No Arabic abstract
We briefly review the general insight into the indirect searches of dark matter. We discuss the primary equation in a three-level multimessenger approach (gamma rays, neutrinos and antiprotons), and we introduce the reader to the main topics and related uncertainties (e.g. dark matter density distribution, cosmic rays, particle physics). As an application of the general concept, we focus on the multi-TeV dark matter candidate among other weak interactive massive particles. We present the state-of-the-art on this sub-field, and we discuss open questions and experimental limitations.
It has been shown that the gamma-ray flux observed by HESS from the J1745-290 Galactic Center source is well fitted as the secondary gamma-rays photons generated from Dark Matter annihilating into Standard Model particles in combination with a simple power law background. The neutrino flux expected from such Dark Matter source has been also analyzed. The main results of such analyses for 50 TeV Dark Matter annihilating into W+W- gauge boson and preliminary results for antiprotons are presented.
This is the mini-review on Dark Matter in the 2012 edition of the Particle Data Groups Review of Particle Properties. After briefly summarizing the arguments in favor of the existence of Dark Matter, we list possible candidates, ranging in mass from a fraction of an eV (e.g., axions) to many solar masses (e.g., primordial black holes), and discuss ways to detect them. The main emphasis is on Weakly Interacting Massive Particles (WIMPs). A large international effort is being made to detect them directly, or else to detect their annihilation products. We explain why we consider all claims to have established a positive signal for WIMPs in either direct or indirect detection to be premature. We also introduce the concept of a {it WIMP safe} minimal mass; below this mass, the interpretation of a given direct search experiment depends strongly on the tail of the WIMP velocity distribution and/or on the experimental energy resolution.
Recent rapid progress in multimessenger observations of neutron stars (NSs) offers great potential to constrain the properties of strongly interacting matter under the most extreme conditions. In order to fully exploit the current observational inputs and to study the impact of future observations, we analyze a large ensemble of randomly generated model-independent equations of state (EoSs) and the corresponding rotating stellar structures without the use of quasi-universal relations. We discuss the compatibility and impact of various hypotheses and measurements on the EoS, including those involving the merger product in GW170817, the binary merger components in GW190814, and radius measurements of PSR J0740+6620. We obtain an upper limit for the dimensionless spin of a rigidly rotating NS, |chi| < 0.81, an upper limit for the compactness of a NS, GM/(Rc^2) < 0.33, and find that the conservative hypothesis that the remnant in GW170817 ultimately collapsed to a black hole strongly constrains the EoS and the maximal mass of NSs, implying M_TOV < 2.53M_sol (or M_TOV < 2.19M_sol if we assume that a hypermassive NS was created). Furthermore, we find that the recent NICER results for the radius of the massive PSR J0740+6620 offer strong constraints for the EoS, and that the indicated radius values for a two-solar mass NS greater than about 11 km are completely compatible with the presence of quark matter in massive NSs.
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field-of-view observatory sensitive to 500 GeV - 100 TeV gamma rays and cosmic rays. With its observations over 2/3 of the sky every day, the HAWC observatory is sensitive to a wide variety of astrophysical sources, including possible gamma rays from dark matter. Dark matter annihilation and decay in the Milky Way Galaxy should produce gamma-ray signals across many degrees on the sky. The HAWC instantaneous field-of-view of 2 sr enables observations of extended regions on the sky, such as those from dark matter in the Galactic halo. Here we show limits on the dark matter annihilation cross-section and decay lifetime from HAWC observations of the Galactic halo with 15 months of data. These are some of the most robust limits on TeV and PeV dark matter, largely insensitive to the dark matter morphology. These limits begin to constrain models in which PeV IceCube neutrinos are explained by dark matter which primarily decays into hadrons.
Well-motivated electroweak dark matter is often hosted by an extended electroweak sector which also contains new lepton pairs with masses near the weak scale. In this paper, we explore such electroweak dark matter via combining dark matter direct detections and high-luminosity LHC probes of new lepton pairs. Using $Z$- and $W$-associated electroweak processes with two or three lepton final states, we show that dependent on the overall coupling constant, dark matter mass up to $170-210$ GeV can be excluded at $2sigma$ level and up to $175-205$ GeV can be discovered at $5sigma$ level at the 14 TeV LHC with integrated luminosities 300 fb$^{-1}$ and 3000 fb$^{-1}$, respectively.