Input parameters of SPheno
General
There are two different ways to define the input parameters which shall be used with SPheno to define a parameter point
- Scalar valued parameters or parameter which are not part of the model are usually given via the
MINPAR
orEXTPAR
blocks in the Les Houches input file - Parameters which are vectors, matrices or higher rank tensors are given via separated blocks in the Les Houches input file.
Using MINPAR and EXTPAR
Conventions
The MINPAR
and EXTPAR
blocks are part of the Susy Les Houches Accord (SLHA), see Refs. . The conventions for these blocks in the Les Houches input file are as follows:
Block MINPAR #
Integer1 Real1 # Comment1
Integer2 Real2 # Comment2
...
Thus, each parameter is identified via an Integer (IntegerX
) and receives a value Real
. The conventions for EXTPAR
are exactly the same. While specific conventions for the MSSM and NMSSM for the entries in MINPAR
and EXTPAR
exist, SARAH does not make any use of them. It offers the user complete freedom in defining the input according to his/her demands.
Complex parameters
In the case of complex parameters, the imaginary parts are given via
Block IMMINPAR #
Integer1 Real1 # Comment1
Integer2 Real2 # Comment2
...
Definition in SARAH
The entries which SPheno expects in MINPAR
or EXTPAR
are defined in SPheno.m via
MINPAR={
{Integer1, ParameterName1},
{Integer2, ParameterName2},
...
};
Again, EXTPAR
is used in exactly the same way.
Remarks
- There is exactly no strict reason to use
EXTPAR
at all for SARAH generated SPheno versions but all parameters can be defined viaMINIPAR
. This option exists only if one wants to mimic the existing SLHA conventions for some models. - The variables
ParameterNameX
must not exist in the model. Otherwise, there will be an error message when compiling SPheno that parameters are defined twice. Note, SARAH also auto-generates for each parameterX
the derived parametersXIN
,XMZ
, andXGUT
which can also not be used inMINPAR
orEXTPAT
- If several, different boundary conditions shall be defined and the boundary conditions needs different input parameters, one can use
MINPAR=Table[{},{N}];
MINPAR[[/1|1]]={
{Integer1a, ParameterName1a},
{Integer2a, ParameterName2a},
...
};
MINPAR[[/1|1]]={
{Integer1b, ParameterName1b},
{Integer2b, ParameterName2b},
...
}:
In that case the input parameters MINPAR[ [X]]
can only be used in the boundary conditions BoundarySUSYScale[ [X]]
, BoundaryHighScale[ [X]]
, BoundaryEWSBScale[ [X]]
.
Example
-
CMSSM: the standard input parameters for the constrained MSSM are defined via MINPAR = {{1,m0}, {2,m12}, {3,TanBeta}, {4,SignMu}, {5,Azero}};
in SPheno.m. Thus, the parameter point for the numerical evaluation is given to SPheno via the Les Houches input via
Block MINPAR # 1 7.000000E+01 # m_0 2 2.500000E+02 # M_1/2 3 1.000000E+01 # Tan(beta) 4. 1.000000E+00 # Sign(mu) 5. 0.000000E+00 # A_0
-
CMSSM and GMSB boundary conditions. In order to define the CMSSM and GMSB boundary conditions in a single SPheno.m, one can use MINPAR=Table[{},{2}];
(* CMSSM input*) MINPAR[[/1|1]]={{1,m0}, {2,m12}, {3,TanBeta}, {4,SignumMu}, {5,Azero}}; (* GMSB input parameters *) MINPAR[[/2|2]]={{1,LambdaInput}, {2,MessengerScale}, {3,TanBeta}, {4,SignumMu}, {6,cGrav}, {7,n5plets}, {8,n10plets}};
In order to switch between both sets of input parameters and the corresponding boundary conditions, the flag
1
inMODSEL
is used:-
CMSSM input Block MODSEL # 1 1 # 1/0: High/low scale input 2 1 # Boundary Condition ... Block MINPAR # Input parameters 1 1.5000000E+03 # m0 2 1.5000000E+03 # m12 3 1.0000000E+01 # TanBeta 4 1.0000000E+00 # SignumMu 5 -2.0000000E+03 # Azero
-
GMSB input Block MODSEL # 1 1 # 1/0: High/low scale input 2 2 # Boundary Condition ... Block MINPAR # Input parameters 1 1.0000000E+05 # LambdaInput 2 2.0000000E+05 # MessengerScale 3 1.0000000E+01 # TanBeta 4 1.0000000E+00 # SignumMu 6 1.0000000E+00 # cGrav 7 1.0000000E+00 # n5plets 8 0.0000000E+00 # n10plets
-
-
NMSSM boundary conditions: for the constrained NMSSM, the input parameters beyond those of the CMSSM are defined in EXTPAR: MINPAR={ {1, m0}, {2, m12}, {3, TanBeta}, {5, Azero}}; EXTPAR = { {61, LambdaInput}, {62, KappaInput}, {63, ALambdaInput}, {64, AKappaInput}, {65, MuEffinput} };
Note, that the entry
4
ofMINPAR
is removed because the phase of μ is not a free parameter in this model. The blocks in the Les Houches input file areBlock MINPAR # Input parameters 1 1.0000000E+03 # m0 2 1.0000000E+03 # m12 3 1.0000000E+01 # TanBeta 5 -2.5000000E+03 # Azero Block EXTPAR # Input parameters 61 1.0000000E-01 # LambdaInput 62 1.1000000E-01 # KappaInput 63 -1.5000000E+03 # ALambdaInput 64 -3.6000000E+01 # AKappaInput 65 9.6500000E+02 # MuEffinput
-
Complex input parameters: in order to set complex input parameters via
MINPAR
orEXTPAR
no changes in SPheno.m are necessary. The imaginary parts can directly be defined via Block IMMINPAR # Input parameters 2 1.0000000E+02 # Im(m12) Block IMEXTPAR # Input parameters 61 1.0000000E-02 # Im(LambdaInput)for instance. In that example, the CNMSSM parameters M1/2 and λ get an imaginary part of 100 GeV, respectively 0.01.
Using parameter specific blocks for the input
Input Conventions
With MINPAR
and EXTPAR
it is hardly possible to define the input value for an entire vector or matrix. For this purpose, in SPheno generated SARAH versions always the option exists to give entire blocks in the Les Houches input file as input. The name of the blocks to define parameters are the same as used in the output (see parameters.m) together with a suffix IN
. Thus the input values for a matrix M could be given as input via
Block MIN # Input for M
1 1 Real11 #
1 2 Real12 #
1 3 Real13 #
2 1 Real21 #
...
If the matrix is diagonal, one can skip all values which a zero:
Block MIN # Input for M
1 1 Real11 #
2 2 Real22 #
3 3 Real33 #
Imaginary parts
The imaginary parts can be defined if the additional prefix IM
is used, e.g.
Block IMMIN # Input for Im(M)
1 1 Real11 #
2 2 Real22 #
3 3 Real33 #
Applied boundary conditions
By default, if parameters receive numerical values in that way, these values are applied at the highest considered scale:
- In High-scale SPheno versions this is the GUT scale
- In Low-scale SPheno versions this is the renormalisation scale
See also Low or High scale SPheno version. One can change this behaviour by using the keyword LHInput
in the defined boundary conditions. With
BoundaryCondition={
...,
{X, LHInput[X]}
};
X the input values are applied at the scale corresponding to the used boundary conditions (BoundaryCondition
=BoundaryEWSBScale
or BoundaryRenScale
for instance), but not at the High scale (BoundaryCondition
=BoundaryHighScale
corresponds to the default choice).
One can also make use of this option to overwrite default boundary conditions, see Boundary conditions in SPheno.
Example
-
Neutrino Yukawa coupling in Seesaw 1: input values for
Y_\nu
, whose SLHA block is calledYV
, are given viaYVIN
Block YVIN # 1 1 1.000000E-03 # Yv(1,1) 1 2 2.000000E-04 # Yv(1,2) 1 3 3.000000E-05 # Yv(1,3) 2 1 0.000000E+00 # Yv(2,1) 2 2 1.000000E-03 # Yv(2,2) 2 3 0.000000E+00 # Yv(2,3) 3 1 0.000000E+00 # Yv(3,1) 3 2 0.000000E+00 # Yv(3,2) 3 3 1.000000E-03 # Yv(3,3)(Note, these are just random values as example and won't explain any neutrino data).
-
Flavour violating squark soft masses can be defined via Block MSQ2IN # 1 1 1.00000E6 # msq2(1,1) 1 2 2.00000E4 # msq2(1,2) 1 3 2.00000E4 # msq2(1,3) 2 1 2.00000E4 # msq2(2,1) 2 2 1.00000E6 # msq2(2,2) 3 1 2.00000E4 # msq2(3,1) 3 3 1.00000E6 # msq2(3,3)
Two remarks:
- All entries which are not defined ((2,3) and (3,2)) are set automatically to zero
- SPheno doesn't make use of the symmetry of the parameters, i.e. it is necessary to define (consistently!) the entire matrix
-
Input at SUSY scale: if one want to set in a non-minimal SUSY model a new coupling
Y_x
at the SUSY instead of the GUT scale, this can be done viaLHInput
.-
Define in SPheno.m BoundarySUSYScale = { ... {Yx, LHInput[Yx]} };
-
The input parameters are given as usual Block YXIN # 1 1 1.000000E-01 # Yx(1,1) 2 2 1.000000E-01 # Yx(2,2) 3 3 1.000000E-01 # Yx(3,3)
-