Probing the heart of matter with Kaons

                         Douglas Bryman
                             TRIUMF
                       4004 Wesbrook Mall
                 Vancouver, B. C. Canada V6T 2A3
                      email: doug@triumf.ca

K mesons have been a rich and often surprising source of information in
particle physics since their discovery 50 years ago.  Recently, the
first evidence for the decay of a K+ meson to a charged pion and
a neutrino-antineutrino pair was reported to occur near the predicted
level of only one in ten billion decays. This is one of the rarest
particle decays ever observed and represents an extremely stringent
test of the present picture of fundamental particles and forces.  In
this colloquium, the K+ ==> pi+ nu-nubar experiment (E787 at
Brookhaven National Laboratory) and related projects dealing with rare
Kaon decays will be described to demonstrate how they enhance our
current understanding of particle physics, and provide opportunities
which may lead to discovery of new effects.