Neutral Higgs boson pair production in photon-photon annihilation in the Two Higgs Doublet Model

Understand

We study double Higgs production in photon-photon collisions as a probe of the new dynamics of Higgs interactions in the framework of two Higgs Doublet Models.

• We analyze neutral Higgs bosons production and decay in the fusion processes, $\gamma \gamma \to S_iS_j$, $S_i=h^0, H^0, A^0$, and show that both $h^0h^0$ and $A^0A^0$ production can be enhanced by threshold effects in the region $E_{\gamma\gamma}\approx 2 m_{H\pm}$.
• Resonant effects due to the heavy Higgs, $H^0$, can also play a role in the cross section enhancement when it is allowed to decay to two light CP-even $h^0$ or to two light CP-odd $A^0$ scalars.
• We have scanned the allowed parameter space of the Two Higgs Doublet Model and found a vast region of the parameter space where the cross section is two orders of magnitude above the Standard Model cross section.