You are an astute observer of human behavior. Initially all CERN could really say was they had found a new boson [impressive enough in and of itself] with the correct mass to within 5σ [impressive also, but the usual criterion is 6σ although we have accepted 5σ in the past.]
However, over the last two years, more and more of the predicted properties required of the Higgs Boson have been confirmed for this particle. It's increasingly unlikely that this particle is not the Higgs Boson.
That is not to say that the Higgs has every property that's possibly been attributed to it. For example, does the Higgs Field give mass to every particle? Probably, but this isn't necessary for the Higgs Boson to be the symmetry breaking particle for the Electroweak Unification, which is what Higgs was theorized for to begin with. Is the Higgs Field the same field as the Inflaton Field [which caused the very early universe to expand at faster than the speed of light?] We will probably not know that for a while. That's also a "nice" proposed property of the Higgs Field, but not a necessary one. The Inflaton Field may manifest itself in a different particle.
Don't we already know that some superparticles exist anyway?
No.
We use positrons in human medicine, and we know experimentally that antiprotons and antiquarks exist.
Superparticles are not antimatter. They are complementarymatter. Here's the deal: Quantum particles with the same quantum numbers are indistinguishable from each other. This means that every electron [for example] in the universe is exactly the same as every other. This is completely different from classical physics, where, in principle, it's possible to label two distinct electrons in an atom and keep them straight. This is actually not possible in quantum mechanics. For example, in Helium, which has two electrons, there are not really two distinct electrons. There is simply a system which has two electrons in it, and there is no "electron 1" and "electron 2."
In order to make this work, the wave function you get when you combine two quantum particles into a two-particle system has to be either symmetric or anti-symmetric.
The anti-symmetric elementary particles are called fermions. Electrons, positrons, protons, anti-protons, neutrons, quarks, anti-quarks -- in fact all particles of what we think of as "matter" [and antimatter] -- are anti-symmetric, called fermions, and have 1/2-intrinsic spin quantum number.
The symmetric particles are the ones we usually associate with forces [energy, interaction, etc.] The symmetric particles are photons, gluons, W/Z particles, gravitons. All have integral intrinsic spin [0,1, or 2], symmetric wave functions on exchange, and are called bosons.
"Supersymmetry" is a theory suggests that every fermion has a corresponding "super" boson type particle that hasn't yet been discovered, and every boson similarly has a corresponding "super" fermion. So, for example, the electron [matter] has a superpartner boson called the selectron. The positron [antimatter] has a superpartner boson also, called the spositron. The photon [light, electromagnetic force] is a boson. It has a fermion superpartner called the photino [the photon is its own antiparticle, so there is no anti-photino.]
In the simplest version of the theory, the masses of the complementary superparticles would be exactly the same as their counterparts. An electron has a mass of 0.511 MeV/c2 so naively, we would expect its superpartner boson to have the same mass. However, for reasons that I can't explain easily, this turns out not to be true; the superpartners must be more massive than their counterparts.
As a consequence we may not yet have reached high enough energies to have seen the very massive superpartners. However, there are some reasons why if those masses are too much larger, a lot of the benefits of supersymmetry goes away, and there's no reason to try to save the theory any longer. I think 10 TeV/c2 is around where most Supersymmetry guys throw in the towel and say if we haven't seen the superpartners at that mass [/energy], then Supersymmetry isn't real.
[If you're REALLY interested, a Czech string theorist by the name of Lubos Motl has a great blog http://motls.blogspot.com/. I do not know him personally, but he is an "out and proud" conservative. His explanations of particle physics are quite accessible to the general reader.]
Supersymmetry allows physicists to come up with explanations for a number of "fine tuning" problems with the Standard Model. However, there are possible other explanations, like extra dimensions. Supersymmetry being "wrong" is not a deal breaker for the Standard Model.
You do an excellent job of explaining physics to those of us who are not smart enough to learn it on our own.
Thanks for clearing up my “superparticle” misunderstanding.
And, the subject of “indistinguishable” electrons is something I've thought about and read about before.
Your discussion was very helpful.