Basic Syntax Rules
Process Examples
PROCESS QCD QED Sample Diagram Notes
uu~ > dd~ 99 99 Both the QCD and QED are set to the a maximum conventional value of 99. This entails that all the possible contributions (W,gluon,photon,Z) appear. In total 4 diagrams appear.
uu~ > dd~ 99 0 The maximum number of QED couplings is set to zero so only QCD is on. The QED  contributions (W,photon,Z) are now off.
uu~ > dd~ /w+ 0 99 The maximum number of QCD couplings is set to zero, and the contribution from an internal W+ (or W-) are eliminated. As a result only the contributions from the exchange of a photon and a Z appear.
uu~ > z > dd~a 0 99 The maximum number of QCD couplings is set to zero, and the presence of a Z in an s-channel diagram is requested. As a result possible contributions from the exchange of a W in the t-channel or a photon in the s-channel are excluded.
gg > tt~ > b b~ e+ e- ve~ ve 02 04 This is t tbar production with semileptonic decays for both tops. The maximum number of QCD couplings is set to 2 and the QED is set to 4 (even though in this specific case 99 for both would have given the same result). The requirement of having the two top on-shell, avoids the generation of non resonant contributions such as gg>bb~ZZ with the subsequent decays of the Z's, giving in total 203 diagrams instead of just 3.
uu > (ul>u n1)(ul>u(n2>e+(el->e-n1)) 02 04 SUSY u squark pair production, with different decay of the two squarks. Only diagrams compatible with the chosen decay chain are generated.
Process Input Examples using Protons and Jets
 
PROCESS QCD QED Directories Subprocesses Notes
pp > e+ ve 0 2 Pdxu_e+ve
Pudx_e+ve
d~ u -> e+ ve
u d~ -> e+ ve
s~ c -> e+ ve
c s~ -> e+ ve
The special codes p and j, sum over gluon, and n light quark flavors and their anti_particles, as specified by the option. MadGraph is able to identify and combine explicitly identical subprocesses.
pp>W+>l+vljj 2 2 Puxu_e+veuxd
Puu_e+veud
...
u~ u -> e+ ve u~ d
g g -> mu+ vm s c~
...
u~ u -> mu+ vm u~ d
g g -> e+ ve s c~
...
In this example, W+ + jets production is requested, with the subsequent leptonic decay of the W+. If l=e,mu is chosen in the options, then both possibilities are included. MadGraph is able to identify and combine explicitly identical subprocesses.