Quark and gluon contributions to the QCD trace anomaly

TL;DR

This paper demonstrates a clear decomposition of the QCD trace anomaly into quark and gluon contributions using dimensional regularization and two-loop calculations, aiding understanding of nucleon structure.

Contribution

It provides the first unambiguous two-loop decomposition of the QCD trace anomaly into quark and gluon parts within the minimal subtraction scheme.

Findings

Decomposition of the trace anomaly into quark and gluon parts at two-loop level.

Constraints on the renormalization group properties of nucleon's gravitational form factors.

Clarification of the trace anomaly's structure in QCD.

Abstract

We show that, in dimensional reguralization in the minimal subtraction scheme, the QCD trace anomaly can be unambiguously decomposed into two parts coming from the renormalized quark and gluon energy momentum tensors. We carry out this decomposition at the two-loop level. The result can be used to constrain the renormalization group properties of the nucleon's twist-four gravitational form factor $\bar{C}_{q,g}$.