Fermions and baryons as open-string states from brane junctions

Abstract

There has been recent progress towards understanding the dynamics of world-volume fermions that arise as open-string modes from brane intersections in the probe limit (Nf/Nc → 0). In this work we consider all possible BPS brane junctions in Type IIA/B supergravity theories. We study in detail the dynamics of these states by deriving their equations of motion. We show the expected degeneracy of the bosonic and fermionic fluctuations as is expected due to the preserved supersymmetry. We also give some supporting evidence and refine the notion that these states can effectively describe baryon operators in a certain regime of the field theory’s parameter space. Our piece of evidence is the demonstration of the expected scaling of the mass in the large-Nc limit of the theory for these fermionic states; M2 ∼ {N}_c^2 . Finally, we explain analytically the avoided level crossing that was observed in a previous work after the inclusion of higher dimension operators in the field theory.