DOI 10.1007/s100529900041
Mixing of two-level unstable systems
G. López Castro1 - J.H. Muñoz1,2 - J. Pestieau3
1 Departamento Física, Centro de Investigación y de Estudios,
Avanzados del IPN, Apdo. Postal 14-740,
07000 México, D.F., México
2 Departamento de Física, Universidad del Tolima,
A.A. 546, Ibagué, Colombia
3 Institut de Physique Théorique, Université Catholique
de Louvain, 2 Ch. du Cyclotron, B-1348 Louvain-la-Neuve, Belgium
Received: 15 December 1998 / Published online: 28 May 1999
Abstract
Unstable particles can be consistently described in the framework of
quantum field theory. Starting from the full S matrix amplitudes of
decays as examples of
processes
where the 
resonances dominate, we propose a
prescription for the mixing of two "quasi-physical'' unstable states that
differs from the one obtained from the
diagonalization of the 
non-Hermitian Hamiltonian. We discuss
some
important consequences for CP violation in the KL-KS system.
Copyright Springer-Verlag
