Perpustakaan Digital ITB

We show that adjoint QCD features very strong Bose-Fermi cancellations in the large-N limit, despite the fact that it is manifestly nonsupersymmetric. The difference between the bosonic and fermionic densities of states in large-N adjoint QCD turns out to have a “two-dimensional” scaling ? expð (formula) plEÞ for large energies E in finite spatial volume, where l is a length scale associated with the curvature of the spatial manifold. In particular, all Hagedorn growth cancels, and so does the growth exp ðV1=4E3=4Þ expected in a standard local four-dimensional theory in spatial volume V. In these ways, large-N adjoint QCD, a manifestly nonsupersymmetric theory, acts similarly to supersymmetric theories.We also show that at large-N the vacuum energy of multiflavor adjoint QCD is non-negative and exponentially small compared to the UV cutoff with several natural regulators.