Elementry particles project by Jyotibhooshan chaturvedi
1. Shri Agrasen Kanya Autonomous P.G. College,
A Project on: Elementary particles
Bachelor of Science
Internal Supervisor External Supervisor Submitted by
Dr. Shubha R. Saxena (HOD) Shweta Shukla
Dr. Sunil Mishra Anjali Singh
Dep. of Physics B. Sc. (Final Year)
Shri A. K. A. P. G. College
2. Sri Agrasen Kanya Autonomous P.G. College
Varanasi – 221001
This is to certify that the Project Work entitled Elementary
Particles in Atom.
A Project report has been undertaken in much supervision
and guidance, the result presented in the project report is based on
her own independent effort that had been checked and verify by
me. I am fully satisfied with the work which is being presented by
Shweta Shukla & Anjali Singh.
Forwarded by Supervised by
Dr. Kumkum Malviya Dr. Shubha R. Saxena (HOD)
Principal Dr. Sunil Mishra
Sri A.K.A.P.G. College Department Of Physics
Bulanala, Varanasi Sri A.K.A.P.G. College
I am thankful to our Principal Dr. Kumkum
Malviya, I am deeply indebted by our Mam Dr. Shubha
R Saxena Head, of Department of Physics, Shri A. K.
A. P.G. College, Varanasi for inspiring and providing
important book S. N. Ghosal, S.Chand & Griffit for this
I am thankful to respected teacher Dr. Sunil
Mishra Department of Physics, Shri A. K. A. P.G. P.G.
College, and Varanasi for helping me lots by; giving
suggestion and guidance.
I am heartily thankful to all our teachers of the
department whose great blessing and love made it
possible for me to go and succeeded in my work.
Shweta Shukla & Anjali Singh
The elementary Particles are separated in to two
general groups called Bosons and Fermions. These
two groups have different type of spin and their
behaviors in controlled by a different kin d of
statistic. (I.e. the Bose statistic and the Fermi
Bosons are particles with intrinsic angular momentum
equal to an integral of one. Fermions are all those
particles with in which the spin is half integral.
7. Production of ElementaryParticles
Bosons are a term which not only includes material particles
but also includes those quanta and photon.
Photon was discovered in 1905 by Einstein.
Photon has no mass and no charge particles.
A mass-less bosons is called a Graviton with probable spin of two units.
Free Graviton is emitted only by large masses (i.e. stars) subject so very
The rest mass of these particles varies between about 250 me and 1000 me .
The mesons particles are lighter than a proton and heavier than an electron
and position i.e. intermediate between the electrons and proton.
When boson created by the field interaction are essentially of one two
distinct kinds. First there are those which are known as pion.
The second groups of Boson are much heavier than of pion and known
Small or light weight particles
Are points like particles- no internal
Electrons e, muon µ tau τ
And their associated neutrinos:
Also, their antiparticles
Neutrinos have tiny mass, ̴̴̴̴̴̴̴̴̴3eV/C2
(strong force interaction, composed of quarks)
We already met the mesons (middle weights)
Decay into electrons, neutrinos and photons
Baryons, i.e. the proton and neutron (the
Still other more exotic baryons:
• ƩɅΩΣΛΞ≡ all are heavier than the proton
• Decay into end products that include a proton
11. Characteristic properties of elementary particles:-
Mass- an elementary particles has always the same rest mass. The
magnitude of the rest mass serves as the principal label to identify the
Charge- all elementary particles have charge +e, -e or zero. This charge
or conserved in any collision process. It may be seen from the following
n + p -> p + p + π¯
Life time- all elementary particles, except photon, electron, proton and
neutrinos, are unstable and decay into other elementary particles of
Spin- the particles of half integral, i.e., spins ,, etc. obeying Fermi-Dirac
statistics, are called Fermions. The particles of spins are electrons,
positrons, protons, neutrons, neutrinos, antineutrinos, µ-mesons and many
hyperons. Particles having zero or integral spins, i.e., 0,1,2 etc. are
bosons because they obey Bose-Einstein statistic.
13. What do youthink?
What is all the matter in the Universe made of?
What holds it together?
All matter is comprised of Leptons and Quarks.
Force carrier particles hold all matter together.
(There are 4 fundamental forces- Strong, Weak,
Electromagnetic, and Gravity).
14. The Four Fundamental Forces
These forces include interactions that are attractive
or repulsive, decay and annihilation.
15. The Strong Forces
The strongest of the 4 forces.
Is only effective at distances less
than 10-15 meters (about the size of
Holds quarks together.
The forces are carried by gluons.
17. Residual Strong Forces
We know that protons andneutrons are bound
together in the nucleus ofan atom
This is due to the residualstrong forces that is
binding the quarks together in eachof the baryons
19. The Weak Forces
A very short-ranged nuclear
interaction that is involved in beta
This is ten thousand billion times
weaker than the strong forces (10-13)
Effective only at distances 1000
times smaller than the strong forces
This force is carried by the W+, W-,
and the Z0 boson particles
21. The Electromagnetic Force
Causes opposite charges to attract
and like charges to repel
Carried by a particles called a
Its effects decrease with the
inverse square of the separation (as
we learned earlier)
Has a negligible effect on elementary
A long-rang forces (as we learned
Carried by the graviton
This is by far the weakest of the 4