1. Elementary Particles
And Their Properties
M.Zeeshan Khalid
09050610-039

2. Elementary particles
• Introduction
The most fundamental constituents of our universe are the
elementary, or fundamental particles. They are the "building
blocks" that make up everything in the universe. Though their
most basic nature is still being debated, most of these particles
have well-documented, experimentally verified properties.
Listed here are the most important of those properties.
However, many aspects of cosmology are still being
developed, and additional elementary particles of higher mass
may be discovered in the near future with the next generation
of particle accelerators.

3. The Structure of Matter
• The Structure of Matter
 The elementary particles known today are divided into three families.
 All "everyday" matter is made up of atoms, once thought to be the
smallest division of matter.
 atoms have a substructure in their own right - they are made of a
negatively charged electron cloud surrounding a positively-charged
nucleus.
 The nucleus in turn can be divided still further into positively charged
protons and neutral neutrons.
 A proton is made of two up-quarks and a down-quark, and a neutron is
made of two down-quarks and an up-quark.

4. Cont…
 e. Protons are made of two up-quarks of electric charge 2/3 each, and one
down-quark of electric charge -1/3; these charges add together to produce
an overall charge of 1.
 Neutrons consist of two down-quarks of -1/3 each and one up-quark of
2/3; these cancel out to an overall charge of 0. Thus, the atom itself is
neutral.

5. The Family Tables
 The following tables summarize most of the properties of the various
particles belonging to the three families of subatomic particles. The
properties listed here, along with the name of the particle, are: mass,
electric charge, strong charge, weak charge. The strong charges of quarks
have been creatively designated red, green, and blue by physicists; they do
not, however, actually have color - they are too small for light waves to
bounce off. A particle's mass determines how it responds to gravity, the
electric charge determines its response to electromagnetism, its strong
charge determines its response to the strong force, and its weak charge
determines its response to the strong force.

6. Family 1
Particle Mass Electric Charge Strong Charge Weak Charge
Electron .0054 -1 0 -1/2
Electron-
<10-8 0 0 1/2
Neutrino
Up Quark .0047 2/3 red, green,
blue
1/2
Down Quark .0074 -1/3 red, green,
blue
-1/2

7. Family 2
Particle Mass Electric Charge Strong Charge Weak Charge
Muon .11 -1 0 -1/2
Muon-Neutrino <.0003 0 0 1/2
Charm Quark 1.6 2/3 red, green,
blue
1/2
Strange Quark .16 -1/3 red, green,
blue
-1/2

8. Family 3
Particle Mass Electric Charge Strong Charge Weak Charge
Tau 1.9 -1 0 -1/2
Tau-Neutrino <.033 0 0 1/2
Top Quark 189 2/3 red, green,
blue
1/2
Bottom Quark 5.2 -1/3 red, green,
blue
-1/2

9. Fundamental Forces:
 There are four fundamental forces in the Universe:
1. gravitation (between particles with mass)
2. electromagnetic (between particles with charge/magnetism)
3. strong nuclear force (between quarks)
4. weak nuclear force (operates between neutrinos and
electrons)