3,073 research outputs found

    Beyond Standard Model Searches in the MiniBooNE Experiment

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    29 pages, 18 figures, preprint of an article submitted in Advances in High Energy Physics http://www.hindawi.com/journals/ahep/Janet Conrad thanks the National Science Foundation for support through NSF-PHY-1205175

    Search for Lorentz Violation in km(3)-Scale Neutrino Telescopes

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    Presented at the Seventh Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 20-24, 2016Presented at the Seventh Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 20-24, 2016G.C., C.A., and J.C. are supported by NSF grants 1505858 and 1505855. T.K. is supported by the Science and Technology Facilities Council, UK. A.K. was supported in part by the NSF under grants 0937462 and 1306958 and by the University of Wisconsin Research Committee

    Benchmarking TPB-coated Light Guides for Liquid Argon TPC Light Detection Systems

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    Scintillation light from liquid argon is produced at 128 nm and thus must be shifted to visible wavelengths in light detection systems used for Liquid Argon Time Projection Chambers (LArTPCs). To date, designs have employed tetraphenyl butadiene (TPB) coatings on photomultiplier tubes (PMTs) or plates placed in front of the PMTs. Recently, a new approach using TPB-coated light guides was proposed. In this paper, we show that the response of lightguides coated with TPB in a UV Transmitting (UVT) acrylic matrix is very similar to that of a coating using a polystyrene (PS) matrix. We obtain a factor of three higher light yield than has been previously reported from lightguides. This paper provides information on the response of the lightguides so that these can be modeled in simulations for future LArTPCs. This paper also identifies areas of R&D for potential improvements in the lightguide respons

    Compatibility of neutrino DIS data and global analyses of parton distribution functions

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    Neutrino\antineutrino deep inelastic scattering (DIS) data provide useful constrains for the flavor decomposition in global fits of parton distribution functions (PDF). The smallness of the cross-sections requires the use of nuclear targets in the experimental setup. Understanding the nuclear corrections is, for this reason, of utmost importance for a precise determination of the PDFs. Here, we explore the nuclear effects in the neutrino\antineutrino-nucleon DIS by comparing the NuTeV, CDHSW, and CHORUS cross-sections to the predictions derived from the latest parton distribution functions and their nuclear modifications. We obtain a good description of these data and find no apparent disagreement between the nuclear effects in neutrino DIS and those in charged lepton DIS. These results also indicate that further improvements in the knowledge of the nuclear PDFs could be obtained by a more extensive use of these sets of neutrino data.Comment: 16 pages, 8 figure

    Garden and landscape-scale correlates of moths of differing conservation status: significant effects of urbanization and habitat diversity

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    Moths are abundant and ubiquitous in vegetated terrestrial environments and are pollinators, important herbivores of wild plants, and food for birds, bats and rodents. In recent years, many once abundant and widespread species have shown sharp declines that have been cited by some as indicative of a widespread insect biodiversity crisis. Likely causes of these declines include agricultural intensification, light pollution, climate change, and urbanization; however, the real underlying cause(s) is still open to conjecture. We used data collected from the citizen science Garden Moth Scheme (GMS) to explore the spatial association between the abundance of 195 widespread British species of moth, and garden habitat and landscape features, to see if spatial habitat and landscape associations varied for species of differing conservation status. We found that associations with habitat and landscape composition were species-specific, but that there were consistent trends in species richness and total moth abundance. Gardens with more diverse and extensive microhabitats were associated with higher species richness and moth abundance; gardens near to the coast were associated with higher richness and moth abundance; and gardens in more urbanized locations were associated with lower species richness and moth abundance. The same trends were also found for species classified as increasing, declining and vulnerable under IUCN (World Conservation Union) criteria

    Principles of meiotic chromosome assembly revealed in S. cerevisiae

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    During meiotic prophase, chromosomes organise into a series of chromatin loops emanating from a proteinaceous axis, but the mechanisms of assembly remain unclear. Here we use Saccharomyces cerevisiae to explore how this elaborate three-dimensional chromosome organisation is linked to genomic sequence. As cells enter meiosis, we observe that strong cohesin-dependent grid-like Hi-C interaction patterns emerge, reminiscent of mammalian interphase organisation, but with distinct regulation. Meiotic patterns agree with simulations of loop extrusion with growth limited by barriers, in which a heterogeneous population of expanding loops develop along the chromosome. Importantly, CTCF, the factor that imposes similar features in mammalian interphase, is absent in S. cerevisiae, suggesting alternative mechanisms of barrier formation. While grid-like interactions emerge independently of meiotic chromosome synapsis, synapsis itself generates additional compaction that matures differentially according to telomere proximity and chromosome size. Collectively, our results elucidate fundamental principles of chromosome assembly and demonstrate the essential role of cohesin within this evolutionarily conserved process

    A Proposal for a Near Detector Experiment on the Booster Neutrino Beamline: FINeSSE: Fermilab Intense Neutrino Scattering Scintillator Experiment

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    219 pages219 pagesUnderstanding the quark and gluon substructure of the nucleon has been a prime goal of both nuclear and particle physics for more than thirty years and has led to much of the progress in strong interaction physics. Still the flavor dependence of the nucleon's spin is a significant fundamental question that is not understood. Experiments measuring the spin content of the nucleon have reported conflicting results on the amount of nucleon spin carried by strange quarks. Quasi-elastic neutrino scattering, observed using a novel detection technique, provides a theoretically clean measure of this quantity. The optimum neutrino beam energy needed to measure the strange spin of the nucleon is 1 GeV. This is also an ideal energy to search for neutrino oscillations at high Δm2\Delta m^2 in an astrophysically interesting region. Models of the r-process in supernovae which include high-mass sterile neutrinos may explain the abundance of neutron-rich heavy metals in the universe. These high-mass sterile neutrinos are outside the sensitivity region of any previous neutrino oscillation experiments. The Booster neutrino beamline at Fermilab provides the world's highest intensity neutrino beam in the 0.5-1.0 GeV energy range, a range ideal for both of these measurements. A small detector located upstream of the MiniBooNE detector, 100 m from the recently commissioned Booster neutrino source, could definitively measure the strange quark contribution to the nucleon spin. This detector, in conjunction with the MiniBooNE detector, could also investigate νμ\nu_{\mu} disappearance in a currently unexplored, cosmologically interesting region
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