Beyond Geolocating: Constraining Higher Dimensional Operators in $H\to 4\ell$ with Off-Shell Production and More

Abstract

We extend the study of Higgs boson couplings in the "golden" $gg\to H\to Z{Z}^{\ast }\to 4\ell$ channel in two important respects. First, we demonstrate the importance of off-shell Higgs boson production ($gg\to H^{\ast }\to ZZ\to 4\ell$) in determining which operators contribute to the $HZZ$ vertex. Second, we include the five operators of lowest non-trivial dimension, including the $Z_{\mu }{Z}^{\mu }\square H$ and $H{Z}_{\mu }\square Z^{\mu }$ operators that are often neglected. We point out that the former operator can be severely constrained by the measurement of the off-shell $H^{\ast }\to ZZ$ rate and/or unitarity considerations. We provide analytic expressions for the off-peak cross-sections in the presence of these five operators. On-shell, the $Z_{\mu }{Z}^{\mu }\square H$ operator is indistinguishable from its Standard Model counterpart $H{Z}_{\mu }{Z}^{\mu }$, while the $H{Z}_{\mu }\square Z^{\mu }$ operator can be probed, in particular, by the $Z^{\ast }$ invariant mass distribution.

Comments: 34 pages, 10 figures