58 research outputs found

    Geotomography with solar and supernova neutrinos

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    We show how by studying the Earth matter effect on oscillations of solar and supernova neutrinos inside the Earth one can in principle reconstruct the electron number density profile of the Earth. A direct inversion of the oscillation problem is possible due to the existence of a very simple analytic formula for the Earth matter effect on oscillations of solar and supernova neutrinos. From the point of view of the Earth tomography, these oscillations have a number of advantages over the oscillations of the accelerator or atmospheric neutrinos, which stem from the fact that solar and supernova neutrinos are coming to the Earth as mass eigenstates rather than flavour eigenstates. In particular, this allows reconstruction of density profiles even over relatively short neutrino path lengths in the Earth, and also of asymmetric profiles. We study the requirements that future experiments must meet to achieve a given accuracy of the tomography of the Earth.Comment: 35 pages, 7 figures; minor textual changes in section

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

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    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV

    Knockdown of Midgut Genes by dsRNA-Transgenic Plant-Mediated RNA Interference in the Hemipteran Insect Nilaparvata lugens

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    BACKGROUND: RNA interference (RNAi) is a powerful technique for functional genomics research in insects. Transgenic plants producing double-stranded RNA (dsRNA) directed against insect genes have been reported for lepidopteran and coleopteran insects, showing potential for field-level control of insect pests, but this has not been reported for other insect orders. METHODOLOGY/PRINCIPAL FINDINGS: The Hemipteran insect brown planthopper (Nilaparvata lugens Stål) is a typical phloem sap feeder specific to rice (Oryza sativa L.). To analyze the potential of exploiting RNAi-mediated effects in this insect, we identified genes (Nlsid-1 and Nlaub) encoding proteins that might be involved in the RNAi pathway in N. lugens. Both genes are expressed ubiquitously in nymphs and adult insects. Three genes (the hexose transporter gene NlHT1, the carboxypeptidase gene Nlcar and the trypsin-like serine protease gene Nltry) that are highly expressed in the N. lugens midgut were isolated and used to develop dsRNA constructs for transforming rice. RNA blot analysis showed that the dsRNAs were transcribed and some of them were processed to siRNAs in the transgenic lines. When nymphs were fed on rice plants expressing dsRNA, levels of transcripts of the targeted genes in the midgut were reduced; however, lethal phenotypic effects after dsRNA feeding were not observed. CONCLUSIONS: Our study shows that genes for the RNAi pathway (Nlsid-1 and Nlaub) are present in N. lugens. When insects were fed on rice plant materials expressing dsRNAs, RNA interference was triggered and the target genes transcript levels were suppressed. The gene knockdown technique described here may prove to be a valuable tool for further investigations in N. lugens. The results demonstrate the potential of dsRNA-mediated RNAi for field-level control of planthoppers, but appropriate target genes must be selected when designing the dsRNA-transgenic plants

    Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

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    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

    Performance of the ATLAS muon trigger in pp collisions at [Formula: see text] TeV

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    The performance of the ATLAS muon trigger system is evaluated with proton-proton collision data collected in 2012 at the Large Hadron Collider at a centre-of-mass energy of 8 TeV. It is primarily evaluated using events containing a pair of muons from the decay of [Formula: see text] bosons. The efficiency of the single-muon trigger is measured for muons with transverse momentum [Formula: see text] GeV, with a statistical uncertainty of less than 0.01 % and a systematic uncertainty of 0.6 %. The [Formula: see text] range for efficiency determination is extended by using muons from decays of [Formula: see text] mesons, [Formula: see text] bosons, and top quarks. The muon trigger shows highly uniform and stable performance. The performance is compared to the prediction of a detailed simulation

    Search for pair and single production of new heavy quarks that decay to a Z boson and a third-generation quark in pp collisions at root s=8 TeV with the ATLAS detector

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    Open Access. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited

    Centrality, rapidity, and transverse momentum dependence of isolated prompt photon production in lead-lead collisions at TeV measured with the ATLAS detector

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    Prompt photon production in sNN=2.76\sqrt{s_{\mathrm{NN}}} = 2.76 TeV Pb+Pb collisions has been measured by the ATLAS experiment at the Large Hadron Collider using data collected in 2011 with an integrated luminosity of 0.14 nb1^{-1}. Inclusive photon yields, scaled by the mean nuclear thickness function, are presented as a function of collision centrality and transverse momentum in two pseudorapidity intervals, η<1.37|\eta| < 1.37 and 1.52<η<2.371.52 < |\eta| < 2.37. The scaled yields in the two pseudorapidity intervals, as well as the ratios of the forward yields to those at midrapidity, are compared to the expectations from next-to-leading order perturbative QCD calculations from JETPHOX. The measured cross sections agree well with the predictions for proton-proton collisions within statistical and systematic uncertainties. Both the yields and ratios are also compared to two other pQCD calculations, one which uses the isospin content appropriate to colliding lead nuclei, and another which includes the EPS09 nuclear modifications to the nucleon parton distribution functions.Comment: 28 pages plus author list (45 pages total), 8 figures, 8 tables, Submitted to Phys. Rev. C., all figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2012-02

    Observation of Associated Near-Side and Away-Side Long-Range Correlations in sqrt[s_{NN}]=5.02  TeV Proton-Lead Collisions with the ATLAS Detector.

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in sqrt[s_{NN}]=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb^{-1} of data as a function of transverse momentum (p_{T}) and the transverse energy (ΣE_{T}^{Pb}) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) "near-side" (Δϕ∼0) correlation that grows rapidly with increasing ΣE_{T}^{Pb}. A long-range "away-side" (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣE_{T}^{Pb}, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣE_{T}^{Pb} dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣE_{T}^{Pb} ranges and particle p_{T}
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