"Output" raises KeyError(0,)

Hi,

Looks like that (at least) one of your lorentz structure is badly defined.
Looks like that the indices present in the lorentz structure are not the one expected.

Cheers,

Olivier

> On Jan 13, 2017, at 13:33, Vincent Groff <email address hidden> wrote:
>
> New question #439035 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/439035
>
> I have imported a model I wrote myself in FeynRules.
> I've generated the interaction I want which worked fine.
> However, once I run "output blah" MG crashes with a KeyError.
>
> Here is the debug log:
> Traceback (most recent call last):
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/madgraph/interface/extended_cmd.py", line 1412, in onecmd
> return self.onecmd_orig(line, **opt)
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/madgraph/interface/extended_cmd.py", line 1367, in onecmd_orig
> return func(arg, **opt)
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/madgraph/interface/master_interface.py", line 287, in do_output
> self.cmd.do_output(self, line, *args, **opts)
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/madgraph/interface/madgraph_interface.py", line 7433, in do_output
> self.finalize(nojpeg, flaglist=flaglist)
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/madgraph/interface/madgraph_interface.py", line 7720, in finalize
> wanted_couplings)
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/madgraph/iolibs/export_v4.py", line 3313, in convert_model
> wanted_lorentz, wanted_couplings)
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/madgraph/iolibs/export_v4.py", line 879, in convert_model
> aloha_model.write(write_dir, 'Fortran')
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/aloha/create_aloha.py", line 1010, in write
> abstract_routine.write(output_dir, language)
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/aloha/create_aloha.py", line 89, in write
> text = writer.write(mode=mode, **opt)
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/aloha/aloha_writers.py", line 241, in write
> core_text = self.define_expression()
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/aloha/aloha_writers.py", line 765, in define_expression
> formatted = self.write_obj(numerator.get_rep([0]))
> File "/mt/home/vgroff/Downloads/MG5_aMC_v2_5_2/aloha/aloha_lib.py", line 1095, in get_rep
> return self[tuple(indices)]
> KeyError: (0,)
>
> Thanks for all your help,
>
> Vincent
>
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Indeed, the last bits of output before MG crashes is:
ALOHA: aloha creates VSS1 routines
ALOHA: aloha creates VVSS1 routines
so it must be VVSS1 causing it to crash.

So where would I be looking for the Lorentz structure? Im guessing in Lorentz.py?

Lorentz.py looks like:

VSS1 = Lorentz(name = 'VSS1',
               spins = [ 3, 1, 1 ],
               structure = 'P(1,2) - P(1,3)')

VVSS1 = Lorentz(name = 'VVSS1',
                spins = [ 3, 3, 1, 1 ],
                structure = '1')

Which looks like it's what I need.
The propagator of this vertex is just 2*i*g_{uv} (which seems to be done in couplings.py) so "1" seems correct.
Perhaps there is another way of writing this structure?

Hi,

> The propagator of this vertex is just 2*i*g_{uv} (which seems to be done in couplings.py) so “1" seems correct.

I’m not sure what you mean by “propagator” of a vertex. (For me a propagator is associated to a particle not to a vertex)
In any case, your lorentz structure is associated to two vector particle. Therefore you should have two lorentz indices associate to that structure.
If I use “g_{uv}” as structure then you will need:

> VVSS1 = Lorentz(name = 'VVSS1',
> spins = [ 3, 3, 1, 1 ],
> structure = ‘Metric(1,2)’)

Cheers,

Olivier

> On Jan 13, 2017, at 15:47, Vincent Groff <email address hidden> wrote:
>
> Question #439035 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/439035
>
> Status: Answered => Open
>
> Vincent Groff is still having a problem:
> Indeed, the last bits of output before MG crashes is:
> ALOHA: aloha creates VSS1 routines
> ALOHA: aloha creates VVSS1 routines
> so it must be VVSS1 causing it to crash.
>
> So where would I be looking for the Lorentz structure? Im guessing in
> Lorentz.py?
>
> Lorentz.py looks like:
>
> VSS1 = Lorentz(name = 'VSS1',
> spins = [ 3, 1, 1 ],
> structure = 'P(1,2) - P(1,3)')
>
> VVSS1 = Lorentz(name = 'VVSS1',
> spins = [ 3, 3, 1, 1 ],
> structure = '1')
>
> Which looks like it's what I need.
> The propagator of this vertex is just 2*i*g_{uv} (which seems to be done in couplings.py) so "1" seems correct.
> Perhaps there is another way of writing this structure?
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Brilliant.

Thank you so much,
Vincent