PHYS 633: Elementary Particle Physics
Homework #5
Fall 2012
Due Date: 11/26/12
1. Problem 7.3
2. What is the expected ratio K L   0 0 / K L     if the pions are in (a)
an I  0 state ( I 
1
3 5
rule), or (b) an I  2 state ( I  or )?
2
2 2
3. Problem 7.8
4. The equation describing K 0  K 0 oscillations contains a term cos( mt)
whereas    e oscillations go as
 m2t 

sin 2 
 4E 
Account for the difference. Start with equation 7.57 of Perkins (for
K 0 oscillations) and derive the form given in equation 9.16a from
section 9.7 (for   oscillations).
5. Given ( K 0    e  e )  ( K 0    e  e )  e . Then if a K 0 is produced
(e.g. in   p  K 0 ), show
BR ( K 0    e  e )
4(m /  ) 2  ( /  ) 2

BR ( K 0    e  e ) 2  4(m /  ) 2  ( /  ) 2
where
  1  2
  1  2
m  mK1  mK 2
Start from equation 7.57 in Perkins. Find a numerical result for the
ratio above, given that m / 1  0.477 .