Towards a supersymmetric description of the Fermi Galactic center excess

Cahill-Rowley, Matthew; Gainer, James S.; Hewett, JoAnne L.; Rizzo, T. G.

doi:10.1007/jhep02(2015)057

Cited by 50 publications

(35 citation statements)

References 101 publications

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“…Let us define the dimensionless ratio δ ≡ (2mχ − (m a + m h ))/2mχ so that δ = 0 corresponds to the annihilation being precisely at threshold. Expanding for δ 1, the cross section for the processχχ → h a is given by [22] σ 19) where the heaviest pseudoscalar is denoted by a 2 (we neglect the small width of the a).…”

Section: Annihilation Into Hamentioning

confidence: 99%

SUSY implications from WIMP annihilation into scalars at the Galactic Center

et al. 2015

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An excess in γ-rays emanating from the galactic centre has recently been observed in the Fermi-LAT data. This signal can be interpreted as resulting from WIMP annihilation, with the spectrum well-fit by dark matter annihilating dominantly into either bottom-quark or Higgs pairs. Supersymmetric models provide a well-motivated framework to study the implications of this signal in these channels. With a neutralino dark matter candidate, the γ-ray excess cannot be easily accommodated in the minimal supersymmetric model, which in any case requires tuning below the percent level to explain the observed Higgs mass. Instead we are naturally led to consider the next-to-minimal model with a singlet superfield. This not only allows for the annihilation channel into bottom-quark pairs to be implemented, but also provides new possibilities for annihilation into Higgs-pseudoscalar pairs. We show that the fit to the γ-ray excess for the Higgs-pseudoscalar channel can be just as good as for annihilation into bottom-quark pairs. Moreover, in the parameter range of interest, the next-to-minimal supersymmetric model solves the µ-problem and can explain the 125 GeV Higgs mass with improved naturalness. We also consider an extension by adding a right-handed neutrino superfield with the right-handed sneutrino acting as a dark matter candidate. Interestingly, this allows for the annihilation into pseudoscalar pairs which also provide a good fit to the γ-ray excess. Furthermore, in the case of a neutralino LSP, the late decay of a sneutrino NLSP can non-thermally produce the observed relic abundance. Finally, the WIMP annihilation into scalar pairs allows for the possibility of detecting the Higgs or pseudoscalar decay into two photons, providing a smoking-gun signal of the model.

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Section: Annihilation Into Hamentioning

confidence: 99%

SUSY implications from WIMP annihilation into scalars at the Galactic Center

et al. 2015

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“…[46] for an analysis of the general NMSSM, which in some cases may also be probed by the searches we present). The first involves a mixed singlino/Higgsino-like neutralino, which, to achieve a Standard Model-(and not singlet-) like 125 GeV Higgs, requires the lightest pseduoscalar to be a nearly pure singlet [16] (i.e.…”

Section: Application To the Nmssmmentioning

confidence: 99%

“…Scenarios featuring a pseudoscalar mediator with a significant invisible branching fraction [22,25,26,[43][44][45][46]. This results in distinctive missing energy signatures at the LHC which can be effectively probed by bb+MET, mono-jet, and other existing and planned LHC searches, as studied in detail in e.g.…”

Section: Jhep04(2015)046mentioning

confidence: 99%

Extending LHC coverage to light pseudoscalar mediators and coy dark sectors

Kozaczuk

Martin

2015

J. High Energ. Phys.

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Many dark matter models involving weakly interacting massive particles (WIMPs) feature new, relatively light pseudoscalars that mediate dark matter pair annihilation into Standard Model fermions. In particular, simple models of this type can explain the gamma ray excess originating in the Galactic Center as observed by the Fermi Large Area Telescope. In many cases the pseudoscalar's branching ratio into WIMPs is suppressed, making these states challenging to detect at colliders through standard dark matter searches. Here, we study the prospects for observing these light mediator states at the LHC without exploiting missing energy techniques. While existing searches effectively probe pseudoscalars with masses between 5-14 GeV and above 90 GeV, the LHC reach can be extended to cover much of the interesting parameter space in the intermediate 20-80 GeV mass range in which the mediator can have appreciable Yukawa-like couplings to Standard Model fermions but would have escaped detection by LEP and other experiments. Models explaining the Galactic Center excess via a light pseudoscalar mediator can give rise to a promising signal in this regime through the associated production of the mediator with bottom quarks while satisfying all other existing constraints. We perform an analysis of the backgrounds and trigger efficiencies, detailing the cuts that can be used to extract the signal. A significant portion of the otherwise unconstrained parameter space of these models can be conclusively tested at the 13 TeV LHC with 100 fb −1 , and we encourage the ATLAS and CMS collaborations to extend their existing searches to this mass range.

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“…As expected the cross section decreases as the mass of the pseudoscalar increases, however we can see that there is still a large range of parameters which fit the Galactic Center excess, even when the pseudoscalar and dark matter masses are far from being in resonance. It is notable that a leptophilic Higgs model furnishes a viable mediator between the visible sector and the dark matter which provides a sufficiently large annihilation cross section; in Type-II Higgs models, a Higgs mediator which can explain the Galactic Center anomaly without a resonance enhancement tends to require additional light states which are well-constrained from direct detection and collider searches [106][107][108][109][110][111][112]. As the mediators considered here are leptophilic, such constraints are easily avoided.…”

Section: B Indirect Detectionmentioning

confidence: 99%

Dark matter in leptophilic Higgs models after the LHC run I

Buckley¹,

Feld²

2015

Phys. Rev. D

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We examine the leptophilic two Higgs doublet model with fermionic dark matter, considering the range of experimental constraints on the Higgs sector. The measurements of the 125 GeV Higgs from the LHC Run-I allow us to focus on those remaining processes that may play an important role at colliders. We find that the leptophilic model allows for a much lighter Higgs than in other two-Higgs models, although discovery at the LHC will be difficult. Adding a dark matter sector motivated by supersymmetric extensions of the leptophilic model, we find the existing parameter space can accommodate constraints from direct detection and the invisible widths of the Higgs and Z, while also fitting the Galactic Center gamma ray excess reported by analyses of Fermi-LAT data. We also discuss the status of the fully supersymmetric version of such models, which include four Higgs doublets and a natural dark matter candidate.

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Towards a supersymmetric description of the Fermi Galactic center excess

Cited by 50 publications

References 101 publications

SUSY implications from WIMP annihilation into scalars at the Galactic Center

SUSY implications from WIMP annihilation into scalars at the Galactic Center

Extending LHC coverage to light pseudoscalar mediators and coy dark sectors

Dark matter in leptophilic Higgs models after the LHC run I

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