GeV excess in the Milky Way: The role of diffuse galactic gamma-ray emission templates

Zhou, Bei; Liang, Yun-Feng; Huang, Xiaoyuan; Li, Xiang; Fan, Yi‐Zhong; Liu, Feng; Chang, Jin

doi:10.1103/physrevd.91.123010

Cited by 164 publications

(132 citation statements)

References 52 publications

Supporting

Mentioning

123

Contrasting

Unclassified

Order By: Relevance

“…Over the past few years, the existence of an unidentified excess of γ-rays with energy 1-3 GeV from the direction of the Galactic Centre has been reported by several groups [30,[104][105][106][107][108][109][110][111][112][113][114] after analysing the Fermi-LAT publicly available data [27]. There are some astrophysical explanations such as unresolved point sources (e.g.…”

Section: Indirect Detectionmentioning

confidence: 99%

Neutrino mass, dark matter and anomalous magnetic moment of muon in a U 1 L μ − L τ $$ \mathrm{U}{(1)}_L{{}_{{}_{\mu}}}_{-}{{}_L}_{{}_{\tau }} $$ model

Biswas

Choubey

Khan

2016

J. High Energ. Phys.

View full text Add to dashboard Cite

The observation of neutrino masses, mixing and the existence of dark matter are amongst the most important signatures of physics beyond the Standard Model (SM). In this paper, we propose to extend the SM by a local L µ −L τ gauge symmetry, two additional complex scalars and three right-handed neutrinos. The L µ − L τ gauge symmetry is broken spontaneously when one of the scalars acquires a vacuum expectation value. The L µ − L τ gauge symmetry is known to be anomaly free and can explain the beyond SM measurement of the anomalous muon (g − 2) through additional contribution arising from the extra Z µτ mediated diagram. Small neutrino masses are explained naturally through the Type-I seesaw mechanism, while the mixing angles are predicted to be in their observed ranges due to the broken L µ − L τ symmetry. The second complex scalar is shown to be stable and becomes the dark matter candidate in our model. We show that while the Z µτ portal is ineffective for the parameters needed to explain the anomalous muon (g − 2) data, the correct dark matter relic abundance can easily be obtained from annihilation through the Higgs portal. Annihilation of the scalar dark matter in our model can also explain the Galactic Centre gamma ray excess observed by Fermi-LAT. We show the predictions of our model for future direct detection experiments and neutrino oscillation experiments.

show abstract

Section: Indirect Detectionmentioning

confidence: 99%

Neutrino mass, dark matter and anomalous magnetic moment of muon in a U 1 L μ − L τ $$ \mathrm{U}{(1)}_L{{}_{{}_{\mu}}}_{-}{{}_L}_{{}_{\tau }} $$ model

Biswas

Choubey

Khan

2016

J. High Energ. Phys.

View full text Add to dashboard Cite

show abstract

“…An anomalous emission line at ∼3.5 keV has been found in a stacked analysis of 73 galaxy clusters [29] and in other regions [30][31][32][33]. Analysis of data from the Fermi Gamma-Ray Telescope (hereafter Fermi) [34] has shown an unexplained spherically symmetric excess of O(GeV) gamma rays at the center of the Galaxy [7,[35][36][37][38][39][40]. Studying expected properties could help discriminate DM against astrophysical backgrounds.…”

Section: Introductionmentioning

confidence: 99%

Spherical cows in dark matter indirect detection

Bernal

Necib

Slatyer

2016

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

Abstract. Dark matter (DM) halos have long been known to be triaxial, but in studies of possible annihilation and decay signals they are often treated as approximately spherical. In this work, we examine the asymmetry of potential indirect detection signals of DM annihilation and decay, exploiting the large statistics of the hydrodynamic simulation Illustris. We carefully investigate the effects of the baryons on the sphericity of annihilation and decay signals for both the case where the observer is at 8.5 kpc from the center of the halo (exemplified in the case of Milky Way-like halos), and for an observer situated well outside the halo. In the case of Galactic signals, we find that both annihilation and decay signals are expected to be quite symmetric, with axis ratios very different from 1 occurring rarely. In the case of extragalactic signals, while decay signals are still preferentially spherical, the axis ratio for annihilation signals has a much flatter distribution, with elongated profiles appearing frequently. Many of these elongated profiles are due to large subhalos and/or recent mergers. Comparing to gamma-ray emission from the Milky Way and X-ray maps of clusters, we find that the gamma-ray background appears less spherical/more elongated than the expected DM signal from the large majority of halos, and the Galactic gamma ray excess appears very spherical, while the X-ray data would be difficult to distinguish from a DM signal by elongation/sphericity measurements alone.

show abstract

“…Currently there is a strong hint from Fermi Large Area Telescope data of dark matter annihilation in the Galactic Center (GC), giving rise to an excess of gamma rays peaking at energies of several GeV [1][2][3][4][5][6]. The morphology is consistent with that expected from dark matter annihilations, and the required cross section is of the right order of magnitude for yielding the correct thermal relic density.…”

Section: Introductionmentioning

confidence: 54%

“…In this study we compared two new data sets, 5 characterizing the excess gamma rays from the Galactic Center, to predictions from models where dark matter annihilates into light mediators that subsequently decay into standard model particles. In contrast to models with direct annihilation into heavy quarks, these are more easily compatible with direct detection and cosmic ray antiproton constraints, as we have demonstrated.…”

Section: Discussionmentioning

confidence: 99%

Multimediator models for the Galactic Center gamma ray excess

et al. 2015

View full text Add to dashboard Cite

Tentative evidence for excess GeV-scale gamma rays from the Galactic Center has been corroborated by several groups, including the Fermi collaboration, on whose data the observation is based. Dark matter annihilation into standard model particles has been shown to give a good fit to the signal for a variety of final state particles, but models with heavy mediators are typically inconsistent with constraints from direct detection or monojets. Models where the dark matter annihilates to mediators that subsequently decay are less constrained. We perform global fits of such models to recent data, allowing branching fractions to all possible fermionic final states to vary. The best fit models, including constraints from the AMS-02 experiment (and also antiproton ratio), require branching primarily to muons, with a ∼10-20% admixture of b quarks, and no other species. This suggests models in which there are two scalar mediators that mix with the Higgs, and have masses consistent with such a decay pattern. The scalar that decays to μ þ μ − must therefore be lighter than 2m τ ≅ 3.6 GeV. Such a small mass can cause Sommerfeld enhancement, which is useful to explain why the best-fit annihilation cross section is larger than the value needed for a thermal relic density. For light mediator masses (0.2-2) GeV, it can also naturally lead to elastic dark matter selfinteractions at the right level for addressing discrepancies in small structure formation as predicted by collisionless cold dark matter.

show abstract

GeV excess in the Milky Way: The role of diffuse galactic gamma-ray emission templates

Cited by 164 publications

References 52 publications

Neutrino mass, dark matter and anomalous magnetic moment of muon in a U 1 L μ − L τ $$ \mathrm{U}{(1)}_L{{}_{{}_{\mu}}}_{-}{{}_L}_{{}_{\tau }} $$ model

Neutrino mass, dark matter and anomalous magnetic moment of muon in a U 1 L μ − L τ $$ \mathrm{U}{(1)}_L{{}_{{}_{\mu}}}_{-}{{}_L}_{{}_{\tau }} $$ model

Spherical cows in dark matter indirect detection

Multimediator models for the Galactic Center gamma ray excess

Contact Info

Product

Resources

About