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SARAH
SARAH

Options_SUSY_Models

Last edited by Martin Gabelmann
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Options SUSY Models

Excluding terms or adding Dirac gaugino mass terms

SARAH uses the information given so far about the vector and chiral superfields to calculate the entire Lagrangian for the gauge eigenstates. This includes in general the kinetic terms, the matter interactions from the superpotential, D- and F-terms as well as soft-breaking terms. However, it is also possible to exclude parts by the following statements:

  • AddTterms = True/False;, default: True, includes/excludes trilinear softbreaking couplings
  • AddBterms = True/False;, default: True, includes/excludes bilinear softbreaking couplings
  • AddLterms = True/False;, default: True, includes/excludes linear softbreaking couplings
  • AddSoftScalarMasses = True/False;, default: True, includes/excludes soft-breaking scalar masses
  • AddSoftGauginoMasses = True/False;, default: True, includes/excludes Majorana masses for gauginos
  • AddSoftTerms = True/False;, default: True, includes/excludes all soft-breaking terms
  • AddDterms = True/False;, default: True, includes/excludes all D-terms
  • AddFterms = True/False;, default: True, includes/excludes all F-terms

On the other hand, Dirac mass terms for gauginos are not written automatically if chiral superfields in the adjoint representation are present. The reason for this is just that models without these terms are still more common, e.g. the NMSSM is usually studied without a bino-singlino Dirac mass term. Therefore, to include Dirac mass terms for gauginos, one has to add explicitly

AddDiracGauginos = True;

to the model file. In this case SARAH writes down all possible mass terms between chiral and vector superfields and the corresponding D-terms for the model. In this context, it uses MD<>v<>c as name for the new mass parameters where v is the name of the vector and c the name of the chiral superfield. If several fields in the adjoint representation of one gauge group are present, SARAH will generate the corresponding terms for all of them. To remove some of them, the parameters can be put to zero in the parameters file of the model definition. Furthermore, if several Abelian gauge groups are present, the impact of kinetic mixing is also respected.

Example

One can add to the particle content of the MSSM, fields in the adjoint representations of the different gauge groups:

SuperFields[[/8|8]] = {S, 1, s, 0, 1, 1};
SuperFields[[/9|9]] = {T, 1, {{T0/Sqrt[2],Tp},{Tm, -T0/Sqrt[2]}}, 0, 3, 1};
SuperFields[[/10|10]] = {oc, 1, Oc, 0, 1, 8};

Here, the triplet superfield is defined as

\hat{T} = \left(\begin{array}{cc} \hat{T}^0/\sqrt{2} & \hat{T}^+ \\ \hat{T}^- & - \hat{T}^0/\sqrt{2} \end{array} \right)

and to include the Dirac mass terms, use

AddDiracGauginos = True;

This leads to the corresponding mass term and the D-terms. SARAH names the new parameters using the corresponding superfield names as MDBS (bino-singlet mass term), MDWBT (wino-triplet mass term), MDGoc (gluino-octet mass term).

See also