Hi

 

Was wondering if GUT symmetry is broken up via spontaneous breaking ?

Or is it that we don't (really) know...

I find the question a bit strange because you use pretty specialized terminology but your question is either beyond my understanding or really basic. So I'll just write a few more general lines before going to a one-line answer:

 

The electroweak symmetry breaking in the Standard Model (SM):

In the SM there is the electroweak symmetry group. This symmetry is not seen in everyday processes. The idea is that the laws of physics do follow the symmetry but that our point of view is shifted so that the symmetry is obscured: The point around which the symmetry hold is not the point we consider as our (everyday) reference point. To achieve this a mechanism is added to the SM which makes the symmetry point a very unfavorable state for the universe to be in (in favor of our reference point, of course). This keeps the electroweak symmetry group in principle but causes nature to favor a reference point from which the full symmetry is not fully apparent. Subsets of the symmetry might still remain.

 

Symmetries of Grand Unified Theories (GUT):

GUT symmetries are symmetries that are larger than the symmetries of the SM (all symmetries of the SM must be contained somehow). It is not expected that in everyday processes nature obeys a larger symmetry group than what is already contained in the standard model. So this extended symmetry must be destroyed somehow (*).

 

The actual answer:

- It is not known whether GUT symmetries exist in nature at all.

- If they do it is only straightforward to assume that the breaking of the symmetry works basically the same as in the breaking of electroweak symmetry.

- I have not heard of any other idea of breaking GUT symmetries. I think GUT is such a speculative thing that you'd make it even more speculative by adding something completely new without the need for it.

- There is the possibility that I simply didn't get the point in "spontaneous symmetry breaking", so take this reply with a grain of salt (e.g. if you consider all I said above as a wrongified baby-language version of what you learn in your grad-school courses then I am probably not the person that should answer questions for you).

 

 

(*) Note with "destroying a symmetry" I do not mean that no hint of it remains; the symmetry just shows in different ways. The electroweak symmetry is broken to leave only electromagnetism. But the remnants of this not-a-symmetry-anymore (and the mechanism by which the reference point was shifted) are still detectable as the weak force and the Higgs-Boson.