ALOHA fails to add form factors when dynamically generating Lorentz structure

[Joshua Berger]

I am running MadGraph 2.6.3.2 with a custom model file that contains form factors. When I have a vertex containing multiple Lorentz structures, some of which have the same coupling, ALOHA dynamically combines the Lorentz structures with the same coupling into a single Lorentz structure. It seems that in this process, the form factors for the Lorentz structures are lost, yielding an undefined variable error when the dynamic vertex is compiled:

     gfortran -O -w -fbounds-check -fPIC -ffixed-line-length-132 -c -o FFV8_0.o FFV8_0.f
     FFV8_0.f:26:40:

            VERTEX = COUP*(-1D0)*(+CI*(MDL_FF1*TMP1+MDL_FFA*TMP2))
                                             1
     Error: Symbol ‘mdl_ff1’ at (1) has no IMPLICIT type
     FFV8_0.f:26:53:

            VERTEX = COUP*(-1D0)*(+CI*(MDL_FF1*TMP1+MDL_FFA*TMP2))
                                                          1
     Error: Symbol ‘mdl_ffa’ at (1) has no IMPLICIT type
     <builtin>: recipe for target 'FFV8_0.o' failed
     make[1]: *** [FFV8_0.o] Error 1

When I combine by hand the two Lorentz structures into one, the bug is averted. I've attached the two model files (one working and one with the bug) as well as the log file. The bug can be reproduced in the buggy version by running:

> import model BoostedDarkMatterFermionEL_bug
> generate chi pr > chi pr
> launch

with the default settings for the run. This is not a pressing bug report, as I have found a workaround, but I thought it was worth knowing!

[Olivier Mattelaer (olivier-mattelaer)]

Thanks a lot,

I have fixed this issue in the development version as well as other issue which
are trigger if you define a restriction model for this model.

Thanks,

Olivier