Author: Elisa FalchiniPublisher:
ISBN:
Category :
Languages : en
Pages : 124
Book Description
AMS-02 Dark Matter Search Inspecting Cosmic Ray Positron Spectrum
Author: Elisa FalchiniIndirect Search for Dark Matter by Measurements of the Cosmic Ray Positron Spectrum with the AMS 02 Experiment
Author: Paolo MaestroMatter, Anti-matter And Dark Matter, Proceedings Of The Second International Workshop
Author: Roberto BattistonPublisher: World Scientific
ISBN: 9814487775
Category : Science
Languages : en
Pages : 269
Book Description
This book presents the progress in cosmic ray physics following the recent results obtained by balloon, satellite and underground experiments. The following topics are reviewed: Composition and propagation of cosmic rays, trapping of charged particles in the earth's magnetic field, atmospheric neutrinos, and high energy photon measurements in space.
Possibility of Testing the Light Dark Matter Hypothesis with the Alpha Magnetic Spectrometer
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 4
Book Description
The spectrum and morphology of gamma-rays from the Galactic Center and the spectrum of synchrotron emission observed from the Milky Way's radio filaments have each been interpreted as possible signals of $\sim$7-10 GeV dark matter particles annihilating in the Inner Galaxy. In dark matter models capable of producing these signals, the annihilations should also generate significant fluxes of $\sim$7-10 GeV positrons which can lead to a distinctive bump-like feature in local cosmic ray positron spectrum. In this letter, we show that while such a feature would be difficult to detect with PAMELA, it would likely be identifiable by the currently operating AMS experiment. As no known astrophysical sources or mechanisms are likely to produce such a sharp feature, the observation of a positron bump at around 7-10 GeV would significantly strengthen the case for a dark matter interpretation of the reported gamma-ray and radio anomalies.
Searching for Dark Matter with Cosmic Gamma Rays
Author: Andrea AlbertPublisher: Morgan & Claypool Publishers
ISBN: 1681742705
Category : Science
Languages : en
Pages : 82
Book Description
Searching for Dark Matter with Cosmic Gamma Rays summarizes the evidence for dark matter and what we can learn about its particle nature using cosmic gamma rays. It has almost been 100 years since Fritz Zwicky first detected hints that most of the matter in the Universe that doesn't directly emit or reflect light. Since then, the observational evidence for dark matter has continued to grow. Dark matter may be a new kind of particle that is governed by physics beyond our Standard Model of particle physics. In many models, dark matter annihilation or decay produces gamma rays. There are a variety of instruments observing the gamma-ray sky from tens of MeV to hundreds of TeV. Some make deep, focused observations of small regions, while others provide coverage of the entire sky. Each experiment offers complementary sensitivity to dark matter searches in a variety of target sizes, locations, and dark matter mass scales. We review results from recent gamma-ray experiments including anomalies some have attributed to dark matter. We also discuss how our gamma-ray observations complement other dark matter searches and the prospects for future experiments.
The Dark Matter Search
Author: Nicolò MasiPublisher:
ISBN: 9783659461385
Category :
Languages : en
Pages : 0
Book Description
Dark Matter Indirect Detection with Charged Cosmic Rays
Author: Gaelle GiesenPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Overwhelming evidence for the existence of Dark Matter (DM), in the form of an unknownparticle filling the galactic halos, originates from many observations in astrophysics and cosmology: its gravitational effects are apparent on galactic rotations, in galaxy clusters and in shaping the large scale structure of the Universe. On the other hand, a non-gravitational manifestation of its presence is yet to be unveiled. One of the most promising techniques is the one of indirect detection, aimed at identifying excesses in cosmic ray fluxes which could possibly be produced by DM annihilations or decays in the Milky Way halo. The current experimental efforts mainly focus in the GeV to TeV energy range, which is also where signals from WIMPs (Weakly Interacting Massive Particles) are expected. Focussing on charged cosmic rays, in particular antiprotons, electrons and positrons, as well as their secondary emissions, an analysis of current and forseen cosmic ray measurements and improvements on astrophysical models are presented. Antiproton data from PAMELA imposes contraints on annihilating and decaying DM which are similar to (or even slightly stronger than) the most stringent bounds from gamma ray experiments, even when kinetic energies below 10 GeV are discarded. However, choosing different sets of astrophysical parameters, in the form of propagation models and halo profiles, allows the contraints to span over one or two orders of magnitude. In order to exploit fully the power of antiprotons to constrain or discover DM, effects which were previously perceived as subleading turn out to be relevant especially for the analysis of the newly released AMS-02 data. In fact, including energy losses, diffusive reaccelleration and solar modulation can somewhat modify the current bounds, even at large DM masses. A wrong interpretation of the data may arise if they are not taken into account. Finally, using the updated proton and helium fluxes just released by the AMS-02 experiment, the astrophysical antiproton to proton ratio and its uncertainties are reevaluated and compared to the preliminarly reported AMS-02 measurements. No unambiguous evidence for a significant excess with respect to expectations is found. Yet, some preference for thicker halos and a flatter energy dependence of the diffusion coefficient starts to emerge. New stringed constraints on DM annihilation and decay are derived. Secondary emissions from electrons and positrons can also be used to constrain DM annihilation or decay in the galactic halo. The radio signal due to synchrotron radiation of electrons and positrons on the galactic magnetic field, gamma rays from bremsstrahlung processes on the galactic gas densities and from Inverse Compton scattering processes on the interstellar radiation field are considered. With several magnetic field configurations, propagation scenarios and improved gas density maps and interstellar radiation field, state-of-art tools allowing the computaion of synchrotron and bremssttrahlung radiation for any WIMP DM model are provided. All numerical results for DM are incorporated in the release of the Poor Particle Physicist Cookbook for DM Indirect Detection (PPPC4DMID). Finally, the possible GeV gamma-ray excess identified in the Fermi-LAT data from the Galactic Center in terms of DM annihilation, either in hadronic or leptonic channels is studied. In order to test this tantalizing interprestation, a multi-messenger approach is used: first, the computation of secondary emisison from DM with respect to previous works confirms it to be relevant for determining the DM spectrum in leptonic channels. Second, limits from antiprotons severely constrain the DM interpretation of the excess in the hadronic channel, for standard assumptions on the Galactic propagation parameters and solar modulation. However, they considerably relax if more conservative choices are adopted.
New Limits on Dark Matter Annihilation from AMS Cosmic Ray Positron Data
Author: Cosmic Rays and Dark Matter
Author: Yasushi MurakiPublisher:
ISBN:
Category : Cosmic rays
Languages : en
Pages : 262
Book Description
A Search for Signatures of Dark Matter in the AMS-01 Electron and Antiproton Spectrum
Author: Gianpaolo Patrick CarosiPublisher:
ISBN:
Category :
Languages : en
Pages : 93
Book Description
If dark matter consists of Weakly Interacting Massive Particles (WIMPs), such as the supersymmetric neutralino, various theories predict that their annihilation in the galaxy can give rise to anomalous features in the otherwise smooth spectra of charged cosmic rays. Up to now searches for these spectral anomalies have focused largely on antiparticles (p, e+) due to their lower astrophysical backgrounds. In this thesis we present results of a search for dark matter annihilation in the charge Z = -1 spectrum of AMS-01 (essentially electrons and antiprotons). To avoid model dependent complications we assume that the primary annihilation channel is through W+W- production. We use the galactic propagation software GALPROP to determine the dark matter spectra at Earth from a smooth isothermal source. Fits to the data did not reveal any contribution from dark matter and limits were placed on the rate of W+W- production in the galaxy and on the corresponding cross-section for WIMP annihilation through the W+W- channel (given a smooth isothermal distribution).