Open Strings on the Neveu-Schwarz Pentabrane

TL;DR

This paper studies open string propagation on the Neveu-Schwarz pentabrane, exploring open descendants, orbifold models, T-duality, and supersymmetry breaking effects due to magnetic fields.

Contribution

It extends analysis of open strings on branes to the N5-brane, including new orbifold models and the impact of magnetic fields on supersymmetry.

Findings

Identification of two classes of open descendants for N5-branes.

Existence of Z_2 projected models at even levels k.

Magnetic fields induce a twist in the current algebra, breaking spacetime supersymmetry.

Abstract

We analyze the propagation of open and unoriented strings on the Neveu-Schwarz pentabrane (N5-brane) along the lines of a similar analysis for the SU(2) WZNW models. We discuss the two classes of open descendants of the diagonal models and a series of Z_2 projected models which exist only for even values of the level k and correspond to branes at D-type orbifold singularities. The resulting configurations of branes and planes are T-dual to those relevant to the study of dualities in super Yang-Mills theories. The association of Chan-Paton factors to D-brane multiplicities is possible in the semi-classical limit k -> infinity, but due to strong curvature effects is unclear for finite k. We show that the introduction of a magnetic field implies a twist of the SU(2) current algebra in the open-string sector leading to spacetime supersymmetry breaking.