Recent content by brodekind

Thanks for your inputs. Well, I thought about active versus passive. But it seems to me that he is transforming the states actively. i.e. D(\Lambda) |p\rangle = \text{something}|\Lambda p\rangle, only the fields passively. Next time in the library I will have a look at that book though.

Ahoy, I was reading parts of Weinberg's QFT book vol. I and was surprised at his definition of a scalar field or Lorentz transformations on fields in general. Usually (e.g. Maggiore, Modern Intro to QFT) I see the scalar field defined as Lorentz transforming via \Phi'(x') = \Phi(x) \text{...

Hi, Thanks for looking into this. But I don't think it's an normalization/averaging problem. Of course you're right: if you want to compute the averaged amplitude you have to sum over final and average over initial states (for vector bosons this means, dividing by a factor of (Nc^2-1)*2 for...

Hi, I attached a notebook with my calculation. So what I wanted to do there is calculate only the 4-vertex squared, using the sum over all gaugefield-polarizations equal to -gαβ instead of -gαβ+(some function involving a vector η perpendicular to physical polarizations). So I used the option...

Hi folks, I was wondering if someone knows enough about the FormCalc package to help me out: I am using FeynArts to generate Feynman-diagrams for certain tree-level processes and FormCalc to calculate the squared amplitude of these processes (http://en.misho-web.com/phys/feynlecture.html gives...