Hierarchies of RG flows in 6d (1, 0) massive E-strings

Abstract We extend the analysis of [9] to the 6d (1, 0) SCFTs known as massive E-string theories, which can be engineered in massive Type IIA with 8 − n 0 < 8 D8-branes close to an O8 − (or O8* if n 0 = 8, 9). For each choice of n 0 = 1, …, 9 the massive E 1 + 8 − n 0 $$ {E}_{1+\left(8-{n}_0\right)} $$ -strings (including the more exotic E ~ 1 $$ {\overset{\sim }{E}}_1 $$ and E 0) are classified by constrained E 8 Kac labels, i.e. a subset of Hom(ℤ k , E 8), from which one can read off the flavor subalgebra of E 1 + 8 − n 0 $$ {E}_{1+\left(8-{n}_0\right)} $$ of each SCFT. We construct hierarchies for two types of Higgs branch RG flows: flows between massive theories defined by the same n 0 but different labels; flows between massive theories with different n 0. These latter flows are triggered by T-brane vev’s for the right SU factor of the SCFT global symmetry, whose rank is a function of both k and n 0, a situation which has so far remained vastly unexplored.