Recent content by TopQuark38

@ Hepth: I carefully analyzed your code: I understand the structure and I did not find any mistakes, so I guess that the answer is right! I made a plot of the total cross-section as a function of the total energy (W boson mass is the threshold energy). Sigma goes to zero for E to infinity, as it...

@ Bill_K: You're right. I would definitely benefit from learning more about the physical interpretations of what I am actually doing. I understand that in some gauges M3^2 does indeed grow with E. However, in this case, being almost finished with this cross-section calculation, I am only...

Hepth, fortunately there is now a theta dependence! However, still the energy behavior cannot be correct... The other partial matrix elements are: \begin{align*} \langle \mathscr{M}_1 \mathscr{M}_1^* \rangle =& - \frac{4 \,\hbar^2 g_{\mathrm{w}}^2 Q_{\mathrm{d}}^2}{9} \left[ \left(...

Hepth, thank you very much for your efforts! I really appreciate that. I looked at your code and it appears that you missed a factor of E^2 in your reply. Because of this additional factor, the energy behavior of M3^2 is the same as what I obtained... I might overlook things, but I do not see...

Thanks Hepth and Bill_K for replying! You guys clearly know more about this kind of calculations than I do as I do not understand all your problems. But perhaps this helps: I forgot to mention that the effect of longitudinally polarized W bosons cancels because of the choice for the gauge...

I am in trouble… I am a master student (first year) in theoretical particle physics and I have been working for several months on the calculation of the total cross-section at leading order for the process: u + \overline{d} \rightarrow W^{+} + \gamma I performed the whole calculation by...

@Sonderval Thank you very much! Things are more clear for me now. I will have a look at the qftfield.info site. My German though is not very good, but perhaps I can understand physics texts.

Quantum field theory predicts a value for the cosmological constant that is 123 orders of magnitude larger than the observed value (if one assumes the Standard Model to be correct up to the Planck scale of 10^19 GeV)! To theoretically predict the value of the cosmological constant, one must, I...