Beyond geolocating: Constraining higher dimensional operators in H →4l with off-shell production and more

We extend the study of Higgs boson couplings in the "golden" gg→H→ZZ∗→4l channel in two important respects. First, we demonstrate the importance of off-shell Higgs boson production (gg→H∗→ZZ→4l) in determining which operators contribute to the HZZ vertex. Second, we include the five operators of lowest nontrivial dimension, including the ZμZμ□H and HZμ□Zμ operators that are often neglected. We point out that the former operator can be severely constrained by the measurement of the off-shell H∗→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 ZμZμ□H operator is indistinguishable from its Standard Model counterpart HZμZμ, while the HZμ□Zμ operator can be probed, in particular, by the Z∗ invariant mass distribution.