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The LHC (again)

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  • edited July 2012
    Glad to see a great scientific discovery is being used to shit on the U.S. As if Americans have never worked for CERN or contributed anything to the LHC. CERN wouldn't be celebrating today without Fermilab's work.
    Post edited by Andrew on
  • edited July 2012
    Glad to see a great scientific discovery is being used to shit on the U.S. As if Americans have never worked for CERN or contributed anything to the LHC.
    Get out of here with your pig disgusting American scientist logic. TODAY IS EUROPEDAY.
    CERN wouldn't be celebrating today without Fermilab's work.
    Illinois's own! The Fighting Tevatrons!
    Post edited by WindUpBird on
  • edited July 2012
    Today is not the day for this.

    Short version: American scientists, good job. American legislature, I am disappointed.
    Post edited by Omnutia on
  • I certainly didn't want it to sound like I'm disparaging the U.S. contribution to science and CERN. The SSC would have very probably had international collaborators as well. Sorry about that.
  • No one was implying you were disparaging the U.S. ~_^
  • WOOT WOOT GOD PARTICLE, NO TIME TO DISPARAGE, GOTTA WORSHIP A PARTICLE WOOT WOOT!
  • That must have been nice for you as a particle physicist to hear the public announcement right before you go on holiday! Now you can relax in the nature going "Ahh, my job is cool!"
    Exciting times!
  • But, I mean, doesn't that pretty much wrap up physics? Clean up,: pack up, last guy out hit the lights?
  • But, I mean, doesn't that pretty much wrap up physics? Clean up,: pack up, last guy out hit the lights?
    Subatomic physics is just stamp collecting.

  • But, I mean, doesn't that pretty much wrap up physics? Clean up,: pack up, last guy out hit the lights?
    Just examining the Higgs will take at least 10 to 20 years and one more big collider. And unless it behaves completely as predicted by the Standard Model there may still be a lot to do with curent equipment.

    If it is completely SM like and nothing else shows up at the LHC, then we (theorists at least) have a problem because we know the SM is faulty and the testable consequences (i.e. new particles) of alternative theories can be arbitrarily heavy meaning there is no good justification to build a collider at any specific energy.

    The LHC was engineered to be a Higgs discovery machine because we had a (albeit wide) range of energies where we knew something was absolutely certain to happen. We didn't know exaclt what, and the Higgs was only the most plausible outcome, but we knew something would be seen at the energies the LHC could achive.

    Supersymetry on the other hand can hide at energies that would require a collider the size of the solar system.
  • I know this question is stupid, but I'm going to say it anyway.

    You know the old slit experiment. When you look to see what slot the photon goes through, it changes.

    How do we know that the Higgs did not appear only because we were looking for it?
  • I'm not going a scientist, but I'm going to guess it has something with that experiment only showing things involving how the human brain works, and the Higgs is being seen by giant science machines which do not have the same flaws.
  • There is a wacky hypothesis (the kind of thing physicists come up with while having a few beers after a long day of smashing matter into antimatter) floating around that the SSC did discovery the Higgs, but as a side effect it created a negative space wedgie of some sort that resulted in the SSC rewriting history and retroactively wiping itself from existence.
  • How do we know that the Higgs did not appear only because we were looking for it?
    Might be irrelevant since the Higgs boson decays so fast that they're instead looking for the decay products.
  • There is a wacky hypothesis (the kind of thing physicists come up with while having a few beers after a long day of smashing matter into antimatter) floating around that the SSC did discovery the Higgs, but as a side effect it created a negative space wedgie of some sort that resulted in the SSC rewriting history and retroactively wiping itself from existence.
    That's just Azathoth hitting the snooze button.
  • You know the old slit experiment. When you look to see what slot the photon goes through, it changes.

    How do we know that the Higgs did not appear only because we were looking for it?
    It's more like it goes through both slits.

    As for the Higgs, we know it's for reals because they've run such an incredible number of collisions. According to theory, the Higgs should produce certain decay products when it decays. Thing is, there are also lots of other ways to get those same decay products. Maybe we just saw those products from another set of particles decaying. So what they do is run trillions and trillions of collisions and see what comes out of all of them.

    They know the total of these particular decay products they expect to see from all the other reactions, and look if they get more than they expect. You may have seen the graph:
    image

    That line is the values you would expect to see if there was no Higgs, and the data points above it are what they actually measured. It's been pretty certain for a while now, they were just running more tests to tighten up the error bounds. It takes a while to get to 99.999% certainty because the error goes something like 1/sqrt(n), where n is your number of trials.

    It's a little long, but you can get the gist of it in this video.
  • As for the Higgs, we know it's for reals because they've run such an incredible number of collisions. According to theory, the Higgs should produce certain decay products when it decays. Thing is, there are also lots of other ways to get those same decay products. Maybe we just saw those products from another set of particles decaying. So what they do is run trillions and trillions of collisions and see what comes out of all of them.
    That sounds wrong. The problem with detecting the Higgs Boson is that is can decay in a variety of ways, not just one.
  • edited July 2012
    You know the old slit experiment. When you look to see what slot the photon goes through, it changes.

    How do we know that the Higgs did not appear only because we were looking for it?
    It's more like it goes through both slits.
    Well, I think Scott's point is about the observer effect - in his example, putting a detector at one of the slits in the double slit experiment makes the difference between not seeing and seeing an interference pattern.

    However, what we measure in looking for the Higgs is the type, energy and momentum of the decay products. As far as I know, these are things we can reasonably measure to a high degree of accuracy without much concern over observer effects. Furthermore, it seems to me that any observer effects present would only add to statistical variance and error - they do not offer an explanation for a high-sigma bump specifically at ~125GeV.
    Post edited by lackofcheese on
  • That sounds wrong. The problem with detecting the Higgs Boson is that is can decay in a variety of ways, not just one.
    You're right.
    image

    image

    There. That was much more enlightening.
  • edited July 2012
    My fist is searching for whoever started the whole Higgs Boson = "God Particle" media habit.
    Apparently "the God particle" was corrupted from "that goddamn particle" due to the latter being rejected by publishers; the term described the difficulty of finding the little bugger.
    Post edited by lackofcheese on
  • [non-working images]
    Can't see shit through them 404's captain.
    Apparently "the God particle" was corrupted from "that goddamn particle" due to the latter being rejected by publishers; the term described the difficulty of finding the little bugger.
    That's interesting to hear. In my opinion, both are perfect. Without those publishers we wouldn't have had DerpParticle.
  • [non-working images]
    Can't see shit through them 404's captain.
    Works fine for me. Emptied the cache and everything.

  • I can see them.
  • Without those publishers we wouldn't have had DerpParticle.
    this is amazing.

    also, i can see them.
  • [non-working images]
    Can't see shit through them 404's captain.
    Everything has been working perfectly on this end the entire time.

  • [non-working images]
    Can't see shit through them 404's captain.
    Works fine for me. Emptied the cache and everything.
    Didn't work for me. They do now though, why I have no clue. I was served error pages last time.
  • [video]
    Nice video.
  • [video]
    Nice video.
    <3 all minutephysics. So fun. Go watch part 1 of that series too. Hell, everyone go watch all the minutephysics videos, they're short and awesome.
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