A gauge-mediated supersymmetry breaking model with an extra singlet Higgs field

TL;DR

The paper tackles the $μ$-problem in gauge-mediated SUSY breaking by augmenting the NMSSM with an extra singlet and explicit messenger-matter couplings. Using a general, $ extbf{Z}_3$-symmetric superpotential, it demonstrates that $μ$ and $B_μ$ can be generated spontaneously at EW scales through RG running and potential minimization, yielding a viable superpartner spectrum with a bino-like LSP and possible $ ilde{ au}_1$-NLSP depending on $ anβ$ and $\\Lambda$. It also shows that messenger sneutrinos can constitute cold dark matter with masses in the 6–25 TeV range, thanks to enhanced annihilation channels from the singlet sector, and that the cosmological domain wall problem can be resolved at the low SUSY-breaking scale characteristic of GMSB via higher-dimensional operators. Collectively, the results present a consistent, testable GMSB NMSSM framework that addresses the $ ext{μ}$-problem, provides DM candidates, and mitigates cosmological issues, albeit with modest fine-tuning remaining in the Higgs sector. The work highlights the importance of messenger-matter couplings and the interplay between singlet dynamics and electroweak symmetry breaking in shaping the low-energy spectrum and cosmology.

Abstract

We study in some detail the next-to-minimal supersymmetric standard model with gauge mediation of supersymmetry breaking. We find that it is feasible to spontaneously generate values of the Higgs mass parameters $μ$ and $B_μ$ consistent with radiative electroweak symmetry breaking. The model has a phenomenologically viable particle spectrum. Messenger sneutrinos with mass in the range 6 to 25 TeV can serve as cold dark matter. It is also possible to evade the cosmological domain wall problem in this scenario.

Figures (5)

• Figure 1: Phenomenologically viable solutions in the $\lambda_{S}$--$\xi_N^{}$, $\lambda_{S}$--$\eta_S^{}$, $\lambda_{S}$--$\eta_N^{}$ and $\lambda_{S}$--$\tan\beta$ planes.
• Figure 2: The allowed region in the (a) $B_{\mu}$--$\mu$ plane and (b) ($B_\mu/\mu$)--$\tan\beta$ plane.
• Figure 3: The percentage fine-tune versus $\tan\beta$ and $\Lambda$.
• Figure 4: Regions of $\tilde{\chi}_1^0$-NLSP and $\tilde{\tau}_1$-NLSP in the ($m_{\tilde{\chi}_{1}^{0}}/m_{\tilde{\tau}_{1}}$)--$\tan\beta$ and ($m_{\tilde{\chi}_{1}^{0}}/m_{\tilde{\tau}_{1}}$)--$\Lambda$ planes.
• Figure 5: Messenger sneutrino masses that do not over-close the universe.