We study the worldvolume dynamics of BPS domain walls in N=1 SQCD with N_f=N
flavors, and exhibit an enhancement of supersymmetry for the reduced moduli
space associated with broken flavor symmetries. We provide an explicit
construction of the worldvolume superalgebra which corresponds to an N=2 Kahler
sigma model in 2+1D deformed by a potential, given by the norm squared of a
U(1) Killing vector, resulting from the flavor symmetries broken by unequal
quark masses. This framework leads to a worldvolume description of novel
two-wall junction configurations, which are 1/4-BPS objects, but nonetheless
preserve two supercharges when viewed as kinks on the wall worldvolume.Comment: 35 pages, 3 figures; v2: minor corrections and a reference added, to
appear in Phys. Rev.