How can we unify electromagnetic force U(1) and weak force SU(2)?

[ndung200790]

Please teach me this:
How can we unify electromagnetic and weak interactions?Is it correct that the SU(2) symmetry(flavor symmetry of fermions) is spontaniously broken(by Higgs Field) and the symmetry(be broken) ''become'' U(1)xSU(2) symmetry that is the symmetry of electroweak interaction?
Thank you very much for your kind helping.

 

[tom.stoer]

It's bit more complicated.

One entangles U(1)_{weak hypercharge} * SU(2)_{weak isospin}, but the SU(2) symmetry which is broken - and therefore the residual U(1)_el.-mag. symmetry which survives and gives us the massless photon - are different ones. The reason is that one applies an U(1) rotation involving the so-called Weinberg angle. This rotation mixes weak hypercharge and the 3-component of the weak isospin.

Have a look at http://en.wikipedia.org/wiki/Glashow-Weinberg-Salam_model