206 research outputs found

    Neutrino-less Double Beta Decay and Particle Physics

    Full text link
    We review the particle physics aspects of neutrino-less double beta decay. This process can be mediated by light massive Majorana neutrinos (standard interpretation) or by something else (non-standard interpretations). The physics potential of both interpretations is summarized and the consequences of future measurements or improved limits on the half-life of neutrino-less double beta decay are discussed. We try to cover all proposed alternative realizations of the decay, including light sterile neutrinos, supersymmetric or left-right symmetric theories, Majorons, and other exotic possibilities. Ways to distinguish the mechanisms from one another are discussed. Experimental and nuclear physics aspects are also briefly touched, alternative processes to double beta decay are discussed, and an extensive list of references is provided.Comment: 96 pages, 38 figures. Published versio

    Supersymmetric Origin of Neutrino Mass

    Get PDF
    Supersymmetry with breaking of R-parity provides an attractive way to generate neutrino masses and lepton mixing angles in accordance to present neutrino data. We review the main theoretical features of the bilinear R-parity breaking (BRpV) model, and stress that it is the simplest extension of the minimal supersymmetric standard model (MSSM) which includes lepton number violation. We describe how it leads to a successful phenomenological model with hierarchical neutrino masses. In contrast to seesaw models, the BRpV model can be probed at future collider experiments, like the Large Hadron Collider or the Next Linear Collider, since the decay pattern of the lightest supersymmetric particle provides a direct connection with the lepton mixing angles determined by neutrino experiments.Comment: 21 pages, 8 figures, review for NJP focus issue on neutrino

    Transtorno mental comum entre estudantes de enfermagem e fatores envolvidos

    Get PDF
    Objetivo: Investigar a ocorrência de sintomas indicativos de Transtornos Mentais Comuns entre estudantes de enfermagem e discutir possíveis fatores envolvidos. Métodos: Estudo descritivo, transversal, quantitativo do qual participaram 88 estudantes, com aplicação de questionário autoaplicável sobre questões diárias, seguido do Self-Reporting Questionnaire (SRQ-20). Resultados: A prevalência geral de TMC foi de 41%. Com relação a outras variáveis, foi constatado que a maioria dos estudantes possui atividade profissional, sendo essa geralmente integral na semana. Foi relatado entre os participantes 12,5% de acompanhamento em saúde mental e uso de medicação psicoativa próxima dos 15%, o que pode sugerir automedicação. Conclusão: Os dados aproximam-se de demais pesquisas com metodologias semelhantes e demonstram a importância de se discutir o problema e pensar estratégias que apoiem esses estudantes para melhora geral em seu estado de saúde e rendimento estudantil

    Models of Neutrino Masses and Mixings

    Full text link
    We review theoretical ideas, problems and implications of neutrino masses and mixing angles. We give a general discussion of schemes with three light neutrinos. Several specific examples are analyzed in some detail, particularly those that can be embedded into grand unified theories.Comment: 44 pages, 2 figures, version accepted for publication on the Focus Issue on 'Neutrino Physics' edited by F.Halzen, M.Lindner and A. Suzuki, to be published in New Journal of Physics

    Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF

    Full text link
    The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described

    Structure formation with strongly interacting neutrinos - implications for the cosmological neutrino mass bound

    Full text link
    We investigate a model where neutrinos are strongly coupled to a new, light scalar field. In this model neutrinos annihilate as soon as they become non-relativistic in the early universe, and a non-zero neutrino mass has a marginal effect on the matter power spectrum. However, the angular power spectrum of the cosmic microwave background (CMB) is changed significantly because the strongly interacting fluid of neutrinos and scalars does not experience any anisotropic stress. Such models are strongly disfavoured by current observations. Interestingly, this leads to the conclusion that the relativistic energy density around the epoch of recombination must be in the form of very weakly interacting particles. This conclusion is independent of the specific interaction model.Comment: 15 pages, 9 figures, minor changes, matches JCAP versio

    Comparison of EGFR and K-RAS gene status between primary tumours and corresponding metastases in NSCLC

    Get PDF
    In non-small-cell lung cancer (NSCLC), epidermal growth factor receptor (EGFR) and K-RAS mutations of the primary tumour are associated with responsiveness and resistance to tyrosine kinase inhibitors (TKIs), respectively. However, the EGFR and K-RAS mutation status in metastases is not well studied. We compared the mutation status of these genes between the primary tumours and the corresponding metastases of 25 patients. Epidermal growth factor receptor and K-RAS mutation status was different between primary tumours and corresponding metastases in 7 (28%) and 6 (24%) of the 25 patients, respectively. Among the 25 primary tumours, three ‘hotspot' and two non-classical EGFR mutations were found; none of the corresponding metastases had the same mutation pattern. Among the five (20%) K-RAS mutations detected in the primary tumours, two were maintained in the corresponding metastasis. Epidermal growth factor receptor and K-RAS mutations were detected in the metastatic tumours of three (12%) and five (20%) patients, respectively. The expressions of EGFR and phosphorylated EGFR showed 10 and 50% discordance, in that order. We conclude that there is substantial discordance in EGFR and K-RAS mutational status between the primary tumours and corresponding metastases in patients with NSCLC and this might have therapeutic implications when treatment with TKIs is considered

    Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications

    Get PDF
    Coherent elastic neutrino-nucleus scattering (CEν\nuNS) is a process in which neutrinos scatter on a nucleus which acts as a single particle. Though the total cross section is large by neutrino standards, CEν\nuNS has long proven difficult to detect, since the deposited energy into the nucleus is \sim keV. In 2017, the COHERENT collaboration announced the detection of CEν\nuNS using a stopped-pion source with CsI detectors, followed up the detection of CEν\nuNS using an Ar target. The detection of CEν\nuNS has spawned a flurry of activities in high-energy physics, inspiring new constraints on beyond the Standard Model (BSM) physics, and new experimental methods. The CEν\nuNS process has important implications for not only high-energy physics, but also astrophysics, nuclear physics, and beyond. This whitepaper discusses the scientific importance of CEν\nuNS, highlighting how present experiments such as COHERENT are informing theory, and also how future experiments will provide a wealth of information across the aforementioned fields of physics

    Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications

    Get PDF
    Coherent elastic neutrino-nucleus scattering (CEν\nuNS) is a process inwhich neutrinos scatter on a nucleus which acts as a single particle. Thoughthe total cross section is large by neutrino standards, CEν\nuNS has longproven difficult to detect, since the deposited energy into the nucleus is\sim keV. In 2017, the COHERENT collaboration announced the detection ofCEν\nuNS using a stopped-pion source with CsI detectors, followed up thedetection of CEν\nuNS using an Ar target. The detection of CEν\nuNS hasspawned a flurry of activities in high-energy physics, inspiring newconstraints on beyond the Standard Model (BSM) physics, and new experimentalmethods. The CEν\nuNS process has important implications for not onlyhigh-energy physics, but also astrophysics, nuclear physics, and beyond. Thiswhitepaper discusses the scientific importance of CEν\nuNS, highlighting howpresent experiments such as COHERENT are informing theory, and also how futureexperiments will provide a wealth of information across the aforementionedfields of physics.<br

    Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment

    Full text link
    The Deep Underground Neutrino Experiment (DUNE) will produce world-leading neutrino oscillation measurements over the lifetime of the experiment. In this work, we explore DUNE's sensitivity to observe charge-parity violation (CPV) in the neutrino sector, and to resolve the mass ordering, for exposures of up to 100 kiloton-megawatt-years (kt-MW-yr). The analysis includes detailed uncertainties on the flux prediction, the neutrino interaction model, and detector effects. We demonstrate that DUNE will be able to unambiguously resolve the neutrino mass ordering at a 3σ\sigma (5σ\sigma) level, with a 66 (100) kt-MW-yr far detector exposure, and has the ability to make strong statements at significantly shorter exposures depending on the true value of other oscillation parameters. We also show that DUNE has the potential to make a robust measurement of CPV at a 3σ\sigma level with a 100 kt-MW-yr exposure for the maximally CP-violating values \delta_{\rm CP}} = \pm\pi/2. Additionally, the dependence of DUNE's sensitivity on the exposure taken in neutrino-enhanced and antineutrino-enhanced running is discussed. An equal fraction of exposure taken in each beam mode is found to be close to optimal when considered over the entire space of interest
    corecore