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Author Bhattacharya, A.; Esmaili, A.; Palomares-Ruiz, S.; Sarcevic, I.
Title Probing decaying heavy dark matter with the 4-year IceCube HESE data Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal (up) J. Cosmol. Astropart. Phys.
Volume 07 Issue 7 Pages 027 - 36pp
Keywords dark matter theory; neutrino astronomy; neutrino detectors; ultra high energy photons and neutrinos
Abstract After the first four years of data taking, the IceCube neutrino telescope has observed 54 high-energy starting events (HESE) with deposited energies between 20TeV and 2PeV. The background from atmospheric muons and neutrinos is expected to be of about 20 events, all below 100TeV, thus pointing towards the astrophysical origin of about 8 events per year in that data set. However, their precise origin remains unknown. Here, we perform a detailed analysis of this event sample (considering simultaneously the energy, hemisphere and topology of the events) by assuming two contributions for the signal events: an isotropic power-law flux and a flux from decaying heavy dark matter. We fit the mass and lifetime of the dark matter and the normalization and spectral index of an isotropic power-law flux, for various decay channels of dark matter. We find that a significant contribution from dark matter decay is always slightly favored, either to explain the excess below 100TeV, as in the case of decays to quarks or, as in the case of neutrino channels, to explain the three multi-PeV events. Also, we consider the possibility to interpret all the data by dark matter decays only, considering various combinations of two decay channels. We show that the decaying dark matter scenario provides a better fit to HESE data than the isotropic power-law flux.
Address [Bhattacharya, Atri] Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Bat B5a, B-4000 Liege, Belgium, Email: a.bhattacharya@ulg.ac.be;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000406420500009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3243
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Author Bertone, G.; Bozorgnia, N.; Kim, J.S.; Liem, S.; McCabe, C.; Otten, S.; Ruiz de Austri, R.
Title Identifying WIMP dark matter from particle and astroparticle data Type Journal Article
Year 2018 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal (up) J. Cosmol. Astropart. Phys.
Volume 03 Issue 3 Pages 026 - 42pp
Keywords dark matter detectors; dark matter experiments; dark matter theory
Abstract One of the most promising strategies to identify the nature of dark matter consists in the search for new particles at accelerators and with so-called direct detection experiments. Working within the framework of simplified models, and making use of machine learning tools to speed up statistical inference, we address the question of what we can learn about dark matter from a detection at the LHC and a forthcoming direct detection experiment. We show that with a combination of accelerator and direct detection data, it is possible to identify newly discovered particles as dark matter, by reconstructing their relic density assuming they are weakly interacting massive particles (WIMPs) thermally produced in the early Universe, and demonstrating that it is consistent with the measured dark matter abundance. An inconsistency between these two quantities would instead point either towards additional physics in the dark sector, or towards a non-standard cosmology, with a thermal history substantially different from that of the standard cosmological model.
Address [Bertone, Gianfranco; Bozorgnia, Nassim; Liem, Sebastian] Univ Amsterdam, GRAPPA Inst, Inst Theoret Phys Amsterdam, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands, Email: g.bertone@uva.nl;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000427501000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3522
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Author Gelmini, G.B.; Takhistov, V.; Witte, S.J.
Title Casting a wide signal net with future direct dark matter detection experiments Type Journal Article
Year 2018 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal (up) J. Cosmol. Astropart. Phys.
Volume 07 Issue 7 Pages 009 - 55pp
Keywords dark matter detectors; dark matter experiments; dark matter theory
Abstract As dark matter (DM) direct detection experiments continue to improve their sensitivity they will inevitably encounter an irreducible background arising from coherent neutrino scattering. This so-called “neutrino floor” may significantly reduce the sensitivity of an experiment to DM-nuclei interactions, particularly if the recoil spectrum of the neutrino background is approximately degenerate with the DM signal. This occurs for the conventionally considered spin-independent (SI) or spin-dependent (SD) interactions. In such case, an increase in the experiment's exposure by multiple orders of magnitude may not yield any significant increase in sensitivity. The typically considered SI and SD interactions, however, do not adequately reflect the whole landscape of the well-motivated DM models, which includes other interactions. Since particle DM has not been detected yet in laboratories, it is essential to understand and maximize the detection capabilities for a broad variety of possible models and signatures. In this work we explore the impact of the background arising from various neutrino sources on the discovery potential of a DM signal for a large class of viable DM-nucleus interactions and several potential futuristic experimental settings, with different target elements. For some momentum suppressed cross sections, large DM particle masses and heavier targets, we find that there is no suppression of the discovery limits due to neutrino backgrounds. Further, we explicitly demonstrate that inelastic scattering, which could appear in models with multicomponent dark sectors, would help to lift the signal degeneracy associated with the neutrino floor. This study could assist with mapping out the optimal DM detection strategy for the next generation of experiments.
Address [Gelmini, Graciela B.; Takhistov, Volodymyr; Witte, Samuel J.] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA, Email: gelmini@physics.ucla.edu;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000437422800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3646
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Author Arguelles, C.A.; Palomares-Ruiz, S.; Schneider, A.; Wille, L.; Yuan, T.L.
Title Unified atmospheric neutrino passing fractions for large-scale neutrino telescopes Type Journal Article
Year 2018 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal (up) J. Cosmol. Astropart. Phys.
Volume 07 Issue 7 Pages 047 - 41pp
Keywords neutrino detectors; neutrino experiments; ultra high energy photons and neutrinos
Abstract The atmospheric neutrino passing fraction, or self-veto, is defined as the probability for an atmospheric neutrino not to be accompanied by a detectable muon from the same cosmic-ray air shower. Building upon previous work, we propose a redefinition of the passing fractions by unifying the treatment for muon and electron neutrinos. Several approximations have also been removed. This enables performing detailed estimations of the uncertainties in the passing fractions from several inputs: muon losses, cosmic-ray spectrum, hadronic-interaction models and atmosphere-density profiles. We also study the passing fractions under variations of the detector configuration: depth, surrounding medium and muon veto trigger probability. The calculation exhibits excellent agreement with passing fractions obtained from Monte Carlo simulations. Finally, we provide a general software framework to implement this veto technique for all large-scale neutrino observatories.
Address [Arguelle, Carlos A.] MIT, Dept Phys, Cambridge, MA 02139 USA, Email: caad@mit.edu;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000439590200003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3677
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Author Caputo, A.; Regis, M.; Taoso, M.; Witte, S.J.
Title Detecting the stimulated decay of axions at radio frequencies Type Journal Article
Year 2019 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal (up) J. Cosmol. Astropart. Phys.
Volume 03 Issue 3 Pages 027 - 22pp
Keywords axions; dark matter theory; dark matter detectors; dwarfs galaxies
Abstract Assuming axion-like particles account for the entirety of the dark matter in the Universe, we study the possibility of detecting their decay into photons at radio frequencies. We discuss different astrophysical targets, such as dwarf spheroidal galaxies, the Galactic Center and halo, and galaxy clusters. The presence of an ambient radiation field leads to a stimulated enhancement of the decay rate; depending on the environment and the mass of the axion, the effect of stimulated emission may amplify the photon flux by serval orders of magnitude. For axion-photon couplings allowed by astrophysical and laboratory constraints (and possibly favored by stellar cooling), we find the signal to be within the reach of next-generation radio telescopes such as the Square Kilometer Array.
Address [Caputo, Andrea; Witte, Samuel J.] Univ Valencia, CSIC, Inst Fis Corpuscular, Apartado Correos 22085, E-46071 Valencia, Spain, Email: andrea0292@hotmail.it;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000461450100002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3944
Permanent link to this record