924 research outputs found

    The hadronic vacuum polarization contribution to aμa_{\mu} from full lattice QCD

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    We determine the contribution to the anomalous magnetic moment of the muon from the αQED2\alpha^2_{\mathrm{QED}} hadronic vacuum polarization diagram using full lattice QCD and including u/du/d quarks with physical masses for the first time. We use gluon field configurations that include uu, dd, ss and cc quarks in the sea at multiple values of the lattice spacing, multiple u/du/d masses and multiple volumes that allow us to include an analysis of finite-volume effects. We obtain a result for aμHVP,LOa_{\mu}^{\mathrm{HVP,LO}} of 667(6)(12)667(6)(12), where the first error is from the lattice calculation and the second includes systematic errors from missing QED and isospin-breaking effects and from quark-line disconnected diagrams. Our result implies a discrepancy between the experimental determination of aμa_{\mu} and the Standard Model of 3σ\sigma.Comment: 14 pages, 10 figures. Discussion of method extended with additional tests and figures added. Typographical errors correcte

    Measuring Active-Sterile Neutrino Oscillations with a Stopped Pion Neutrino Source

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    The question of the existence of light sterile neutrinos is of great interest in many areas of particle physics, astrophysics, and cosmology. Furthermore, should the MiniBooNE experiment at Fermilab confirm the LSND oscillation signal, then new measurements are required to identify the mechanism responsible for these oscillations. Possibilities include sterile neutrinos, CP or CPT violation, variable mass neutrinos, Lorentz violation, and extra dimensions. In this paper, we consider an experiment at a stopped pion neutrino source to determine if active-sterile neutrino oscillations with delta-m greater than 0.1 eV2 can account for the signal. By exploiting stopped pi+ decay to produce a monoenergetic nu_mu source, and measuring the rate of the neutral current reaction nu_x + 12C -> nu_x +12C* as a function of distance from the source, we show that a convincing test for active-sterile neutrino oscillations can be performed.Comment: 10 pages, 9 figure

    Experimental Nephrolithiasis in Rats: The Effect of Ethylene Glycol and Vitamin D3 on the Induction of Renal Calcium Oxalate Crystals

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    Using ethylene glycol (EG) and vitamin D3 as crystal-inducing diet (CID) in rats, we investigated the effect of the dosage of EG on the generation of chronic calcium oxalate (CaOx) nephrolithiasis. We collected weekly 24 hour urines and measured herein the amount of oxalate, calcium, glycosaminoglycans (GAG\u27s), creatinine, protein, alkaline phosphatase (AP), -glutamyl transpeptidase (GT), and N-acetyl--glucosaminidase (NAG). The potential of these urines to inhibit crystal growth and agglomeration was also evaluated. After four weeks, the kidneys were screened by histology and radiography for the presence of CaOx crystals and the amount of kidney-associated oxalate was biochemically measured. Using 0.5 vol.% EG, only a part of the rats showed CaOx deposition in the renal cortex and/or medulla, without obvious differences between Wistar and Sprague-Dawley (SD) rats. If a dietary EG concentration of 0. 75, 1.0. or 1.5 vol.% was used, the amount of kidney-associated oxalate was proportionally higher and CaOx crystal formation was consistently found in all rats. Most crystals were encountered in the cortex, whereas in the medulla and the papillary region, crystals were only occasionally detected. From these data, we conclude that in the chronic rat model, based on EG and vitamin D3, a consistent deposition of CaOx crystals is obtained using a EG concentration of at least 0.75%

    Monitoring and evaluating capacity building activities in low and middle income countries: challenges and opportunities.

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    BACKGROUND: Lower and middle income countries (LMICs) are home to >80% of the global population, but mental health researchers and LMIC investigator led publications are concentrated in 10% of LMICs. Increasing research and research outputs, such as in the form of peer reviewed publications, require increased capacity building (CB) opportunities in LMICs. The National Institute of Mental Health (NIMH) initiative, Collaborative Hubs for International Research on Mental Health reaches across five regional 'hubs' established in LMICs, to provide training and support for emerging researchers through hub-specific CB activities. This paper describes the range of CB activities, the process of monitoring, and the early outcomes of CB activities conducted by the five research hubs. METHODS: The indicators used to describe the nature, the monitoring, and the early outcomes of CB activities were developed collectively by the members of an inter-hub CB workgroup representing all five hubs. These indicators included but were not limited to courses, publications, and grants. RESULTS: Results for all indicators demonstrate a wide range of feasible CB activities. The five hubs were successful in providing at least one and the majority several courses; 13 CB recipient-led articles were accepted for publication; and nine grant applications were successful. CONCLUSIONS: The hubs were successful in providing CB recipients with a wide range of CB activities. The challenge remains to ensure ongoing CB of mental health researchers in LMICs, and in particular, to sustain the CB efforts of the five hubs after the termination of NIMH funding

    Pollen-Mediated Gene Flow from Genetically Modified Herbicide Resistant Creeping Bentgrass

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    Approximately 162 ha of multiple experimental fields of creeping bentgrass (Agrostis stolonifera L.) genetically modified for resistance to Roundup ®herbicide, were planted in central Oregon in 2002. When the fields flowered for the first time in the summer of 2003, a unique opportunity was presented to evaluate methods to monitor potential pollen-mediated gene flow from the experimental GM crop fields to compatible sentinel and resident plants that were located in surrounding, primarily non-agronomic areas

    A Letter of Intent to Build a MiniBooNE Near Detector: BooNE

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    There is accumulating evidence for a difference between neutrino and antineutrino oscillations at the 1\sim 1 eV2^2 scale. The MiniBooNE experiment observes an unexplained excess of electron-like events at low energies in neutrino mode, which may be due, for example, to either a neutral current radiative interaction, sterile neutrino decay, or to neutrino oscillations involving sterile neutrinos and which may be related to the LSND signal. No excess of electron-like events (0.5±7.8±8.7-0.5 \pm 7.8 \pm 8.7), however, is observed so far at low energies in antineutrino mode. Furthermore, global 3+1 and 3+2 sterile neutrino fits to the world neutrino and antineutrino data suggest a difference between neutrinos and antineutrinos with significant (sin22θμμ35\sin^22\theta_{\mu \mu} \sim 35%) νˉμ\bar \nu_\mu disappearance. In order to test whether the low-energy excess is due to neutrino oscillations and whether there is a difference between νμ\nu_\mu and νˉμ\bar \nu_\mu disappearance, we propose building a second MiniBooNE detector at (or moving the existing MiniBooNE detector to) a distance of 200\sim 200 m from the Booster Neutrino Beam (BNB) production target. With identical detectors at different distances, most of the systematic errors will cancel when taking a ratio of events in the two detectors, as the neutrino flux varies as 1/r21/r^2 to a calculable approximation. This will allow sensitive tests of oscillations for both νe\nu_e and νˉe\bar \nu_e appearance and νμ\nu_\mu and νˉμ\bar \nu_\mu disappearance. Furthermore, a comparison between oscillations in neutrino mode and antineutrino mode will allow a sensitive search for CP and CPT violation in the lepton sector at short baseline (Δm2>0.1\Delta m^2 > 0.1 eV2^2).Comment: 43 pages, 40 figure

    The OscSNS White Paper

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    There exists a need to address and resolve the growing evidence for short-baseline neutrino oscillations and the possible existence of sterile neutrinos. Such non-standard particles require a mass of 1\sim 1 eV/c2^2, far above the mass scale associated with active neutrinos, and were first invoked to explain the LSND νˉμνˉe\bar \nu_\mu \rightarrow \bar \nu_e appearance signal. More recently, the MiniBooNE experiment has reported a 2.8σ2.8 \sigma excess of events in antineutrino mode consistent with neutrino oscillations and with the LSND antineutrino appearance signal. MiniBooNE also observed a 3.4σ3.4 \sigma excess of events in their neutrino mode data. Lower than expected neutrino-induced event rates using calibrated radioactive sources and nuclear reactors can also be explained by the existence of sterile neutrinos. Fits to the world's neutrino and antineutrino data are consistent with sterile neutrinos at this 1\sim 1 eV/c2^2 mass scale, although there is some tension between measurements from disappearance and appearance experiments. In addition to resolving this potential major extension of the Standard Model, the existence of sterile neutrinos will impact design and planning for all future neutrino experiments. It should be an extremely high priority to conclusively establish if such unexpected light sterile neutrinos exist. The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, built to usher in a new era in neutron research, provides a unique opportunity for US science to perform a definitive world-class search for sterile neutrinos.Comment: This white paper is submitted as part of the SNOWMASS planning proces
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