# New MHV paper

1. Oct 31, 2005

### Kea

From Trees to Loops and Back
Andreas Brandhuber, Bill Spence, Gabriele Travaglini
49 pages, 17 figures
http://www.arxiv.org/abs/hep-th/0510253

We argue that generic one-loop scattering amplitudes in supersymmetric Yang-Mills theories can be computed equivalently with MHV diagrams or with Feynman diagrams....

2. Oct 31, 2005

### Hans de Vries

Last edited: Oct 31, 2005
3. Nov 1, 2005

Staff Emeritus
No you won't find MHV in Road to Reality that's a later parley by Witten and company from string theory through twister space to QCD.

But did you follow that "Feynmann Tree Formula"? How neat! And how Feynman! Express the Feynman propagator as an advanced (retarded) propagator plus a $$\delta(P^2-m^2)$$. Then use simple light cone techniques to simplify.

Of course this was all natural for RF, he had been working with advanced and retarded in Minkowski space since his PhD thesis. As the title of the book where the authors of this paper found the tequnique puts it: Magic without magic.

4. Nov 1, 2005

### Hans de Vries

Magic without magic seems hard to get but it's also in:

"Selected papers of Richard Feynman: Closed Loop And Tree Diagrams,
867-887, Brown, L. M. (ed.)" which I have.

Laurie Brown is also the editor of the brandnew:

"Feynman’s Thesis: A New Approach To Quantum Theory"

http://physicsweb.org/press/10433
http://www.amazon.com/gp/product/9812563806/103-1417335-7282252?v=glance&n=283155&s=books&v=glance

Richard Feynman's never previously published doctoral thesis.
I hope to receive my copy in 2 or 3 days

Regards, Hans

5. Nov 1, 2005

### Kea

One might well say so! As selfAdjoint says, its new physics, so not in Road to Reality. However, one can only imagine that Penrose would be pleased. Thanks for the Feynman references.