Distribution of electron energies in beta decay is a

1
Distribution of electron energies in beta decay
is a continuum. What is the approximate function?
2
Kurie plot
3

• How does the beta decay lifetime depend on the
  energy? Two decays are identical in every detail
  except that one has twice the endpoint of the
  other Emax_II2 Emax_I. What is tau_I/tau_II?
  (Assume Emaxgtgt me c2)
• A. 21
• B. 22
• C. 23
• D. 24
• E. 25

4
Current-Current interaction EM
two point static charges
charge distrb.
static
with
dynamic
5
Current-Current interaction EM vs WEAK
WEAKness is due to short range
6
Current-Current interaction EM vs WEAK
time component
space component
Interference between A and V yields parity
violation observables
7
Charged weak decays in the Standard Model
Q
I
0
Leptons
1/2
-1
2/3
Quarks
-1/3
Weak
Mass
Eigen-states
8
Manifestations of the mixing
One manifestation of the mixing is flavor
oscillations e.g. ns, K0s
Another is the alteration of the decay strength.
9
Alteration of the decay strength.
10
A bit of history
Cabibbo proposed
However, it became clear that there was a neutral
component
Yet, the process KL0?mm- could not be
observed. Why not??
G.I.M. proposed
m-
m
Z0
s
Want CP-violation? Add top,bottom
d