QuantumField is the head of quantized fields and their derivatives.
QuantumField[par, ftype, {lorind}, {sunind}] denotes a quantum field of type ftype with (possible) Lorentz-indices lorind and SU(N) indices sunind. The optional first argument par denotes a partial derivative acting on the field.
Overview, FeynRule, FCPartialD, ExpandPartialD.
This denotes a scalar field.
QuantumField[S]S
Quark fields
QuantumField[AntiQuarkField]\bar{\psi }
QuantumField[QuarkField]\psi
This is a field with a Lorentz index.
QuantumField[B, {\[Mu]}]B_{\mu }
Color indices should be put after the Lorentz ones.
QuantumField[GaugeField, {\[Mu]}, {a}] // StandardForm
(*QuantumField[GaugeField, LorentzIndex[\[Mu]], SUNIndex[a]]*)A_{\Delta}^a is a short form for \Delta ^{mu } A_{mu }^a
QuantumField[A, {OPEDelta}, {a}]A_{\Delta }^a
The first list of indices is usually interpreted as type LorentzIndex, except for OPEDelta, which gets converted to type Momentum.
QuantumField[A, {OPEDelta}, {a}] // StandardForm
(*QuantumField[A, Momentum[OPEDelta], SUNIndex[a]]*)Derivatives of fields are denoted as follows.
QuantumField[FCPartialD[LorentzIndex[\[Mu]]], A, {\[Mu]}]\left.(\partial _{\mu }A_{\mu }\right)
QuantumField[FCPartialD[OPEDelta], S]\left.(\partial _{\Delta }S\right)
QuantumField[FCPartialD[OPEDelta], A, {OPEDelta}, {a}]\left.(\partial _{\Delta }A_{\Delta }^a\right)
QuantumField[FCPartialD[OPEDelta]^OPEm, A, {OPEDelta}, {a}]\partial _{\Delta }^m{}^{A\Delta a}
QuantumField[QuantumField[A]] === QuantumField[A]\text{True}