1. Introducing II MadGraph Automated Tree-Level Feynman Diagram and Helicity Amplitude Generation +

2. Outline What is MadGraph? What’s New in MadGraph II? Why use MadGraph? Example: Top production at FNAL Future Plans

3. What is MadGraph? Fortran computer program that: –Generates fortran helicity code (HELAS) to calculate tree level matrix elements –Includes color/symmetry factors –Creates postscript file of Feynman diagrams.

4. What’s New in MadGraph II? User defined models –Standard Model –MSSM Unlimited external particles –Within reason! (12?) Color Flow Information –Helps interface with HERWIG/PYTHIA Required/Excluded particles –uu~ > W+ W- b b~ g –uu~ > tt~ >W+ W- b b~ g // Z

5. Powerful (Lots of diagrams/external particles) Relatively fast –Amplitude generation –Matrix element evaluation  N not N 2 Keeps Spin Information –Easy to add decay chains Why use MadGraph? User interface ………NOT

6. Top Pairs at Fermilab Signaluu~ > tt~ > e+ ve b e- ve~ b~ Background: uu~ > e+ ve b e- ve~ b~ Radiation: uu~ > tt~ > e+ ve b e- ve~ b~ g

7. Signal (1) uu~ > tt~ > e+ ve b e- ve~ b~

8. Feynman Diagrams Background (66)

9. Signal+Radiation (7)

10. Future of MadGraph Tell me what you want! Improved Interface –User –PYTHIA/HERWIG –Integration Improved Speed

11. Signal+Radiation (7)

12. Feynman Diagrams Background (66)

13. Top Pairs at Fermilab