A question about the Higgs

  1. BiGyElLoWhAt

    BiGyElLoWhAt 851
    Gold Member

    So I've done some research, but to no avail. Can anyone link me to some reasonably detailed information regarding the Higgs experiment at CERN?

    I'm kind of new when it comes to this sort of thing. So a walkthrough of the experiment would be great (What they were looking for and why they were looking for that, as well as what measurements were taken)

    Thanks in advance
     
  2. jcsd
  3. mfb

    Staff: Mentor

    The most detailed (public) information are the publications. I guess this is not the level you are interested in - it would help to know what you are looking for and what you know about particle physics so far.

    Just searching for "Higgs" and related keywords should give hundreds of news articles and web pages explaining the idea.
     
  4. BiGyElLoWhAt

    BiGyElLoWhAt 851
    Gold Member

    My biggest question is what measurement did they take? I know for things, like the antihydrogen experiment, they were measuring gamma rays. What exactly were they measuring wrt those photons? I'm not sure.

    I wouldn't say I know a whole lot. I've read up a lot about annihilation and decay, which seems to encompass a good amount of experiments. If I had to guess, I would say that the experiment had something to do with decay, partly because of the fact that everything I read makes a huge deal about the short lifetime of the higgs boson. That would imply that they are measuring something they expected to occur via the decay process. Photons? Exchange Particles? Wicked Voodoo Magic? I'm not sure. This is just more or less to satisfy my curiousity.
     
  5. Drakkith

    Staff: Mentor

  6. The basic gist of it is that they crash protons together, which one time in a billion or so produces a Higgs boson. The Higgs then decays (essentially instantly) into various other particles, which pass through the big detectors surrounding the collision points. These machines identify these particles and measure various things about them, and record it all for later analysis. Of course lots of other processes can produce the same particles, so one then does a lot of statistics and tries to determine whether non-Higgs processes can account for the data collected. If the fit to the data is much better when you assume there are Higgs bosons decaying in there somewhere, then hooray, you say you see a Higgs boson signal.

    Obviously it is vastly more complicated than that in reality, but that is more or less how the story goes :). As Drakkith links for you, the different "decay channels" are the different final state particles which the Higgs can decay into. The analysis is divided up into several pieces by looking just at the subset of LHC collisions which result in each of these same final state particles. Thus there are "searches for the Higgs boson in the two-photon channel", "searches for the Higgs boson in the 4-lepton channel" and so on, depending on which final state particles are being selected for in each particular analysis.
     
  7. BiGyElLoWhAt

    BiGyElLoWhAt 851
    Gold Member

    Aha, so it is the decay that they're measuring?

    Like I said, I'm still pretty new to this stuff, and Decay Channel is not a term I'm familiar with, and thus would have never looked it up :P.

    Thanks everyone, I'll come back later if I haven't dug up what I'm looking for.
     
  8. mfb

    Staff: Mentor

    Yes - nearly all analyses in high-energy physics measure (or look for) decay products only. There are just a few particles actually flying through the detectors - pions, kaons, electrons, protons, neutrons (and the corresponding antiparticles) and rarely a few other particles. All those particles are known for decades now, and most suggested new particles would have very short lifetimes. There are a few exceptions, but those are quite exotic.
     
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: CERN, higgs boson