4th fundamental force

1. SUBMITTED TO: Dr. K. Dhoot and Mr. Giriraj Chayal
SUBMITTED BY: Vishal Kumar Jangid
M.Sc Final (Physics)-2017

2.  Gravitational force
 Electromagnetic force
 Nuclear force
 Weak force

3.  Before 1930, neutron haven’t discovered yet.
 There is dilemma of how p-p reside inside
the nucleus.
 In 1932, James Chadwick discover neutron.
 After that nuclear force came into existence.
 Definition: a strong attractive force between
nucleons in the atomic nucleus that holds the
nucleus together.

4.  Charge independent.
 Very strong in nature.
 Short range force.
 Repulsive at vey short distance(~0.5 fm).
 Saturated.
 Non central.
 Spin and angular momentum dependent.
 Velocity dependent.
 Exchange force.

5.  When the two nucleon are interacting then
there is field associated with it and cause of
field is that the nucleon are exchanging the
quantum between them.
 The exchange quanta is П meson.
 In p-n interaction
p n ∏+ ∏+ n p

6.  In n-p interaction
 In p-p/n-n interaction
n p ∏- ∏- p n
p P’ ∏0 ∏0 p p’

7.  Why pions are emitted ??
 Using uncertainty principal
cmct
s
E
t
tE
cm
10
10
13
24
2
2.1
4
.











8.  Q: Pick up wrong statement (GATE-2009)
 (a) the nuclear force is independent of electric
charge.
 (b)the Yukawa potential is proportional to
where r is the separation between two
nucleon.
 (c)the range of nuclear force is of the order of
10-18 -10-19 m.
 (d) the nucleon interact among each other by
the exchange of meson.
)exp(
1
h
mcr
r