The Standard ModelThe Standard Modeland and

BeyondBeyondHarrison B. Prosper

6 July, 2010Fermilab Summer Lecture Series

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Where Do We Come From? What Are We?

Where Are We Going? Paul Gauguin

(1897) Museum of Fine Arts, Boston

The Standard ModelThe Standard Model

4

What is the Standard Model?What is the Standard Model?

The Standard Model (SM) is a quantum field theoryquantum field theory

that describes the excitationsexcitations of quantum fields quantum fields in spacetime

We interpret these excitations as particlesparticles

Matter

Up quark Down quark

e

Electron Antielectron Neutrino

νe

u d

ForcesForcesStrong Force 11 (Gluons)(Gluons)

Binds protons and neutrons to form nuclei

Electromagnetic Force 1010-2-2 (Photon)(Photon)Binds electrons and nuclei to form atoms

Weak Force 1010-5-5 (W & Z Bosons)(W & Z Bosons)Causes radioactivity

Gravitational Force 1010-39-39 (Graviton)(Graviton)Binds matter on large scales

Discovery, Electron – 18971897

J.J Thomson

Discovery, Top Quark – 19951995 CDF & DØ

A Century of High Energy PhysicsA Century of High Energy Physics

1897 – ELECTRON discovery Thomson1909 – PROTON discovery Rutherford

1928 – ANTIMATTER theory Dirac1930 – NEUTRINO theory Pauli1932 – NEUTRON discovery Chadwick1932 – POSITRON discovery Anderson1935 – EXCHANGE theory Yukawa

1948 – QED theory Feynman,…1961 - ELECTROWEAK theory Glashow 1964 – QUARK theory Gell-Man, Zweig1964 – HIGGS theory Higgs, Englert,…1967 – ELECTROWEAK theory Weinberg, Salam,…

A Century of Particle PhysicsA Century of Particle Physics

1971 – 73 QCD theory ‘t Hooft, Veltman, Gell-Man, Frisch,

Gross, Wilzcek, Politzer

1974 – CHARM discovery Ting, Richter1977 – BOTTOM discovery Lederman1979 – GLUON1979 – GLUON discovery TASSO, JADEJADE,

MARK-J, PLUTO1983 – W & Z discovery Rubbia/UA1, UA2

1995 – TOP1995 – TOP discovery DDØØ & CDF

A Century of Particle PhysicsA Century of Particle Physics

N

Neutron

Proton

P

e

Electron νe

Anti-electron neutrino

Fermi’s 1934 theory of beta-decay

Enrico Fermi 1901 - 1954

1934 – Theory of Beta Decay1934 – Theory of Beta Decay

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1935 – Particle Exchange Theory1935 – Particle Exchange Theory

Hideki Yukawa (1935) showed that the potential energypotential energy between two particles has the form

mm is the mass of the particleparticle exchanged between the them

RR = = hc hc / mcmc2 is the range of the force

U (r) =−

g2

4πrexπ −

rR

⎛⎝⎜

⎞⎠⎟

Hideki Yukawa 1907 - 1981

12

1948 – Quantum Electrodynamics1948 – Quantum Electrodynamics

Feynman invented a systematic way to calculate the force between electrically charged particles, based on Yukawa’s idea of particle exchange

g g

y y

f

Richard P. Feynman 1918 - 1988

Feynman Diagram

N

Neutron

Proton

P

e

Electron

The Weak ForceThe Weak ForceGiven the success of QED it was natural to try to create an analogous theory of the weak force

νe

Anti-electron neutrino

N

Neutron

Proton

P

e

Electron

The Weak ForceThe Weak ForceGiven the success of QED it was natural to try to create an analogous theory of the weak force

νe

Anti-electron neutrino

W-

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1961 – The Electroweak Theory1961 – The Electroweak Theory

Glashow Theory + Higgs Theory Electroweak Theory

(1967)

Steven Weinberg Abdus Salam

Sheldon Glashow (1961)

u d e

s μ

νe

νμ

Quarks Leptons+2/3 -1/3 -1 0

1964 – The Quark Model1964 – The Quark Model

Gell-Man and Zweig

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The Quark ModelThe Quark Model

u ud

d du

Proton Neutron

uuu

Delta++

The Delta++ puzzle

+1 0 +2

u

s

d e νe

Quarks Leptons+2/3 -1/3 -1 0

The Quark ModelThe Quark Model

u u u d d d

s s s

One possible solution: color charge color charge

(Greenberg, Frizsch, Gell-Man, Leutwyler)

μ νμ

u uu

d ud

u du

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The Quark ModelThe Quark Model

Proton Neutron Delta++

Problem solved !

+1 0 +2

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1971 – The Theories Make Sense!1971 – The Theories Make Sense!

Martinus Veltman Gerard 't Hooft

1971 - Proved that theories of the sort created by Glashow, Weinberg and Salam are consistent

The Strong ForceThe Strong ForceProton

u

u d

u

u d

u

u d

gg

g

u

u d

u

u d

u

u d

1972-73 Quantum Chromodynamics (QCD)

Gross

Politzer

Wilczek

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Discovery of the GluonDiscovery of the Gluongqqee

1979 TASSOMARK-JJADEJADEPLUTO

DESYHamburg,Germany

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Discovery of Top the QuarkDiscovery of Top the Quark

1995CDFDØDØ

Fermilab

p π→ t→ e νe b

t → q ′q b

u u u d d d e

b b b t

c c c s s s μ

g g g g g g g g

g Z W+

νe

νt

νμ

Quarks Leptons+2/3 -1/3 -1 0

I

II

III

Bos

ons

Ferm

ions

The Standard ModelThe Standard Model

H

t t t

W-

……And BeyondAnd Beyond

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SupersymmetrySupersymmetry

CompositenessCompositeness

StringsStrings

MultiverseMultiverse

TechnicolorTechnicolor

Extra DimensionsExtra Dimensions

Brane WorldsBrane Worlds

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PuzzlesPuzzlesThe Identity Puzzle

What makes a top quark a top quark, an electron an electron, and a neutrino a neutrino? (Chris Quigg, 2007)

The Mass PuzzleWhat is the origin of the mass of fundamental

particles?

The Matter PuzzleWhy is there overwhelmingly more matter than

antimatter?

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The Just-So PuzzleWhat determines the values of the Standard Model

parameters? Or, are we special?

The Gravity PuzzleWhy strongstrong: emem: weakweak: gravitygravity = 11: : 1010-2-2: : 1010-5-5: 10: 10-39-39 ?

The Dark Matter PuzzleWhat is dark matter?

The Dark Energy PuzzleWhy is dark energy?

PuzzlesPuzzles

The Mass Puzzle

u d

u

Total mass 9.6 MeV

Total mass 938 MeV !!

m =Ec2

The Proton BasketThe Proton Basket2.3 MeV 5 MeV

2.3 MeV

The Mass Puzzle – A Solution?

B. Robson, “The Generation Model and the Origin of Mass”,Int. J. Mod. Phys. E18 (2009)

T T

VT T

T

T

V

V

e

V

V

VV

V

V

T

V

V T

T

V T

T

T

u d

ν ν

d u e−

The Just-So Puzzle

d u

d

NeutronProton

u d

u

2.3 MeV2.3 MeV5.0 MeV_______9.6 MeV

5.0 MeV5.0 MeV2.3 MeV_______12.3 MeV

938.3 MeV – 9.6 MeV928.7 MeV928.7 MeV

939.6 MeV–12.3 MeV927.3 MeV927.3 MeV

Are we special?

Life in the Multiverse

Alejandro JenkinsFlorida State University

Scientific AmericanJanuary 2010

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The Gravity PuzzleThe Gravity Puzzle

1010-39-39

Gravity on the BraneGravity on the Brane

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Isaac Newton(1687)

F =GμMr2

rg ⋅d

rA=4πGM—∫

Gauss’ Law

Our 3-D brane

Gravity in 3 + n DimensionsGravity in 3 + n Dimensions

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F ~ GnmMrn2

Arkani-Hamed, Dimopoulos, Dvali

(1998)

rg ⋅d

rA=4πGM—∫

Gauss’ Law

Our 3-D brane

36

R

Gravity in 3 + n DimensionsGravity in 3 + n Dimensions

F ~ GnmMrn2

Suppose that gravity can propagate a distance R away from our 3-D brane world

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When r >> R, the gravity force should look like Newton’s law of gravity

RThis yieldsthe relationGG = = GGn n / / RRnn

F ~Gn

Rn⎛⎝⎜

⎞⎠⎟μMr2

Gravity in 3 + n DimensionsGravity in 3 + n Dimensions

Searching for Branes at Fermilab!Searching for Branes at Fermilab!

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G

p p

g

One way: look for photon + unexplained amounts of missing momentum

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The Era of the Large Hadron ColliderThe Era of the Large Hadron Collider

CERN

Geneva

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The EndThe EndCERN