Non-Abelian string junctions as confined monopoles

Various dynamical regimes associated with confined monopoles in the Higgs phase of N=2 two-flavor QCD are studied. The microscopic model we deal with has the SU (2) (1) gauge group, with a Fayet--Iliopoulos term of the U (1) factor, and large and (nearly) degenerate mass terms of the matter hypermultiplets. We present a complete quasiclassical treatment of the BPS sector of this model, including the full set of the first-order equations, derivations of all relevant zero modes, and derivation of an effective low-energy theory for the corresponding collective coordinates. The macroscopic description is provided by a CP^1 model with or without twisted mass. The confined monopoles---string junctions of the microscopic theory---are mapped onto BPS kinks of the CP^1 model. The string junction is 14 BPS. Masses and other characteristics of the confined monopoles are matched with those of the CP^1-model kinks. The matching demonstrates the occurrence of an anomaly in the monopole central charge in 4D Yang--Mills theory. We study what becomes of the confined monopole in the bona fide non-Abelian limit of degenerate mass terms where a global SU (2) symmetry is restored. The solution of the macroscopic model is known, e. g. , from the mirror description of the CP^1 model. The monopoles, aka CP^1-model kinks, are stabilized by nonperturbative dynamics of the CP^1 model. We explain an earlier rather puzzling observation of a correspondence between the BPS kink spectrum in the CP^1 model and the Seiberg--Witten solution.