Domain walls with non-Abelian orientational moduli

Abstract

Domain walls with non-Abelian orientational moduli are constructed in U(N) gauge theories coupled to Higgs scalar fields with degenerate masses. The associated global symmetry is broken by the domain walls, resulting in the Nambu-Goldstone (and quasi-Nambu-Goldstone) bosons, which form the non-Abelian orientational moduli. As walls separate, the wave functions of the non-Abelian orientational moduli spread between domain walls. By taking the limit of Higgs mass differences to vanish, we clarify the convertion of wall position moduli into the non-Abelian orientational moduli. The moduli space metric and its Kahler potential of the effective field theory on the domain walls are constructed. We consider two models: a U(1) gauge theory with several charged Higgs fields, and a U(N) gauge theory with 2N Higgs fields in the fundamental representation. More details are found in our paper published in Phys. Rev. D77 (2008) 125008 [arXiv:0802.3135 [hep-th]].