Theoretical predictions of a new scalar boson near 0.5 TeV

In one of our recent papers, a second Higgs-like boson $h^{\mathrm{\prime }}$ with the mass near 0.5~TeV was predicted from a dual holographic model (borrowed from the AdS/QCD approach) for a hypothetical strongly-coupled BSM sector. In the present work, we reproduce this prediction within the framework of more traditional phenomenological approaches to effective description of a strongly-coupled field theory – the Nambu–Jona-Lasinio model and spectral sum rules. A good quantitative agreement between these three drastically different methods is obtained. Interestingly, the existence of the $h^{\mathrm{\prime }}$ with the predicted mass turns out to be a minimal possibility to cancel the quadratic divergence in the vacuum energy density. We argue also that the dominant channel for the production of $h^{\mathrm{\prime }}$ should be $h\to h^{\mathrm{\prime }}h$, where $h$ is the standard Higgs boson. Hence, the $H(650)$ resonance observed recently at the LHC can be naturally interpreted as an enhancement due to the $h{h}^{\mathrm{\prime }}$-threshold. Within the considered scenario, the $h$ and $h^{\mathrm{\prime }}$ bosons in a conjectured BSM theory play the role of the $\pi$ and $\sigma$ mesons in low-energy descriptions of QCD. Our result can be understood as a quantitative consequence of universality of strong coupling regime in both theories, i.e., the prediction represents a BSM analogue of the numerical QCD relation $m_{\sigma }\simeq 4m_{\pi }$. We argue that the obtained result is a model-independent consequence of the assumed universality.