Global monopoles in the two-Higgs-doublet-model

We discuss monopoles formed due to the spontaneous breakdown of a global \(SO(3)_{\rm HF}\) 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, \(R^A=(R^0,R^a,R^4,R^5)\) for \(a=1,2,3\), with 5 independent components describing the Higgs family symmetry and another, \(n^a\), 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 spherical symmetric solution which is an approximately uniform, unit winding of the sphere in both the \(R^a\) and \(n^a\) 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.