## Twist2QuarkOperator

Twist2QuarkOperator[p] or Twist2QuarkOperator[p,_,_] yields the quark-antiquark operator (p is momentum in the direction of the incoming quark). Twist2QuarkOperator[{p,q}] yields the 2-quark operator for non-zero momentum insertion (p is momentum in the direction of the incoming quark). Twist2QuarkOperator[{p1,___}, {p2,___}, {p3, mu, a}] or Twist2QuarkOperator[p1,_,_, p2,_,_, p3,mu,a] is the quark-antiquark-gluon operator, where p1 is the incoming quark, p2 the incoming antiquark and p3 denotes the incoming gluon momentum. Twist2QuarkOperator[{p1}, {p2}, {p3, mu, a}, {p4, nu, b}] or Twist2QuarkOperator[{p1,___}, {p2,___}, {p3, mu, a}, {p4, nu, b}] or Twist2QuarkOperator[p1,_,_, p2,_,_, p3,mu,a, p4, nu, b] gives the Quark-Quark-Gluon-Gluon-operator. The setting of the option Polarization (unpolarized: 0; polarized: 1) determines whether the unpolarized or polarized operator is returned.

### See also

[Overview](Extra/FeynCalc.md), [Twist2GluonOperator](Twist2GluonOperator.md).

### Examples