Global monopoles in the two-Higgs-doublet-model

We discuss monopoles formed due to the spontaneous breakdown of a global SO(3)HF symmetry within the global two-Higgs doublet model. We explain that the Higgs sector dynamics can be described in terms of two vectors one of which is null, RA=(R0,Ra,R4,R5) for a=1,2,3, with 5 independent components describing the Higgs family symmetry and another, na, with 3 independent components related to the “would-be” Goldstone bosons. When formed from random initial conditions we find that monopoles are formed with a charged vacuum in the centre which couples the two fields together. We find a spherically symmetric solution which is an approximately uniform, unit winding of the sphere in both the Ra and na vectors. These global monopoles are closely related to the Nambu monopole. The additional complexity and structure contained in these monopoles does not appear to prevent the scaling of their density.