Resolving the tensor structure of the Higgs coupling to Z bosons via Higgs-strahlung

We propose differential observables for pp -> Z (l(+)l(-))h (b (b) over bar) that can be used to completely determine the tensor structure of the hZZ*/hZ (f) over barf couplings relevant to this process in the dimension-six Standard Model (SM) effective field theory. In particular, we propose a strategy to probe the anomalous hZ(mu nu)Z(mu nu) and hZ(mu nu) (Z) over tilde (mu nu) vertices at the percent level. We show that this can be achieved by resurrecting the interference term between the transverse Zh amplitude, which receives contributions from the above couplings, and the dominant SM longitudinal amplitude. These contributions are hard to isolate without knowledge of the analytical amplitude, as they vanish unless the process is studied differentially in three different angular variables at the level of the Z-decay products. By also including the differential distributions with respect to energy variables, we obtain projected bounds for the two other tensor structures of the Higgs coupling to Z bosons.