# Feynman Graph

1. ### ballestic2001

4
Hi there, I need to draw the Feynman graphs for D→KK meson . I would be appreciate if anyone can help me.

Thank you so much.

2. ### Hepth

517
Get JaxoDraw from : http://jaxodraw.sourceforge.net/

If you have a java runtime enviroment it should work(you probably have java). If not find a JRE.

The only tricky part comes when you want to put labels in. Then you need a TeX installation like MikTeX, and to set it up properly and export it.
But if you just want diagrams and the ability to draw them, and to export them as say a .bmp or .jpg or .eps (and then edit them elsewhere to add the labels), then JaxoDraw is the easiest imho.

There are others though and maybe someone else will inform you, I just don't have the expertise.

### Staff: Mentor

If you just need that one diagram, every image editing program will do the job.

Are you asking how to find the diagram, or how to make a nice computer picture of the existing diagram?

4. ### ballestic2001

4
thanks for your help, do you know how many graphs does the decay of D→KK meson have? i would be grateful if you know a source which i can find more information about decay of D→KK meson graph.

### Staff: Mentor

Assuming you mean ##D^0 \to K^+ K^-##, there is just one dominant (tree-level) diagram. If you mean something different, please be more specific.

Feynman diagrams of D meson decays follow the general rules of Feynman diagrams, there is no need for something specific for this decay process.

6. ### ChrisVer

2,291
yes indeed without knowing the D meson, you have to write several diagrams (=for D0, D+,D- or Ds's ) of course some of them can't occur (GIM suppressed) or can occur in higher than tree level diagrams.

Last edited: Aug 24, 2014
7. ### ballestic2001

4
Where I can find more information about D 0 →K+ K−? I am studying the Decay rate in QCD factorization so need more sources.