Supersymmetry relics in one-flavor QCD from a new 1/N expansion

We suggest a new large-N/sub c/ limit for multiflavor QCD. Since fundamental and two-index antisymmetric representations are equivalent in SU(3), we have the option to define SU(N/sub c/) QCD keeping quarks in the latter. We can then define a new 1/N/sub c/ expansion (at a fixed number of flavors N/sub f/) that shares appealing properties with the topological (fixed N/sub f//N/sub c/) expansion while being more suitable for theoretical analysis. In particular, for N/sub f/=1, our large-N/sub c/ limit gives a theory that we recently proved to be equivalent, in the bosonic sector, to N=1 supersymmetric gluodynamics. Using known properties of the latter, we derive several qualitative and semiquantitative predictions for N/sub f/=1 massless QCD that can be easily tested in lattice simulations. Finally, we comment on possible applications for pure SU(3) Yang-Mills theory and real QCD. (17 refs).