HidSecSOFTSUSY

SOFTSUSY is a software package for computing the MSSM spectrum given a set of boundary conditions in the UV.

The project's homepage can be reached from here.

HidSecSOFTSUSY is an extension of this package which incorportates 1-loop effects due to particles in a calculable hidden sector.

The main features are:

• 1-loop contributions of "hidden" charged particles to the beta function of the gauge couplings, gaugino masses and scalar masses.
• Gauge mediation with multiple messenger scales.
• Doublet-triplet splitting in the messenger sector.
• Usage of the RGE engine of SOFTSUSY to compute the running of parameters in the hidden sector.

These modifications are relevant for models of direct mediation, "Extra-Ordinary" Gauge mediation , extra vector-like matter and many other extensions of the MSSM.

If you use HidSecSOFTSUSY to write a paper, please cite

B.~Keren-Zur, "Incorporating effects from hidden sectors in the numerical computation of the MSSM spectrum," arXiv:1004.0792 [hep-ph]

You are welcome to email me at kerenzu@post.tau.ac.il and I will be happy to hear your comments and/or assist in the usage of the program. The package includes a sample executable and input files. A detailed manual for advanced usage can be found here.

Installation

Begin by installing SOFTSUSY according to the installation instructions appearing here (the attached configuration files assume that the recent version (3.1) is being used).

Next, save this file in the new SOFTSUSY source directory (the name of the directory is softsusy-#, where # stands for the version of softsusy).

Before unpacking the zipped file, it is recommended bakcup the files makefile.am and makefile.in because they will be overwritten:

> mv  Makefile.am Makefile.am.original
> mv  Makefile.in Makefile.in.original 

Now unpack the zipped file:

> gunzip hidsecsoftsusy.tar.gz
> tar -xvf hidsecsoftsusy.tar 

To compile the code,

> ./configure
> make 

There is a sample program which uses an input file in the SUSY LesHouchesAccord format (the source file is hidsecmain.cpp).

It can be run by the command

> ./hidsecsoftsusy.x < HidSecInput_SU5adjoint

(for a model of gauge mediation with a pseudomodulus in the adjoint representation od SU(5)),

or

> ./hidsecsoftsusy.x < HidSecInput_EOGM

(for a model of gauge mediation with doublet-triplet splitting and multiple messenger scales).

Classes

The HidSecSOFTSUSY extension of SOFTSUSY consists of two additional classes:

• class HidField:

  Contains information about a superfield in the hidden sector. The relevant parameters are the fermion mass, the representation under the MSSM gauge group and the number of 'flavors'.

  If the field is to be considered as a messenger, the user should provide the contribution of this field to Λ_g and Λ_s. Also, in the case of multiple messenger scales, the super-trace of the mass should also be provided (in an intermediate scale, where there is a dynamical messenger, there is a 2-loop contribution to the scalar mass beta function which is proportional to this quantity).

• class HidSecSoftsusy:

  This is a derived class of MssmSoftsusy, a class which computes the MSSM spectrum. The additional members in the derivd class are a list of all the additional fields, a list of the relevant hidden sector parameters and, if necessary, pointers to user defined functions which will be described below. The interface is similar to that of MssmSoftsusy, but the RG flow includes the following modifications:

  • The RG running is divided into steps according to the masses of fields in the hidden sector.
  • The beta function is modified to include the contribution of hidden sector fields through gauge interactions (including messengers if the current scale is above the messenger mass).
  • Messengers can be introduced as hidden fields, and not only via the boundary condition of a gauge mediation model. This feature allows a more detailed description of the messenger sector, accomodating models of multiple scale messengers and doublet triplet splitting.
  • When messengers are integrated out (or integrated in), the threshold effect is taken into account.
  • The software allows further modification of the beta functions and threshold effects using user defined functions.
  • If RG flow in the hidden sector is relevant, these user defined functions can include beta functions for the hidden sectors paratemers.
  The software also includes a check of MSSM anomaly cancellation.

Input

• MSSM input

  The general information regarding the MSSM parameters and mediation scheme is given by the same format as described in the SOFTSUSY documentation.

• Hidden sector fields data

  The sample program 'hidsecmain.cpp' accepts input using files in the SUSY LesHouches Accord (see in the SOFTSUSY documentation). In order to add a hidden sector field, add a block in the following format:

  Block HIDFIELD               # SU2 doublet messenger
      1   1.000000000e+10	     # Mass 
      2   1.000000000e+04      # Super Trace of the mass squared (only for messengers)
      3   1.000000000e+00	     # Number of flavors         
      4   0.500000000e+00      # Hypercharge
      5   2.000000000e+00	     # SU2 rep (SINGLET=1, FUND=2, ANTIFUND=3, ADJOINT=4)
      6   1.000000000e+00	     # SU3 rep (SINGLET=1, FUND=2, ANTIFUND=3, ADJOINT=4)
      7   2.000000000e+05      # LambdaG
      8   4.000000000e+10      # LambdaS squared    
      0   0.0                  # End of HidField Block  
  

  Comments:
  • Every HidField block should end with a '0' line.
  • At the moment the allowed representations for SU(2) and SU(3) are singlet, (anti-)fundamental and adjoint. Additional representations can be easily added to the code if required.
  • Lines 2, 7 and 8 are relevant only for messengers, and may be dropped from the HidField block.
  • Masses are given in GeV.
  • By 'Number of flavors' we mean the number of superfields in the model with the same mass and quantum numbers.

• Hidden sector parameters input

  The required information regarding the hidden sector parameters is their value at the boundary

  Block HIDSECPARS             # Input parameters
      1   3.000000000e+00	     # Number of HidSecPars
      2   1.000000000e-01	     # 
      2   1.000000000e-02	     #
      2   1.000000000e-03	     # 
  

• User defined functions (optional)

  Advanced users might wish to include additional modifications to the RG flow. The software allowes two intervension points:

  • The member function which calculates the beta function can (if supplied with the necessary function pointer) call a function defined as

     void userDefinedHidSecBeta (const HidSecSoftsusy * h, DoubleVector & d);
    

    The vector d contains the numerical values of the beta functions for all parameters at the current mass scale. In the user defined function the user can compute additional contibutions to the beta function, and modify d accordingly.

  • An additional point in which physical effects should be taken into account is the threshold where hidden sector fields are integrated in or out. For example, when a messenger of gauge mediation is integrated out, the soft SUSY breaking terms of the MSSM receive significant contributions. In the effective theory above the threshold, these contributions should be removed. This effect is computed in the member function 'AddOrRemoveMessenger'.

    However, the user might wish to include additional threshold effects. For this purpose, the software (again, if supplied with the required pointers) calls the user defined function at the thresholds:

    void userDefinedIntegrateOutHidField (HidSecSoftsusy * h , int i);
    void userDefinedIntegrateInHidField (HidSecSoftsusy * h , int i);
    

    These functions are allowed to make changes in all the MSSM parameters, so the user should be careful not to make unwanted changes.