UV completed composite Higgs model with heavy composite partners

We study electroweak symmetry breaking in minimal composite Higgs models $SU(4)/Sp(4)$ with purely fermionic UV completions based on a confining hypercolor gauge group and find that the extra Higgs potential from the underlying preon mass can destruct the correlation between the mass of Higgs and composite partners. Thus, the composite partners can be very heavy for successful electroweak symmetry breaking without enhancing the separation between the new physical scale and Higgs vacuum expectation value. So this kind of model can be easily realized by ordinary strong dynamics theories without artificial assumptions and, more likely, consistent with lattice simulations. The UV completion of partial compositeness predicts a light singlet Goldstone boson, which interacts with QCD and electroweak gauge bosons through Wess-Zumino-Witten terms. It can be produced through gluon fusion at LHC and decay into gauge boson pairs. We briefly discuss its phenomenology and derive its bounds from LHC searches.

Figure 1

Scatter plot of the tuning $\mathrm{\Delta }$ in the model with ordinary maximal symmetry as function of mass of $\eta$ (black), lightest top partner (blue), and vector meson $\rho$ (red) for $\xi =0.05$, $m_{\eta }>m_h/2$, $M>0.5\mathrm{TeV}$, and $m_{\rho }>2.5\mathrm{TeV}$. The Higgs mass is fixed at 125 GeV and the top mass range is $m_t\in [140,160]\mathrm{GeV}$. Parameter $M$ is the mass of the lightest top partner.

Figure 2

Scatter plot of the tuning $\mathrm{\Delta }$ in the minimal maximal symmetric model as function of mass of $\eta$ (black), lightest top partner (blue), and vector meson $\rho$ (red) for $\xi =0.1$, $m_{\eta }>m_h/2$, $M>0.5\mathrm{TeV}$, and $m_{\rho }>2.5\mathrm{TeV}$. The Higgs mass is fixed at 125 GeV and the top mass range is $m_t\in [140,160]\mathrm{GeV}$.

Figure 3

Bounds from LHC detections on the mass of $\sigma$ for different hypercolor group $G_{\mathrm{HC}}=Sp(2N_{\mathrm{HC}})$ with $2N_{\mathrm{HC}}\le 36$ and decay constant fixed at $f_{\sigma }=800\mathrm{GeV}$. The different color regions represent the excluded parameter space via $\sigma$ different decay channels. The cross sections of the channels with $\gamma \gamma$ and $gg$ final states at 8 TeV LHC are always smaller than the experimental value and thus there are no constraints on $m_{\sigma }$.