Symmetries in subatomic physics and “what is the dark matter?”

Abstract

Coming back to think about it, it may be the time to come back to work on the standard-model building. Neutrinos are massive, against what was anticipated in the minimal standard model. On the other hand, we know nowadays that, in our Universe, the dark matter occupies about 25% of the content, compared to only 5% of the “visible” ordinary matter as described in the minimal standard model. In this talk, we describe the proposal that the description of the dark matter would be an “orthogonal” extension of the Standard Model – “family” as the gauge axis. We all know that in the Standard Model we have three generations but still don't know why - the so-called “family problem”. On other hand, in view of the masses and oscillations, the neutrinos now present some basic difficulty in the Standard Model. Thus, on top of the S U c ( 3 ) × S U ( 2 ) × U ( 1 ) standard model there is an “orthogonal” S U f ( 3 ) gauge axis – a simple S U c ( 3 ) × S U ( 2 ) × U ( 1 ) × S U f ( 3 ) extended standard model. The family gauge bosons (familons) are massive through the so-called “colored” Higgs mechanism while the remaining Higgs particles are also massive. The three neutrinos, the electron-like, muon-like, and tao-like neutrinos, form the basic family triplets. Hopefully all the couplings to the “visible” matter are through the neutrinos, explaining naturally why the dark matter is a lot of more than the visible matter in our Universe.