A pitfall in applying non-anticommuting ${\gamma }_5$ in $q\overline{q}\to ZH$ amplitudes

Abstract

In computing the two-loop QCD corrections to a class of Feynman diagrams for the process $q\overline{q}\to ZH$ in Higgs effective field theory, we discover a striking phenomenon. We find the need for an additional local composite operator in the renormalised Lagrangian while employing a non-anticommuting ${\gamma }_5$ in dimensional regularisation. The computation using anticommuting ${\gamma }_5$, however, does not require any such amendment.

Comments: Contribution to the 15th International Symposium on Radiative Corrections (RADCOR) and the XIX Workshop on Radiative Corrections for the LHC and Future Colliders (LoopFest)