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Proton Beams Sent Around the LHC

Posted by kdawson on from the going-in-circles dept.

feldhaus writes "The BBC reports that the first beams for over one year have been successfully sent around the complete circumference of the Large Hadron Collider. Engineers do not yet have a stable circulating beam but they hope to by 0600 GMT on Saturday."

6 of 115 comments (clear)

  1. Remember, this is only ONE hurdle to clear... by mmell · · Score: 5, Funny
    They still have many engineering challenges to complete before the LHC can start looking for the Higgs Boson.

    Assuming it exists. After all, this is an experiment designed to determine the accurace of a theory, not to confirm it.

    Of course, I believe they'll find it. My wife goes to 'mass' every weekend; I'm assuming that's where Higgs particles come from? I wouldn't know, as I haven't gone. You could describe me as 'massless'. :)

  2. 'Pew Pew' noises uttered by people with PHDs by Kenja · · Score: 5, Funny

    Come on, you know someone did it...

    --

    "Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
  3. Real-time Updates by SMQ · · Score: 5, Informative

    http://twitter.com/CERN

    --
    SMQ 90AE4B2BC4F6BEAF7340F0B40BA2DEF7340F6BC2D0392
  4. Re:A picture from LHC by Mike+Van+Pelt · · Score: 5, Funny

    Ha ha, funny guy.

    They've set up some webcams so you can watch what's going on at the LHC for yourself.

    http://www.cyriak.co.uk/lhc/lhc-webcams.html

  5. Re:Still alive. by ae1294 · · Score: 5, Funny

    We're doing science and we're still alive.

    Is that the headcrab typing?

  6. Re:why protons and not neutrons? by KingOfTheDustBunnies · · Score: 5, Informative

    so if the only difference is one is udd and the other is uud, then the "mass" in each is the same I suppose.

    Very nearly. The mass of the proton is 938 MeV; the neutron is 939 MeV. And the physics at a proton-neutron or neutron-neutron collider would be very similar to that at a proton-proton collider. But neutrons are neutral, as you and others have pointed out, and therefore much more difficult to accelerate.

    Now you could imagine a collider with a stationary neutron target and a high-energy proton beam. But remember that what you get out depends on the energy as measured in the center-of-mass frame of the colliding particles. To reach the LHC design energy of 14 TeV, you can collide two protons, each with an energy of 7 TeV in the lab frame, or you can collide a neutron at rest and a proton with an energy of ... excuse me while I dig out my TI-85 ... 104 PeV. Holy cow. I don't think anyone here has any idea how to get a 100-PeV beam in a working collider experiment, and I'm sure we don't have the money. So protons it is.

    And each would contain roughly the same exotic particles as the other.

    I think there's a misconception here. Protons (and neutrons) don't "contain" Higgs bosons, or W and Z bosons, or top quarks, or high-pT jets, or any of the other interesting things that we see at the Tevatron and will see at the LHC. These things are created from the kinetic energy of the two colliding protons. But otherwise yes, if you could find a way to build a neutron collider, you'd see pretty much the same stuff as at a proton collider of the same energy.

    Oh, and I must rant:

    Please don't call it the "God particle". This unfortunate nickname was coined as a marketing ploy and is not apt. Physicists do not call it the God particle. Reporters call it the God particle. And the main result is that people become confused, frightened, or angry.

    I'm tempted to point out that if you're interested in a theory describing the universe we happen to live in, the Higgs boson is far more likely to be relevant than string theory. But maybe I should leave that discussion for another thread.