(Apologies for the painful number of typos in the preceding post. I was typing it in a rather non-ideal environment…)
[Bolding mine]
I thought if it looks like a duck, quacks like duck, etc.
There are exactly similar decay paths that ”add up" in energy to other particles?
Or did they not know which decay products were the right ones, which would’ve made the whole endeavor trivial?
For any individual case, we have no way of knowing whether the decay products are coming from a Higgs. At the end of the day we look for two photons, or four muons, etc, and there are various ways you can get two photons or four muons, which are not the Higgs. These different ways of producing the same final set of particles you are looking for are called “backgrounds.” There are various backgrounds for each channel of the Higgs analysis. For example, in the channel that looks for the Higgs decaying to two photons, one of the backgrounds is the case in which a spray of hadrons is wrongly identified as a photon. Another background is when two photons are produced directly from the proton collision. Another background is when the proton collision produces various mesons and two of them decay to photons. Some of these backgrounds can be eliminated by looking carefully for other particles in each event, but many of them are “irreducible.” For each of these “backgrounds” there is a distribution of invariant masses of the two photons which can be roughly theoretically predicted. When you look for the Higgs, you look for a “peak” in the invariant mass spectrum of the two photons above the expected background distribution.
Economist had a good article on Higgs. The article mentioned one theory, dubbed “technicolor” (I think) that involves Higgs particles being comprised of quarks (new kind?), held together with a new variety of strong force. (And I gathered, this was to explain away some element of precision the Stand Model predicts about some characteristic of the Higgs.)
Would anyone who’s “in the trenches” of theoretical or experimental physics care to comment on how prevalent, and what the general feeling about, this theory is?
Technicolor is a possibility that is taken seriously and experimentally searched for by mainstream particle physicists. It is nowhere as popular a theory as the Higgs, but it has its adherents. But for a while now it has been nearly ruled out by experiment, and now with the new LHC data (125 GeV Higgs mass), it is almost certainly ruled out for good.
You won’t be able to read the article without a subscription, but the decay data on the particle announced July 4th may indicate that while it may be something similar to the Higgs, it might not be the genuine article.
The most concerning item is the fact that no decays into tau leptons have been detected (beyond background). According to the article, since leptons are fermions (which have mass), if it’s not decaying into taus, it’s probably not giving them mass either.
But there are also problems with other decay paths as well. For example the decay into 2 photons seems to happen far too frequently.
This is still preliminary, but there is already speculation that this particle and the Higgs itself if this isn’t it, might well be a composite just like a proton or neutron. That would open up a lot of possibilities.
Please be aware that the “problems” you mention are not yet problems, because they are not statistically significant. The experiments have also updated their results since July 4th (see for example, here), and the not-yet-statistically-significant deviations from Standard Model behavior are starting to get smaller. But it will take a while. The tau tau channel, in particular, simply requires much more data before being able to say something meaningful. It is not unexpected that the experiments haven’t observed many events above background. The photon photon channel is a bit more interesting, but it will still take another year to be sure if something funny is going on. I’m as eager as anyone else to find something new and interesting going on here, but I wouldn’t start getting excited just yet.
You get the Jesus H. Christ particle — which I’m all sure we can guess what the ‘H.’ really stands for.