55 research outputs found

    First simultaneous optical/near-infrared imaging of an X-ray selected, high-redshift cluster of galaxies with GROND: the galaxy population of XMMU J0338.7+0030 at z=1.1

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    The XMM-Newton Distant Cluster Project is a serendipitous survey for clusters of galaxies at redshifts z>=0.8 based on deep archival XMM-Newton observations. ... Low-significance candidate high-z clusters are followed up with the seven-channel imager GROND (Gamma-Ray Burst Optical and Near-Infrared Detector) that is mounted at a 2m-class telescope. ... The test case is XMMU J0338.7+0030, suggested to be at z~1.45+/-0.15 from the analysis of the z-H vs H colour-magnitude diagram obtained from the follow-up imaging. Later VLT-FORS2 spectroscopy enabled us to identify four members, which set this cluster at z=1.097+/-0.002. To reach a better knowledge of its galaxy population, we observed XMMU J0338.7+0030 with GROND for about 6 hr. The publicly available photo-z code le Phare was used. The Ks-band number counts of the non-stellar sources out of the 832 detected down to z'~26 AB-mag in the 3.9x4.3 square arcmin region of XMMU J0338.7+0030 imaged at all GROND bands clearly exceed those computed in deep fields/survey areas at ~20.5 - 22.5 AB-mag. The photo-z's of the three imaged spectroscopic members yield z=1.12+/-0.09. The spatial distribution and the properties of the GROND sources with a photo-z in the range 1.01 - 1.23 confirm the correspondence of the X-ray source with a galaxy over-density at a significance of at least 4.3 sigma. Candidate members that are spectro-photometrically classified as elliptical galaxies define a red locus in the i'-z' vs z' colour-magnitude diagram that is consistent with the red sequence of the cluster RDCS J0910+5422 at z=1.106. XMMU J0338.7+0030 hosts also a population of bluer late-type spirals and irregulars. The starbursts among the photometric members populate both loci, consistently with previous results. The analysis of the available data set indicates that XMMU J0338.7+0030 is a low-mass cluster (M_200 ~ 1E14 M_sun) at z=1.1. (Abridged)Comment: accepted for publication in Astronomy & Astrophysics Main Journal, 27 pages, 24 figures, 1 tabl

    Optical and Infrared Photometry of the Nearby Type Ia Supernovae 1999ee, 2000bh, 2000ca, and 2001ba

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    We present near infrared photometry of the Type Ia supernova 1999ee; also, optical and infrared photometry of the Type Ia SNe 2000bh, 2000ca, and 2001ba. For SNe 1999ee and 2000bh we present the first-ever SN photometry at 1.035 microns (the Y-band). We present K-corrections which transform the infrared photometry in the observer's frame to the supernova rest frame. Using our infrared K-corrections and stretch factors derived from optical photometry, we construct JHK templates which can be used to determine the apparent magnitudes at maximum if one has some data in the window -12 to +10 d with respect to T(B_max). Following up previous work on the uniformity of V minus IR loci of Type Ia supernovae of mid-range decline rates, we present unreddened loci for slow decliners. We also discuss evidence for a continuous change of color at a given epoch as a function of decline rate.Comment: 53 pages, 14 figures, to be published in the March 2004 issue of the Astronomical Journa

    Comparison of two modes of vitamin B12 supplementation on neuroconduction and cognitive function among older people living in Santiago, Chile: a cluster randomized controlled trial. a study protocol [ISRCTN 02694183]

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    BACKGROUND: Older people have a high risk of vitamin B12 deficiency; this can lead to varying degrees of cognitive and neurological impairment. CBL deficiency may present as macrocytic anemia, subacute combined degeneration of the spinal cord, or as neuropathy, but is often asymptomatic in older people. Less is known about subclinical vitamin B12 deficiency and concurrent neuroconduction and cognitive impairment. A Programme of Complementary Feeding for the Older Population (PACAM) in Chile delivers 2 complementary fortified foods that provide approximately 1.4 μg/day of vitamin B12 (2.4 μg/day elderly RDA). The aim of the present study is to assess whether supplementation with vitamin B12 will improve neuroconduction and cognitive function in older people who have biochemical evidence of vitamin B12 insufficiency in the absence of clinical deficiency. METHODS: We designed a cluster double-blind placebo-controlled trial involving community dwelling people aged 70-79 living in Santiago, Chile. We randomized 15 clusters (health centers) involving 300 people (20 per cluster). Each cluster will be randomly assigned to one of three arms: a) a 1 mg vitamin B12 pill taken daily and a routine PACAM food; b) a placebo pill and the milk-PACAM food fortified to provide 1 mg of vitamin B12; c) the routine PACAM food and a placebo pill.The study has been designed as an 18 month follow up period. The primary outcomes assessed at baseline, 4, 9 and 18 months will be: serum levels of vitamin B12, neuroconduction and cognitive function. CONCLUSIONS: In view of the high prevalence of vitamin B12 deficiency in later life, the present study has potential public health interest because since it will measure the impact of the existing program of complementary feeding as compared to two options that provide higher vitamin B12 intakes that might potentially may contribute in preserving neurophysiologic and cognitive function and thus improve quality of life for older people in Chile. TRIAL REGISTRATION: ISRCTN: ISRCTN02694183

    Anti-tumour necrosis factor discontinuation in inflammatory bowel disease patients in remission: study protocol of a prospective, multicentre, randomized clinical trial

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    Background: Patients with inflammatory bowel disease who achieve remission with anti-tumour necrosis factor (anti-TNF) drugs may have treatment withdrawn due to safety concerns and cost considerations, but there is a lack of prospective, controlled data investigating this strategy. The primary study aim is to compare the rates of clinical remission at 1?year in patients who discontinue anti-TNF treatment versus those who continue treatment. Methods: This is an ongoing, prospective, double-blind, multicentre, randomized, placebo-controlled study in patients with Crohn?s disease or ulcerative colitis who have achieved clinical remission for ?6?months with an anti-TNF treatment and an immunosuppressant. Patients are being randomized 1:1 to discontinue anti-TNF therapy or continue therapy. Randomization stratifies patients by the type of inflammatory bowel disease and drug (infliximab versus adalimumab) at study inclusion. The primary endpoint of the study is sustained clinical remission at 1?year. Other endpoints include endoscopic and radiological activity, patient-reported outcomes (quality of life, work productivity), safety and predictive factors for relapse. The required sample size is 194 patients. In addition to the main analysis (discontinuation versus continuation), subanalyses will include stratification by type of inflammatory bowel disease, phenotype and previous treatment. Biological samples will be obtained to identify factors predictive of relapse after treatment withdrawal. Results: Enrolment began in 2016, and the study is expected to end in 2020. Conclusions: This study will contribute prospective, controlled data on outcomes and predictors of relapse in patients with inflammatory bowel disease after withdrawal of anti-TNF agents following achievement of clinical remission. Clinical trial reference number: EudraCT 2015-001410-1

    Long-baseline neutrino oscillation physics potential of the DUNE experiment

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    The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to neutrino oscillation is determined, based on a full simulation, reconstruction, and event selection of the far detector and a full simulation and parameterized analysis of the near detector. Detailed uncertainties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE will resolve the neutrino mass ordering to a precision of 5σ, for all ΑCP values, after 2 years of running with the nominal detector design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3σ (5σ) after an exposure of 5 (10) years, for 50% of all ΑCP values. It will also make precise measurements of other parameters governing long-baseline neutrino oscillation, and after an exposure of 15 years will achieve a similar sensitivity to sin22θ13 to current reactor experiments

    First results on ProtoDUNE-SP liquid argon time projection chamber performance from a beam test at the CERN Neutrino Platform

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    The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber with an active volume of 7.2× 6.1× 7.0 m3. It is installed at the CERN Neutrino Platform in a specially-constructed beam that delivers charged pions, kaons, protons, muons and electrons with momenta in the range 0.3 GeV/c to 7 GeV/c. Beam line instrumentation provides accurate momentum measurements and particle identification. The ProtoDUNE-SP detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment, and it incorporates full-size components as designed for that module. This paper describes the beam line, the time projection chamber, the photon detectors, the cosmic-ray tagger, the signal processing and particle reconstruction. It presents the first results on ProtoDUNE-SP\u27s performance, including noise and gain measurements, dE/dx calibration for muons, protons, pions and electrons, drift electron lifetime measurements, and photon detector noise, signal sensitivity and time resolution measurements. The measured values meet or exceed the specifications for the DUNE far detector, in several cases by large margins. ProtoDUNE-SP\u27s successful operation starting in 2018 and its production of large samples of high-quality data demonstrate the effectiveness of the single-phase far detector design

    Long-baseline neutrino oscillation physics potential of the DUNE experiment

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    The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to neutrino oscillation is determined, based on a full simulation, reconstruction, and event selection of the far detector and a full simulation and parameterized analysis of the near detector. Detailed uncertainties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE will resolve the neutrino mass ordering to a precision of 5σ, for all δ_(CP) values, after 2 years of running with the nominal detector design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3σ (5σ) after an exposure of 5 (10) years, for 50% of all δ_(CP) values. It will also make precise measurements of other parameters governing long-baseline neutrino oscillation, and after an exposure of 15 years will achieve a similar sensitivity to sin²θ₁₃ to current reactor experiments

    Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment

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    The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE’s sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach

    Experiment Simulation Configurations Approximating DUNE TDR

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    The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment consisting of a high-power, broadband neutrino beam, a highly capable near detector located on site at Fermilab, in Batavia, Illinois, and a massive liquid argon time projection chamber (LArTPC) far detector located at the 4850L of Sanford Underground Research Facility in Lead, South Dakota. The long-baseline physics sensitivity calculations presented in the DUNE Physics TDR, and in a related physics paper, rely upon simulation of the neutrino beam line, simulation of neutrino interactions in the near and far detectors, fully automated event reconstruction and neutrino classification, and detailed implementation of systematic uncertainties. The purpose of this posting is to provide a simplified summary of the simulations that went into this analysis to the community, in order to facilitate phenomenological studies of long-baseline oscillation at DUNE. Simulated neutrino flux files and a GLoBES configuration describing the far detector reconstruction and selection performance are included as ancillary files to this posting. A simple analysis using these configurations in GLoBES produces sensitivity that is similar, but not identical, to the official DUNE sensitivity. DUNE welcomes those interested in performing phenomenological work as members of the collaboration, but also recognizes the benefit of making these configurations readily available to the wider community.Comment: 15 pages, 6 figures, configurations in ancillary files, v2 corrects a typ

    Prospects for Beyond the Standard Model Physics Searches at the Deep Underground Neutrino Experiment

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    The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach
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