Polarized and unpolarized off-shell H^→ ZZ→ 4 decay above the 2mZ threshold

An analysis of the off-shell decay width is presented for both unpolarized and polarized gauge bosons in the scenario with the most general vertex function, which is expressed in terms of two -even ( and ) and one -odd ( ) anomalous couplings. The SM contributions to the coupling up to the one-loop level are also included. Explicit analytic results for the unpolarized and polarized square amplitudes and the four-body phase space are presented, out of which several observable quantities can be obtained straightforwardly. Regarding numerical analysis, a cross-check was performed via , where our model was implemented with the aid of FeynRules. We then considered the most stringent bounds on anomalous complex couplings and analyzed the effects of the polarizations of the gauge bosons through the polarized decay width as well as left-right and forward-backward asymmetries, which were found to be sensitive to new-physics effects. Particular focus was put on the effects of the absorptive parts of the anomalous couplings, which have been largely overlooked up to now in LHC analyses. It was found that the studied observable quantities, particularly the left-right asymmetries, can be helpful to search for effects of -violation in the coupling and set bounds on the absorptive parts. For completeness, we also analyzed the case of unpolarized gauge bosons.