Subatomic Physics

9.9. References 275
9.27. Assume that K 0 is produced at t =0.
(a) Justify that the wave function of K 0 at rest at time t can be written as
|t〉 =
� �
1
|K
2
0 �
−im1c
1〉 exp
2t �
+|K 0 2 〉 exp
� −im2c 2 t
where mi and τi are mass and lifetime of Ki.
(b) Express |t〉 as a function of |K 0 〉 and |K 0 〉.
�
− t
�
2τ1
− t
��
,
2τ2
(c) Compute the probability of finding K 0 at time t as a function of ∆m =
m1 − m2.
(d) Sketch the probability for
9.28. K 0 1 and K0 2
∆m =0, ∆m = �
c2 , ∆m =
τ1
2�
c2 .
τ1
have slightly different rest masses.
(a) Estimate the magnitude of the mass difference by assuming that the
splitting is due to a second-order weak effect and that the weak interaction
is about a factor of 10 7 weaker than the hadronic one.
(b) Describe how the magnitude of the mass difference can be determined.
(c) Compare the actually observed value with your estimate.
9.29. (a) Assume that K 0 and K 0 beams, of equal energy, pass through a slab of
matter. Will the beams be attenuated equally? If not, why not?
(b) A pure K0 2
beam still be a pure K0 2
beam passes through a slab of matter. Will the emerging
beam? Explain your answer.
(c) How can it be experimentally decided if the K 0 2 beam is still pure after
passage through the slab?
9.30. ∗ Describe the experimental arrangements that were used to detect the twopion
decay of the long-lived neutral kaon.
9.31. Assume that you are in contact with physicists on another galaxy. The contact
is restricted to exchange of information. Can you find out if the other
physicists are built from matter or antimatter? Discuss the following three
possibilities: