  CERN COMPASS plans measurements of gamma-pi and gamma-K interactions using
50-280 GeV pion (kaon) beams and a virtual photon target. Pion (kaon)
polarizabilities and radiative transitions will be measured via Primakoff
effect reactions such as pi+gamma->pi'+gamma and pi+gamma->meson. The former
can test a precise prediction of chiral symmetry; the latter for
pi+gamma->a1(1260) is important for understanding the polarizability. The
radiative transition of a pion to a low mass two-pion system, pi+gamma->pi+pi0,
can also be studied to measure the chiral anomaly amplitude F(3pi)
(characterizing gamma->3pi), arising from the effective Chiral Lagrangian. We
review here the motivation for the above physics program. We describe the beam,
target, detector, and trigger requirements for these experiments. We also
describe FNAL SELEX attempts to study related physics via the interaction of
600 GeV pions with target electrons. Data analysis in progress aims to identify
the reactions pi+e->pi'+e'+pi0 related to the chiral anomaly, and
pi+e->pi'+e'+gamma related to pion polarizabilities.
