ABSTRACT
In this section we illustrate the characteristic phenomenology of the violation of CP symmetry in the decays of neutral K mesons.
Hamiltonian for the neutral K mesons. In the rest system of the meson, the Hamiltonian reduces to a 2× 2 matrix which we write in the basis:
K0 =
( 1 0
) ; K¯0 =
( 0 1
) ; (12.1)
M =
( M11 M12 M21 M22
) . (12.2)
To complete the description of neutral K mesons, we must take account of the fact that these are unstable particles. Similarly to the case of the Z0, Section 7.4, we write the total Hamiltonian in the rest system:
H =M− i 2 Γ (12.3)
where Γ is the Hermitian matrix which describes the overall set of K0 and K¯0
decays:
Γ =
( Γ11 Γ12 Γ21 Γ22
) ;
Γ11, Γ22 real, Γ21 = Γ ∗ 12. (12.4)
Finally, we write the matrix H in the form:
H =
( h l m n
) (12.5)
with complex h, · · ·n, and we determine the eigenvalues and eigenvectors to connect to the quantities physically measurable in the decays of neutral K mesons (for an analysis of CP and CPT symmetries in these decays, see [40], [35] and [41]).