Name: V. Shtabovenko Date: 04/01/20-05:57:02 PM Z
Ok. You can see the issue by running
CreateFeynAmp[DiagramExtract[sesi, 5], Truncated -> True,
MomentumConservation -> False, GaugeRules -> {},
AmplitudeLevel -> Generic]
FCFAConvert[%]
FeynRules uses hard-coded propagators for the fields appearing in
the model and for some reason the 2-tensor vector boson propagator
includes only the massive version. What FeynRules puts as the
propagator for h^{mu nu} is given e.g. in Eq. A.1 of hep-ph/9811350.
Terms that go like q^mu q^nu / m_h^2 obviously blow up for m_h = 0
(as you have it in your model). This happens already when FeynArts
writes down the amplitude.
The corresponding piece of the FeynRules code is around the line 662
in FeynArtsInterface.m. This is what goes into the .gen file of your
model
(after (*tensor propagator:*))
You could contact the FeynRules developers, but it is difficult to say
if and
when they are going to fix that. The more pragmatic approach is to
edit
your .gen file by hand and put there the correct expression for the
massless
graviton propagator. Then you should be able to get your amplitudes
without
issues and evaluate them with FeynCalc or whatever else.
PS It is also possible to send files to this mailing list by just
attaching them
to your e-mail.
Cheers,
Vladyslav
Am 01.04.20 um 14:49 schrieb Huan Souza:
> I sended you an email with the FeynRules .fr file and the
Mathematica file. Thank you for your help.
>