We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor similar to 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. We quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals.
Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background / Ackermann M; Ajello M; Albert A; Baldini L; Barbiellini G; Bastieri D; Bechtol K; Bellazzini R; Bissaldi E; Bloom ED; Bonino R; Bregeon J; Bruel P; Buehler R; Buson S; Caliandro GA; Cameron RA; Caragiulo M; Caraveo PA; Cecchi C; Charles E; Chekhtman A; Chiang J; Chiaro G; Ciprini S; Claus R; Cohen-Tanugi J; Conrad J; Cuoco A; Cutini S; DAmmando F; de Angelis A; de Palma F; Dermer CD; Digel SW; Drell PS; Drlica-Wagner A; Favuzzi C; Ferrara EC; Franckowiak A; Fukazawa Y; Funk S; Fusco P; Gargano F; Gasparrini D; Giglietto N; Giordano F; Giroletti M; Godfrey G; Guiriec S; Gustafsson M; Hewitt JW; Hou X; Kamae T; Kuss M; Larsson S; Latronico L; Longo F; Loparco F; Lovellette MN; Lubrano P; Malyshev D; Massaro F; Mayer M; Mazziotta MN; Michelson PF; Mitthumsiri W; Mizuno T; Monzani ME; Morselli A; Moskalenko IV; Murgia S; Negro M; Nemmen R; Nuss E; Ohsugi T; Orienti M; Orlando E; Ormes JF; Paneque D; Perkins JS; Pesce-Rollins M; Piron F; Pivato G; Raino S; Rando R; Razzano M; Reimer A; Reimer O; Sanchez-Conde M; Schulz A; Sgro C; Siskind EJ; Spandre G; Spinelli P; Strong AW; Suson DJ; Tajima H; Takahashi H; Thayer JG; Thayer JB; Tibaldo L; Tinivella M; Torres DF; Troja E; Uchiyama Y; Vianello G; Werner M; Winer BL; Wood KS; Wood M; Zaharijas G. - In: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS. - ISSN 1475-7516. - STAMPA. - 9:(2015), pp. 008.1-008.41. [10.1088/1475-7516/2015/09/008]
Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background
D'AMMANDO, FILIPPO;
2015
Abstract
We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor similar to 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. We quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
