Define coannihilators manually

Asked by Jose María Pérez Poyatos

Hi everyone:

I am working in a BSM model with a Z2 discrete symmetry that I implemented in Feynrules. When I define the dark matter particle, Maddm is suppose to recognize automatically all the rest Z2 odd particles. However, when I type "display z2-odd", not all of them are in the list and I can not choose as coannihilators those particles that do not belong to that list. Is there any way to tell Maddm manually the particles that I want to act as coannihilators? All of them share the same mass.

Jose M.

Question information

English Edit question
Needs information
MadDM Edit question
Daniele Massaro Edit question
Last query:
Last reply:
Revision history for this message
Olivier Mattelaer (olivier-mattelaer) said :

Did you check the define command ?
I guess that "define coannihilators XXX" should be the correct syntax, but please check
"help define "



Revision history for this message
Jose María Pérez Poyatos (jmpp28) said (last edit ):

Thank you very much for your quick answer:

Until now the procedure I followed is first use the"define darkmatter" command and then Maddm shows the Z2-odd particles (it does not include the full set of Z2-odd particles of my model). Then I try with the "define coannihilator" command and I only can select those particles it considers that are Z2-odd. Selecting another one, Maddm says, for instance:

define coannihilator ~xmmu

ERROR: '~xmmu' is not allowed (either does not exist or is not z2-odd or is a dark matter candidate). Particles allowed: ~eh-, ~muh-, ~tah-

I checked "help define" but it does not give me any hint about how to proceed. I also tried to type "define coannihilator" and then hit enter and it returns the same list of coannihilators as before

INFO: Found coannihilator(s): ~eh-, ~muh-, ~tah-

Is there anything that I am missing?

Thanks in advance,


Revision history for this message
Daniele Massaro (dmassaro) said :


to understand what the problem could be, we need to inspect your model.
Could you attach both the UFO model and all the FeynRules files and notebooks you used to export it?


Can you help with this problem?

Provide an answer of your own, or ask Jose María Pérez Poyatos for more information if necessary.

To post a message you must log in.