  The known fundamental symmetries and interactions are well described by the
Standard Model. Features of this powerful theory, which are described but not
deeper explained, are addressed in a variety of speculative models.
Experimental tests of the predictions in such approaches can be either through
direct observations at the highest possible accelerator energies or through
precision measurements in which small deviations from calculated values within
the Standard Model are searched for. Antiproton physics renders a number of
possibilities to search for new physics.
