-- Main.CarlBlaksley - 2010-05-14

I'm currently using your wonderfull software to do part of my thesis work and I have a question about an error which I'm recieving during event generation.

Firstlly I'm using Feynrules to generate a custom model file for madgraph. In this model I'm adding a heavy majorana neutrino to the SM. I done several test runs of various process in order to check against know results and everything seems to work properly. I am also using pythia and pgs, both of which are called properly and seem to produce reasonable output. However when I use ./generate_events for the process e-p>N>jjj (where N is the newly defined heavy neutrino) and I request say 8000 events in the run card I get errors such as

Iteration 1 too large truncation 0.80087054 16448
Iteration 2 too large truncation 0.776286553 14161
Iteration 3 too large truncation 0.749106612 12168
Iteration 4 too large truncation 0.713902874 10651
Iteration 5 too large truncation 0.668213925 9604
Iteration 6 too large truncation 0.608896207 8593
Iteration 7 too large truncation 0.531810516 7968
Iteration 8 too large truncation 0.431607365 7506
Iteration 9 too large truncation 0.301343267 7040
Iteration 10 too large truncation 0.131999941 6788
Iteration 11 too few events 0.00611880098 5881
Iteration 12 too large truncation 0.0102608429 6219
Iteration 13 too few events 0.0031598871 4792
Iteration 14 too few events 0.00374115521 5033
Iteration 15 too few events 0.00438546641 5344
Iteration 16 too few events 0.00509948601 5590
Iteration 17 too few events 0.00600499241 5860
Iteration 18 too few events 0.00767212702 6222
Failed to find requested number of unweighted events 80000 6222
Unable to get 80000 events. Writing 6222

and in the end I only get a fraction of the events I request. Each of my collaborators, working on different systems from their own model files are also getting similar errors.

So my question is: Is this something I can ignore and just combine events from multiple runs or is this an issue?

(In the case that it isn't a problem, I am also having difficult with the multi_run script. It doesn't seem to actually call madgraph (generate_events).)

Thank you very much in advance for your response and or help.

-Carl

P.S. I apologize in advance if this topic isn't in the correct area.