[Physics Class Notes] on Boson Pdf for Exam

Bosons are a class of fundamental/elementary subatomic particles in particle physics, named after an Indian Physicist and Professor at the University of Calcutta and the University of Dhaka, Satyendra Nath Bose to remember his contributions to science.

In quantum mechanics, a boson is a subatomic particle like a photon or a meson. These particles have zero quantum numbers that are governed by S.N. Bose and Albert Einstein or Bose-Einstein Statistics.

A Boson has the Following Properties:

On this page, we will understand what boson is, with various examples of bosons and types.

History of Boson

Boson was trying to realize the enormous breakthrough he made. Coupled with, Einstein took Bose’s work further. 

An English theoretical physicist Paul Adrien Maurice Dirac used the term “boson” for the first time to describe the particles that obeyed Bose-Einstein statistics, to celebrate Bose’s contribution to developing this theory.

An Indian physicist and professor of Physics at the University of Calcutta and Dhaka, coupled with Albert Einstein, developed Boson.

They both worked together, so the theory was named Bose-Einstein statistics to theorize the characteristics of elementary particles.

Examples of Bosons

Examples of Bosons are Fundamental Particles, Such As;

• Photons

• Gluons 

• W bosons

• Z bosons Or W and Z bosons

• Four force-carrying gauge bosons of the Standard Model 

• Higgs boson

• A hypothetical graviton of quantum gravity

• Bosons are also counted under composite particles, such as;

1. Mesons

2. Stable nuclei having an even mass number as that of deuterium 

(atomic number = 2 with one proton and one neutron)

3. Other elements, like helium – 4, and lead – 208

• Bosons are quasiparticles; for instance,. Cooper pairs, plasmons, and phonons.

Superfluidity by Bosons

There is no restriction on the number of bosons that occupy a constant quantum state.

Helium – 4 exemplifies this attribute. Helium – 4 when supercooled, becomes a superfluid.

A superfluid is a state of matter that assumes to be a liquid with zero viscosity.

Talking about bosons, 2 identical fermions cannot occupy a constant quantum state. 

Fermions are the elementary particles that make up matter, like leptons and quarks.

The elementary bosons are force carriers that operate like the ‘glue’ that holds matter along.

This property holds for all particles with whole-number spin (s = zero, 1, 2, etc.) as a consequence of the spin-statistics theorem. 

When a gas of Bose particles cools to temperatures terribly near to absolute temperature, their kinetic energy decreases to a negligible quantity. 

Furthermore, they condense into a very cheap energy state. We term this state a Bose-Einstein condensate. This property is additionally the reason for superfluidity.

Elementary Particles

All noticed elementary particles are either fermions or bosons. Out of these, elementary bosons are gauge bosons, like photons, W and Z bosons, gluons, except the Higgs boson, a scalar boson.

Photons are the force carriers of the electromagnetic field (light and radio waves).

W and Z bosons are the force carriers that mediate the weak force.

Gluons are the basic force carriers underlying the strong force/interaction.

Higgs bosons provide W and Z bosons mass via the Higgs mechanism.

Types of Bosons

Bosons are elementary, likewise photons, or composite, like mesons.

Though most bosons are composite particles, in the Standard Model of Particle Physics; additionally, there are five bosons which are elementary:

The Standard Model requires at least one scalar boson, with a zero spin.

1. H0 Higgs Boson

Higgs Boson Meaning: Four-vector bosons with a spin  = 1.  These are the gauge bosons for the Standard Model:

2. γ   Photon

3. g   Gluons (eight types)

4. Z   Neutral weak boson

5. W±  =  Weakly charged bosons (two types)

6. Graviton

Graviton is a hypothetical sixth tensor boson (elementary particle) with a spin = 2.

We assume it to be a force carrier for gravity. So far, graviton attempts to incorporate gravitation into the Standard Model have failed. 

If the graviton exists, then it must be a boson, and can conceivably be a gauge boson.

7. We discussed composite bosons such as helium – 4 atoms, these are important elements in superfluidity. Also, for the applications of Bose-Einstein condensates.

8. Goldstone Boson:

Goldstone boson is a massless and spinless particle that relates to the spontaneous symmetry breaking of global symmetries in quantum theory.

Higgs Boson Collider

In the first place,  Peter Higgs, François Englert, and four other theorists put forward the Higgs boson in 1964 to elaborate why certain particles have mass. 

In 2012, coupled, scientists confirmed its existence via ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN in Switzerland. 

Furthermore, this discovery landed a Nobel Prize in Physics to Higgs and Englert in 2013

LHC or a Large Boson Boson Collider is the world’s most powerful particle accelerator. 

It accelerates and demolishes protons and other atom
ic nuclei to study matter’s fundamental properties.

Do You Know?

We call the Goldstone boson a Nambu-Goldstone boson. Additionally, the mechanism for spontaneous symmetry breaking to generate them was originally discovered within the context of electrical conduction by Yoichero Nambu, and later generalized and processed by Jeffrey Goldstone.