86 research outputs found

    Asymmetric relativistic Fermi gas model for quasielastic lepton-nucleus scattering

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    We develop an asymmetric relativistic Fermi gas model for the study of the electroweak nuclear response in the quasielastic region. The model takes into account the differences between neutron and proton densities in asymmetric (N>Z) nuclei, as well as differences in the neutron and proton separation energies. We present numerical results for both neutral and charged-current processes, focusing on nuclei of interest for ongoing and future neutrino oscillation experiments. We point out some important differences with respect to the commonly employed symmetric Fermi gas model.University of Turin BARM-RILO-17Junta de Andalucía FQM160Spanish Ministerio de Economía y Competitividad and ERDF (European Regional Development Fund) FIS2014-53448-C2-1, FIS2017-88410-

    Charged-current quasielastic neutrino scattering cross sections on 12 C with realistic spectral and scaling functions

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    Charge-current quasielastic (anti)neutrino scattering cross sections on a 12C target are analyzed using a spectral function S(p,E) that gives a scaling function in accordance with the (e,e′) scattering data. The spectral function accounts for the nucleon-nucleon (NN) correlations, it has a realistic energy dependence, and natural orbitals (NOs) from the Jastrow correlation method are used in its construction. In all calculations the standard value of the axial mass MA=1.032 GeV/c2 is used. The results are compared with those when NN correlations are not included, as in the relativistic Fermi gas model, or when harmonic-oscillator single-particle wave functions are used instead of NOs. The role of the final-state interactions (FSIs) on the theoretical spectral and scaling functions, as well as on the cross sections, is accounted for. A comparison of the results for the cases with and without FSI, as well as to results from the phenomenological scaling function obtained from the superscaling analysis, is carried out. Our calculations based on the impulse approximation underpredict the MiniBooNE data but agree with the data from the NOMAD experiment. The possible missing ingredients in the considered theoretical models are discussed.DGI y FEDER FIS2011-28738-C02-01 FPA2010-17142Junta de AndalucíaPrograma Consolider-Ingenio 2000 CSD2007-0004

    Constraints in modeling the quasielastic response in inclusive lepton-nucleus scattering

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    We show that the quasielastic (QE) response calculated with the superscaling approach (SuSAv2) model, that relies on the scaling phenomenon observed in the analysis of (e,e′) data and on the relativistic mean-field theory, is very similar to that from a relativistic distorted-wave impulse approximation model when only the real part of the optical potentials is employed. The coincidence between the results from these two completely independent approaches, which satisfactorily agree with the inclusive data, reinforces the reliability of the quasielastic predictions stemming from both models and sets constraints for the QE response. We also study the low-energy and momentum-transfer region of the inclusive response by confronting the results of the relativistic mean-field model with those of the Hartree-Fock continuum random-phase approximation model, which accounts for nuclear long-range correlations. Finally, we present a comparison of our results with the recent Jefferson Laboratory (JLab) (e,e′) data for argon, titanium, and carbon, finding good agreement with the three data sets.Spanish Ministerio de Economia y Competitividad and European Regional Development Fund) FIS2017-88410-PJunta de Andalucia FQM 160, SOMM17/6105/UGRConsolider-Ingenio 2000 program CPAN (CSD2007-0042)Spanish Government (FPA2015-65035P and RTI2018-098868-B-I00

    Justice and Global Environment Challenges:The Promises of Benefit-Sharing

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    Neutral current quasielastic (anti)neutrino scattering cross sections on a C12 target are analyzed using a realistic spectral function S(p,E) that gives a scaling function in accordance with the (e,e′) scattering data. The spectral function accounts for the nucleon-nucleon (NN) correlations by using natural orbitals from the Jastrow correlation method and has a realistic energy dependence. The standard value of the axial mass MA=1.032 GeV is used in all calculations. The effect of the final-state interaction on the spectral and scaling functions, as well as on the cross sections, is accounted for. A comparison of the calculations with the empirical data of the MiniBooNE and BNL experiments is performed. Our results are analyzed in comparison with those when NN correlations are not included and, also, with results from other theoretical approaches, such as the relativistic Fermi gas, the relativistic mean field, and the relativistic Green's function, as well as with the SuperScaling Approach based on the analysis of quasielastic electron scattering.DGI y FEDER FIS2011-28738-C02-01 FPA2013-41267Junta de AndalucíaPrograma Consolider-Ingenio 2000 CSD2007-0004

    Imprint of DES superstructures on the cosmic microwave background

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    Small temperature anisotropies in the cosmic microwave background (CMB) can be sourced by density perturbations via the late-time integrated Sachs-Wolfe (ISW) effect. Large voids and superclusters are excellent environments to make a localized measurement of this tiny imprint. In some cases excess signals have been reported. We probed these claims with an independent data set, using the first year data of the Dark Energy Survey (DES) in a different footprint, and using a different superstructure finding strategy. We identified 52 large voids and 102 superclusters at redshifts 0.2 < z < 0.65. We used the Jubilee simulation to a priori evaluate the optimal ISW measurement configuration for our compensated top-hat filtering technique, and then performed a stacking measurement of the CMB temperature field based on the DES data. For optimal configurations, we detected a cumulative cold imprint of voids with DeltaTf ≈ -5.0 ± 3.7 muK and a hot imprint of superclusters DeltaTf ≈ 5.1 ± 3.2 muK; this is ˜1.2sigma higher than the expected |DeltaTf| ≈ 0.6 muK imprint of such superstructures in Lambda cold dark matter (LambdaCDM). If we instead use an a posteriori selected filter size (R/Rv = 0.6), we can find a temperature decrement as large as DeltaTf ≈ -9.8 ± 4.7 muK for voids, which is ˜2sigma above LambdaCDM expectations and is comparable to previous measurements made using Sloan Digital Sky Survey superstructure data

    Small Bowel Enteroscopy - A Joint Clinical Guideline by the Spanish and Portuguese Small-Bowel Study Groups

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    The present evidence-based guidelines are focused on the use of device-assisted enteroscopy in the management of small-bowel diseases. A panel of experts selected by the Spanish and Portuguese small-bowel study groups reviewed the available evidence focusing on the main indications of this technique, its role in the management algorithm of each indication, and its diagnostic and therapeutic yield. A set of recommendations was issued accordingly.info:eu-repo/semantics/publishedVersio

    Search for Gamma-Ray and Neutrino Coincidences Using HAWC and ANTARES Data

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    In the quest for high-energy neutrino sources, the Astrophysical Multimessenger Observatory Network (AMON) has implemented a new search by combining data from the High Altitude Water Cherenkov (HAWC) observatory and the Astronomy with a Neutrino Telescope and Abyss environmental RESearch (ANTARES) neutrino telescope. Using the same analysis strategy as in a previous detector combination of HAWC and IceCube data, we perform a search for coincidences in HAWC and ANTARES events that are below the threshold for sending public alerts in each individual detector. Data were collected between July 2015 and February 2020 with a livetime of 4.39 years. Over this time period, 3 coincident events with an estimated false-alarm rate of <1< 1 coincidence per year were found. This number is consistent with background expectations.Comment: 12 pages, 5 figures, 3 table

    Small bowel enteroscopy - A joint clinical guideline from the spanish and portuguese small bowel study groups

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    The present evidence-based guidelines are focused on the use of device-assisted enteroscopy in the management of small-bowel diseases. A panel of experts selected by the Spanish and Portuguese small bowel study groups reviewed the available evidence focusing on the main indications of this technique, its role in the management algorithm of each indication and on its diagnostic and therapeutic yields. A set of recommendations were issued accordingly.Estas recomendações baseadas na evidência detalham o uso da enteroscopia assistida por dispositivo no manejo clínico das doenças do intestino delgado. Um conjunto de Gastrenterologistas diferenciados em patologia do intestino delgado foi selecionado pelos grupos de estudos Espanhol e Português de intestino delgado para rever a evidência disponível sobre as principais indicações desta técnica, o seu papel nos algoritmos de manejo de cada indicação e sobre o seu rendimento diagnóstico e terapêutico. Foi gerado um conjunto de recomendações pelos autores

    EUSO-SPB1 mission and science

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    The Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) was launched in 2017 April from Wanaka, New Zealand. The plan of this mission of opportunity on a NASA super pressure balloon test flight was to circle the southern hemisphere. The primary scientific goal was to make the first observations of ultra-high-energy cosmic-ray extensive air showers (EASs) by looking down on the atmosphere with an ultraviolet (UV) fluorescence telescope from suborbital altitude (33 km). After 12 days and 4 h aloft, the flight was terminated prematurely in the Pacific Ocean. Before the flight, the instrument was tested extensively in the West Desert of Utah, USA, with UV point sources and lasers. The test results indicated that the instrument had sensitivity to EASs of ⪆ 3 EeV. Simulations of the telescope system, telescope on time, and realized flight trajectory predicted an observation of about 1 event assuming clear sky conditions. The effects of high clouds were estimated to reduce this value by approximately a factor of 2. A manual search and a machine-learning-based search did not find any EAS signals in these data. Here we review the EUSO-SPB1 instrument and flight and the EAS search

    Neutrino Target-of-Opportunity Observations with Space-based and Suborbital Optical Cherenkov Detectors

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    Cosmic-ray accelerators capable of reaching ultra-high energies are expected to also produce very-high energy neutrinos via hadronic interactions within the source or its surrounding environment. Many of the candidate astrophysical source classes are either transient in nature or exhibit flaring activity. Using the Earth as a neutrino converter, suborbital and space-based optical Cherenkov detectors, such as EUSO-SPB2 and POEMMA, will be able to detect upward-moving extensive air showers induced by decay tau-leptons generated from cosmic tau neutrinos with energies ∼10 PeV and above. Both EUSO-SPB2 and POEMMA will be able to quickly repoint, enabling rapid response to astrophysical transient events. we calculate the transient sensitivity and sky coverage for both EUSO-SPB2 and POEMMA, accounting for constraints imposed by the Sun and the Moon on the observation time. We also calculate both detectors\u27 neutrino horizons for a variety of modeled astrophysical neutrino fluences. We find that both EUSO-SPB2 and POEMMA will achieve transient sensitivities at the level of modeled neutrino fluences for nearby sources. We conclude with a discussion of the prospects of each mission detecting at least one transient event for various modeled astrophysical neutrino sources
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