Dirac Spinors
Event generators and programs for calculating Feynman Diagrams are normally written for Dirac spinors, but SARAH does all internal calculations for Weyl spinors. Therefore, it is necessary to define, how the Weyl spinors combine to Dirac spinors. That can be done for each all eigenstates separately
DEFINITION[$EIGENSTATES][DiracSpinors]={
Dirac Spinor -> {Weyl 1, Weyl 2},
...
}
Dirac Spinor
is the new name of the Dirac spinor, while Weyl 1
and Weyl 2
the names of the Weyl spinors building the left respectively right component of the Dirac spinor.
Example
The electron Fe
is built from the components FeL
and FeR
by
DEFINITION[EWSB][DiracSpinors]={
Fe -> {FeL, FeR},
...
}
while the neutralinos Chi
, which are Majorana particles, consists only of the Weyl spinor L0
Chi -> {L0, conj[L0]}