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The violation parameters and

The two pion decay modes of neutral kaons can be decomposed into a and amplitude. This allows to make use of the fact that the amplitude is the dominant decay mode of neutral kaons:

Allowing for violation in the amplitudes, we can write (use ) :

 

where are the weak decay amplitudes, the strong interaction phase shifts and violating amplitudes.

Assuming only small violation, we can write for any CP=+1 final state:

In addition to violation occuring in mixing we get two additional terms:

, a purely imaginary part from a possible phase difference of the decay amplitude compared to ,
, a real part which can either come directly from violation of the decay amplitudes or from an interference of two decay amplitudes with a different phase. In the case of only one contributing amplitude, this term is violating.

For the and final states, we obtain by using only terms linear in ( ):

with

or using eq.34:

with

using that and therefore .

In the limit of a dominating violation in the amplitude, e.g. , we can write:



Thomas Ruf
Fri Aug 9 14:24:14 MET DST 1996