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QCD Correction to DIS

  1. Feb 19, 2016 #1


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    I am considering the following virtual correction to the DIS process between a quark and photon. The process on the left in the attachment is one such QCD correction I can make but the diagram on the right is another (I just changed where the gluon vertices lie). It seems to me that both diagrams should give equal weighting as a correction, but I don't see this come through in the math.

    In both cases, I need to evaluate a trace, where in case a) this is equal to $$\text{Tr}((\not p + \not q) \gamma^{\nu} \not p \gamma^{\sigma} (\not p - \not l) \gamma_{\nu} (\not p + \not q + \not l) \gamma_{\sigma})$$ and in case b) it is $$\text{Tr}(\not p \gamma^{\nu} (\not p + \not q) \gamma^{\sigma} (\not q + \not p - \not l) \gamma_{\nu} (\not p - \not l) \gamma_{\sigma})$$ and a lorentz invariant phase space for one final state species premultiplying it which is equal to ##\int d^{(d)} p \delta^{(d)}(p+q-p)## up to some factors. I am just trying to see if first my intuition about these giving same contributions is indeed correct and, if so, how I can see this explicitly - I thought about using the integral over all p to shift the momenta but shifting by such and such an amount did not give agreement.

    Thanks for any tips!

    Attached Files:

  2. jcsd
  3. Feb 24, 2016 #2
    Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
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