Intermediate Boson missing from events in LHE output file

I'm using MadGraph on the web to generate the process e+ e- > a > mu+ mu-. My end goal is to create a ROOT file from the LHE output. The online generation works fine.

Next I use the "Code Download " option after the generation completes to download the code to my computer. I untar the file and edit run_card.dat by changing the beam type from 1 to 0, and also change nevents to 10. These are the only lines I edit in run_card.dat and the only file I edit in the Card directory. So the lines I edited look like this:

     10 = nevents ! Number of unweighted events requested

      0 = lpp1 ! beam 1 type
      0 = lpp2 ! beam 2 type

Then from the MadEvent directory I type ./bin/generate_events

This works successfully and generates the 10 events. I untar "unweighted_events.gz" and the file "unweighted_events.lhe" opens successfully.

The problem is that the events in the output LHE file do not contain statistics for the photon. How can I get the intermediate photon to show up in the event information as well?

A sample events looks like this:

<event>
 4 0 0.4975400E-04 0.1183216E+03 0.7957747E-01 0.1139134E+00
      -11 -1 0 0 0 0 0.00000000000E+00 0.00000000000E+00 0.70000000000E+04 0.70000000000E+04 0.00000000000E+00 0. 1.
       11 -1 0 0 0 0 0.00000000000E+00 0.00000000000E+00 -0.70000000000E+04 0.70000000000E+04 0.00000000000E+00 0. -1.
      -13 1 1 2 0 0 -0.67882574179E+04 -0.42589375412E+03 -0.16547434057E+04 0.70000000000E+04 0.00000000000E+00 0. 1.
       13 1 1 2 0 0 0.67882574179E+04 0.42589375412E+03 0.16547434057E+04 0.70000000000E+04 0.00000000000E+00 0. -1.
</event>

I feel like what should have happened is that the photon shows up as an intermediary in the LHE file. I'm able to generate this same event in Pythia and that does occur. So what I'm asking is how to get the photon to show up (if it's possible at all).

Thanks a bunch for the help.

Regards,

Christopher Willis
PhD student in Physics
Michigan State University