Special fields and parameters in SARAH

General

SARAH treats some parameters or particles in a model in a specific way if they are associated with SM and MSSM parameters. In order to make this association, the Description statement in particles.m and parameters.m is used.

Usage of parameters

SARAH makes use of the information that some particles/parameters correspond to specific SM or MSSM parameters/particles for the following purposes:

For particles:

FlavorKit generates the code to calculate flavour observables in the model by knowing what are the SM fermions are
For SM fields the pole masses are used for the decays in SPheno
The effective diphoton/digluon vertices for CP-even and CP-odd Higgs states are calculated by SPheno
...

For parameters:

The running of the strong coupling is included in the CalcHep/CompHep, WHIZARD, UFO output.
Automatic matching of parameters in the model to measured SM values in SPheno
VEVs are related to tan β and M_Z in SPheno
Giving the option to write the spectrum file of SPheno in the SCKM basis
...

List of keyword

Particles

The following keywords to assign particles are understood by SARAH:

Leptons
Down-Quarks
Up-Quarks
Photon
Gluon
W-Boson
Z-Boson
Up-Squarks
Higgs
Pseudo-Scalar Higgs
Charged Higgs
Neutrinos
Sneutrinos

Parameters

The following keywords to assign parameters are understood by SARAH:

Up-Yukawa-Coupling
Down-Yukawa-Coupling
Lepton-Yukawa-Coupling
Hypercharge-Coupling
Left-Coupling
Strong-Coupling
Up-Squark-Mixing-Matrix
Down-Squark-Mixing-Matrix
Left-Lepton-Mixing-Matrix
Right-Lepton-Mixing-Matrix
Left-Down-Mixing-Matrix
Right-Down-Mixing-Matrix
Left-Up-Mixing-Matrix
Right-Up-Mixing-Matrix
Weinberg-Angle
Down-VEV
Up-VEV
Scalar-Mixing-Matrix
Pseudo-Scalar-Mixing-Matrix
Softbreaking right Down-Squark Mass
Softbreaking right Up-Squark Mass
Softbreaking left Slepton Mass
Softbreaking right Slepton Mass
Softbreaking left Squark Mass
Trilinear-Up-Coupling
Trilinear-Down-Coupling
Trilinear-Lepton-Coupling

Examples

The SM parameters are set in parameters.m via ParameterDefinitions = { {g1, { Description -> "Hypercharge-Coupling"}}, {g2, { Description -> "Left-Coupling"}}, {g3, { Description -> "Strong-Coupling"}}, {Yu, { Description -> "Up-Yukawa-Coupling" }}, {Yd, { Description -> "Down-Yukawa-Coupling"}}, {Ye, { Description -> "Lepton-Yukawa-Coupling"}}, ... };
The SM particles are set in particles.m via ParticleDefinitions[EWSB] = { {hh , { Description -> "Higgs"}}, {Ah , { Description -> "Pseudo-Scalar Higgs"}}, {VP, { Description -> "Photon"}}, {VZ, { Description -> "Z-Boson"}}, {VG, { Description -> "Gluon" }}, {VWm, { Description -> "W-Boson" }}, {Fd, { Description -> "Down-Quarks"}}, {Fu, { Description -> "Up-Quarks"}}, {Fe, { Description -> "Leptons" }}, {Fv, { Description -> "Neutrinos" }}, ... };

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