gluons and gluons existed until existed until about 10about 10-5-5 secondsseconds

• atoms formed atoms formed at about at about 300,000 years300,000 years

• stars formed at stars formed at about 1 billion about 1 billion yearsyears

• solar systems solar systems and life at and life at about 12 billion about 12 billion yearsyears

Neutron Neutron StarsStars

• Different phases of Different phases of hadronic matter can hadronic matter can co-exist within a co-exist within a neutron star.neutron star.

• For this sample For this sample neutron star, it is neutron star, it is expected that quark expected that quark matter becomes a matter becomes a stable phase 1km stable phase 1km beneath the beneath the surface.surface.

• In the central core In the central core quark matter is quark matter is dominant.dominant.

Neutron Star: Phase vs DensityNeutron Star: Phase vs Density• Protons and Protons and

neutrons are neutrons are collectively collectively referred to as referred to as nucleonsnucleons

• Ordinary Ordinary nuclear matter nuclear matter density is density is approximately approximately 0.17 0.17 nucleons/fmnucleons/fm-3-3

Quantum Chromodynamics Quantum Chromodynamics ((QQCCDD))

All hadrons are color-singlet (“All hadrons are color-singlet (“whitewhite”):”):• Baryons contain three quarks (Baryons contain three quarks (red red + +

blueblue + + greengreen) - Different baryons ) - Different baryons arise from the three quarks having arise from the three quarks having different flavor combinations.different flavor combinations.

• Mesons contain colour + anticolour Mesons contain colour + anticolour combinations of quark and antiquark combinations of quark and antiquark pairs (pairs (redred + + anti-redanti-red,, greengreen ++ anti-anti-greengreen, , blueblue + anti-blue + anti-blue) - ) - Different Different mesons arise from different flavor mesons arise from different flavor combinations of the pair. combinations of the pair.

• Each flavor of quark cycles through Each flavor of quark cycles through the three colors by exchanging the three colors by exchanging gluons with the other quarks or anti-gluons with the other quarks or anti-quark.quark.

•A A red red quarkquark emitting a emitting a redred--anti-blue gluon to anti-blue gluon to leave a leave a blueblue quark. quark.

•The quark The quark flavorflavor (i.e., u,d,s,c,b,or t) (i.e., u,d,s,c,b,or t) does not change does not change during this during this process, since process, since gluons carry no gluons carry no flavor. flavor.

QQCCDD: Nuclear Forces: Nuclear Forces

… … and hence to atoms, molecules, chemistry, and all of biology.and hence to atoms, molecules, chemistry, and all of biology.

All hadrons are color-singlet (neutral or colorless or “All hadrons are color-singlet (neutral or colorless or “whitewhite”) ”) combinations of quarks (3 quarks for baryons or quark-combinations of quarks (3 quarks for baryons or quark-antiquark pair for mesons). But just as electrically neutral antiquark pair for mesons). But just as electrically neutral atoms interact by van der Waals forces, so can color neutral atoms interact by van der Waals forces, so can color neutral particles. This has particles. This has very importantvery important consequences … the consequences … the strong strong nuclear forcenuclear force..

… … leads to leads to ….….

Two protons attract despite their e.m. repulsion ………… Two protons attract despite their e.m. repulsion ………… stable nucleus stable nucleus

QQCCDD: Baryons and Antibaryons: Baryons and Antibaryons• Baryons are Baryons are

color-singlet color-singlet combinationcombinations of three s of three quarks.quarks.

• Anti-baryons Anti-baryons are color-are color-singlet singlet combinationcombinations of three s of three anti-quarks.anti-quarks.

QQCCDD: Mesons: Mesons• Mesons are Mesons are

made up of a made up of a quark - anti-quark - anti-quark pair quark pair with equal with equal and opposite and opposite color color charges charges giving a giving a color-singlet.color-singlet.

ConfinementConfinement• The strong force between two quarks arises from the The strong force between two quarks arises from the

exchange of gluons.exchange of gluons.• There is also a strong force between two gluons - There is also a strong force between two gluons -

since they carry color themselves they can interact since they carry color themselves they can interact with each other. This is not the case for photons in with each other. This is not the case for photons in QED since they carry no electric charge.QED since they carry no electric charge.

• The force between two quarks is constant, i.e., The force between two quarks is constant, i.e., independent of their separation. This corresponds to independent of their separation. This corresponds to a linearly rising potential between them, which is a linearly rising potential between them, which is referred to as a “referred to as a “string tensionstring tension”. ”.

• This force between colored objects is equivalent to a This force between colored objects is equivalent to a wieight of approximately 10 tons! - This is why no free wieight of approximately 10 tons! - This is why no free quarks or gluons are ever seen. quarks or gluons are ever seen. QQCCD D has the property has the property ofof CONFINEMENTCONFINEMENT..

String Breaking: Quark - Anti-String Breaking: Quark - Anti-quark Pairsquark Pairs

““Gluons” are well-named since they Gluons” are well-named since they lead to the confinement of color lead to the confinement of color particles - no free colored objects have particles - no free colored objects have EVER been seen in nature.EVER been seen in nature.

What happens when we try to pull apart What happens when we try to pull apart two colored objects by pumping more and two colored objects by pumping more and more energy into the system, e.g., through more energy into the system, e.g., through energetic collisions at a particle energetic collisions at a particle accelerator?accelerator?

•When the energy put in is large enough to When the energy put in is large enough to make a quark - anti-quark pair, then a make a quark - anti-quark pair, then a meson can be created and the string is meson can be created and the string is ““brokenbroken”.”.•ConfinementConfinement survives however as no free survives however as no free color particles are produced.color particles are produced.

Asymptotic FreedomAsymptotic Freedom• In quantum In quantum

electrodynamics (electrodynamics (QEDQED) the ) the fine structure constant is fine structure constant is 1/137. 1/137.

• In In QQCCD D thethe coupling “coupling “runsruns” ” by decreasing with by decreasing with increasing energy scale, increasing energy scale, i.e., at short distances.i.e., at short distances.

• At the energy scale of the ZAt the energy scale of the Z00 mass the strong coupling mass the strong coupling constant has decreased to a constant has decreased to a value value s s 0.12.0.12.

• Quarks and gluons appear Quarks and gluons appear almost free at high almost free at high energies. energies.

• At low energies At low energies s s 1, i.e., 1, i.e., the coupling is very the coupling is very STRONG and perturbation STRONG and perturbation theory fails.. theory fails..

ASYMPTOTIASYMPTOTIC FREEDOMC FREEDOM

Strong Coupling Constant at Z Strong Coupling Constant at Z MassMass

• At the energy scale At the energy scale of the Zof the Z00 mass the mass the strong coupling strong coupling constant has constant has decreased to decreased to s s 0.12.0.12.

• This has been This has been confirmed in a confirmed in a variety of different variety of different experiments with a experiments with a remarkable degree remarkable degree of consistency. of consistency.

QQCCD D Produces 98% of Your Produces 98% of Your MassMass •Proton mass is 938 MeV = Proton mass is 938 MeV =

0.938 GeV.0.938 GeV.

•Up and down quark Up and down quark masses are approximately 3 masses are approximately 3 and 6 MeV respectively.and 6 MeV respectively.Where does the rest of the Where does the rest of the

hadron mass come from?hadron mass come from?•The interactions in the low-energy (long-distance) are so The interactions in the low-energy (long-distance) are so strong (i.e., non-perturbative) that they induce a mass in strong (i.e., non-perturbative) that they induce a mass in the quarks of approximately 300 MeV. This is referred to the quarks of approximately 300 MeV. This is referred to as “dynamical mass generation”. This is how three quarks as “dynamical mass generation”. This is how three quarks in a bound state can have a mass exceeding their naïve in a bound state can have a mass exceeding their naïve sum.sum.

•The fact that the up and down quarks are so light and The fact that the up and down quarks are so light and because of this mass-generation, Goldstone’s theorem because of this mass-generation, Goldstone’s theorem states that there will be nearly massless Goldstone bosons states that there will be nearly massless Goldstone bosons associated with the spontaneous breaking of this symmetry associated with the spontaneous breaking of this symmetry - these Goldstone bosons are the pions which are - these Goldstone bosons are the pions which are anomalously light mesons. This is the basis of what is anomalously light mesons. This is the basis of what is called “chiral symmetry” and “dynamical chiral symmetry called “chiral symmetry” and “dynamical chiral symmetry breaking”.breaking”.

Lattice Gauge TheoryLattice Gauge Theory• Physicists at the Physicists at the CSSMCSSM and elsewhere use the and elsewhere use the

techniques of lattice gauge theory to put all of four-techniques of lattice gauge theory to put all of four-dimensional space-time on a grid or lattice.dimensional space-time on a grid or lattice.

• We formulate the gauge field theory (e.g., QED, We formulate the gauge field theory (e.g., QED, QQCCDD, , etc.)etc.) on this discrete lattice with finite-difference on this discrete lattice with finite-difference techniques. This is done in Euclidean space-time for techniques. This is done in Euclidean space-time for numerical reasons. We use methods adapted from numerical reasons. We use methods adapted from statistical mechanics to study the physical properties of statistical mechanics to study the physical properties of the theory from the confining to the asymptotically free the theory from the confining to the asymptotically free regimes. regimes.

• We use this to study and model subatomic particles and We use this to study and model subatomic particles and their interactions. It is VERY computationally expensive their interactions. It is VERY computationally expensive to do this - Teraflop-years of computer time are needed.to do this - Teraflop-years of computer time are needed.

• More accurate results need a finer lattice with larger More accurate results need a finer lattice with larger space-time volumes. This is what makes it space-time volumes. This is what makes it computationally costly. computationally costly.

Lattice Lattice QQCCDDDepiction of electron scattering from quark through a virtual Depiction of electron scattering from quark through a virtual photon exchange in a background gluon field. Lattice QCD does photon exchange in a background gluon field. Lattice QCD does weighted averages over gauge field configurations to obtain weighted averages over gauge field configurations to obtain physical quantities of interest. physical quantities of interest.

Lattice Lattice QQCCDD: Gluon : Gluon ConfigurationsConfigurations

•Typical gluon Typical gluon field field configuration configuration used in lattice used in lattice calculations, (3-calculations, (3-dim slice of 4-dim slice of 4-dim lattice dim lattice showing action showing action density, where density, where red depicts red depicts highest).highest).

•The estimate of The estimate of the integral over the integral over gluon fields does gluon fields does a weighted a weighted average over average over hundreds of hundreds of these.these.

Fluctuations in Fluctuations in the the QQCCD D vacuum.vacuum.

High-Performance ComputingHigh-Performance Computing

• Traditionally supercomputers were very expensive, Traditionally supercomputers were very expensive, contained purpose-built hardware, and were obsolete contained purpose-built hardware, and were obsolete within 5 years.within 5 years.

• Most modern high-performance computing uses cost-Most modern high-performance computing uses cost-effective clusters of mass-produced commodity off-the-effective clusters of mass-produced commodity off-the-shelf (COTS) hardware, rather than expensive proprietary shelf (COTS) hardware, rather than expensive proprietary hardware.hardware.

• These clusters of workstations or PC’s are connected These clusters of workstations or PC’s are connected either by commodity Fast Ethernet or Gigabit switched either by commodity Fast Ethernet or Gigabit switched networking or by (more expensive) special ultrafast, low-networking or by (more expensive) special ultrafast, low-latency networks for clustering (e.g., Myrinet, ServerNet, latency networks for clustering (e.g., Myrinet, ServerNet, GigaNet, SCI, etc).GigaNet, SCI, etc).

• Clusters are flexible in their design and easy to build and Clusters are flexible in their design and easy to build and upgrade - e.g., add more nodes; upgrade some or all of upgrade - e.g., add more nodes; upgrade some or all of the nodes; upgrade some or all of the networking.the nodes; upgrade some or all of the networking.

• Can get an Can get an order of magnitudeorder of magnitude better price/performance better price/performance ratio!ratio!

Top 500 SupercomputersTop 500 Supercomputers

• Clusters of PCs or Unix workstations have become Clusters of PCs or Unix workstations have become incredibly popular in the last few years -- ranging from incredibly popular in the last few years -- ranging from a few networked PCs to around 1000 Compaq Alpha a few networked PCs to around 1000 Compaq Alpha workstations.workstations.

• The unit used to measure the performance of computers The unit used to measure the performance of computers is the “flop”, i.e., 1 flop = 1 floating-point operation per is the “flop”, i.e., 1 flop = 1 floating-point operation per second. second.

• In other words: In other words: 1 flop = 1 calculation per second1 flop = 1 calculation per second..• The 12 fastest supercomputers in the world all exceed 1 The 12 fastest supercomputers in the world all exceed 1

Teraflop, i.e., 1 Teraflop = 1,000 Gigaflops = 1,000 Teraflop, i.e., 1 Teraflop = 1,000 Gigaflops = 1,000 billion calculations per second.billion calculations per second.

• The current fastest is 7.2 Teraflops, (cluster with 8,192 The current fastest is 7.2 Teraflops, (cluster with 8,192 CPU’s called “ASCI White” at Lawrence Livermore CPU’s called “ASCI White” at Lawrence Livermore National Laboratory in the USA- models nuclear National Laboratory in the USA- models nuclear explosions in place of nuclear tests). explosions in place of nuclear tests).

• Three of the top 4 machines serve this same purpose.Three of the top 4 machines serve this same purpose.

Top 500 Supercomputers Top 500 Supercomputers (cont.)(cont.)

• The fastest supercomputer in Australia at present is the The fastest supercomputer in Australia at present is the NEC SX-5/32M2 at the CSIRO Bureau of Meteorology in NEC SX-5/32M2 at the CSIRO Bureau of Meteorology in Melbourne. It is number 99 in the world and is 241.4 Melbourne. It is number 99 in the world and is 241.4 /(256 peak) Gigaflops./(256 peak) Gigaflops.

• The current second fastest is the APAC facility at ANU The current second fastest is the APAC facility at ANU in Canberra, which is a Compaq alpha workstation in Canberra, which is a Compaq alpha workstation cluster and is number 134 in the world and 167.5/(245 cluster and is number 134 in the world and 167.5/(245 peak) Gigaflops. It will very soon be upgraded to 980 peak) Gigaflops. It will very soon be upgraded to 980 peak Gigaflops (almost a Teraflop peak) and at that time peak Gigaflops (almost a Teraflop peak) and at that time will be Australia’s fastest.will be Australia’s fastest.

• The third is a similar Compaq cluster run by VPAC in The third is a similar Compaq cluster run by VPAC in Melbourne and is number 151 at 149.1/(213 peak) Melbourne and is number 151 at 149.1/(213 peak) Gigaflops.Gigaflops.

• Fourth is our own Sun cluster in Adelaide, called Fourth is our own Sun cluster in Adelaide, called “Orion”, which is number 246 at 110/(144 peak) “Orion”, which is number 246 at 110/(144 peak) Gigaflops.Gigaflops.

Cluster Computing Cluster Computing ArchitecturesArchitectures

• Many possible design choices in building a compute Many possible design choices in building a compute cluster -- depends on type of application (or applications).cluster -- depends on type of application (or applications).

• Unix workstations or Beowulf PC cluster?Unix workstations or Beowulf PC cluster?• What processor, clock speed, cache, bus speed, etc?What processor, clock speed, cache, bus speed, etc?• Single processor or Shared-Memory Processor (SMP) Single processor or Shared-Memory Processor (SMP)

nodes?nodes?• Linux or commercial operating system (OS)?Linux or commercial operating system (OS)?• How much memory and disk per node?How much memory and disk per node?• Buy from vendor or systems integrator, or build it Buy from vendor or systems integrator, or build it

yourself?yourself?• What networking technology to use?What networking technology to use?

– Commodity Fast or Gigabit switched ethernet is Commodity Fast or Gigabit switched ethernet is relatively cheap, but has high latency.relatively cheap, but has high latency.

– Low-latency, ultra-fast networks are significantly more Low-latency, ultra-fast networks are significantly more expensive, but far superior.expensive, but far superior.

Orion SupercomputerOrion Supercomputer•Orion is a Sun Technical Orion is a Sun Technical Compute Farm with 40 Sun Compute Farm with 40 Sun E420R 4-way SMP nodes E420R 4-way SMP nodes (160 processors). Fast (160 processors). Fast switched ethernet AND switched ethernet AND high-speed Myrinet high-speed Myrinet network. network. •110/(144 peak) Gflops, 160 110/(144 peak) Gflops, 160 Gigabytes RAM, 640 Gigabytes RAM, 640 Megabytes cache memory.Megabytes cache memory.• Fastest computer in Fastest computer in Australia when installed in Australia when installed in June 2000 and now number June 2000 and now number 4.4.•The CSSM together with The CSSM together with lattice theorists from UNSW lattice theorists from UNSW and the University of and the University of Melbourne obtained RIEF Melbourne obtained RIEF funds to seed the National funds to seed the National Computing Facility for Computing Facility for Lattice Gauge Theory Lattice Gauge Theory (NCFLGT) which houses the (NCFLGT) which houses the Orion supercomputer.Orion supercomputer.

Built in partnership with Built in partnership with Sun MicrosystemsSun Microsystems..

Orion: SoftwareOrion: Software• Nodes run Solaris and standard Sun software and compilers.Nodes run Solaris and standard Sun software and compilers.• Sun HPC ClusterTools includes Sun HPC ClusterTools includes

– Sun Cluster Runtime Environment (CRE)Sun Cluster Runtime Environment (CRE)– Sun MPI, optimized for SMP cluster (and recently for Sun MPI, optimized for SMP cluster (and recently for

Myrinet)Myrinet)– Sun Scientific Software Library (S3L)Sun Scientific Software Library (S3L)– Prism debugger and performance analysis toolPrism debugger and performance analysis tool

• S3L and Prism are developed from CM software.S3L and Prism are developed from CM software.• Sun Fortran 90/95 compiler, supports automated Sun Fortran 90/95 compiler, supports automated

parallelisation and OpenMP directives for shared memory parallelisation and OpenMP directives for shared memory parallelism.parallelism.

• Portland Group HPF compiler, converts code to Sun F77/90 Portland Group HPF compiler, converts code to Sun F77/90 plus MPI.plus MPI.

• Sun Grid Engine (formerly CODINE) cluster management Sun Grid Engine (formerly CODINE) cluster management system is more advanced than CRE, supports batch queueing, system is more advanced than CRE, supports batch queueing, detailed logging of system usage, access levels, etc.detailed logging of system usage, access levels, etc.

Centre for High-Performance Centre for High-Performance

Computing and Applications (Computing and Applications (CHPCACHPCA) ) • The CHPCA is a newly created cross-disciplinary Research The CHPCA is a newly created cross-disciplinary Research

Centre at Adelaide University. Its goal is to bring together Centre at Adelaide University. Its goal is to bring together all researchers with an interest and commitment to High-all researchers with an interest and commitment to High-Performance Computing (HPC) in order to share expertise Performance Computing (HPC) in order to share expertise and to develop a very large shared computing platform. and to develop a very large shared computing platform. [Director: AGW; Deputy Directors: Paul Coddington [Director: AGW; Deputy Directors: Paul Coddington (DHPC), Derek Lienweber (CSSM), and Francis Vaughan (DHPC), Derek Lienweber (CSSM), and Francis Vaughan (SAPAC)].(SAPAC)].

• Partner researchers include: Physics, Chemistry, Partner researchers include: Physics, Chemistry, Engineering, Biology and Bioinformatics, Plant Science, Engineering, Biology and Bioinformatics, Plant Science, Geology and Geophysics, Water Resource Management, etc. Geology and Geophysics, Water Resource Management, etc.

• Next year (2002) the CHPCA already has enough funds from Next year (2002) the CHPCA already has enough funds from its members and partners to construct a 250+ Gigaflop its members and partners to construct a 250+ Gigaflop cluster consisting of 40 dual processor 2 GHz Pentium 4 cluster consisting of 40 dual processor 2 GHz Pentium 4 nodes with Myrinet 2000 cluster networking.nodes with Myrinet 2000 cluster networking.

• The goal is to raise funds to turn this into a Teraflop The goal is to raise funds to turn this into a Teraflop supercomputer.supercomputer.

CHPCACHPCA: Engineering : Engineering ApplicationsApplications

• Computational fluid dynamics.Computational fluid dynamics.• Drag and noise reduction in planes, ships, submarines, etc.Drag and noise reduction in planes, ships, submarines, etc.• Petroleum geology, oil and gas reservoir modeling.Petroleum geology, oil and gas reservoir modeling.• Flow through porous media.Flow through porous media.• Water quality management and salinity.Water quality management and salinity.• Optimization of distribution systems for water piplines, power Optimization of distribution systems for water piplines, power

lines, and telecommunication networks.lines, and telecommunication networks.• Optimization of engineering design over a large parameter Optimization of engineering design over a large parameter

spacespace– search over multiple parameters using task farm approach, search over multiple parameters using task farm approach,

many sequential jobs each with different parametersmany sequential jobs each with different parameters

CHPCACHPCA: Biological Applications: Biological Applications• Bluegene - IBM plans to build a 1 Petaflop computer to study Bluegene - IBM plans to build a 1 Petaflop computer to study

fundamental problems in computational biology and protein fundamental problems in computational biology and protein science - (1 Petaflop = 1,000 Teraflops!) - 1 million science - (1 Petaflop = 1,000 Teraflops!) - 1 million processors and each processor with multiple CPU’s and processors and each processor with multiple CPU’s and memory and communication logic built in.memory and communication logic built in.

• Bluegene will focus on protein folding in particular.Bluegene will focus on protein folding in particular.• Modelling heart and brain function, organ and arterial Modelling heart and brain function, organ and arterial

simulation - chaos, heart fibrillation, epileptic seizures, etc.simulation - chaos, heart fibrillation, epileptic seizures, etc.• The “virtual human” project - Oak Ridge National Laboratory.The “virtual human” project - Oak Ridge National Laboratory.• DNA and protein sequence analysis and classification.DNA and protein sequence analysis and classification.• Genome data and bioinformatics - “data farming” for efficient Genome data and bioinformatics - “data farming” for efficient

storage, recovery, searching and matching of vast biological storage, recovery, searching and matching of vast biological data, e.g., for efficient drug design, etc.data, e.g., for efficient drug design, etc.

Conclusions and OutlookConclusions and Outlook• This is an exciting time for theoretical subatomic physics in This is an exciting time for theoretical subatomic physics in

Australia.Australia.• The CSSM is continuing to build on its successes and is highly The CSSM is continuing to build on its successes and is highly

productive.productive.• The Australian lattice QCD program is now well-established and The Australian lattice QCD program is now well-established and

runs a world-class supercomputing facility.runs a world-class supercomputing facility.• With the establishment of a cross-disciplinary CHPCA the path to a With the establishment of a cross-disciplinary CHPCA the path to a

Teraflop computer and a world-class resource for the coming years Teraflop computer and a world-class resource for the coming years is becoming a reality.is becoming a reality.

• We look forward to new discoveries and new opportunities in We look forward to new discoveries and new opportunities in subatomic physics over the next few years.subatomic physics over the next few years.

• Cross-disciplinary activity in High-Performance Computing research Cross-disciplinary activity in High-Performance Computing research is becoming increasingly important for the HPC field in order that is becoming increasingly important for the HPC field in order that research areas that depend on it continue to thrive. - We are research areas that depend on it continue to thrive. - We are working on that.working on that.

• Thank you for your attention. Thank you for your attention.

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