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Four particle production

  1. Aug 10, 2010 #1

    I am doing some tree level calculations of production of four final leptons and have some trouble with the kinematics. Does anybody know any good references where to read up a bit this topic and/or good variables/frames to use in order for the description to be as easy as possible? My problem is to choose a frame/variables where I can find a resonably simple description of the matrix element and also solve the phase-space integrals.

    A typical process would be
    e+ e- --> gamma --> W+ W- --> e+ e- anti-v v

    Thanks alot!
  2. jcsd
  3. Aug 10, 2010 #2

    Vanadium 50

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    Why not just use the zero width approximation and do it in pieces? (i.e. decay the W's independently)
  4. Aug 11, 2010 #3
    Maybe.. can you direct me to any place where I can find out more about what that is?
  5. Aug 12, 2010 #4
    Vanadium 50 is talking about Narrow Width Approximation. Check for example arXiv:0807.4112v2. If you'll need any help with that just ask.
  6. Aug 12, 2010 #5
    Thank you, will take a closer look at that but a first thought is that it cannot help me with the problem at hand because I want to be able to have a calculation which is valid also if one of the W is interchanged with the gamma.. and the gamma can not be on shell..
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