FeynCalc manual (development version)

QuarkGluonVertex

QuarkGluonVertex[mu, a] gives the Feynman rule for the quark-gluon vertex.

QGV can be used as an abbreviation of QuarkGluonVertex.

The dimension and the name of the coupling constant are determined by the options Dimension and CouplingConstant.

See also

Overview, GluonVertex.

Examples

QuarkGluonVertex[\[Mu], a, Explicit -> True]

igsTa.γμi g_s T^a.\gamma ^{\mu }

QGV[\[Mu], a]

QaμQ_a^{\mu }

Explicit[%]

igsTa.γμi g_s T^a.\gamma ^{\mu }

QuarkGluonVertex[\[Mu], a, CounterTerm -> 1, Explicit -> True]

2igs3Sn(CFCA2)Ta.γμε\frac{2 i g_s^3 S_n \left(C_F-\frac{C_A}{2}\right) T^a.\gamma ^{\mu }}{\varepsilon }

QuarkGluonVertex[\[Mu], a, CounterTerm -> 2, Explicit -> True]

3iCAgs3SnTa.γμε\frac{3 i C_A g_s^3 S_n T^a.\gamma ^{\mu }}{\varepsilon }

QuarkGluonVertex[\[Mu], a, CounterTerm -> 3, Explicit -> True]

2igs3Sn(CA+CF)Ta.γμε\frac{2 i g_s^3 S_n \left(C_A+C_F\right) T^a.\gamma ^{\mu }}{\varepsilon }

QuarkGluonVertex[{p, \[Mu], a}, {q}, {k}, OPE -> True, Explicit -> True]

ΩΔμgs(γΔ).Ta(i=02+m(1)i(kΔ)i(Δq)2i+m)+igsTa.γμ\Omega \Delta ^{\mu } g_s (\gamma \cdot \Delta ).T^a \left(\sum _{i=0}^{-2+m} (-1)^i (k\cdot \Delta )^i (\Delta \cdot q)^{-2-i+m}\right)+i g_s T^a.\gamma ^{\mu }

QuarkGluonVertex[{p, \[Mu], a}, {q}, {k}, OPE -> False, Explicit -> True]

igsTa.γμi g_s T^a.\gamma ^{\mu }