= {{{DMSimpt}}}: A general framework for t-channel dark matter models at NLO in QCD =

=== Contact Information ===

Benjamin Fuks
 * LPTHE / Sorbonne U.
 *  fuks @ lpthe.jussieu.fr

Chiara Arina
 * UC Louvain
 * chiara.arina @ uclouvain.be

Luca Mantani
 * UC Louvain
 * luca.mantani @ uclouvain.be

See arXiv:2001.05024 [hep-ph].

=== Model Description and FeynRules Implementation ===

We extend the Standard Model by a dark matter candidate X and a coloured mediator Y. The model includes several spin possibilities for X and Y, the dark matter being either of a Majorana nature or not and of spin equal to 0, 1/2 or 1. The mediator is accordingly of spin 1/2 (scalar or bosonic dark matter) or 0 (fermionic dark matter). The model Lagrangian is given by 
{{{ 
#!latex 
\begin{equation*}
  \mathcal{L} = \mathcal{L}_{\rm SM} + \mathcal{L}_{\rm kin} + \mathcal{L}_F(\chi) + \mathcal{L}_F(\tilde\chi) + \mathcal{L}_S(S) + \mathcal{L}_S(\tilde S)
       + \mathcal{L}_V(V)    + \mathcal{L}_V(\tilde V) \ .
\end{equation*}
}}}
The first term consists in the Standard Model Lagrangian, the second one includes gauge-invariant kinetic and mass terms for all new fields and the last ones describe the interactions of the dark matter state with the mediator and the Standard Model. The latter focus respectively on Dirac fermion, Majorana fermion, complex scalar, real scalar, complex vector and real vector dark matter, and are given by
{{{ 
#!latex 
\begin{eqnarray*}
   \mathcal{L}_F(X)& = & \Big[
           {\bf \lambda_{Q}} \bar X Q_L \varphi^\dag_{Q}
     \!+\! {\bf \lambda_{u}} \bar X u_R \varphi^\dag_{u}
     \!+\! {\bf \lambda_{d}} \bar X d_R \varphi^\dag_{d}
     \!+\! {\rm h.c.} \Big] \ ,\\
   \mathcal{L}_S(X)& = & \Big[
          {\bf \hat\lambda_{Q}} \bar\psi_{Q} Q_L X
    \!+\! {\bf \hat\lambda_{u}} \bar\psi_{u} u_R X
    \!+\! {\bf \hat\lambda_{d}} \bar\psi_{d} d_R X
    \!+\! {\rm h.c.} \Big] \ , \\
   \mathcal{L}_V(X)& = & \Big[
          {\bf \hat\lambda_{Q}} \bar\psi_{Q} \gamma^\mu X_\mu Q_L
    \!+\! {\bf \hat\lambda_{u}} \bar\psi_{u} \gamma^\mu X_\mu u_R
    \!+\! {\bf \hat\lambda_{d}} \bar\psi_{d} \gamma^\mu X_\mu d_R
    \!+\! {\rm h.c.} \Big] \ ,
\end{eqnarray*}
}}}
where φ and ψ consists in coloured scalar and fermionic mediators.

The above Lagrangian was implemented in the Feynman gauge into !FeynRules 2.3.35. QCD renormalisation and R,,2,, rational counterterms were determined using NLOCT v1.02 and !FeynArts 3.9. Feynman rules were collected into a [/raw-attachment/wiki/TypeIISeesaw/dmsimpt_v1_2.ufo.tar.gz single UFO], in which 5 flavours of massless quarks are considered, which enables tree-level calculations at LO and NLO QCD and loop-induced calculations at LO QCD using MadGraph_aMC@NLO.

The above new physics couplings can be controlled on run-time through the Les Houches blocks DMS3Q, DMS3U, DMS3D (scalar mediator interactions with the Q,,L,,, u,,R,, and d,,R,, quarks), as well as DMF3Q, DMF3U, DMF3D (scalar mediator interactions with the Q,,L,,, u,,R,, and d,,R,, quarks). The mass of the new particles can be modified through the usual mass blocks. The PDG codes of the new particles are:
 * Dark matter: 51 (real scalar), 52 (Majorana fermion), 53 (real vector), 56 (complex scalar), 57 (Dirac fermion) and 58 (complex vector). 
 * Scalar mediators: 1000001 (φ,,dL,,), 1000002 (φ,,uL,,), 1000003 (φ,,sL,,), 1000004 (φ,,cL,,), 1000005 (φ,,bL,,), 1000006 (φ,,tL,,), 2000001 (φ,,dR,,), 2000002 (φ,,uR,,), 2000003 (φ,,sR,,), 2000004 (φ,,cR,,), 2000005 (φ,,bR,,) and 2000006 (φ,,tR,,).
 * Fermionic mediators: 5910001 (ψ,,dL,,), 5910002 (ψ,,uL,,), 5910003 (ψ,,sL,,), 5910004 (ψ,,cL,,), 5910005 (ψ,,bL,,), 5910006 (ψ,,tL,,), 5920001 (ψ,,dR,,), 5920002 (ψ,,uR,,), 5920003 (ψ,,sR,,), 5920004 (ψ,,cR,,), 5920005 (ψ,,bR,,) and 5920006 (ψ,,tR,,).

More information can be found in arXiv:2001.05024 [hep-ph].


=== Model Files (and more) ===

 * !FeynRules model files:
   * [/raw-attachment/wiki/DMsimpt/sm.fr sm.fr]: Accompanying SM implementation.
   * [/raw-attachment/wiki/DMsimpt/dmsimpt_v1.2.fr dmsimpt_v1.2.fr]: Main DMSimpt !FeynRules model.
   * [/raw-attachment/wiki/DMsimpt/Massless_5f.rst Restriction file] relevant for the 5FNS (5 massless quarks).
   * [/raw-attachment/wiki/DMsimpt/DiagonalCKM.rst Restriction file] relevant for a diagonal CKM matrix.
   * [/raw-attachment/wiki/DMsimpt/use-DMsimpt.nb use-DMsimpt.nb]: Illustrative Mathematica notebook using the DMSimpt !FeynRules model.

 * UFO models
   * [/raw-attachment/wiki/DMsimpt/dmsimpt_v1.3.1.tgz dmsimpt_v1.3.ufo.tgz]: Standalone NLO UFO folder in the 5FNS, including all 18 restrictions of arXiv:2001.05024 [hep-ph].
   * [/raw-attachment/wiki/DMsimpt/dmsimpt_v1.2_s3dur.ufo.tar.gz dmsimpt_v1.2_s3dur.ufo.tar.gz]: Standalone UFO LO folder, in the S3D_uR restriction, with 6 massive quarks.
   * [/raw-attachment/wiki/DMsimpt/dmsimpt_v1.2_s3mur.ufo.tar.gz dmsimpt_v1.2_s3mur.ufo.tar.gz]: Standalone UFO LO folder, in the S3M_uR restriction, with 6 massive quarks.
   * [/raw-attachment/wiki/DMsimpt/UFO_all_mq.zip UFO_all_mq.zip]: Standalone UFO LO folder with 6 massive quarks in the general model case.

 * !CalcHep models
   * [/raw-attachment/wiki/DMsimpt/dmsimpt_v1.2_s3dur.ch.tar.gz dmsimpt_v1.2_s3dur.ch.tar.gz]: Standalone !CalcHep model files with massive quarks, in the S3D_uR restriction.
   * [/raw-attachment/wiki/DMsimpt/dmsimpt_v1.2_s3mur.ch.tar.gz dmsimpt_v1.2_s3mur.ch.tar.gz]: Standalone !CalcHep model files with massive quarks, in the S3M_uR restriction.



=== Leptophilic Model Description and FeynRules Implementation ===

We also provide a very generic t-channel model in which the dark matter candidate couples to the SM leptons only. The dark matter can be again self-conjugate or not, and can be spin 0, spin 1/2 and spin 1. The mediator  particles are non-coulored and couple the dark matter either to the right-handed charged lepton or the left-handed SU(2) leptonic doublet. Neutrinos are described as in the SM and do not have a right-handed field. The naming of the dark matter candidates and mediators is as in the coloured case, described above. 

For further details and if you use this model please cite arXiv:2102.XXXXX [hep-ph].

=== Model Files for Leptophilic dark matter ===

 * !FeynRules model file:
   * [/raw-attachment/wiki/DMsimpt/dmsimpt_leptons.fr dmsimpt_leptons.fr]: Main DMSimpt leptohpilic !FeynRules model ( to be used with the same SM fr file as above).
   * [/raw-attachment/wiki/DMsimpt/DiagonalCKM.rst Restriction file] relevant for a diagonal CKM matrix.

 * UFO and CH model for MadDM and micrOMEGAs (LO, all quark massive)
   * [/raw-attachment/wiki/DMsimpt/DMSimpt_leptons_UFO.zip DMSimpt_leptons_UFO.zip]: Standalone UFO model files for MadDM at LO.
   * [/raw-attachment/wiki/DMsimpt/DMSimpt_leptons_CH.zip DMSimpt_leptons_CH.zip]: Standalone !CalcHep model files.