Low-Energy Supersymmetry Breaking from String Flux Compactifications: Benchmark Scenarios

Abstract

Soft supersymmetry breaking terms were recently derived for type IIB string flux compactifications with all moduli stabilised. Depending on the choice of the discrete input parameters of the compactification such as fluxes and ranks of hidden gauge groups, the string scale was found to have any value between the TeV and GUT scales. We study the phenomenological implications of these compactifications at low energy. Three realistic scenarios can be identified depending on whether the Standard Model lies on D3 or D7 branes and on the value of the string scale. For the MSSM on D7 branes and the string scale between 10^12 GeV and 10^17 GeV we find that the LSP is a neutralino, while for lower scales it is the stop. At the GUT scale the results of the fluxed MSSM are reproduced, but now with all moduli stabilised. For the MSSM on D3 branes we identify two realistic scenarios. The first one corresponds to an intermediate string scale version of split supersymmetry. The second is a stringy mSUGRA scenario. This requires tuning of the flux parameters to obtain the GUT scale. Phenomenological constraints from dark matter, (g-2)_mu and BR(b->s gamma) are considered for the three scenarios. We provide benchmark points with the MSSM spectrum, making the models suitable for a detailed phenomenological analysis.

Figures (7)

• Figure 1: Evolution of the lightest stop and neutralino masses for the $m_s\sim 10^9$GeV and $m_s = m_{GUT}$ scenarios. The tree level stop mass squared is negative for renormalisation mass scales in the range $10^3-10^7$GeV in the former case, so $\sqrt{|m_{\tilde{t_1}}^2|}$ is plotted. The boundary condition is $M=350$GeV and $\tan \beta = 10$, $\mu$ positive.
• Figure 2: Ratio $B({m_s})/2M$ for (a) $\mu>0$ and (b) $\mu<0$, $M=350$GeV and $M=1300$GeV.
• Figure 3: Contour plots of $\delta a_{\mu}$ and $BR(b\to s\gamma)$ on $\tan\beta$ and $M$ for (a) $\mu>0$ and (b) $\mu<0$ and $m_s\sim 10^9$ GeV. $2\sigma$ bounds are used for $\mu>0$ while $3\sigma$ ones are used for $\mu<0.$
• Figure 4: Contour plots of $\delta a_{\mu}$, $BR(b\to s\gamma)$ and $\Omega h^2$ on $\tan\beta$ and $M$ for (a) $\mu>0$ and (b) $\mu<0$ and $m_s\sim 10^{12}$ GeV. $2\sigma$ bounds are used for $\mu>0$ while $3\sigma$ ones are used for $\mu<0.$
• Figure 5: The value of the Higgs mass against $\tan\beta$ for $\tilde{m} = 10^6$GeV and $\tilde{m} = 10^8$GeV.