We study the large N θ dependence and the η′ potential in supersymmetric QCD with small soft SUSY-breaking terms. Known exact results in SUSY QCD are found to reflect a variety of expectations from large N perturbation theory, including the presence of branches and the behavior of theories with matter (both with Nf ≪ N and Nf ∼ N ). However, there are also striking departures from ordinary QCD and the conventional large N description: instanton effects, when under control, are not exponentially suppressed at large N , and branched structure in supersymmetric QCD is always associated with approximate discrete symmetries. We suggest that these differences motivate further study of large N QCD on the lattice.
- Phase Diagram of QCD
- Supersymmetric Effective Theories
ASJC Scopus subject areas
- Nuclear and High Energy Physics