On the $ZH$ amplitudes at two loop in QCD

Abstract

Through this article, we show that the amplitudes for the $b\bar{b}\to ZH$ in the presence of bottom-Higgs Yukawa coupling can be constructed, up to a few anomalous diagrams, solely from a set of vector form factors of properly grouped classes of diagrams. Thereby, we can completely bypass the subtle issues involving the chiral quantity ${\gamma }_5$. In the second part, we demonstrate that while computing the $q\bar{q}\to ZH$ amplitudes in Higgs effective field theory employing a non-anticommuting ${\gamma }_5$ in dimensional regularization, we need to introduce a four-point effective composite operator to the renormalized Lagrangian in order to retain the physical properties of the amplitude.

Comments: Proceedings for the European Physical Society Conference on High Energy Physics (EPS-HEP2021), 26-30 July 2021