590 10 Particle Physics – II
Since f
=f, we conclude that some of theKS-state has regenerated. The
regeneration of the short livedK 1 -component in a long-livedKLbeam was
experimentally confirmed from observation of two-pion decay mode (1956).
10.3.6 Electro-weakInteractions ...........................
10.93
Fig. 10.13(a)
νμ+e– →z 0 →νμ+e–
A charged current weak interaction is mediated by the exchange of W±
boson, as for the decayμ− →e−+νe+νμ. Neutral current interaction
is mediated by the exchange ofZ^0 , as in the scattering,νμ+p→νμ+p.
Forνμ+e− →νμ+e−, the Feynman diagram for weak neutral current
shown in Fig. 10.13a is unambiguous.
νe+e– →z 0 →νe+e– νe+e– →w →νe+e–
Fig. 10.13(b), (c)