N=2 SCFT and M theory on AdS(4) x Q(1,1,1)
Abstract Coincident M2 branes at a conical singularity are related to M theory on AdS 4 × X 7 for an appropriate 7 dimensional Sasaki-Einstein manifold X 7 . For X 7 = Q 1,1,1 =( SU (2)× SU (2)× SU (2))/( U (1)× U (1)) which was found sometime ago, the infrared limit of the theory on N M2 branes was constructed recently. It is the SU ( N )× SU ( N )× SU ( N ) gauge theories with three series of chiral fields A i , i =1,2 transforming in the (N, N ,1) representation, B j , j =1,2 transforming in the (1,N, N ) representation and C k , k =1,2 transforming in the ( N ,1,N) representation. From the scalar Laplacian of X 7 on the supergravity side, we discuss the spectrum of chiral primary operators of dual N =2 superconformal field theory in 3 dimensions. We study M5 branes wrapped over 5-cycle of X 7 which were identified as (three types of) baryon like operators made out of N chiral fields recently. We consider M5 brane wrapped over 3-cycle of X 7 which plays the role of domain wall in AdS 4 . The new aspect arises when baryon like operators (M5 branes wrapped over 5-cycle) cross a domain wall (M5 brane wrapped over 3-cycle), M2 brane between them must be created.