DOWNLOAD-DESKTOP-NOTEBOOK.nb (418 KB)
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Hi Wen! Wonderful work!
I’ve been looking into various HEP Mathematica packages (like FeynArts, FeynCalc, FeynHelpers, LoopTools, Package-X etc.) recently and got frustrated with how hard it is to get some results without digging very hard into theory and specific methods. I wonder how easier it is to compute a g-factor using AmpRed, at least for a single loop like it is done here for example? We need to calculate the form factor somehow by turning them into divergent single-loop integrals, simplifying amplitudes, and substituting all the constants. All of which require some steep learning curve actually to execute in practice.
I would really like to see these tools to have a more human design for particle physics in the future, similar to how it is easier to compute with molecules, bio-sequences, astronomical objects, and other physical entities now with the Wolfram Language.
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Thanks for the good question.
To my knowledge, some specialized techniques (other than the standard modern multi-loop techniques) have been developed for the state-of-art calculations of g-2. Nevertheless, for lower-loop calculations, AmpRed remains a highly suitable tool. It allows us to decouple the loop integrals from the spinor chain from the very beginning, and it provides tools to automatically convert Dirac spinors and gamma matrices to Weyl spinors and Pauli matrices. Furthermore, the decoupled loop integrals can be evaluated with a single command.
To illustrate this in detail, I’ll prepare a short notebook in about one month.
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I hope you can do better than this FeynCalc example.
Also it would be highly appreciated by everyone in this field if the conspiracy theory put forward by Oliver Consa about inability for anyone to verify the infamous IIc Feynman Diagram by running some Mathematica code.
With the finite part popping out like this:
Which of course also has divergent parts and other regularization artifacts, like in most of the diagrams, that cancel each other to yield actual physical result (seems like the gist of the conspiracy is trying to prescribe some physical meaning to a single diagram, which is just wrong):
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Hi,
Sorry for the long delay. A short notebook on calculating g-2 is attached. Please let me know if there are any questions or suggestions.
Many thanks.
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