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4 Higgs Doublets Vev matching in SPheno.m

Posted: 21. May 2018, 13:26
by johnny
Hey,

I try to implement a SUSY model which has a additional U(1) (SMgauge x U(1)). In this model I have four Higgs-doublets. As soon as the additional U(1) is broken those Higgs doublets mix to one light pair (=> MSSM Higgs doublets) and one heavy pair (=> no vev/ integrated out). So far I have found out that I have to give the matching conditions in the SPheno.m file as:

(* Matching for VEVs *)
{vvu, Fvvu[vSM,TanBeta,etc...]},
{vwu, Fvwu[vSM,TanBeta,etc...]},
{vvd, Fvvd[vSM,TanBeta,etc...]},
{vwd, Fvwd[vSM,TanBeta,etc...]},

The functions (Fvvu,...) depend on vSM,TanBeta the vev of the field breaking the extra U(1) and other model parameters which appear in the Superpotential. The problem is now that those functions are to complicated to be solved for {vSM,TanBeta} by mathematica. But this seems to be needed in order to evaluate MakeSPheno[]. I wonder If I could define one or more new mixing angles and use them to simplify the matching conditions. But this new angles have then to be complicated functions of other model paramters like the vev of the field breaking the extra U(1) etc.... How do I give SARAH this dependence, as DependenceSPheno -> .... in the parameters.m file ? What would be the best approach to this problem :?:

Any help would be much appreciated.
johnny

Re: 4 Higgs Doublets Vev matching in SPheno.m

Posted: 22. May 2018, 09:44
by FStaub
Hi johnny,

in principle, the inversion of these expressions is hardly needed. If I'm not mistaken, SARAH only needs the expressions once when it wants to calculate the running angles from the running VEVs. However, this is in principle only necessary when you want to define the angles at another scale than the scale at which the masses are calculated.
You can try to modify Package/SPheno/SPhenoLoopMasses.m and change

Code: Select all

WriteString[sphenoLoop, "\n ! Running angles \n"];
For[i = 1, i <= Length[AnglesInMatching],
  WriteString[sphenoLoop,    ToString[AnglesInMatchingQ[[i]]] <> " = " <>     SPhenoForm[AnglesInMatching[[i]] /. SolutionForRunningAngles] <>     "\n"];
  i++;];
WriteString[sphenoLoop, "\n \n"];
to

Code: Select all

WriteString[sphenoLoop, "\n ! Running angles \n"];
For[i = 1, i <= Length[AnglesInMatching],
  WriteString[sphenoLoop,    ToString[AnglesInMatchingQ[[i]]] <> " = " <>      ToString[AnglesInMatching[[i]]]<>     "\n"];
  i++;];
WriteString[sphenoLoop, "\n \n"];
(Untested! Please come back if this doesn't work)

Cheers,
Florian

Re: 4 Higgs Doublets Vev matching in SPheno.m

Posted: 4. Jun 2018, 16:54
by johnny
Hi Florian,

at first glance it seems to work but there are other problems with the model. This is why we decided to go to a simplified version of the model. If I later come back to this model I will report if it works in SPheno....