Scalar Hint from the Diboson Excess?

In view of the recent diboson resonant excesses reported by both ATLAS and CMS Collaborations, we suggest that a new weak singlet pseudoscalar particle η(WZ) may decay into two weak bosons while being produced in gluon fusion at the LHC. The couplings to the gauge bosons can arise from a Wess-Zumino-Witten anomaly term and thus we study an effective model based on the anomaly term as a well motivated phenomenological model. In models where the pseudoscalar particle arises as a composite state, the coefficients of the anomalous couplings can be related to the fermion components of the underlying dynamics. We provide an example to test the feasibility of the idea.

Higgs couplings: disentangling new physics with off-shell measurements.

After the discovery of a scalar resonance, resembling the Higgs boson, its couplings have been extensively studied via the measurement of various production and decay channels on the invariant mass peak. Recently, the possibility of using off-shell measurements has been suggested: in particular, the CMS Collaboration has published results based on the high-invariant mass cross section of the process gg→ZZ, which contains a contribution from the Higgs boson. While this measurement has been interpreted as a constraint on the Higgs width after very specific assumptions are taken on the Higgs couplings, in this Letter, we show that a much more model-independent interpretation is possible.