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Related papers: Multiple Gamma Lines from Semi-Annihilation

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Photons produced in the annihilations of dark matter particles can be detected by gamma-ray telescopes; this technique of indirect detection serves as a cornerstone of the upcoming assault on the dark matter paradigm. The main obstacle to…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-08 Eric J. Baxter , Scott Dodelson

We calculate, using unitarity, a lower bound on the branching ratio $\chi\chi\to \gamma\gamma$ and $\chi\chi\to \gamma Z$, where $\chi$ is any halo dark matter particle that has $W^+W^-$ as one of the major annihilation modes. Examples of…

High Energy Physics - Phenomenology · Physics 2010-11-30 L. Bergstrom , J. Kaplan

We search for spectral features in Fermi-LAT gamma-rays coming from regions corresponding to eighteen brightest nearby galaxy clusters determined by the magnitude of their signal line-of-site integrals. We observe a double peak-like excess…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Andi Hektor , Martti Raidal , Elmo Tempel

Detection of gamma rays from dark matter annihilation in the galactic center is one of the feasible techniques to search for dark matter. We evaluate the gamma ray flux in the case that the dark matter has an electroweak SU(2)_L charge.…

High Energy Physics - Phenomenology · Physics 2009-11-10 Junji Hisano , Shigeki. Matsumoto , Mihoko M. Nojiri , Osamu Saito

Decaying or annihilating dark matter particles could be detected through gamma-ray emission from the species they decay or annihilate into. This is usually done by modelling the flux from specific dark matter-rich objects such as the Milky…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-01 Deaglan J. Bartlett , Andrija Kostić , Harry Desmond , Jens Jasche , Guilhem Lavaux

In some scenarios, the dark matter relic abundance is set by the semi-annihilation of two dark matter particles into one dark matter particle and one Standard Model particle. These semi-annihilations might still be occurring today in the…

High Energy Physics - Phenomenology · Physics 2025-04-08 Boris Betancourt Kamenetskaia , Motoko Fujiwara , Alejandro Ibarra , Takashi Toma

Neutralino dark matter can be indirectly detected by observing the gamma ray lines from the annihilation processes XX-->gg and XX-->gZ. In this paper we study the implications that the observation of these two lines could have for the…

High Energy Physics - Phenomenology · Physics 2010-01-08 Carlos E. Yaguna

The gamma-ray excess observed from the Galactic Center can be interpreted as dark matter particles annihilating into Standard Model fermions with a cross section near that expected for a thermal relic. Although many particle physics models…

High Energy Physics - Phenomenology · Physics 2014-08-19 Asher Berlin , Pierre Gratia , Dan Hooper , Samuel D. McDermott

Evidence for an excess of gamma rays with O(GeV) energy coming from the center of our galaxy has been steadily accumulating over the past several years. Recent studies of the excess in data from the Fermi telescope have cast doubt on an…

High Energy Physics - Phenomenology · Physics 2014-10-01 Seyda Ipek , David McKeen , Ann E. Nelson

Dark matter particle annihilation or decay can produce monochromatic gamma-ray lines and contribute to the diffuse gamma-ray background. Flux upper limits are presented for gamma-ray spectral lines from 7 to 200 GeV and for the diffuse…

High Energy Astrophysical Phenomena · Physics 2015-06-05 LAT Collaboration , M. Ackermann , M. Ajello , A. Albert , L. Baldini , G. Barbiellini , K. Bechtol , R. Bellazzini , B. Berenji , R. D. Blandford , E. D. Bloom , E. Bonamente , A. W. Borgland , M. Brigida , R. Buehler , S. Buson , G. A. Caliandro , R. A. Cameron , P. A. Caraveo , J. M. Casandjian , C. Cecchi , E. Charles , A. Chekhtman , J. Chiang , S. Ciprini , R. Claus , J. Cohen-Tanugi , J. Conrad , F. D'Ammando , F. de Palma , C. D. Dermer , E. do Couto e Silva , P. S. Drell , A. Drlica-Wagner , Y. Edmonds , R. Essig , C. Favuzzi , S. J. Fegan , Y. Fukazawa , S. Funk , P. Fusco , F. Gargano , D. Gasparrini , S. Germani , N. Giglietto , F. Giordano , M. Giroletti , T. Glanzman , G. Godfrey , I. A. Grenier , S. Guiriec , M. Gustafsson , D. Hadasch , M. Hayashida , D. Horan , R. E. Hughes , T. Kamae , J. Knödlseder , M. Kuss , J. Lande , A. M. Lionetto , M. Llena Garde , F. Longo , F. Loparco , M. N. Lovellette , P. Lubrano , M. N. Mazziotta , P. F. Michelson , W. Mitthumsiri , T. Mizuno , A. A. Moiseev , C. Monte , M. E. Monzani , A. Morselli , I. V. Moskalenko , S. Murgia , M. Naumann-Godo , J. P. Norris , E. Nuss , T. Ohsugi , A. Okumura , E. Orlando , J. F. Ormes , D. Paneque , J. H. Panetta , M. Pesce-Rollins , F. Piron , G. Pivato , T. A. Porter , D. Prokhorov , S. Rainò , R. Rando , M. Razzano , O. Reimer , M. Roth , C. Sbarra , J. D. Scargle , C. Sgrò , E. J. Siskind , A. Snyder , P. Spinelli , D. J. Suson , H. Takahashi , T. Tanaka , J. G. Thayer , J. B. Thayer , L. Tibaldo , M. Tinivella , D. F. Torres , G. Tosti , E. Troja , J. Vandenbroucke , V. Vasileiou , G. Vianello , V. Vitale , A. P. Waite , B. L. Winer , K. S. Wood , Z. Yang , S. Zimmer

An excess of gamma rays at GeV energies has been detected in the Fermi-LAT data. This signal comes from a narrow region around the Galactic Center and has been interpreted as possible evidence for light (30 GeV) dark matter particles.…

High Energy Astrophysical Phenomena · Physics 2015-01-30 Thomas Lacroix

Dark matter (DM) in the Milky Way halo may annihilate or decay to photons, producing monochromatic gamma rays. We search for DM-induced spectral lines using 14 years of data from the Large Area Telescope onboard the Fermi Gamma-ray Space…

High Energy Physics - Phenomenology · Physics 2023-06-07 Joshua W. Foster , Yujin Park , Benjamin R. Safdi , Yotam Soreq , Weishuang Linda Xu

This study reanalyzes the detection prospects of dark matter (DM) annihilation signals in the Galactic Center, focusing on velocity-dependent dynamics within a spike density near the supermassive black hole (Sgr~A$^{\star}$). We investigate…

High Energy Physics - Phenomenology · Physics 2024-10-25 MeiWen Yang , Zhi-Qi Guo , Xiao-Yi Luo , Zhao-Qiang Shen , Zi-Qing Xia , Chih-Ting Lu , Yue-Lin Sming Tsai , Yi-Zhong Fan

Annihilation of light dark matter of $m_{\rm DM} \approx (10-40)$ GeV into the Standard Model fermions has been suggested as a possible origin of the gamma-ray excess at GeV energies in the Fermi-LAT data. In this paper, we examine possible…

High Energy Physics - Phenomenology · Physics 2015-06-19 Kyoungchul Kong , Jong-Chul Park

There is evidence for a 130 GeV gamma-ray line at the Galactic Center in the Fermi Large Area Telescope data. Dark matter candidates that explain this feature should also annihilate to Standard Model particles, resulting in a continuous…

High Energy Physics - Phenomenology · Physics 2015-06-05 Timothy Cohen , Mariangela Lisanti , Tracy R. Slatyer , Jay G. Wacker

Dark matter decay or annihilation may produce monochromatic signals in the gamma-ray energy range. In this work we argue that there are strong theoretical motivations for studying these signals in the framework of gravitino dark matter…

Using 14 years of Fermi-LAT data and 10 years of H.E.S.S. observations in the direction of the galactic center, we derive limits on gamma-ray lines originated from dark matter annihilations for fermionic and scalar fields. We describe the…

High Energy Physics - Phenomenology · Physics 2026-03-10 Lucia Angel , Guillermo Gambini , Leticia Guedes , Farinaldo S. Queiroz , Vitor de Souza

Cross-correlating the gamma-ray background with local galaxy catalogs potentially gives stringent constraints on dark matter annihilation. We provide updated theoretical estimates of sensitivities to the annihilation cross section from…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-27 Shin'ichiro Ando

A long time ago (in 2014), in galaxies and galaxy clusters far, far away, several groups have reported hints for a yet unidentified line in astrophysical X-ray signals at an energy of 3.5\,keV. While it is not unlikely that this line is…

High Energy Physics - Phenomenology · Physics 2018-02-07 Vedran Brdar , Joachim Kopp , Jia Liu , Xiao-Ping Wang

We study the gamma rays observed by the Fermi Gamma Ray Space Telescope from the direction of the Galactic Center and find that their angular distribution and energy spectrum are well described by a dark matter annihilation scenario. In…

High Energy Physics - Phenomenology · Physics 2009-11-11 Lisa Goodenough , Dan Hooper