I am studying Strominger's paper, "Open p-branes" [arXiv:hep-th/9512059v1]. On page 5, referring to the 6-dimensional (0,2) theory on the M5-brane of M-Theory, he says
Since this is a chiral theory it is not possible for extra massless fields to appear when the fivebrane positions coincide.
Yes, the 6d (0,2) theory (in modern parlance the (2,0) theory) is chiral, but why does that mean no extra massless fields will appear when the fivebranes coincide?
I know that the NS5-brane of Type-IIA string theory carries a self-dual antisymmetric tensor, and not a gauge field (in contrast to a Dp-brane or even an NS5-brane of Type-IIB), so when parallel NS5-branes in Type-IIA become coincident, one does not get enhanced gauge symmetries but rather a critical point with tensionless strings. I guess if you compactify the M5-brane along a transverse direction, you should get the Type-IIA NS5-brane with (1,1) worldvolume supersymmetry. So the type-IIA NS5-brane has a nonchiral worldvolume theory.
Is he referring to some general result that if the worldvolume theory on a brane is chiral, a stack of such branes will not produce extra massless fields?
This post imported from StackExchange Physics at 2016-10-23 22:31 (UTC), posted by SE-user leastaction