## CounterTerm

`CounterTerm[name]` is a database of counter terms. `CounterTerm` is also an option for the Feynman rule functions `QuarkGluonVertex`, `GluonPropagator`, `QuarkPropagator`.

### See also

[Overview](Extra/FeynCalc.md), [CounterT](CounterT.md), [QuarkGluonVertex](QuarkGluonVertex.md), [GluonPropagator](GluonPropagator.md), [QuarkPropagator](QuarkPropagator.md).

### Examples

```mathematica
CounterTerm[Zm]
```

$$\frac{C_F g_s^4 \left(\frac{4 \left(\frac{11 C_A}{2}+\frac{9 C_F}{2}-2 N_f T_f\right)}{\varepsilon ^2}+\frac{2 \left(\frac{97 C_A}{12}+\frac{3 C_F}{4}-\frac{5 N_f T_f}{3}\right)}{\varepsilon }\right)}{256 \pi ^4}+\frac{3 C_F g_s^2}{8 \pi ^2 \varepsilon }+1$$