Domain Walls with Massive Hypermultiplets

Domain walls play a central role in a subject of recent interest, the braneworld scenario. In particular, BPS domain walls are investigated in detail in D = 4, N = 1 SUSY theories. We should consider hypermultiplets to realize D = 4, N = 1 SUSY theory on the world-volume. In order to have a potential with discrete degenerate vacua, they must have gauge interaction, or nonlinearity of kinetic term, namely nonlinear sigma models (NLSM). The latter case can be obtained from the former case in the strong gauge coupling limit. A lot of interesting solitons have been discussed in hypermultiplets with or without taking this limit. In this talk, the hyper-Kähler (HK) quotient method is generalized to the massive models and the BPS domain wall in the simplest case is given. Keeping essential properties of eight supercharges, we discuss a simpler and