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Top heavier than Higgs. Why not found at Fermilab?

  1. Nov 14, 2012 #1

    nrqed

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    The title says it all. The top is heavier than the Higgs boson. In that case, why was the LHC needed to find the Higgs conclusively? (a related question is: how strong was the evidence for the Higgs from the Tevatron?) Is the answer simply a question of higher luminosity at the LHC?? Or is the fact of working at higher energy at the LHC leads to much higher cross sections for Higgs production?


    Thanks!
     
  2. jcsd
  3. Nov 14, 2012 #2

    mfb

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    See that thread for an earlier discussion.

    Top-quarks have a very clear decay signature and a large production cross-section.

    I think the last update had something like 2.5-3 standard deviations.

    Higher luminosity and higher energy are both important. And the detectors are better.
     
  4. Nov 14, 2012 #3

    nrqed

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    Thank you for your reply and for your posts in the other thread. Very illuminating.

    I see that the fact that much fewer clean channels in the Higgs case makes a higher luminosity critical. I would like to understand better the role of the energy. Having a higher center of mass energy increases the production rates, certainly. Are the production rates very sensitive to the energy? I mean, does going from 2 TeV to 7 TeV make a big difference in the number of events or is it a very small factor compared to the luminosity role?

    Thank you for your expertise.

    Patrick
     
  5. Nov 14, 2012 #4

    mfb

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    For the top-quark, the the higher energy at the LHC increased the cross-section (and therefore the particles per integrated luminosity) by a factor of 20-30.
    Higgs: ~1pb at the tevatron, ~15pb at the LHC (7 TeV) according to this article.
    Energy is really important for heavy particles.
     
  6. Nov 14, 2012 #5

    Vanadium 50

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    Let's use the other thread, please.
     
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