Abstract
If a γ-ray line is observed in the near future, it will be important to determine what kind of dark matter (DM) particle could be at its origin. We investigate the possibility that the γ-ray line would be induced by a slow DM particle decay associated to the fact that the DM particle would not be absolutely neutral. A “millicharge” for the DM particle can be induced in various ways, in particular from a kinetic mixing interaction or through the Stueckelberg mechanism. We show that such a scenario could lead in specific cases to an observable γ-ray line. This possibility can be considered in a systematic model-independent way, by writing down the corresponding effective theory. This allows for a multi-channel analysis, giving in particular upper bounds on the intensity of the associated γ-ray line from cosmic rays emission. Our analysis includes the possibility that in the two-body decay the photon is accompanied with a neutrino. We show that, given the stringent constraints which hold on the millicharge of the neutrinos, this is not an option, except if the DM particle mass lies in the very light KeV-MeV range, allowing for a possibility of explanation of the recently claimed, yet to be confirmed, ~ 3.5 KeV X-ray line.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
L. Bergstrom and H. Snellman, Observable Monochromatic Photons From Cosmic Photino Annihilation, Phys. Rev. D 37 (1988) 3737 [INSPIRE].
S. Rudaz, On the Annihilation of Heavy Neutral Fermion Pairs Into Monochromatic gamma-rays and Its Astrophysical Implications, Phys. Rev. D 39 (1989) 3549 [INSPIRE].
A. Bouquet, P. Salati and J. Silk, γ-ray lines as a probe for a cold dark matter halo, Phys. Rev. D 40 (1989) 3168 [INSPIRE].
CTA collaboration, M. Doro et al., Dark Matter and Fundamental Physics with the Cherenkov Telescope Array, Astropart. Phys. 43 (2013) 189 [arXiv:1208.5356] [INSPIRE].
Fermi-LAT collaboration, M. Ackermann et al., Search for Gamma-ray Spectral Lines with the Fermi Large Area Telescope and Dark Matter Implications, Phys. Rev. D 88 (2013) 082002 [arXiv:1305.5597] [INSPIRE].
HESS collaboration, Y. Becherini and M. Punch, Performance of HESS-II in multi-telescope mode with a multi-variate analysis, AIP Conf. Proc. 1505 (2012) 741 [INSPIRE].
E. Dudas, Y. Mambrini, S. Pokorski and A. Romagnoni, Extra U(1) as natural source of a monochromatic gamma ray line, JHEP 10 (2012) 123 [arXiv:1205.1520] [INSPIRE].
M. Gustafsson, T. Hambye and T. Scarna, Effective Theory of Dark Matter Decay into Monochromatic Photons and its Implications: Constraints from Associated Cosmic-Ray Emission, Phys. Lett. B 724 (2013) 288 [arXiv:1303.4423] [INSPIRE].
B. Holdom, Two U(1)’s and Epsilon Charge Shifts, Phys. Lett. B 166 (1986) 196 [INSPIRE].
R. Foot and X.-G. He, Comment on ZZ′ mixing in extended gauge theories, Phys. Lett. B 267 (1991) 509 [INSPIRE].
X. Chu, T. Hambye and M.H.G. Tytgat, The four basic ways of creating dark matter through a portal, JCAP 05 (2012) 034 [arXiv:1112.0493] [INSPIRE].
B. Körs and P. Nath, A Stueckelberg extension of the standard model, Phys. Lett. B 586 (2004) 366 [hep-ph/0402047] [INSPIRE].
D. Feldman, Z. Liu and P. Nath, Probing a very narrow Z′ boson with CDF and D0 data, Phys. Rev. Lett. 97 (2006) 021801 [hep-ph/0603039] [INSPIRE].
G. Shiu, P. Soler and F. Ye, Millicharged Dark Matter in Quantum Gravity and String Theory, Phys. Rev. Lett. 110 (2013) 241304 [arXiv:1302.5471] [INSPIRE].
T. Banks and N. Seiberg, Symmetries and Strings in Field Theory and Gravity, Phys. Rev. D 83 (2011) 084019 [arXiv:1011.5120] [INSPIRE].
J. Redondo and A. Ringwald, Light shining through walls, Contemp. Phys. 52 (2011) 211 [arXiv:1011.3741].
M. Fairbairn et al., Stable massive particles at colliders, Phys. Rept. 438 (2007) 1 [hep-ph/0611040] [INSPIRE].
S. Davidson, S. Hannestad and G. Raffelt, Updated bounds on millicharged particles, JHEP 05 (2000) 003 [hep-ph/0001179] [INSPIRE].
A.A. Prinz et al., Search for millicharged particles at SLAC, Phys. Rev. Lett. 81 (1998) 1175 [hep-ex/9804008] [INSPIRE].
A.D. Dolgov, S.L. Dubovsky, G.I. Rubtsov and I.I. Tkachev, Constraints on millicharged particles from Planck data, Phys. Rev. D 88 (2013) 117701 [arXiv:1310.2376] [INSPIRE].
S.L. Dubovsky and D.S. Gorbunov, Small second acoustic peak from interacting cold dark matter?, Phys. Rev. D 64 (2001) 123503 [astro-ph/0103122] [INSPIRE].
S.D. McDermott, H.-B. Yu and K.M. Zurek, Turning off the Lights: How Dark is Dark Matter?, Phys. Rev. D 83 (2011) 063509 [arXiv:1011.2907] [INSPIRE].
C. Dvorkin, K. Blum and M. Kamionkowski, Constraining Dark Matter-Baryon Scattering with Linear Cosmology, Phys. Rev. D 89 (2014) 023519 [arXiv:1311.2937] [INSPIRE].
N. Fornengo, P. Panci and M. Regis, Long-Range Forces in Direct Dark Matter Searches, Phys. Rev. D 84 (2011) 115002 [arXiv:1108.4661] [INSPIRE].
L. Chuzhoy and E.W. Kolb, Reopening the window on charged dark matter, JCAP 07 (2009) 014 [arXiv:0809.0436] [INSPIRE].
M. Cirelli, N. Fornengo and A. Strumia, Minimal dark matter, Nucl. Phys. B 753 (2006) 178 [hep-ph/0512090] [INSPIRE].
R. Essig, E. Kuflik, S.D. McDermott, T. Volansky and K.M. Zurek, Constraining Light Dark Matter with Diffuse X-Ray and Gamma-Ray Observations, JHEP 11 (2013) 193 [arXiv:1309.4091] [INSPIRE].
ATLAS collaboration, Search for charginos nearly mass degenerate with the lightest neutralino based on a disappearing-track signature in pp collisions at \( \sqrt{s} \) = 8 TeV with the ATLAS detector, Phys. Rev. D 88 (2013) 112006 [arXiv:1310.3675] [INSPIRE].
Particle Data Group collaboration, J. Beringer et al., Review of Particle Physics (RPP), Phys. Rev. D 86 (2012) 010001 [INSPIRE].
ATLAS collaboration, Search for direct production of charginos, neutralinos and sleptons in final states with two leptons and missing transverse momentum in pp collisions at \( \sqrt{s} \) = 8 TeV with the ATLAS detector, JHEP 05 (2014) 071 [arXiv:1403.5294] [INSPIRE].
PAMELA collaboration, O. Adriani et al., PAMELA results on the cosmic-ray antiproton flux from 60 MeV to 180 GeV in kinetic energy, Phys. Rev. Lett. 105 (2010) 121101 [arXiv:1007.0821] [INSPIRE].
Fermi-LAT collaboration, A.A. Abdo et al., The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data, Phys. Rev. Lett. 104 (2010) 101101 [arXiv:1002.3603] [INSPIRE].
A. Albert, Search for Gamma-ray Spectral Lines in the Milky Way Diffuse with the Fermi Large Area Telescope, Fourth International Fermi Symposium, 28 October - 2 November 2012, Monterey, U.S.A., http://fermi.gsfc.nasa.gov/science/mtgs/symposia/2012/program/fri/AAlbert.pdf.
H.E.S.S. collaboration, A. Abramowski et al., Search for photon line-like signatures from Dark Matter annihilations with H.E.S.S, Phys. Rev. Lett. 110 (2013) 041301 [arXiv:1301.1173] [INSPIRE].
M. Cirelli et al., PPPC 4 DM ID: A Poor Particle Physicist Cookbook for Dark Matter Indirect Detection, JCAP 03 (2011) 051 [Erratum ibid. 1210 (2012) E01] [arXiv:1012.4515] [INSPIRE].
D. Feldman, Z. Liu and P. Nath, The Stueckelberg Z-prime Extension with Kinetic Mixing and Milli-Charged Dark Matter From the Hidden Sector, Phys. Rev. D 75 (2007) 115001 [hep-ph/0702123] [INSPIRE].
M. Marinelli and G. Morpurgo, The Electric Neutrality of Matter: A Summary, Phys. Lett. B 137 (1984) 439 [INSPIRE].
J. Baumann, J. Kalus, R. Gahler and W. Mampe, Experimental Limit for the Charge of the Free Neutron, Phys. Rev. D 37 (1988) 3107 [INSPIRE].
S.N. Gninenko, N.V. Krasnikov and A. Rubbia, Search for millicharged particles in reactor neutrino experiments: A Probe of the PVLAS anomaly, Phys. Rev. D 75 (2007) 075014 [hep-ph/0612203] [INSPIRE].
G.G. Raffelt, Limits on neutrino electromagnetic properties: An update, Phys. Rept. 320 (1999) 319 [INSPIRE].
N.F. Bell, A.J. Galea and K. Petraki, Lifetime Constraints for Late Dark Matter Decay, Phys. Rev. D 82 (2010) 023514 [arXiv:1004.1008] [INSPIRE].
M. Frigerio, T. Hambye and E. Masso, Sub-GeV dark matter as pseudo-Goldstone from the seesaw scale, Phys. Rev. X 1 (2011) 021026 [arXiv:1107.4564] [INSPIRE].
E. Bulbul et al., Detection of An Unidentified Emission Line in the Stacked X-ray spectrum of Galaxy Clusters, Astrophys. J. 789 (2014) 13 [arXiv:1402.2301] [INSPIRE].
A. Boyarsky, O. Ruchayskiy, D. Iakubovskyi and J. Franse, An unidentified line in X-ray spectra of the Andromeda galaxy and Perseus galaxy cluster, arXiv:1402.4119 [INSPIRE].
H. Ishida, K.S. Jeong and F. Takahashi, 7 keV sterile neutrino dark matter from split flavor mechanism, Phys. Lett. B 732 (2014) 196 [arXiv:1402.5837] [INSPIRE].
D.P. Finkbeiner and N. Weiner, An X-Ray Line from eXciting Dark Matter, arXiv:1402.6671 [INSPIRE].
T. Higaki, K.S. Jeong and F. Takahashi, The 7 keV axion dark matter and the X-ray line signal, Phys. Lett. B 733 (2014) 25 [arXiv:1402.6965] [INSPIRE].
J. Jaeckel, J. Redondo and A. Ringwald, A 3.55 keV hint for decaying axion-like particle dark matter, Phys. Rev. D 89 (2014) 103511 [arXiv:1402.7335] [INSPIRE].
A. Boyarsky, D. Iakubovskyi and O. Ruchayskiy, Next decade of sterile neutrino studies, Phys. Dark Univ. 1 (2012) 136 [arXiv:1306.4954] [INSPIRE].
C. El Asati, T. Hambye and T. Scarnà, in preparation.
Open Access
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1403.1280
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
El Aisati, C., Hambye, T. & Scarnà, T. Can a millicharged dark matter particle emit an observable γ-ray line?. J. High Energ. Phys. 2014, 133 (2014). https://doi.org/10.1007/JHEP08(2014)133
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP08(2014)133