Di-Higgs Decay of Stoponium at Future Photon-Photon Collider

Abstract

We study the detectability of the stoponium in the di-Higgs decay mode at the photon-photon collider option of the International $e^{+}{e}^{-}$ Linear Collider (ILC), whose center-of-mass energy is planned to reach $\sim 1$ TeV. We find that $5\sigma$ detection of the di-Higgs decay mode is possible with the integrated electron-beam luminosity of $1{\mathrm{ab}}^{-1}$ if the signal cross section, $\sigma (\gamma \gamma \to {\sigma }_{{\tilde{t}}_1}\to hh)$, of $\mathcal{O}(0.1)$ fb is realized for the stoponium mass smaller than $\sim$ 800 GeV at 1 TeV ILC. Such a value of the cross section can be realized in the minimal supersymmetric standard model (MSSM) with relatively large trilinear stop-stop-Higgs coupling constant. Implication of the stoponium cross section measurement for the MSSM stop sector is also discussed.

Comments: 20 pages, 5 figures