Higgs Boson-The God’s Particle Higgs Boson-The God’s Particle & The mystery of mass& The mystery of mass

Dr.S.Sanyasi RajuReader & H.O.D. of PhysicsM.R.College(A), VizianagaramE-mail: ssraju_lec@yahoo.comWeb-site: www.ssrajuphysics.com

The Higgs Boson is a theoretical elementary, subatomic particle

predicted to exist by the Standard Model of particle physics. It is the

only Standard Model (SM) particle that has not yet been observed.

Dubbed “the God” particle by Nobel Prize winning physicist Leon

Lederman, the Higgs is thought to impart mass to all other particles in

the universe.

The Higgs particle is named after the British theorist Peter Higgs

who along with Robert Brout and François Englert theorized its

existence in 1964. The search for the Higgs remains one of the most

important objective of research in elementary particle physics today.

33

44

d

The Matter ParticlesThe Matter Particles

e

Neutrino

Electron

ProtonMass: 1.7 10-27 kgcharge: +1

Mass: ~<10-9 proton mass?Charge: 0

Mass: 0.0005 proton mass charge: -1

u

ud

Neutron Charge: 0u

d

The particles of Matter The particles of Matter

e

u

d

uu

dd

Come in 3 versions, known as colours

neutrino

Electron

up’ quark

‘down’ quark

66

The Matter particlesThe Matter particles

u

d

e

1st GenerationOrdinary matter

2nd GenerationCosmic rays

s

c

3rd GenerationAccelerators

b

t

77

The particles of MatterThe particles of Matter

u

d

e

All ordinary matter is composed of these

(There is a corresponding antiparticle for each)

88

The Matter particlesThe Matter particles

u

d

e

1st Generation

2nd Generation

s

c

3rd Generation

b

t

0.1GeV

1.7GeV

4.5GeV

175GeV

E=mc2

1GeV~Proton Mass

1.7GeV

99

The Matter particlesThe Matter particles

u

d

e

1st Generation

2nd Generation

s

c

3rd Generation

b

t

1974

1977

2000 1995

19751897

1010

How do quarks combine?How do quarks combine?

u

ud

A proton:two ‘u’ quarks and one ‘d’ quark

d

ud

A neutron: 2 ‘d’ quarks and 1 ‘u’ quark

u

d

Mesons have a quark and an anti-quark-

Many created, not stable

With 6 quark types there are hundreds of combinations

1111

+

Forces in Ordinary PhysicsForces in Ordinary PhysicsClassically, forces are described by

+

Field

charges and fields

++

1212

Continuous field exchange of quanta

+ +

For Electromagnetism

The quanta are photons,

High energies and small distances quantum mechanics

Forces in Particle PhysicsForces in Particle Physics

1313

The Forces of NatureThe Forces of Nature

Force Realm Particle

Electro-magnetism

Magnets, DVD players

Strong Fusion Gluon

Weak -decay, (sunshine)

W+,W-, Z0

Gravitation Not in the same framework

Higgs may give a link?

1414

The Forces of NatureThe Forces of Nature

Force Mass, GeV Particle

Electro-magnetism

0

Strong 0 Gluon

Weak

W’s Z

Gravitation Not in the same framework

1515

Feynman DiagramPositron (anti-electron)

Mediation of the ForcesMediation of the Forces

Electron

At each ‘vertex’ charge is conserved. Heisenberg Uncertainty allows energy borrowing.

1616

Particles and forcesParticles and forces

‘u’ quarks ‘d’ quarks electron neutrino

E.M.charge

+2/3

Strongforce

yes yes no no

Weakforce

yes yes yes yes

Heavier generations have identical pattern