Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 37
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Book Description
The Cryogenic Dark Matter Search (CDMS-II) employs low-temperature Ge and Si detectors to seek Weakly Interacting Massive Particles (WIMPs) via their elastic scattering interactions with nuclei. Simultaneous measurements of both ionization and phonon energy provide discrimination against interactions of background particles. For recoil energies above 10 keV, events due to background photons are rejected with> 99.99% efficiency. Electromagnetic events very near the detector surface can mimic nuclear recoils because of reduced charge collection, but these surface events are rejected with> 96% efficiency by using additional information from the phonon pulse shape. Efficient use of active and passive shielding, combined with the 2090 m.w.e. overburden at the experimental site in the Soudan mine, makes the background from neutrons negligible for this first exposure. All cuts are determined in a blind manner from in situ calibrations with external radioactive sources without any prior knowledge of the event distribution in the signal region. Resulting efficiencies are known to (almost equal to)10%. A single event with a recoil of 64 keV passes all of the cuts and is consistent with the expected misidentification rate of surface-electron recoils. Under the assumptions for a standard dark matter halo, these data exclude previously unexplored parameter space for both spin-independent and spin-dependent WIMP-nucleon elastic scattering. The resulting limit on the spin-independent WIMP-nucleon elastic-scattering cross-section has a minimum of 4 x 10−43 cm2 at a WIMP mass of 60 GeV c−2. The minimum of the limit for the spin-dependent WIMP-neutron elastic-scattering cross-section is 2 x 10−37 cm2 at a WIMP mass of 50 GeV c−2.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 37
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Book Description
Author: Kazuharu Bamba
Publisher: MDPI
ISBN: 303921764X
Category : Science
Languages : en
Pages : 236
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Book Description
Various cosmological observations support not only cosmological inflation in the early universe, which is also known as exponential cosmic expansion, but also that the expansion of the late-time universe is accelerating. To explain this phenomenon, the existence of dark energy is proposed. In addition, according to the rotation curve of galaxies, the existence of dark matter, which does not shine, is also suggested. If primordial gravitational waves are detected in the future, the mechanism for realizing inflation can be revealed. Moreover, there exist two main candidates for dark matter. The first is a new particle, the existence of which is predicted in particle physics. The second is an astrophysical object which is not found by electromagnetic waves. Furthermore, there are two representative approaches to account for the accelerated expansion of the current universe. One is to assume the unknown dark energy in general relativity. The other is to extend the gravity theory to large scales. Investigation of the origins of inflation, dark matter, and dark energy is one of the most fundamental problems in modern physics and cosmology. The purpose of this book is to explore the physics and cosmology of inflation, dark matter, and dark energy.
Author: Saranya Samik Ghosh
Publisher: Springer Nature
ISBN: 3030537838
Category : Science
Languages : en
Pages : 77
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Book Description
This primer describes the general model independent searches for new physics phenomena beyond the Standard Model of particle physics. First, the motivation for performing general model independent experimental searches for new physics is presented by giving an overview of the current theoretical understanding of particle physics in terms of the Standard Model of particle physics and its shortcomings. Then, the concept and features of general model independent search for new physics at collider based experiments is explained. This is followed by an overview of such searches performed in past high energy physics experiments and the current status of such searches, particularly in the context of the experiments at the LHC. Finally, the future prospects of such general model independent searches, with possible improvements using new tools such as machine learning techniques, is discussed.
Author: Gianfranco Bertone
Publisher: Cambridge University Press
ISBN: 0521763681
Category : Science
Languages : en
Pages : 763
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Book Description
Describes the dark matter problem in particle physics, astrophysics and cosmology for graduate students and researchers.
Author: Robert Hudson
Publisher: Oxford University Press, USA
ISBN: 0199303282
Category : Education
Languages : en
Pages : 299
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Book Description
In Seeing Things, Robert Hudson argues that robustness reasoning lacks the special value it is often claimed to have. Robustness reasoning claims that an observation report is more likely to be true if the report is produced by multiple, independent sources.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4
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Book Description
We report new results from the Cryogenic Dark Matter Search (CDMS II) at the Soudan Underground Laboratory. Two towers, each consisting of six detectors, were operated for 74.5 live days, giving spectrum-weighted exposures of 34 kg-d for germanium and 12 kg-d for silicon targets after cuts, averaged over recoil energies 10-100 keV for a WIMP mass of 60GeV/c2. A blind analysis was conducted, incorporating improved techniques for rejecting surface events. No WIMP signal exceeding expected backgrounds was observed. When combined with our previous results from Soudan, the 90% C.L. upper limit on the spin-independent WIMP-nucleon cross section is 1.6 x 10−43 cm2 from Ge, and 3 x 10−42 cm2 from Si, for a WIMP mass of 60GeV/c2. The combined limit from Ge (Si) is a factor of 2.5 (10) lower than our previous results, and constrains predictions of supersymmetric models.
Author: Sunil Ramanlal Golwala
Publisher:
ISBN:
Category :
Languages : en
Pages : 544
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Book Description
Author: Biswajit Paul
Publisher:
ISBN:
Category : Materials
Languages : en
Pages : 248
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Book Description
Author: European Organization for Nuclear Research
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 568
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Book Description
This journal is devoted to the latest research on physics, publishing articles on everything from elementary particle behavior to black holes and the history of the universe.
