141 research outputs found

    Nuclear aspects of neutral current non-standard ν\nu-nucleus reactions and the role of the exotic μe\mu^-\to e^{-} transitions experimental limits

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    The nuclear aspects of flavour changing neutral current (FCNC) processes, predicted by various new-physics models to occur in the presence of nuclei, are examined by computing the relevant nuclear matrix elements within the context of the quasi-particle RPA using realistic strong two-body forces. One of our aims is to explore the role of the non-standard interactions (NSI) in the leptonic sector and specifically: (i) in lepton flavour violating (LFV) processes involving the neutral particles ν\nu_\ell and ν~\tilde{\nu}_\ell, =e,μ,τ\ell = e,\mu,\tau and (ii) in charged lepton flavour violating (cLFV) processes involving the charged leptons \ell^- or +\ell^+. As concrete nuclear systems we have chosen the stopping targets of μe\mu^-\rightarrow e^- conversion experiments, i.e. the 48Ti^{48}\mathrm{Ti} nucleus of the PRIME/PRISM experiment at J-PARC and the 27Al^{27}\mathrm{Al} of the COMET at J-PARC as well as of the Mu2e at Fermilab. These experiments have been designed to reduce the single event sensitivity down to 101610^{-16}--101810^{-18} in searching for charged lepton mixing events. Our goal is, by taking advantage of our detailed nuclear structure calculations and using the present limits or the sensitivity of the aforementioned exotic μe\mu^- \rightarrow e^- experiments, to put stringent constraints on the parameters of NSI Lagrangians.Comment: 8 pages, 4 figures, 3 Tables, Physics Letters B accepte

    Neutrino transition magnetic moments within the non-standard neutrino-nucleus interactions

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    Tensorial non-standard neutrino interactions are studied through a combined analysis of nuclear structure calculations and a sensitivity χ2\chi^2-type of neutrino events expected to be measured at the COHERENT experiment, recently planned to operate at the Spallation Neutron Source (Oak Ridge). Potential sizeable predictions on transition neutrino magnetic moments and other electromagnetic parameters, such as neutrino milli-charges, are also addressed. The non-standard neutrino-nucleus processes, explored from nuclear physics perspectives within the context of quasi-particle random phase approximation, are exploited in order to estimate the expected number of events originating from vector and tensor exotic interactions for the case of reactor neutrinos, studied with TEXONO and GEMMA neutrino detectors.Comment: 7 pages, 6 Figures, 2 Tables, Accepted for publication to Physics Letters

    Constraining nuclear physics parameters with current and future COHERENT data

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    Motivated by the recent observation of coherent elastic neutrino-nucleus scattering (CEν\nu NS) at the COHERENT experiment, our goal is to explore its potential in probing important nuclear structure parameters. We show that the recent COHERENT data offers unique opportunities to investigate the neutron nuclear form factor. Our present calculations are based on the deformed Shell Model (DSM) method which leads to a better fit of the recent CEν\nu NS data, as compared to known phenomenological form factors such as the Helm-type, symmetrized Fermi and Klein-Nystrand. The attainable sensitivities and the prospects of improvement during the next phase of the COHERENT experiment are also considered and analyzed in the framework of two upgrade scenarios.Comment: 13 pages, 5 figures, 2 tables; v2: minor corrections, version to appear in PL

    Gonadal abnormalities in frogs (\u3ci\u3eLithobates\u3c/i\u3e spp.) collected from managed wetlands in an agricultural region of Nebraska, USA

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    Nebraska’s Rainwater Basin (RWB) provides important wetland habitat for North American migratory birds. Concern exists that pesticide and nutrient runoff from surrounding row-crops enters wetlands degrading water quality and adversely affecting birds and wildlife. Frogs may be especially vulnerable. Plains leopard (Lithobates blairi) metamorphs from RWB wetlands with varying concentrations of pesticides were evaluated for a suite of biomarkers of exposure to endocrine active chemicals. Froglets had ovarian dysgenesis, high rates of testicular oocytes, and female-biased sex ratios however, there was no clear statistical association between pesticide concentrations and biomarkers. Data interpretation was hindered because timing and duration of exposures were unknown and due to an incomplete understanding of L. blairi sexual development. Emphasis is on describing the complex developmental biology of closely-related leopard frogs, how this understanding can explain RWB L. blairi anomalies, and the need for sampling at the appropriate life stage

    Facilitating mental health research for patients, clinicians and researchers: a mixed-method study

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    OBJECTIVES: Research registers using Consent for Contact (C4C) can facilitate recruitment into mental health research studies, allowing investigators to contact patients based on clinical records information. We investigated whether such a register was useful for mental health research, seeking the perspectives of patients and research investigators. SETTING AND DESIGN: In 2012, a C4C register was developed in a large secondary mental health provider within the UK; almost 9000 patients have joined. This mixed-method study audited the effectiveness of the register. PARTICIPANTS: A 'mystery shopper' exercise was conducted, and patients (n=21) were recruited to ask clinicians about the availability of research opportunities. Structured interviews were conducted with patients (n=52) about their experiences of being on the register. Similar interviews were conducted with 18 investigators from 19 studies, who had attempted to use the register to recruit participants. OUTCOME MEASURES: The impact of C4C on study recruitment, and whether it helped patients learn about research. RESULTS: So far, the register has provided 928 individuals with 1085 research opportunities (in 60% of cases, the individual agreed to participate in the study). Clinicians were willing to link patients to research opportunities, but often lacked information about studies. For patients, the register provided opportunities which they may not otherwise have; 27 of 52 had participated in studies since joining the register (18 participating for the first time). Most investigators used the register to supplement recruitment to their studies, but described problems in prescreening potential participants from a clinical record for complex studies. CONCLUSIONS: Although the register helped investigators recruit for studies, and provided patients with research opportunities, clinicians' input is still useful for identifying suitable participants. C4C registers should be adapted to provide clinicians with automatically updated information on local studies allowing them to match patients on their caseload with active studies

    Novel neutrino-floor and dark matter searches with deformed shell model calculations

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    Event detection rates for WIMP-nucleus interactions are calculated for 71^{71}Ga, 73^{73}Ge, 75^{75}As and 127^{127}I (direct dark matter detectors). The nuclear structure form factors, that are rather independent of the underlying beyond the Standard Model particle physics scenario assumed, are evaluated within the context of the deformed nuclear shell model (DSM) based on Hartree-Fock nuclear states. Along with the previously published DSM results for 73^{73}Ge, the neutrino-floor due to coherent elastic neutrino-nucleus scattering (CEν\nuNS), an important source of background to dark matter searches, is extensively calculated. The impact of new contributions to CEν\nuNS due to neutrino magnetic moments and ZZ^\prime mediators at direct dark matter detection experiments is also examined and discussed. The results show that the neutrino-floor constitutes a crucial source of background events for multi-ton scale detectors with sub-keV capabilities.Comment: 16 pages, 12 figures, 3 Tables; 1 figure and 1 table added; references added; matches published versio

    Widespread occurrence of intersex in black basses (\u3ci\u3eMicropterus\u3c/i\u3e spp.) from U.S. rivers, 1995–2004

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    Intersex occurrence in freshwater fishes was evaluated for nine river basins in the United States. Testicular oocytes (predominantly male testes containing female germ cells) were the most pervasive form of intersex observed, even though similar numbers of male (n = 1477) and female (n = 1633) fish were examined. Intersex was found in 3% of the fish collected. The intersex condition was observed in four of the 16 species examined (25%) and in fish from 34 of 111 sites (31%). Intersex was not found in multiple species from the same site but was most prevalent in largemouth bass (Micropterus salmoides; 18% of males) and smallmouth bass (M. dolomieu; 33% of males). The percentage of intersex fish per site was 8–91% for largemouth bass and 14–73% for smallmouth bass. The incidence of intersex was greatest in the southeastern United States, with intersex largemouth bass present at all sites in the Apalachicola, Savannah, and Pee Dee River Basins. Total mercury, trans-nonachlor, p,p\u27-DDE, p,p\u27-DDD, and total PCBs were the most commonly detected chemical contaminants at all sites, regardless of whether intersex was observed. Although the genotype of the intersex fish was not determined, the microscopic appearance of the gonads, the presence of mature sperm, and the concentrations of sex steroid hormones and vitellogenin indicate the intersex bass were males. Fewre productive endpoints differed significantly among male and intersex bass; plasma vitellogenin concentration in males was not a good indicator of intersex presence. Hierarchical linkages of the intersex condition to reproductive function will require a more quantitative measure of intersex (e.g. severity index) rather than presence or absence of the condition. The baseline incidence of intersex gonadal tissue in black basses and other freshwater fishes is unknown, but intersex prevalence may be related to collection season, age, and endocrine active compounds in the environment. Intersex was not found in largemouth bass older than five years and was most common in 1–3-year-old male largemouth bass. The cause(s) of intersex in these species is also unknown, and it remains to be determined whether the intersex we observed in largemouth and smallmouth bass developed during sex differentiation in early life stages, during exposure to environmental factors during adult life stages, or both
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