This document discusses elementary particles and their classification. It states that quarks are currently believed to be fundamental particles as they are not made of anything smaller. It provides classifications for elementary particles such as hadrons, baryons, mesons, and leptons. It also discusses nuclear quantum numbers, conservation laws in interactions between elementary particles, and provides an example question.

1. Elementary particle
SUBMITTED TO: Dr. K Dhoot and Giriraj Chayal
SUBMITTED BY: VISHAL KUMAR JANGID,M.Sc(Final) 2016-17
JNVU (Department of Physics)

2. People have long asked:
"What is the world made of?" and
"What holds it together?"
 What is the World Made of?
 People have come to realize that the matter of the world is made
from a few fundamental building blocks of nature.
 The word "fundamental" is key here. By fundamental building
blocks we mean objects that are simple and structureless -- not
made of anything smaller.
 Even in ancient times, people sought to organize the world around
them into fundamental elements, such as earth, air, fire, and water.

3. The ATOM
 Is the Atom is fundamental ???
 Nope
 Is the Nucleus Fundamental?
 Because it appeared small, solid, and dense, scientists
originally thought that the nucleus was fundamental. Later,
they discovered that it was made of protons (p+), which are
positively charged, and neutrons (n), which have no charge

4.  Are protons and neutrons fundamental?
 Physicists have discovered that protons and neutrons are composed
of even smaller particles called quarks.
 As far as we know, quarks are like points in geometry. They're not
made up of anything else.
 After extensively testing this theory, scientists now suspect that
quarks and the electron are fundamental.

5. CLASSIFICATION
ELEMENTRYPARTICLE
MATTER PARTICLE
HADRON
BARYON
MESON
LEPTON
QUANTA OF FORCE Photon,gluon,graviton

6. Interaction

7. Leptons (Greek word : light)

8. Hadron(Greek word:middle)
 Baryon
 Are fermions
 Obey fermi-dirac statistics
 Meson
 Are bosons
 Obey bose-einstein statistics

9. Nuclear quantum number
 Spin
 Charge
 Lepton and baryon number
 Parity
 Isospin
 Strangeness
 Gell-mann-nishijima scheme
 Hyper charge

10. Conservation law
 Conservation of Charge
 Conservation of Lepton number {WEAK INTERACTION}
 Conservation of Baryon number { ALL INTERACTION}
 Conservation on Isospin {STRONG INTERACTION}
 Conservation of Parity
{STRONG,ELECTROMAGNETIC INTERACTION}
 Conservation of component of Isospin
{STRONG,ELECTROMAGNETIC INTERACTION}
 Conservation of Hypercharge
STRONG,ELECTROMAGNETIC INTERACTION

11. Example
 Which of the following high eneergy processes is allowed by
conervation? [GATE 2014]
(A) 𝜇+
→ 𝑒+
+ 𝛾 (B) 𝑛 → 𝑝 + 𝑒−
+ 𝜗𝑒
(C) 𝜋− + 𝑝 → 𝜋0 + 𝑛0 (D) 𝑝 + 𝑝 → Ʌ0 + Ʌ0
Answer:(c)
Using conservation of baryon number and lepton number.