E-MODULE

SUBJECT PHYSICS

PAPER PARTICLE PHYSICS

MODULE NO. 1

TOPIC Introduction to Standard Model

PREPARED BY Dr. Anil Kumar, Post Graduate

Department of Physics, JC DAV

College, Dasuya, Punjab

INTRODUCTION

What’s fundamental

The Standard model is the quantum

theory that describes strong

interaction and electroweak

interaction

Scale of subatomic matter

Ancient times People think that earth, air, fire, and water are the fundamental elements.

1802 Dalton’s Atomic theory began forming.

1897 J. J. Thompson discovered the electron.

1911 Rutherford discovered positive nucleus.

1930 Pauli invented the neutrino particle.

1932 James Chadwick discovered the neutron.

1937 The muon was discovered by J. C. Street and E. C. Stevenson.

1956 First discovery of the neutrino by an experiment: the electron neutrino.

1962 Discovery of an other type of neutrino: the muon neutrino.

1969 Friedman, Kendall, and Taylor found the first evidence of quarks.

1974 The charmed quark was observed.

1976 The tau lepton was discovered at SPEAR.

1977 Experimenters found proof of the bottom quark.

1983 Carlo Rubbia and Simon Van der Meer discovered the W and Z bosons.

1991 LEP experiments show that there are only three light neutrinos.

1995 The top quark was found at Fermilab.

1998 Neutrino oscillations may have been seen in LSND and Super-Kamiokande.

2000 The tau neutrino was observed at Fermilab.

2003 A Five-Quark State has been discovered.

A short summary of events

p

W h a t a j u n g l e !

Standard model

The Standard Model describes the properties and interactions of the fundamental particles which are the building blocks of the universe.

It organizes all the matter and energy (well most of it)

Matter Vs. Antimatter

Charge

Annihilation

Pair production

Standard Model

The fundamental model for elementary particles.

Point Particles not strings !

No gravity !

What are the 3 families of particles?

What’s a Boson, Fermion, Lepton and quark?

What are Higgs particles??

Fermion Flavors

Leptons and Quarks

Leptons

Solitary particles

Charge on

particles Vs.

antiparticles

Generations or

Families

Leptons

Lepton family conservation-

separate conservation law for

electron, muon and tau family.

Neutrino’s and conservation laws

Mediate decays

Quarks

Generations or

families

Charge

Combinations

Particles Vs.

antiparticles

What are Protons and Neutrons made of ?

Quarks have both electric and color charge

Color charges: Red, green & blue {1,2,3}

And Flavors: { u d c s t b }

Combinations of quarks –

Hadrons

Baryons

Examples of

Baryon particles

Spin and

consequences

Combinations of quarks - Hadrons

Mesons- quark-

antiquark

Examples of

Mesons

Spin and

consequences

Quarks and Anti-Quarks

Baryons and Mesons are colorless.

Bosons

Spin

Mediate forces (Fields Vs. exchange particles)

Electromagnetic

Weak

Strong

Gravity

Higgs Boson adds particle mass

These spin-less force particles give other

particles their mass.

The addition of the Higgs field (a field

implies there are associated force

particles) again helps to renormalize the

theory.. gets rid of infinities.

Extension of the local U(1) symmetry of

QED to include QCD SU(3), was done by

Yang and Mills in 1954. Electroweak

theory proven 1983.

Science needs advanced technology

How to Obtain Particles Accelerator

Modern Detectors Bubble Chamber

http://particleadventure.org/particleadventure/index.html

The Nobel Prize winner

1979 Nobel Prize-- GLASHOW, SALAM and WEINBERG

the theory of the unified weak and electromagnetic interaction.

1984 Nobel Prize-- RUBBIA and VAN DER MEER

the discovery of the field particles W and Z, communicators of weak

interaction.

CONCLUSION

THE STANDARD MODEL

Fermions Bosons

Leptons Quarks

Baryons Mesons