3.37 Sspd_chapter 1_part 14_bosons , fermions and physics of laser

SSPD_Chapter 1_Part 14_BOSONS , FERMIONS and Physics of LASER ACTION.

The essence of creation is formless and uniform. There is one law for all. This is the state of super symmetry. There is a quantum-gravity theory.

After the Big Bang as expansion takes place, space and time is created, energy density falls and temperature falls. Super symmetry is broken. Different energy particles and material particles are created.

Among these the fundamental particles are:

Intermediate Vector Bosons, leptons and lepton neutrino.

Hadrons are composite particles, composed of three generation of quarks and three generation of antiquarks. Triplets of quarks and anti-quarks are called Baryons and doublets of quarks and anti-quarks are called Mesons.

In 1910, Satyendra Nath Bose made an unique proposition while laying down the theoretical foundations of Black Body Radiation.

According to him all the integer number spin particles tend to aggregate together and these are called Bosons. In the energy spectrum their distribution function is defined as below:

P(ћω)=P(E)= 1/[Exp{( ћω)/(kT)} - 1] ………………………………… 1.136.

Where E = ћω ;

And P(E) = Probability of occupancy at the energy level E;

In contrast to this the particles which have half integer spin namely (1/2) ћ

or (3/2) ћ , they tend to lead solitary life and they are called Fermions. Their distribution function in the energy spectrum is the following:

P(E)= 1/[Exp{(E-E F )/(kT)} + 1] ……………………………………….. 1.137.

Where E F = Fermi Energy Level= the maximum energy level occupied by the particle in question at 0 K or where the Probability of Occupancy is (1/2) at any temperature T Kelvin.

Why do we encounter these two kinds of statistics or these two kinds of tendencies in nature: one of aggregation and the other of segregation?

If we look closely at these two particles we find a very significant feature between these two particles. Bosons are indistinguishable whereas Fermions are distinguishable.

1.14.1. THE EFFECT OF DISTINGUISH ABILITY ON DICE GAME.

Dice game is played as a game of gambling in almost all countries.

In its simplest form there are two coins each with two sides: head and tail. Therefore if they are played together and if the two coins are distinguishable then there are 4 distinct permutations:

Coin A- head, Coin B- tail;

Coin A- tail, Coin B- head;

Coin A- head, Coin B- head;

Coin A- tail, Coin B- tail.

But if the two particles are indistinguishable then we have only three combinations:

First combination: head and tail or tail and head;

Second combination: head and head;

Third combination: tail and tail.

When distinguishable coins are present then probability of occurrence of each of the four permutations is quarter(1/4).

When indistinghuishable coins are then probability of occurrence of each of the three combinations is one-third (1/3).

Thus indistinguishability has increased the probability of occurrence to: