2013

2013-12

http://arxiv.org/abs/1312.3945
Combined Flux and Anisotropy Searches Improve Sensitivity to Gamma Rays from Dark Matter

Sheldon S. Campbell and John F. Beacom

A first combined line search with Fermi-LAT would provide powerful new sensitivity; one with the proposed GAMMA-400 would be dramatically better.

For a future instrument such as GAMMA-400 [42], where the expected angular resolution and energy resolution are both improved from Fermi-LAT by a factor of 10 and the effective area is about 5/8 smaller, the improved energy resolution affects both methods similarly, but the improved angular resolution gives added benefit to the anisotropy method. Table I specifies relevant parameters for Fermi-LAT and GAMMA-400.

The presence or absence of the 135 GeV line signal in the 5-year Fermi-LAT DGRB flux and anisotropy data will have interesting consequences for the question of the line's existence. Angular spectrum searches become much more sensitive in a proposed experiment like GAMMA-400.

[42] A.M. Galper, O. Adriani, R.L. Aptekar, I.V. Arkhangelskaja, A.I. Arkhangelskiy, G.A. Avanesov, L. Bergstrom and E.A. Bogomolov et al., arXiv:1306.6175 [astro-ph.IM].

2013-12
RAA 2014 Vol. 14 No. 5, 520–526

http://arxiv.org/abs/1312.0357
The spatial distribution of dark-matter-annihilation originated gamma-ray line signal

Tong-Suo Lu, Tie-Kuang Dong, Jian Wu

The GeV-TeV-ray line signal is the smoking gun signature of the dark matter annihilation or decay. The detection of such a signal is one of the main targets of some space-based telescopes, including Fermi-LAT and the upcoming CALET, DAMPE and Gamma-400.

We use these upper limits to estimate the "maximal" number of -ray line photons detectable for Fermi-LAT, DAMPE and Gamma-400 and then investigate the spatial distribution of these photons.

That's why the detection of such a signal is one of the main targets of some space-based telescopes, including Fermi-LAT and the upcoming CALorimetric Electron Telescope(CALET)(http://calet.phys.lsu.edu ), DArk Matter Particle Explorer (DAMPE) and Gamma-400 (//gamma400.lebedev.ru/indexeng.html).

For example, CALET, DAMPE and Gamma-400, three upcoming spaced-based telescopes with an energy resolution ∼ 1-2% above 100 GeV, may contribute significantly to the γ-ray line search (Li & Yuan 2012; Bergstrom et al. 2012).

2013-11

J. Phys. G: Nucl. Part. Phys. (2014) 41 055006

http://arxiv.org/abs/1311.1164

Testing No-Scale Supergravity with the Fermi Space Telescope LAT Tianjun Li, James A. Maxin, Dimitri V. Nanopoulos, and Joel W. Walker

Regardless of whether the existing marginal 133 GeV gamma ray line eventually is shown to be a systematic or statistical effect, upcoming data from the Fermi Space Telescope (or future projects including Gamma-400, DAMPE and HERD) may provide exclusive insights into the SUSY parameter space in the No-Scale F-SU(5) model.

2013-10

http://arxiv.org/abs/1310.7040

Indirect Dark Matter Detection

CF2 Working Group Summary

J. Buckley, D.F. Cowen, S. Profumo

2013-10

http://arxiv.org/abs/1310.6047

Gamma-ray constraints on dark-matter annihilationto electroweak gauge and Higgs bosons

Michael A. Fedderke, Edward W. Kolb, Tongyan Lin, and Lian-Tao Wang

Looking forward, Ref. [49] indicates that it would be appropriate to consider a factor of 3-5 improvement in the present best limits from the next generation of indirect detection experiments looking at photon uxes (GAMMA-400, CTA, H.E.S.S.-II).

[49] L. Bergstrom, G. Bertone, J. Conrad, C. Farnier, and C. Weniger, (2012), 1207.6773

2013-10

http://arxiv.org/abs/1310.3474

130GeV gamma-ray line through axion conversion

Masato Yamanaka, Kazunori Kohri, Kunihito Ioka, and Mihoko M. Nojiri

Next generation axion search experiments are planned to reach the sensitivity in the near future [80, 81]. Future gamma-ray observations such as H.E.S.S.II, Cherenkov Telescope Array (CTA) or GAMMA-400 will also observe the 130 GeV lines with much better sensitivities and discern a model from others [82, 83].

[80] P. W. Graham and S. Rajendran, Phys. Rev. D 84 (2011) 055013 [arXiv:1101.2691 [hep-ph]].

[81] I. G. Irastorza, F. T. Avignone, S. Caspi, J. M. Carmona, T. Dafni, M. Davenport, A. Dudarev and

G. Fanourakis et al., JCAP 1106 (2011) 013 [arXiv:1103.5334 [hep-ex]].

[82] L. Bergstrom, G. Bertone, J. Conrad, C. Farnier and C. Weniger, JCAP 1211, 025 (2012) [arXiv:1207.6773 [hep-ph]].

[83] C. Weniger, M. Su, D. P. Finkbeiner, T. Bringmann and N. Mirabal, arXiv:1305.4710 [astro-ph.HE].

2013-10
www.pnas.org/cgi/doi/10.1073/pnas.1308728111

http://arxiv.org/abs/1310.2695v1

Indirect Detection of Dark Matter with gamma rays

Stefan Funk

It should be noted, that the planned Russian/Italian space-mission Gamma-400 [102] aims to significantly improve the energy resolution which might be relevant for line searches.

[102] Moiseev, A. A. et al., (2013), Dark Matter Search Perspectives with GAMMA-400, arXiv1307.2345

2013-09

Physica Scripta T158 (2013) 014014
http://arxiv.org/abs/1309.7267v1

Cosmology and the Dark Matter Frontier

L. Bergstrom

At energies, say, below 150 GeV, the Fermi-LAT instrument will in terms of energy resolution be superior to imaging air Cherenkov telescopes like the CTA, which will have its greatest sensitivity in the TeV range. However, new space detectors are currently being planned with a tenfold increase in energy resolution, an example being GAMMA-400 [76], which has a launch from Russia around 2018 approved. It is planned to have a slightly smaller effective area than Fermi-LAT, but with improved angular resolution. It will also have better energy resolution than Fermi-LAT by an order of magnitude. This would take the search for unique gamma-ray signatures of DM to another level of sensitivity. If the present indication of a line signal would persist, it should be seen in GAMMA-400 with a significance of the order of 10? [77]. It turns out, however, that in most models the rate is a factor of 3 - 10 smaller (see, e.g., [74]), but this could still be detectable, over a large energy range. There is also a similar project planned by Chinese scientists [78].

[76] A. A. Moiseev, A. M. Galper, O. Adriani, R. L. Aptekar, I. V. Arkhangelskaja, A. I. Arkhangelskiy, G. A. Avanesov and L. Bergstrom et al., arXiv:1307.2345 [astro-ph.IM].

[77] L. Bergstrom, G. Bertone, J. Conrad, C. Farnier and C. Weniger, JCAP 1211 (2012) 025 [arXiv:1207.6773 [hep-ph]].

[78] Y. Li and Q. Yuan, Phys. Lett. B 715 (2012) 35 [arXiv:1206.2241 [astro-ph.HE]].

2013-07

http://arxiv.org/abs/1307.6480
Scalar Dark Matter Models with Significant Internal Bremsstrahlung
Federica Giacchino, Laura Lopez-Honorez, Michel H.G. Tytgat

2013-07

http://arxiv.org/abs/1307.6434
Indirect Searches for Decaying Dark Matter
Alejandro Ibarra, David Tran, Christoph Weniger
neration instruments like CTA and
Indirect Searches for Decaying Dark Matter
Alejandro Ibarra, David Tran, Christoph Weniger
Next-generation instruments like CTA and GAMMA-400 are expected to improve the limits on gamma-ray lines by up to an order of magnitude within the upcoming ten years or so [168].
[168] L. Bergstrom, G. Bertone, J. Conrad, C. Farnier and C. Weniger, JCAP 1211, 025 (2012), arXiv:1207.6773 [hep-ph].

2013-07
http://arxiv.org/abs/1307.4400
In Wino Veritas? Indirect Searches Shed Light on Neutralino Dark Matter
JiJi Fan and Matthew Reece
Given the reach quoted in a recent look at the prospects for future gamma-ray observatories to detect lines [99], it appears that HESS-II, CTA, and GAMMA-400 will all fall significantly short of the reach needed to exclude thermal pure higgsino dark matter, although they could still set interesting constraints on lighter nonthermal higgsinos.
[99] L. Bergstrom, G. Bertone, J. Conrad, C. Farnier, and C. Weniger, "Investigating Gamma-Ray Lines from Dark Matter with Future Observatories," Journal of Cosmology and Astroparticle Physics 11 (2012) 025, arXiv:1207.6773 [hep-ph].

2013-06
Journal of Cosmology and Astroparticle Physics 12 (2013) 046
http://arxiv.org/abs/arXiv:1306.6342
Internal bremsstrahlung signatures in light of direct dark matter searches
Mathias Garny, Alejandro Ibarra, Miguel Pato and Stefan Vogl

Future gamma-ray telescopes with enhanced energy resolution (such as GAMMA-400 [22] or DAMPE [23]) or with larger effective areas (such as H.E.S.S. II [24], MAGIC-II [25], or CTA [26]) will continue closing in over the next years on the search for the spectral feature of internal bremsstrahlung.
[22] A. Galper, O. Adriani, R. Aptekar, I. Arkhangelskaja, A. Arkhangelskiy, et al., Status of the GAMMA-400 Project, Adv. Space Res. 51 (2013) 297-300, [arXiv:1201.2490].

2013-06

Journal of Cosmology and Astroparticle Physics 09 (2013) 025
http://arxiv.org/abs/1306.4681

Novel Gamma-ray Spectral Features in the Inert Doublet Model

Camilo Garcia-Cely, Alejandro Ibarra

Future instruments, such as DAMPE [58], GAMMA-400 [59] or CTA [60] will, however, close in on the signal of internal bremsstrahlung from the inert doublet model.

Future searches for gamma-ray spectral features by DAMPE, GAMMA-400 or CTA will continue closing in on the parameter space of the inert doublet dark matter model.

[59] A. Galper, O. Adriani, R. Aptekar, I. Arkhangelskaja, A. Arkhangelskiy, et al., Status of the GAMMA-400 Project, Adv. Space Res. 51 (2013) 297-300, [arXiv:1201.2490].

2013-05

http://arxiv.org/abs/1305.2348

Experimental Summary:

Very High Energy Cosmic Rays and their Interactions

Karl-Heinz Kampert

...Similarly, Gamma-400 is planned to be flown on a Russian satellite and will combine for the first time photon and particle (electrons and nuclei) detection aiming at an angular resolution and sensitivity about 5 times better than Fermi-LAT.

2013-04

Physical Review D 88, 043006 (2013)

http://arxiv.org/abs/1304.5524

A Clustering Analysis of the Morphology of the 130 GeV Gamma-Ray Feature

Eric Carlson¹, Tim Linden¹, Stefano Profumo^1;2, and Christoph Weniger³

Present and future observatories have the potential toshed additional light on the presence and characteristicsof the 130 GeV line [79]. Improvements to the H.E.S.S.telescope (H.E.S.S.-II) have reduced the gamma-ray thresholdto around 50 GeV, allowing for the independent determination of a line signal from the GC region. This isespecially important, as the 10⁴ m²collecting area of theH.E.S.S. telescope will quickly alleviate the low-statisticsissues involved in Fermi-LAT studies [60]. Furthermore,future instruments such as Gamma-400 [80] and CTA [81]are likely to provide the necessary effective area andenergy-resolution to definitively and conclusively test theexistence and nature the 130 GeV line feature.

[80] A.M. Galper, O. Adriani, R.L. Aptekar, I.V. Arkhangelskaja, A.I. Arkhangelskiy, M. Boezio, V. Bonvicini, K.A. Boyarchuk, Y.V. Gusakov, M.O. Farber, et al., ArXiv e-prints (2012), 1201.2490.

2013-04

http://arxiv.org/abs/1304.4611

Astrophysical and cosmological problems of invisible mass and dark energy in the Universe

P.Belli, L.A.Berdina, R.Bernabei, A.Bogdan, R.S.Boiko, A.Yu.Burgazli, F.Cappella, R.Cerulli,D.M.Chernyak, F.A.Danevich, A.d'Angelo, M.V.Eingorn, S.H.Fakhr, E.Fedorova,E.N.Galashov, A.Giuliani, B.I.Hnatyk, A.Incicchitti, G.Ivashchenko, V.V.Kobychev,O.O.Kobzar, H.Kraus, B.N.Kropivyansky, A.V.Kudinova, Yu.A.Kulinich, M.Laubenstein, V.V.Marchenko, S.Marnieros, V.B.Mikhailik, A.A.Minakov, V.M.Mokina, L.L.Nagornaya, A.S.Nikolaiko, C.Nones, B.S.Novosyadlyj, E.Olivieri, V.O.Pelykh, D.V.Poda,R.B.Podviyanuk, O.G.Polischuk, O.N.Sergijenko, V.N.Shlegel, V.M.Shulga, V.M.Sliusar,O.B.Sushchov, Y.V.Taistra, M.Tenconi, O.Torbaniuk, V.I.Tretyak, V.S.Tsvetkova,V.G.Vakulik, Ya.V.Vasiliev, A.Vasylenko, O.Vasylenko, V.I.Zhdanov, A.I.Zhuk

Acceleration mechanisms and sources of ultra-high energy cosmic rays (UHECRs) are still unclear. Galactic component is, probably, accelerated in Supernova remnants. Extragalactic component of the observed flux of cosmic rays gives valuable information about the physical conditions in places of acceleration (it's probably active galactic nuclei) and in the intergalactic medium. Recent observational data from detectors HiRes, Auger, Telescope Array on the energy spectrum and chemical composition of UHECRs confirm the theoretically predicted cut-off of energy spectrum at energies above 1019.7 eV (GZK effect), but the chemical composition at the highest energies remains uncertain. This paper presents the results of theoretical modeling of the observed UHECR spectrum and shows that proton model explains all the features of the energy spectrum of cosmic rays in a wide energy range 10¹⁷-10²⁰eV, including the region of transition from galactic to extragalactic component in the total flux of cosmic rays. New results of Supernova remnant investigation are presented. The prospects of using planned space missionsLomonosov (experiment TUS) and GAMMA-400 to establish the nature of UHECRs are discussed (in Ukrainian).

[24]. A.M. Galper et al., The possibilities of simultaneous detection of gamma rays, cosmic-ray electrons and positrons on the GAMMA-400 space observatory, Astrophys. Space Sci. Trans. 7 (2011) 75.

2013-03

http://arxiv.org/abs/1303.4423

Effective Theory of Dark Matter Decay into Monochromatic Photons and its Implications: Constraints from Associated Cosmic-Ray Emission

Michael Gustafsson, Thomas Hambye and TizianaScarna

One of the best "smoking-gun" signals for establishing the existence of an annihilating or decaying dark matter (DM)particle is the possible observation of a cosmic g-ray line [1]. Forthcoming satellites [2] and air Cherenkov telescopes [3-5], but also current instruments like the Fermi large area telescope [6, 7] and the HESS instrument [8, 9], will allow to probe this possibility with further sensitivity.

In this case the A-E lines would lower accordingly. Similarly, Gamma-400 [2] and/or the CTA telescope [3-5] could improve the g-line sensitivities by one order of magnitude depending on the energy range and sky region (see [15] for the case of decaying DM).

[2] A.M. Galper, O. Adriani, R.L. Aptekar, I.V. Arkhangelskaja, A.I. Arkhangelskiy, M. Boezio, V. Bonvicini, K.A. Boyarchuk et al., AIP Conf. Proc. 1516, 288 (2012) [arXiv:1210.1457 [astro-ph.IM]].

2013-03

Physical Review D 87, 123534 (2013)

http://arxiv.org/abs/1303.2384

Gamma Rays from Bino-like Dark Matter in the MSSM

Jason Kumar¹ and Pearl Sandick²

Although this type of analysis is relevant to an understanding of the implications of the Fermi-LAT data, its utility extends beyond that particular observed excess, which may simply be a statistical or systematic effect [9]. Rather, one can consider the implications of the detection of a line signal with future experiments, such as GAMMA-400 [11] or Cherenkov Telescope Array (CTA) [12], or the emergence of such a signal in the data from the Fermi satellite or ground-based gamma-ray detectors such as VERITAS [13] and HESS [14]. The ground-based CTA will have an effective area several orders of magnitude larger than the effective area of space-based telescopes, but will suffer from the background of cosmic ray induced Cherenkov showers. The GAMMA-400 satellite, by contrast is not expected to have a significantly larger effective area than the Fermi-LAT, but it may have much better energy resolution. Here we will assume that relevant experiments can distinguish a true line signal

from a very hard continuum spectrum, as might arise from a three-body annihilation process such as

[11] A.M. Galper, O. Adriani, R.L. Aptekar, I.V. Arkhangelskaja, A.I. Arkhangelskiy, M. Boezio, V. Bonvicini, K.A. Boyarchuk et al., Adv. Space Res. 51, 297 (2013) [arXiv:1201.2490 [astro-ph.IM]];

A.M. Galper, O. Adriani, R.L. Aptekar, I.V. Arkhangelskaja, A.I. Arkhangelskiy, M. Boezio, V. Bonvicini, K.A. Boyarchuk et al., AIP Conf. Proc. 1516, 288 (2012) [arXiv:1210.1457 [astro-ph.IM]].

2013-02

http://arxiv.org/abs/1302.1802

Gamma-ray lines and One-Loop Continuum from s-channel Dark Matter Annihilations

C. B. Jackson^a, GéraldineServant^b,c,d, Gabe Shaughnessy^e, Tim M.P. Tait^f, and Marco Taoso^d,g

We single out very simple models with a large line over continuum ratio and present general predictions for a large range of WIMP masses that are relevant not only for Fermi and Hess II but also for the next generation of telescopes such as CTA and Gamma-400.