MIMAC-He3: a new detector for non-baryonic dark matter search

The project of a micro-TPC matrix of cells of 3He for direct detection of non-baryonic dark matter is presented. The privileged properties of 3He for this detection are highlighted. The double detection: ionization-projection of tracks is explained and its rejection evaluated. The specific capabilities of this project with respect to other experiments are mentioned and its complementarities concerning the supersymmetric phenomenology explicitly showed.Comment: to appear in Proc. of 5th International Workshop on the Identification of Dark Matter (IDM2004), Sept. 2004, Edinburgh (Scotland

Search for a Dark Matter annihilation signal from the Galactic Center with H.E.S.S.

texte intégral disponible sur http://proc.sf2a.asso.fr/2006/2006sf2a.conf..0171M.pdfInternational audienceThe annihilations of WIMPs that may compose Dark Matter in the Galaxy would produce high energy gamma-rays in the final state. It is shown that the spectrum of the source HESS J1745-290 in the Galactic Center region is unlikely to be interpreted by such a signal. Constraints will be derived on a possible component due to Dark Matter annihilation. Future observations of dwarf spheroidal galaxies are also promising for detecting a possible gamma-ray signal from Dark Matter. The predictions for Sagittarius dwarf spheroidal galaxy in the framework of the supersymmetric and Kaluza-Klein models are also discussed

Projet de détecteur de nouvelle génération pour la recherche de matière sombre non-baryonique : MACHe3, MAtrice à Cellules d'Helium 3 superfluide

MACHe3 est un projet de recherche de matière sombre on-baryonique utilisant l'3He superfluide comme milieu sensible. Les simulations réalisées sur un détecteur granulaire i.e. possédant un grand nombre de cellules, indiquent une très bonne réjection du bruit de fond. L'expérience sur une cellule prototype a mis en évidence la détection des neutrons ainsi que celle des muons cosmiques. Les premiers résultats sur le prototype multi-cellulaire ont permis de valider la détection d'électrons de conversion de basses énergies et confirment la possibilité de signer les événements en coïncidence entre les cellules. Une étude phénoménologique dans le cadre d'un modèle MSSM effectif a été réalisée pour tester la complémentarité de MACHe3 avec les détecteurs de matière sombre existants

Prospects for Annihilating Dark Matter in the inner Galactic halo by the Cherenkov Telescope Array

We compute the sensitivity to dark matter annihilations for the forthcoming large Cherenkov Telescope Array (CTA) in several primary channels and over a range of dark matter masses from 30 GeV up to 80 TeV. For all channels, we include inverse Compton scattering of e$^\pm$ by dark matter annihilations on the ambient photon background, which yields substantial contributions to the overall gamma-ray flux. We improve the analysis over previous work by: i) implementing a spectral and morphological analysis of the gamma-ray emission; ii) taking into account the most up-to-date cosmic ray background obtained from a full CTA Monte Carlo simulation and a description of the diffuse astrophysical emission; and iii) including the systematic uncertainties in the rich observational CTA datasets. We find that our spectral and morphological analysis improves the CTA sensitivity by roughly a factor 2. For the hadronic channels, CTA will be able to probe thermal dark matter candidates over a broad range of masses if the systematic uncertainties in the datasets will be controlled better than the percent level. For the leptonic modes, the CTA sensitivity will be well below the thermal value of the annihilation cross-section. In this case, even with larger systematics, thermal dark matter candidates up to masses of a few TeV will be easily studied.Comment: 15 pages, 4 figures, v2: Jfactors for two different DM profiles in Tab.1 added; two new plots added; some clarifications and some references added; results unchanged; matches version published on Phys. Rev.

Search for primordial black hole dark matter with X-ray spectroscopic and imaging satellite experiments and prospects for future satellite missions

Ultra-light primordial black holes (PBHs) in the mass range of 10$^{16}$ - 10$^{22}$ g are allowed by current observations to constitute a significant fraction, if not all, of the dark matter in the Universe. In this work, we present limits on ultra-light, non-rotating PBHs which arise from the non-detection of the Hawking radiation signals from such objects in the keV-MeV energy band. Namely, we consider observations from the current-generation missions XMM-Newton and INTEGRAL/SPI and discuss the observational perspectives of the future missions Athena, eXTP, and THESEUS for PBH searches. Based on 3.4 Msec total exposure time XMM-Newton observations of Draco dwarf spheroidal galaxy, we conclude that PBH with masses $\lesssim 10^{16}$ g can not make all dark matter at 95% confidence level. Our ON-OFF-type analysis of $>100$ Msec of INTEGRAL/SPI data on the Milky Way halo puts significantly stronger constraints. Only $\lesssim 10$% dark matter can be presented by PBHs with masses $\lesssim 3\cdot 10^{16}$ g while the majority of dark matter can not be represented by PBHs lighter than $7\cdot 10^{16}$ g at 95% confidence level. We discuss the strong impact of systematic uncertainty related to the variations of instrumental and astrophysical INTEGRAL/SPI background on the derived results and estimate its level. We also show that future large-field-of-view missions such as THESEUS/X-GIS will be able to improve the constraints by a factor of 10-100 depending on the level of control under the systematics of these instruments.Comment: To match accepted for publication in Phys. Rev. D. versio

Limits on the Primordial Black Holes Dark Matter with current and future missions

In this proceeding we consider primordial black holes (PBHs) as a dark matter candidate. We discuss the existing limits on the fraction $f_{pbh}$ of the dark matter constituting of PBHs as a function of PBHs mass. The discussed limits cover almost all possible mass range with the currently only open window in $3\cdot 10^{16}-10^{18}$ g in which the PBHs can make up to 100% of the dark matter content of the universe. We present the estimates of the capabilities of the near-future instruments (Einstein Probe/WXT, SVOM/MXT) and discuss the potential of next-generation missions(Athena, THESEUS, eXTP) to probe this mass range. We discuss the targets most suitable for the PBH dark matter searches with these missions and the potential limiting factor of the systematics on the derived results.Comment: to appear in PoS (MULTIF2023

The Cosmic Ray Lepton Puzzle

Recent measurements of cosmic ray electrons and positrons by PAMELA, ATIC, Fermi and HESS have revealed interesting excesses and features in the GeV-TeV range. Many possible explanations have been suggested, invoking one or more nearby primary sources such as pulsars and supernova remnants, or dark matter. Based on the output of the TANGO in PARIS --Testing Astroparticle with the New GeV/TeV Observations in Positrons And electRons : Identifying the Sources-- workshop held in Paris in May 2009, we review here the latest experimental results and we discuss some virtues and drawbacks of the many theoretical interpretations proposed so far.Comment: 6 pages, 3 figures, Extended version of the proceeding of the annual meeting of the French Astronomical & Astrophysical Society (sf2a

Towards the ultimate reach of current Imaging Atmospheric Cherenkov Telescopes to TeV Dark Matter

Indirect detection opens a unique window for probing thermal dark matter (DM): the same annihilation process that determined the relic abundance in the early Universe drives the present day astrophysical signal. While TeV-scale particles weakly coupled to the Standard Model face undoubted challenges from decades of null searches, the scenario remains compelling, and simple realizations such as Higgsino DM remain largely unexplored. The fate of such scenarios could be determined by gamma-ray observations of the centre of the Milky Way with Imaging Atmospheric Cherenkov Telescopes (IACTs). We consider the ultimate sensitivity of current IACTs to a broad range of TeV-scale DM candidates - including specific ones such as the Wino, Higgsino, and Quintuplet. To do so, we use realistic mock H.E.S.S.-like observations of the inner Milky Way halo, and provide a careful assessment of the impact of recent Milky Way mass modeling, instrumental and astrophysical background uncertainties in the Galactic Center region, and the theoretical uncertainty on the predicted signal. We find that the dominant systematic for IACT searches in the inner Galaxy is the unknown distribution of DM in that region, however, beyond this the searches are currently statistically dominated indicating a continued benefit from more observations. For two-body final states at $1~{\rm TeV}$, we find a H.E.S.S.-like observatory is sensitive to $\langle \sigma v \rangle \sim 3 \times 10^{-26}-4 \times 10^{-25}~{\rm cm}^3{\rm s}^{-1}$, except for neutrino final states, although we find results competitive with ANTARES. In addition, the thermal masses for the Wino and Quintuplet can be probed; the Higgsino continues to be out of reach by at least a factor of a few. Our conclusions are also directly relevant to the next generation Cherenkov Telescope Array, which remains well positioned to be the discovery instrument for thermal DM.Comment: 22 pages, 12 figures, 3 tables, including appendi

Gamma ray constraints on Decaying Dark Matter

18 pages, 3 figuresInternational audienceWe derive new bounds on decaying Dark Matter from the gamma ray measurements of (i) the isotropic residual (extragalactic) background by Fermi and (ii) the Fornax galaxy cluster by HESS. We find that those from (i) are among the most stringent constraints currently available, for a large range of DM masses and a variety of decay modes, excluding half-lives up to ~10^26 to few 10^27 seconds. In particular, they rule out the interpretation in terms of decaying DM of the e^\pm spectral features in Pamela, Fermi and HESS, unless very conservative choices are adopted. We also discuss future prospects for CTA bounds from Fornax which, contrary to the present HESS constraints of (ii), may allow for an interesting improvement and may become better than those from the current or future extragalactic Fermi data