The exploitation of polarization degrees of freedom of hadron beams and/or targets offers a wealth of observables that are not accessible with unpolarized particles. These observables can be used to test the conservation or violation of fundamental symmetries like parity, charge conjugation, time reversal or combinations thereof.

This paper describes some of the physics that can be pursued with polarized hadron beams or polarized targets using the CRYRING and the Experimental Storage Ring (ESR) at GSI/FAIR in Darmstadt after the completion of the experimental program with the Cooler Synchrotron COSY at Forschungszentrum Jülich.