'''EWFF4DM: DM effective field theory with hypercharge electromagnetic form factors'''


'''Authors''' 

Andrew Cheek  [[BR]]
    * andrew.cheek@uclouvain.be [[BR]]
Luca Pagani  [[BR]]
    * luca.pagani7@unibo.it [[BR]]
Ken Mimasu [[BR]]
    * ken.mimasu@uclouvain.be [[BR]]
Chiara Arina [[BR]]
    * chiara.arina@uclouvain.be [[BR]]


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'''Model description'''

We consider the effective interactions of a fermionic singlet dark matter particle with the SM hypercharge gauge boson field. The only non zero form factor operator for Majorana dark matter is the dimension-6 anapole moment, while for Dirac dark matter there exist the dimension-5 magnetic and electric dipole operators and the dimension-6 anapole and charge radius operators. 

The Lagrangian is given by 

[[Image(lag_maj.png)]], 

for a Majorana singlet and 


[[Image(lag_dir.png)]], 

for a Dirac singlet. more information can be found in arXiv:2005.XXXXX [hep-ph].

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'''Description of the Model Files'''


* Feynrules model file [[BR]]
  * EWFF4DM.fr, Main FeynRules model for the model, it already contains the SM Feynrules model.[[BR]]

* UFO model files [[BR]]
  * EWFF4DM_UFO.tar.gz, Standalone LO UFO folder in the EWFF4DM models.[[BR]]

The actual files are provided in attachment. The dark matter candidate is called chi and psi for the Majorana and Dirac cases respectively.