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Higgs Decay Modes

  1. Oct 16, 2013 #1
    Under the Higgs in wiki it says "Another possibility is for the Higgs to split into a pair of massive gauge bosons. The most likely possibility is for the Higgs to decay into a pair of W bosons (the light blue line in the plot), which happens about 23.1% of the time for a Higgs boson with a mass of 126 GeV/c^2."

    But.. the mass of 2 W-bosons is 160 GeV/c^2...

    How can a Higgs decay to 2 W bosons when they weigh more then the Higgs?
  2. jcsd
  3. Oct 16, 2013 #2
    It's a virtual Higgs particles. Virtual particles don't follow the dispersion relation E2 = (cp)2 + (mc2)2. With that equation out of the way it is possible for a Higgs to have enough energy to decay into two bosons.
  4. Oct 16, 2013 #3
    Thanks, does that mean that the final decay products have to be less then 126 GeV, or can they go up to the mass of the 2 W Bosons, Ie, 160 GeV?
  5. Oct 16, 2013 #4


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    The final decay products will have total energy equal to whatever was available in the collision to start with.

    Note that although the Higgs boson is virtual and isn't required to be exactly 125 GeV, the probability of forming it increases the closer it is to 125 GeV. Remember that the W bosons are virtual also, and not required to be 160 GeV either.
  6. Oct 16, 2013 #5


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    The W bosons are much more likely to be virtual, compared to the Higgs. Just one of them has to be far away from its mass, so you usually see the decay products of a W boson with ~80 GeV and the decay products of a W boson with at most ~46 GeV, and if you combine both they come from a single particle with an energy very close to 126 GeV.

    (all values refer to the invariant mass of the sum of the decay products)
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