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Search For Gamma Ray Spectral Lines With The Fermi Large Area Telescope And Dark Matter Implications
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Book Synopsis Search for Gamma-ray Spectral Lines with the Fermi Large Area Telescope and Dark Matter Implications by : Andrea Marie Albert
Download or read book Search for Gamma-ray Spectral Lines with the Fermi Large Area Telescope and Dark Matter Implications written by Andrea Marie Albert and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Measurements indicate that ~85% of the matter in the universe neither emits nor reflects light--appropriately called "dark matter". We believe dark matter may be primary composed of new particles, but we know very little about their nature. What dark matter is and how it interacts is one of the top cosmological mysteries today. Detecting a signal from particle dark matter would not only offer insight into the fundamental nature of dark matter, but it would also be strong evidence for physics existing beyond the Standard Model. A promising dark matter candidate is a weakly interacting massive particle (WIMP). Measurements indicate that the Milky Way Galaxy resides in a halo of dark matter, making it an ideal laboratory for investigating these elusive particles. As WIMPs are predicted to be heavy, their interactions should produce high-energy gamma rays that would be detected by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope (Fermi). If WIMPs annihilate directly into gamma rays, the gamma-ray energy would be the same as the rest mass energy of the WIMPs, which is currently unknown. This process would cause a "pile-up" of gamma rays at a specific energy, producing a sharp line (or bump) in the otherwise relatively smooth gamma-ray energy spectrum. This distinctive signal would not only be strong evidence for the existence of WIMPs, but would also provide information about their mass. We have searched for spectral lines in the energy range 5 to 300 GeV using 3.7 years of Fermi LAT data, reprocessed with updated calorimeter calibration constants, and an improved energy dispersion model from previous LAT Collaboration line searches. We search in five regions selected to optimize sensitivity to different theoretically-motivated density distributions of WIMPs. We do not find any globally significant lines in our a priori search regions and present 95% confidence limits for annihilation cross section and decay lifetimes. We extensively discuss potential systematic effects in the search. Finally, we consider claims of evidence for a spectral line at 130 GeV, compare our results to previous work, and discuss why this search finds a somewhat lower statistical significance for a potential line than other works.
Book Synopsis A Search for Spectral Lines from WIMP Annihilation in the Milky Way Using the Fermi Large Area Telescope by : Yvonne Vasetta Edmonds
Download or read book A Search for Spectral Lines from WIMP Annihilation in the Milky Way Using the Fermi Large Area Telescope written by Yvonne Vasetta Edmonds and published by Stanford University. This book was released on 2011 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most popular class of dark matter candidates is the class of weakly-interacting massive particles (WIMPs). The Fermi Large Area Telescope has the possibility of indirectly detecting WIMPs by the flux from their annihilation/decay products. When a WIMP annihilates or decays directly into a photon gamma and another particle Y the photons are monochromatic. Detection of the resulting spectral line(s) would provide convincing evidence for particulate dark matter and could provide the WIMP mass. In the case of no detection, knowledge of the dark matter distribution can be used to place limits on the annihilation cross section and lifetime for the WIMP(s) to Y-gamma channel. We present the spectrum from 4.8 to 264 GeV and spectral line flux upper limits, obtained from a subset of this spectrum, from 7 to 200 GeV. The spatial region of the dataset covers a large portion of the sky, the high latitudes plus the Galactic Center. We report upper limits on the WIMP cross sections for annihilation to gamma-gamma and Z-gamma and lower limits on the WIMP lifetime for decay to gamma-neutrino. We discuss the implications of the spectrum and line flux limits for several dark matter models with optimistic branching ratios for photon channels.
Book Synopsis Searching for Dark Matter with Cosmic Gamma Rays by : Andrea Albert
Download or read book Searching for Dark Matter with Cosmic Gamma Rays written by Andrea Albert and published by Morgan & Claypool Publishers. This book was released on 2016-09-06 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Indirect Searches for Dark Matter with the Fermi Large Area Telescope by :
Download or read book Indirect Searches for Dark Matter with the Fermi Large Area Telescope written by and published by . This book was released on 2015 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce [gamma] rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for [gamma]-ray spectral lines and [gamma]-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.
Book Synopsis Optimized Dark Matter Searches in Deep Observations of Segue 1 with MAGIC by : Jelena Aleksić
Download or read book Optimized Dark Matter Searches in Deep Observations of Segue 1 with MAGIC written by Jelena Aleksić and published by Springer. This book was released on 2015-11-06 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the results of indirect dark matter searches in the gamma-ray sky of the near Universe, as seen by the MAGIC Telescopes. The author has proposed and led the 160 hours long observations of the dwarf spheroidal galaxy Segue 1, which is the deepest survey of any such object by any Cherenkov telescope so far. Furthermore, she developed and completely characterized a new method, dubbed “Full Likelihood”, that optimizes the sensitivity of Cherenkov instruments for detection of gamma-ray signals of dark matter origin. Compared to the standard analysis techniques, this novel approach introduces a sensitivity improvement of a factor of two (i.e. it requires 4 times less observation time to achieve the same result). In addition, it allows a straightforward merger of results from different targets and/or detectors. By selecting the optimal observational target and combining its very deep exposure with the Full Likelihood analysis of the acquired data, the author has improved the existing MAGIC bounds to the dark matter properties by more than one order of magnitude. Furthermore, for particles more massive than a few hundred GeV, those are the strongest constraints from dwarf galaxies achieved by any gamma-ray instrument, both ground-based or space-borne alike.
Book Synopsis The Search for WIMP Dark Matter Continuum Gamma-ray Emission from Dark Matter Satellites in the Milky Way Using the Fermi LAT by : Wang Ping
Download or read book The Search for WIMP Dark Matter Continuum Gamma-ray Emission from Dark Matter Satellites in the Milky Way Using the Fermi LAT written by Wang Ping and published by Stanford University. This book was released on 2011 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on the search for unknown dark matter (DM) satellites in the Milky Way using the Fermi Large Area Space Telescope (LAT). The Fermi Gamma-ray Space Telescope (Fermi) is a next generation space observatory, which was successfully launched on June 11th, 2008. The LAT is the principal scientific instrument onboard. Its unprecedented angular resolution and sensitivity in the 100 MeV to > 300 GeV energy range makes it an excellent instrument for probing the sky for DM satellites. Current N-body simulations based on the Lambda-CDM cosmology model predict a large number of as yet unobserved DM satellites in our galaxy; some satellites are predicted to be extended sources (> 1deg extension) as seen by the LAT. Our work assumes that a significant component of DM is a Weakly Interacting Massive Particle (WIMP) in the 100 GeV mass range. The annihilation of WIMPs results in many high energy gamma rays that can be well measured by the LAT. The WIMP produced gamma-ray spectrum from the putative DM satellites is considerably harder than most astrophysical sources. Also, DM satellites have no astronomical counterparts in the X-ray and radio bands, and the emission has no time variability. My thesis will focus on a blind analysis in the search for unknown DM satellites using one year of LAT data, and setting constraints on some WIMP models based on the results of our analysis in which we find no candidates.
Book Synopsis A Search for Spectral Lines from WIMP Annihilation in the Milky Way Using the Fermi Large Area Telescope by : Yvonne Vasetta Edmonds
Download or read book A Search for Spectral Lines from WIMP Annihilation in the Milky Way Using the Fermi Large Area Telescope written by Yvonne Vasetta Edmonds and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The most popular class of dark matter candidates is the class of weakly-interacting massive particles (WIMPs). The Fermi Large Area Telescope has the possibility of indirectly detecting WIMPs by the flux from their annihilation/decay products. When a WIMP annihilates or decays directly into a photon gamma and another particle Y the photons are monochromatic. Detection of the resulting spectral line(s) would provide convincing evidence for particulate dark matter and could provide the WIMP mass. In the case of no detection, knowledge of the dark matter distribution can be used to place limits on the annihilation cross section and lifetime for the WIMP(s) to Y-gamma channel. We present the spectrum from 4.8 to 264 GeV and spectral line flux upper limits, obtained from a subset of this spectrum, from 7 to 200 GeV. The spatial region of the dataset covers a large portion of the sky, the high latitudes plus the Galactic Center. We report upper limits on the WIMP cross sections for annihilation to gamma-gamma and Z-gamma and lower limits on the WIMP lifetime for decay to gamma-neutrino. We discuss the implications of the spectrum and line flux limits for several dark matter models with optimistic branching ratios for photon channels.
Book Synopsis Searching for Dark Matter with the ATLAS Detector by : Steven Schramm
Download or read book Searching for Dark Matter with the ATLAS Detector written by Steven Schramm and published by Springer. This book was released on 2016-11-23 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the search for Dark Matter at the LHC in the mono-jet plus missing transverse momentum final state, using the full dataset recorded in 2012 by the ATLAS Experiment. It is the first time that the number of jets is not explicitly restricted to one or two, thus increasing the sensitivity to new signals. Instead, a balance between the most energetic jet and the missing transverse momentum is required, thus selecting mono-jet-like final states. Collider searches for Dark Matter have typically used signal models employing effective field theories (EFTs), even when comparing to results from direct and indirect detection experiments, where the difference in energy scale renders many such comparisons invalid. The thesis features the first robust and comprehensive treatment of the validity of EFTs in collider searches, and provides a means by which the different classifications of Dark Matter experiments can be compared on a sound and fair basis.
Book Synopsis Particles in the Dark Universe by : Yann Mambrini
Download or read book Particles in the Dark Universe written by Yann Mambrini and published by Springer Nature. This book was released on 2021-09-02 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive and instructive coverage of particle physics in the early universe, in a logical way. It starts from the thermal history of the universe by investigating some of the main arguments such as Big Bang nucleosynthesis, the cosmic microwave background (CMB) and the inflation, before treating in details the direct and indirect detection of dark matter and then some aspects of the physics of neutrino. Following, it describes possible candidates for dark matter and its interactions. The book is targeted at theoretical physicists who deal with particle physics in the universe, dark matter detection and astrophysical constraints, and at particle physicists who are interested in models of inflation or reheating. This book offers also material for astrophysicists who work with quantum field theory computations. All that is useful to compute any physical process is included: mathematical tables, all the needed functions for the thermodynamics of early universe and Feynman rules. In light of this, this book acts as a crossroad between astrophysics, particle physics and cosmology.
Book Synopsis Particle Dark Matter by : Gianfranco Bertone
Download or read book Particle Dark Matter written by Gianfranco Bertone and published by Cambridge University Press. This book was released on 2010-01-07 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the dark matter problem in particle physics, astrophysics and cosmology for graduate students and researchers.
Book Synopsis The Search for Dark Matter with the Fermi Gamma Ray Space Telescope by :
Download or read book The Search for Dark Matter with the Fermi Gamma Ray Space Telescope written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fermi Gamma-Ray Space Telescope has been scanning the gamma ray sky since it was launched by NASA in June 2008 and has a mission lifetime goal of 10 years. Largely due to our particle physics heritage, one of the main physics topics being studied by the Fermi LAT Collaboration is the search for dark matter via indirect detection. My talk will review the progress of these studies, something on how the LAT detector enables them, and expectations for the future. I will discuss both gamma-ray and (electron + positron) searches for dark matter, and some resulting theoretical implications.
Book Synopsis The Search for WIMP Dark Matter Continuum Gamma-ray Emission from Dark Matter Satellites in the Milky Way Using the Fermi LAT by : Wang Ping
Download or read book The Search for WIMP Dark Matter Continuum Gamma-ray Emission from Dark Matter Satellites in the Milky Way Using the Fermi LAT written by Wang Ping and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on the search for unknown dark matter (DM) satellites in the Milky Way using the Fermi Large Area Space Telescope (LAT). The Fermi Gamma-ray Space Telescope (Fermi) is a next generation space observatory, which was successfully launched on June 11th, 2008. The LAT is the principal scientific instrument onboard. Its unprecedented angular resolution and sensitivity in the 100 MeV to> 300 GeV energy range makes it an excellent instrument for probing the sky for DM satellites. Current N-body simulations based on the Lambda-CDM cosmology model predict a large number of as yet unobserved DM satellites in our galaxy; some satellites are predicted to be extended sources (> 1deg extension) as seen by the LAT. Our work assumes that a significant component of DM is a Weakly Interacting Massive Particle (WIMP) in the 100 GeV mass range. The annihilation of WIMPs results in many high energy gamma rays that can be well measured by the LAT. The WIMP produced gamma-ray spectrum from the putative DM satellites is considerably harder than most astrophysical sources. Also, DM satellites have no astronomical counterparts in the X-ray and radio bands, and the emission has no time variability. My thesis will focus on a blind analysis in the search for unknown DM satellites using one year of LAT data, and setting constraints on some WIMP models based on the results of our analysis in which we find no candidates.
Book Synopsis Cosmic Rays for Particle and Astroparticle Physics by : S. Giani
Download or read book Cosmic Rays for Particle and Astroparticle Physics written by S. Giani and published by World Scientific. This book was released on 2011 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: The conference was aimed at promoting contacts between scientists involved in solar-terrestrial physics, space physics, astroparticle physics and cosmology both from the theoretical and the experimental approach. The conference was devoted to physics and physics requirements, survey of theoretical models and performances of detectors employed (or to be employed) in experiments for fundamental physics, astroparticle physics, astrophysics research and space environment OCo including Earth magnetosphere and heliosphere and solar-terrestrial physics. Furthermore, cosmic rays have been used to extend the scientific research experience to teachers and students with air shower arrays and other techniques. Presentations included the following subjects: advances in physics from present and next generation ground and space experiments, dark matter, double beta decay, high-energy astrophysics, space environment, trapped particles, propagation of cosmic rays in the Earth atmosphere, Heliosphere, Galaxy and broader impact activities in cosmic rays science. The open and flexible format of the Conference was conducive to fruitful exchanges of points of view among participants and permitted the evaluation of the progresses made and indicated future research directions. The participants were experienced researchers but also graduate students (MSc and PhD) and recent postdoctoral fellows."
Book Synopsis Fermi LAT Search for Dark Matter in Gamma-Ray Lines and the Inclusive Photon Spectrum by :
Download or read book Fermi LAT Search for Dark Matter in Gamma-Ray Lines and the Inclusive Photon Spectrum written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background by :
Download or read book Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background written by and published by . This book was released on 2015 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 ~ 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. As a result, 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.
Book Synopsis From the Fermi Scale to Cosmology by : Alberto Salvio
Download or read book From the Fermi Scale to Cosmology written by Alberto Salvio and published by Frontiers Media SA. This book was released on 2019-12-06 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Advances in Modern and Applied Sciences by : Sujay Pal
Download or read book Advances in Modern and Applied Sciences written by Sujay Pal and published by Scientific Research Publishing, Inc. USA. This book was released on 2022-11-10 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book Advances in Modern and Applied Science materializes our long-cherished dream of publishing a series of volumes consisting of review papers on contemporary research fields from a broad spectrum of basic sciences. The present volume, which is our first baby-step towards that fulfilment, includes a collection of twenty-five review articles contributed by about fifty researchers and scientists whose vocations are in diverse fields of science including astrophysics, astronomy, high energy physics, space science, atmospheric sciences, computer sciences to material sciences.
