  Backward angle (u-channel) scattering provides complementary information for
studies of hadron spectroscopy and structure, but has been less comprehensively
studied than the corresponding forward angle case. As a result, the physics of
u-channel scattering poses a range of new experimental and theoretical
opportunities and questions. We summarize recent progress in measuring and
understanding high energy reactions with baryon charge exchange in the
u-channel, as discussed in the first backward angle (u-channel) Physics
Workshop. In particular, we discuss backward angle measurements and their
theoretical description via both hadronic models and the collinear
factorization approach, and discuss planned future measurements of u-channel
physics. Finally, we propose outstanding questions and challenges for u-channel
physics.
