Figure 1

Hidden photon mass $m_{{\gamma }^{\prime }}$ induced by radiative hidden gauge symmetry breaking, scanned over $m_S$ and ${\alpha }_S\equiv \frac{{\lambda }_S^2}{4\pi }$. In both, $m_H=A_S=100\mathrm{GeV}$, ${\alpha }_h=0.0417$. Left: $M_{\lambda }=71\mathrm{GeV}$, right: $M_{\lambda }=50\mathrm{GeV}$. All values given at ${10}^{16}\mathrm{GeV}$. The black region shows no stable symmetry breaking.Reuse & Permissions

Figure 2

Annihilation diagrams: $s$-channel annihilation on the left, resonant at $m_{{\gamma }^{\prime }}=2m_{\psi }$; $t$-channel on the right, accessible and dominant when $m_{\psi }>m_{{\gamma }^{\prime }}$.Reuse & Permissions

Figure 3

DM relic abundance and direct-detection cross section in agreement with CoGeNT and DAMA for a Dirac fermion DM candidate with a mass of 6 GeV in the SMH (left) and 7 GeV in the Einasto halo model (right) with $\kappa =0.1$ for both. The grey labeled regions are excluded by different searches as shown in the left plot: the anomalous magnetic moment of electron and muon $a_e$ and $a_{\mu }$, EWPT, model dependent BABAR searches, $e^{+}{e}^{-}$ collisions in KLOE, the electron fixed target experiments A1 and APEX, the electron beam dump experiments E774, E141, E173, and Orsay as well as the proton beam dump at Serpukhov (cf. Sec. 3a for details and references). The colored lines with corresponding labels in the right plot correspond to sensitivities of the already running experiments A1 and APEX as well as the planned fixed target experiment HPS (see Sec. 3a). The thin dark green regions (horizontal line at $\chi \sim {10}^{-5}$ continuing towards the resonance) give the correct relic abundance, light green (grey area above $\chi \sim {10}^{-5}$) is subdominant DM, and white is overabundant and therefore excluded. The scattering cross sections are such that they can explain the CoGeNT observation in the purple area, the DAMA observation in the red area, and both experiments at the same time in the blue area which is only possible for the Einasto profile in the right plot (direct detection regions as almost vertical dark grey bands). The blue line in the right hand plot is the XENON100 bound which excludes all the dashed shaded area above the line.Reuse & Permissions

Figure 4

Scan over hidden photon mass $m_{{\gamma }^{\prime }}$, kinetic mixing $\chi$ and hidden Dirac fermion mass $m_{\psi }$ over the range from 0.8 to 25 GeV, using (left) the SMH and (right) Einasto constraints given in Ref. 81. Dark colored regions indicate that the correct relic abundance can be found, and lighter colors indicate that the hidden fermion is a subdominant dark matter candidate. Green regions (lightest and second lightest grey) are thus simply WMAP allowed, but also shown are regions where the direct-detection cross section can explain the signal from either CoGeNT (purple), DAMA (red) or both at the same time (blue or darker shades of grey). The parameter $\kappa$ has been fixed to 1. For subdominant DM, the scattering cross sections have been rescaled. All points shown in the figure are in agreement with all direct-detection constraints. The constraint from electroweak precision tests is shown as the almost horizontal long-dashed blue line, the (model-dependent) BABAR limit is shown as a dashed dark line, and the muon $g-2$ constraint is given as dashed-dotted line at the top left corner of the plot.Reuse & Permissions

Figure 5

Allowed space of models with radiatively induced breaking, showing hidden photon mass against the magnitude of kinetic mixing. Dark green areas (darker grey) allow for the correct dark matter relic density and light green (lighter grey) for subdominant dark matter. The lines represent the constraints from EWPT (long-dashed blue), model-dependent BABAR search (dashed dark line) and muon $g-2$ (dashed-dotted). The SMH has been used, and all DD constraints are imposed except for the SIMPLE exclusion limit. Left: $\kappa =1$, right: $0.1\le \kappa \le 10$.Reuse & Permissions

Figure 6

Allowed space of models with radiatively induced breaking, showing hidden photon mass against the magnitude of kinetic mixing. Dark green areas (darker grey) allow for the correct dark matter relic density and light green (lighter grey) for subdominant dark matter. The lines represent the constraints from EWPT (long-dashed blue), model-dependent BABAR search (dashed dark line) and muon $g-2$ (dashed-dotted). The SMH has been used, and all DD constraints are imposed including the SIMPLE exclusion limit. Left: $\kappa =1$, right: $0.1\le \kappa \le 10$.Reuse & Permissions

Figure 7

Direct detection cross sections for radiatively induced breaking where the DM candidate is a Majorana fermion, using SMH, scanning over $0.1\le \kappa \le 10$. Dark green areas (darker grey) allow for the correct dark matter relic density and light green (lighter grey) for subdominant dark matter. Top: spin-dependent scattering cross section (${\sigma }_p^{\mathrm{SD}}$) on protons with experimental exclusion contours; SIMPLE is shown as the lowest-lying, short-dashed brown curve, and above it is the PICASSO long-dashed orange line, there above the COUPP2011 dashed-dotted turquoise limit, then the COUPP2007 dotted blue line and at the right of the plot starts the dashed black Super-K limit. Left bottom: spin-independent scattering cross section on protons (${\sigma }_p^{\mathrm{SI}}$) together with signal contours from CoGeNT (purple ellipsoid more to the left) and DAMA (red ellipsoid more to the right) as well as exclusion limits from CDMS (dashed turquoise) and XENON100 (dashed-dotted blue). Right bottom: spin-dependent scattering cross section on neutrons (${\sigma }_n^{\mathrm{SD}}$) together with limits from XENON10 (dashed-dotted blue), Zeplin (dotted pink) and CDMS (dashed turquoise). In both plots on the bottom, points in yellow and orange lie above the SIMPLE limit while giving a subdominant and total DM abundance, respectively.Reuse & Permissions

Figure 8

Allowed space of models with visible-sector induced breaking as a function of the hidden photon mass and the magnitude of kinetic mixing, showing dark green areas (lighter grey) where the correct dark matter relic abundance can be found and light purple (darker grey) where the CoGeNT signal can be explained with a subdominant dark matter candidate. The lines represent the constraints from EWPT (long-dashed blue line), model dependent BABAR search (dashed dark) and muon $g-2$ (dashed-dotted). The SMH has been used, and all DD constraints are imposed including the SIMPLE exclusion limit. Left: $\kappa =1$, right: $0.1\le \kappa \le 10$.Reuse & Permissions

Figure 9

Allowed space of models with the visible-sector induced breaking in function of the hidden photon mass and the magnitude of kinetic mixing, scanned over $0.1\le \kappa \le 10$, showing different halo models. Left: Isothermal halo model; right: Einasto halo model. Here, the red region shows the space explaining the DAMA signal, the purple region explains the CoGeNT signal, and the blue one explains both DAMA and CoGeNT, all signal regions (darker grey shadings) having a subdominant dark matter density. All DD constraints including SIMPLE are imposed. The lines represent the constraints from EWPT (long-dashed blue line), model-dependent BABAR search (dashed dark) and muon $g-2$ (dashed-dotted).Reuse & Permissions

Figure 10

Spin-dependent scattering cross sections on protons (left) and on neutrons (right) for visible-sector induced breaking together with the exclusion contours from the corresponding direct-detection experiments (the lowest lying, short-dashed brown line in the left plot is the SIMPLE limit; the other lines are as explained in Fig. 7, and in addition the long-dashed green line is the KIMS limit). Here, only the Majorana dark matter candidate ${\tilde{o}}_1$ is shown (the cross sections for the Dirac fermion ${\tilde{o}}_7$ are too small to appear). In the right plot, points in yellow and orange lie above the SIMPLE limit while giving a subdominant and total DM abundance respectively. The SMH has been used, and $0.1\le \kappa \le 10$.Reuse & Permissions

Figure 11

Spin-independent scattering cross sections for visible-sector induced breaking using (left) the SMH and (right) the Einasto profile as given in Ref. 81 and $0.1\le \kappa \le 10$. The signal contours from CoGeNT (purple ellipsoid more to the left) and DAMA (red ellipsoid more to the right) are shown, which overlap for the right-hand plot; the exclusion limits from CDMS and XENON100 are shown as dashed turquoise and dashed-dotted blue curves, respectively. The plot splits into two disjoint green areas: in the upper, the Dirac fermion ${\tilde{o}}_7$ is the dark matter candidate, while in the lower one, it is the Majorana fermion ${\tilde{o}}_1$. In both plots, points in yellow and orange lie above the SIMPLE limit while giving a subdominant and total DM abundance, respectively.Reuse & Permissions