Implications of perturbative unitarity for scalar di-boson resonance searches at LHC

We study the constraints implied by partial wave unitarity on new physics in the form of spin-zero di-boson resonances at LHC. We derive the scale where the effective description in terms of the SM supplemented by a single resonance is expected to break down depending on the resonance mass and signal cross-section. Likewise, we use unitarity arguments in order to set perturbativity bounds on renormalizable UV completions of the effective description. We finally discuss under which conditions scalar di-boson resonance signals can be accommodated within weakly-coupled models.
Comment: 34 pages, 9 figures. Revised version, to appear in EPJC. v3: mistake in Appendix A.2 corrected