(De)constructing intersecting M5-branes

We describe intersecting M5-branes, as well as M5-branes wrapping the holomorphic curve xy=c, in terms of a limit of a defect conformal field theory (dCFT) with two-dimensional (4,0) supersymmetry. This defect CFT describes the low-energy theory of intersecting D3-branes at a C-2/Z(k) orbifold. In an appropriate k-->infinity limit, two compact spatial directions are generated. By identifying moduli of the M5-M5 intersection in terms of those of the defect CFT, we argue that the SU(2)(L) R symmetry of the (4,0) defect CFT matches the SU(2) R symmetry of the N=2, d=4 theory of the M5-M5 intersection. We find a 't Hooft anomaly in the SU(2)(L) R symmetry, suggesting that tensionless strings give rise to an anomaly in the SU(2) R symmetry of intersecting M5-branes.