59 research outputs found

    First Results from a Broadband Search for Dark Photon Dark Matter in the 4444 to 52μ52\,\mueV range with a coaxial dish antenna

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    We present first results from a dark photon dark matter search in the mass range from 44 to 52 μeV\mu{\rm eV} (10.712.5GHz10.7 - 12.5\,{\rm GHz}) using a room-temperature dish antenna setup called GigaBREAD. Dark photon dark matter converts to ordinary photons on a cylindrical metallic emission surface with area 0.5m20.5\,{\rm m}^2 and is focused by a novel parabolic reflector onto a horn antenna. Signals are read out with a low-noise receiver system. A first data taking run with 24 days of data does not show evidence for dark photon dark matter in this mass range, excluding dark photon - photon mixing parameters χ1012\chi \gtrsim 10^{-12} in this range at 90% confidence level. This surpasses existing constraints by about two orders of magnitude and is the most stringent bound on dark photons in this range below 49 μ\mueV.Comment: 7 pages, 4 figure

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

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    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

    Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

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    A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

    Searching for Axion and New Forces of Nature

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    Various theories in physics predict the possible existence of new particles in nature. These particles mediate novel forces that are not part of the Standard Model in physics. This talk focuses on some elegant non-accelerator-based techniques that look for these forces and particles, which could solve the long-standing mystery of dark matter

    Experimental constraints on exotic spin-dependent interactions using specialized materials

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    Various theories predict the possible existence of symmetry violating forces with mesoscopic range interactions from mm-m [1]. These forces can arise from the coupling of a spin 0 boson to spin 1/2 fermions through scalar (gs) and pseudoscalar (gp) couplings. We discuss two experiments that can investigate these interactions using nucleon rich, impressively low magnetic susceptibility (5-100 times lower than pure water) test masses and electron-spin rich, polarized test masses (spin density: 10 20 h/cm3 ). The first experiment looks for a P-odd, T-odd interaction potential proportional to (S.r) where S is the spin of one particle and r is the unit vector pointing from the first particle to the second. We use ensembles of polarized nuclei and the unpolarized low magnetic susceptibility masses along with NMR techniques to search for such a potential over sub-mm ranges. We established an improved upper bound on the product gsgnp of the scalar coupling to particles in the unpolarized mass and the pseudoscalar coupling of polarized neutrons for force ranges from 10 -4 to 10 -2 m, corresponding to a mass range of 2*10 -3 to 2*10 -5 eV for the exchange boson [2]. The second experiment proposes to investigate several electron-spin dependent potentials. It will use polarized electron masses as the source of pseudo scalar vertex and double planar 1kHz mechanical oscillators to look for such potentials over the sub-mm range. The projected sensitivity for this experiment surpasses the existing experimental limits for several of the spin dependent interactions by 4-8 orders of magnitude for ranges below 10 -3m [3]

    Broadband solenoidal haloscope for terahertz axion detection

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    We introduce the Broadband Reflector Experiment for Axion Detection (BREAD) conceptual design and science program. This haloscope plans to search for bosonic dark matter across the [ 10 − 3 , 1 ]     eV ([0.24, 240] THz) mass range. BREAD proposes a cylindrical metal barrel to convert dark matter into photons, which a novel parabolic reflector design focuses onto a photosensor. This unique geometry enables enclosure in standard cryostats and high-field solenoids, overcoming limitations of current dish antennas. A pilot 0.7     m 2 barrel experiment planned at Fermilab is projected to surpass existing dark photon coupling constraints by over a decade with one-day runtime. Axion sensitivity requires < 10 − 20     W / √ Hz sensor noise equivalent power with a 10 T solenoid and 10     m 2 barrel. We project BREAD sensitivity for various sensor technologies and discuss future prospects

    Broadband Solenoidal Haloscope for Terahertz Axion Detection

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    We introduce the Broadband Reflector Experiment for Axion Detection (BREAD) conceptual design and science program. This haloscope plans to search for bosonic dark matter across the [10^{-3},1]  eV ([0.24, 240] THz) mass range. BREAD proposes a cylindrical metal barrel to convert dark matter into photons, which a novel parabolic reflector design focuses onto a photosensor. This unique geometry enables enclosure in standard cryostats and high-field solenoids, overcoming limitations of current dish antennas. A pilot 0.7  m^{2} barrel experiment planned at Fermilab is projected to surpass existing dark photon coupling constraints by over a decade with one-day runtime. Axion sensitivity requires <10^{-20}  W/sqrt[Hz] sensor noise equivalent power with a 10 T solenoid and 10  m^{2} barrel. We project BREAD sensitivity for various sensor technologies and discuss future prospects

    Measurement of the charge ratio of atmospheric muons with the CMS detector

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    We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/ c to 1 TeV/ c . The surface flux ratio is measured to be 1.2766±0.0032(stat.)±0.0032(syst.) , independent of the muon momentum, below 100 GeV/ c . This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments.We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c. The surface flux ratio is measured to be 1.2766 \pm 0.0032(stat.) \pm 0.0032 (syst.), independent of the muon momentum, below 100 GeV/c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments

    Transverse-momentum and pseudorapidity distributions of charged hadrons in pppp collisions at s\sqrt{s} = 7 TeV

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    Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at s=7\sqrt{s} = 7~TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit-pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity \dnchdeta|_{|\eta| < 0.5} = 5.78\pm 0.01\stat\pm 0.23\syst for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from s=0.9\sqrt{s} = 0.9 to 7~TeV is 66.1\%\pm 1.0\%\stat\pm 4.2\%\syst. The mean transverse momentum is measured to be 0.545\pm 0.005\stat\pm 0.015\syst\GeVc. The results are compared with similar measurements at lower energies.Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at sqrt(s) = 7 TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit-pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity, dN(charged)/d(eta), for |eta| < 0.5, of 5.78 +/- 0.01 (stat) +/- 0.23 (syst) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from sqrt(s) = 0.9 to 7 TeV is 66.1% +/- 1.0% (stat) +/- 4.2% (syst). The mean transverse momentum is measured to be 0.545 +/- 0.005 (stat) +/- 0.015 (syst) GeV/c. The results are compared with similar measurements at lower energies
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