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:

1. FlavorKit generates the code to calculate flavour observables in the model by knowing what are the SM fermions are
2. For SM fields the pole masses are used for the decays in SPheno
3. The effective diphoton/digluon vertices for CP-even and CP-odd Higgs states are calculated by SPheno
4. ...

• For parameters:

1. The running of the strong coupling is included in the CalcHep/CompHep, WHIZARD, UFO output.
2. Automatic matching of parameters in the model to measured SM values in SPheno
3. VEVs are related to tan β and M_Z in SPheno
4. Giving the option to write the spectrum file of SPheno in the SCKM basis
5. ...

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

1. 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"}}, ... };

2. 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" }}, ... };

See also