Today, 12/12/12, the following paper arised in the arxiv http://arxiv.org/abs/1212.2339
This interesting paper reviews the last bounds about Beyond Stantard Model particles (both, fermions and bosons) for a large class of models until the end of this year, 2012. Particle hunters, some theoretical physicists are! The fundamental conclusions of this paper are encoded in a really beautiful table:
There, we have:
1. Extra gauge bosons . They are excluded below 1-2 TeV, depending on the channel/decay mode.
2. Heavy neutrinos . They are excluded with softer lower bounds.
3. Fourth generation quarks and vector-like quarks are also excluded with bounds.
4. Exotic quarks with charge are also excluded below 0.6 TeV.
We continue desperately searching for deviations to the Standard Model (SM). SUSY, 4th family, heavy likely right-handed neutrinos, tecnifermions, tecniquarks, new gauge bosons, Kalula-Klein resonances (KK particles), and much more are not appearing yet, but we are seeking deeply insight the core of the matter and the deepest structure of the quantum vacuum. We know we have to find “something” beyond the Higgs boson/particle, but what and where is not clear for any of us.
Probably, we wish, some further study of the total data in the next months will clarify the whole landscape, but these data are “bad news” and “good news” for many reasons. They are bad, since they point out to no new physics beyond the Higgs up to 1 TeV (more or less). They are good since we are collecting many data and hopefully, we will complement the collider data with cosmological searches next year, and then, some path relative to the Standard Model extension and the upcoming quantum theory of gravity should be enlightened, or at least, some critical models and theories will be ruled out! Of course, I am being globally pesimist but some experimental hint beyond the Higgs (beyond collider physics) is necessary in order to approach the true theory of this Universe.
And if it is not low energy SUSY (it could if one superparticle is found, but we have not found any superparticle yet), what stabilizes the Higgs potential and provides a Higgs mass, i.e, what does that “job”/role? What is forbidding the Higgs mass to receive Planck mass quantum corrections? For me, as a theoretical physicist, this question is mandatory! If SUSY fails to be the answer, we really need some good theoretical explanation for the “light” mass the Higgs boson seems to have!