Mirage models confront the LHC. II. Flux-stabilized type IIB string theory

We continue the study of a class of string-motivated effective supergravity theories in light of current data from the CERN Large Hadron Collider (LHC). In this installment we consider type IIB string theory compactified on a Calabi-Yau orientifold in the presence of fluxes, in the manner originally formulated by Kachru et al. We allow for a variety of potential uplift mechanisms and embeddings of the Standard Model field content into $D3$-and $D7$-brane configurations. We find that an uplift sector independent of the Kähler moduli, as is the case with anti-$D3$-branes, is inconsistent with data unless the matter and Higgs sectors are localized on $D7$ branes exclusively, or are confined to twisted sectors between $D3$-and $D7$-branes. We identify regions of parameter space for all possible $D$-brane configurations that remain consistent with Planck observations on the dark matter relic density and measurements of the $CP$-even Higgs mass at the LHC. Constraints arising from LHC searches at $\sqrt{s}=8\mathrm{TeV}$ and the LUX dark matter detection experiment are discussed. The discovery prospects for the remaining parameter space at dark matter direct-detection experiments are described, and signatures for detection of superpartners at the LHC with $\sqrt{s}=14\mathrm{TeV}$ are analyzed.

Figure 1

Histogram of gluino masses for all modular weight combinations. Distribution of gluino masses, in GeV, aggregated across all modular weights in the global scan. Blue bars represent the distribution when only proper EWSB and neutralino LSP are imposed. The inset with the yellow bars shows the distribution after imposing the Higgs mass constraint and an upper bound on thermal neutralino relic density.

Figure 2

Histogram of LSP masses for all modular weight combinations. Distribution of the mass of the lightest neutralino, in GeV, aggregated across all modular weights in the global scan. Blue bars represent the distribution when only proper EWSB and neutralino LSP are imposed. The yellow bars show the distribution after imposing the Higgs mass constraint and an upper bound on the thermal neutralino relic density. The inset with the red bars is the result of requiring the relic density to be within $3\sigma$ of the Planck measurement ${\mathrm{\Omega }}_{\text{CDM}}{h}^2=0.1199\pm 0.0027$.

Figure 3

Allowed parameter space for $(n_M,n_H)=(0,0)$ for a bino-like LSP. Parameter combinations of $\{\alpha ,M_0\}$ consistent with proper EWSB, Higgs mass measurements, and the upper bound on thermal relic abundance. The gluino mass, in units of TeV, is given by the color as indicated by the scale to the right.

Figure 4

Allowed parameter space for $(n_M,n_H)=(0,\frac{1}{2})$. The left panel is the bino-like LSP case with stau coannihilation, summed over all values $10\le \tan \beta \le 30$. The right panel is the Higgsino-like LSP case with chargino/neutralino coannihilation and $\tan \beta =48$. The color gives the gluino mass in units of TeV, as indicated by the scale to the right.

Figure 5

Total allowed parameter space for $(n_M,n_H)=(0,0)$ (left) and $(0,\frac{1}{2})$ (right). In both cases, the parameter space is aggregated over all values of $\tan \beta$ in the targeted scans. The allowed region near $\alpha =1$ in both cases has a bino-like LSP, while the region near $\alpha =2$ in both cases has a Higgsino-like LSP. The color indicates the gluino mass, in units of TeV, as given by the color scale to the right.

Figure 6

Allowed parameter space (left) and LSP phenomenology (right) for $(n_M,n_H)=(\frac{1}{2},0)$ and $\tan \beta =16$. The left panel gives allowed parameter combinations of $\{\alpha ,M_0\}$ consistent with proper EWSB, Higgs mass measurements, and the upper bound on thermal relic abundance. The gluino mass, in units of TeV, is given by the color as indicated by the scale to the right. The right panel plots the mass difference between the lightest chargino and lightest neutralino versus the mass difference between the lightest stau and the lightest neutralino. The color in this panel indicates the fraction of the LSP wave function that is bino-like.

Figure 7

Allowed parameter space for $(n_M,n_H)=(\frac{1}{2},\frac{1}{2})$ for the bino-like LSP case. The left panel gives the mass degeneracy between the lightest stau and the lightest neutralino in units of GeV, as indicated by the color scale to the right of the plot. The right panel gives the gluino mass in units of TeV, as indicated by the color scale to the right of the plot.

Figure 8

Allowed parameter space for $(n_M,n_H)=(\frac{1}{2},\frac{1}{2})$ for the Higgsino-like LSP case (left) and combined cases (right). Both panels give the allowed parameter combinations of $\{\alpha ,M_0\}$ consistent with proper EWSB, Higgs mass measurements, and the upper bound on thermal relic abundance. The gluino mass, in units of TeV, is given by the color as indicated by the scale to the right of each panel. The left panel is solely the part of the parameter space with a Higgsino-like LSP, while the right panel combines this space with the region shown in Fig. 7.

Figure 9

Allowed parameter space for $(n_M,n_H)=(0,1)$ (left) and for $(n_M,n_H)=(\frac{1}{2},1)$ (right). In the left panel, the two regions correspond to two different choices of the parameter $\tan \beta$. The region in the upper left has $\tan \beta =51$, while the lower disconnected region has $\tan \beta =52$. In the right panel, the region at $\alpha \simeq 0$ is the bino-like case, while the region at $\alpha \simeq 2$ is the Higgsino-like case. As before, the gluino mass, in units of TeV, is indicated by the color scale to the right of each plot.

Figure 10

Allowed parameter space for the cases $(n_M,n_H)=(1,0)$, $(1,\frac{1}{2})$ and (1,1). All three of these cases involve a Higgsino-like LSP. The lowest region corresponds to $(n_M,n_H)=(1,0)$, while the region at the highest values of $\alpha$ corresponds to $(n_M,n_H)=(1,1)$. As with the other figures, the gluino mass, in units of TeV, is indicated by the color scale to the right of each plot.

Figure 11

Allowed parameter space for all modular weight combinations in the flux-compactified type IIB model. The left panel aggregates all the cases with a bino-like LSP. The right panel aggregates all cases where the LSP is Higgsino-like. All points shown are reproduced from plots earlier in this section. The gluino mass, in units of TeV, is indicated for each point by the color scheme to the right of the plot.

Figure 12

Dark matter detection prospects for bino-like LSP points. The left panel shows the distribution in neutralino-nucleon scattering cross sections versus neutralino mass for the bino-like segment of the type IIB flux compactification scenario. The solid magenta line represents the limit set by the recent results from LUX. The right panel gives the rate of nuclear recoils, integrated over the recoil energy range of 5–25 keV, after 1 ton-year of exposure. Both panels aggregate all the cases with a bino-like LSP for all modular weight combinations.

Figure 13

Dark matter detection prospects for Higgsino-like LSP points. The left panel shows the distribution in neutralino-nucleon scattering cross sections versus neutralino mass for the Higgsino-like segment of the type IIB flux compactification scenario. The solid magenta line represents the limit set by the recent results from LUX. The right panel gives the rate of nuclear recoils, integrated over the recoil energy range of 5–25 keV, after 1 ton-year of exposure. Both panels aggregate all the cases with a Higgsino-like LSP for all modular weight combinations.