Experimental Chiral Dynamics: New Opportunities with Polarized Internal   Targets and Almost-Real Photon Tagging
  Experiments on pion (Goldstone Boson) photoproduction from the nucleon tests the ability to make QCD predictions at confinement scale energies. Experiments with both polarized beams and targets have the potential sensitivity to demonstrate the dynamic isospin breaking effects of the up and down quark mass difference, whereas experiments on Compton scattering from the nucleon will incisively probe its chiral structure by measuring all of the spin dependent amplitudes. These and other types of photo-induced measurements on nuclei could be possible at BLAST with the addition of an almost-real photon tagging system and a forward low energy recoil ion hodoscope. 
A.M. Bernstein, M.M. Pavan (Lab for Nuclear Science, M.I.T.,   Cambridge, MA, U.S.A.)