2. What is particle physics:-
Particle Physics is a branch of physics that
studies the nature of particles that
constitutes matter and radiation.
OR
The branch of physics that deals with the
properties, relationships and interactions of
subatomic particles.
3. INTRODUCTION:-
By the year 1932,only three elementary particles
namely electron, proton and photon.
The discovery of neutron by chadwick in 1932 raised
their number to four.
The elementary particles have characteristic
properties such as rest mass, electric charge and
intrinsic angular momentum.
The elementary particles discovered so far from a
long list of around two hundred. These particles are
elementary in the sense that they are structure less.
4. Elementary particles:-
The most fundamental constituent 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 particles accelerators.
5.
6.
7.
8. Characteristic properties of
Elementary Particles:-
MASS:-
An elementary particles has always the same rest
mass. The magnitude of rest mass serves as the
principal label to identify the particle uniquely.
CHARGE:-
All elementary particles have charge +e,-e or zero.
This charge is conserved in any collision process. It
may be seem from the following (n-p) collision
n+p = p+p+ ╥ -
n+p = n+n+ ╥ +
n+p = n+p+k- + k +
9. Cont…
Life time:-
All elementary particles except photon, electron
proton and neutrinos, are unstable and decay
into other elementary particles of smaller
mass.
SPIN:- The fermions have half integral spin. The
bosons have zero or integral spin i.e 0,1,2
etc…
10. STRANGNESS:-
Strangeness is a property of particle expressed as
quantum number for describing decay of particle in
strong and electromagnetic interaction which occurs
in a short period of time.
COLOR:-
There is no actual color, quarks have color, the
particles that they make up are colorless.
11. Conservation of
strangeness In modern Physics Strangeness is conserved during the
strong and electromagnetic interactions but not during weak
interaction, consequently the light particles containing a
strange quark cannot decay by the string interaction and
must instead decay via the much slower weak interaction.
STRANGENESS PRODUCTION:-
It is a signature and diagnostic tool of quark-gluon plasma
formation and properties.
Unlike up and down quarks from which everyday matter is
made strange quarks are formed in pair production process
in collision between constituent of plasma.
The dominant mechanism of production involves gluons
only present when matter has become quark gluon plasma.
12. What is quark in physics
A quark is a type of elementary particle and
fundamental constituent of matter, quark combines
to form composite particles called hadrons the most
stable of which are protons and neutrons which are
the components of atomic nuclei.
Quarks have various intrinsic properties including
electric charge, mass, color charge and spin.
There are six types known as “Flavor” of quarks
such as Up,Down,Strange,charm,bottom,top.
The quark Model was independently proposed by
physicists M. Gell-Mann and George zweig in 1964
15. What is strangeness of strange
quark:-
The long observed lifetime helped a new
conservation law for such decays called
conservation of strangeness. The
presence of a strange quark in a particle
is denoted by a quantum number S=-1.
Particle decay by the strong or
electromagnetic interactions preserve
the strangeness quantum number.
