17,649 research outputs found

    Is simultaneous yy and ξ\xi--scaling in the quasi-elastic region accidental?

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    We study the yy and ξ\xi--scaling of the nuclear response at large momentum transfer in order to understand how scaling based on very different descriptions of the elementary interaction can occur simultaneously. We find that the approximate validity of ξ\xi-scaling at low energy loss arises from the coincidental behavior of the quasielastic and deep inelastic cross sections.Comment: 4 pages, 3 Postscript figure

    Superconducting On-chip Fourier Transform Spectrometer

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    The kinetic inductance effect is strongly nonlinear with applied current in NbTiN, TiN and NbN thin films. This can be utilized to realize novel devices. We present results from transmission lines made with these materials, where DC (current) control is used to modulate the phase velocity thereby enabling on-chip spectrometers. Utility of such compact spectrometers is discussed, along with their natural connection with parametric amplifiers

    Measurement of the SOC State Specific Heat in ^4He

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    When a heat flux Q is applied downward through a sample of liquid 4He near the lambda transition, the helium self organizes such that the gradient in temperature matches the gravity induced gradient in Tlambda. All the helium in the sample is then at the same reduced temperature tSOC = ((T[sub SOC] - T[sub lambda])/T[sub lambda]) and the helium is said to be in the Self-Organized Critical (SOC) state. We have made preliminary measurements of the 4He SOC state specific heat, C[del]T(T(Q)). Despite having a cell height of 2.54 cm, our results show no difference between C[del]T and the zero-gravity 4He specific heat results of the Lambda Point Experiment (LPE) [J.A. Lipa et al., Phys. Rev. B, 68, 174518 (2003)] over the range 250 to 450 nK below the transition. There is no gravity rounding because the entire sample is at the same reduced temperature tSOC(Q). Closer to Tlambda the SOC specific heat falls slightly below LPE, reaching a maximum at approximately 50 nK below Tlambda, in agreement with theoretical predictions [R. Haussmann, Phys. Rev. B, 60, 12349 (1999)]

    "He was distraught, I was distraught.." Parents' experiences of accessing emergency care following an avulsion injury to their child

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    Objective To explore how parents access emergency care for their children following avulsion of a permanent tooth. Method Semi-structured qualitative interviews were undertaken with parents of children who had suffered a tooth avulsion injury in the previous two years. The interviews were recorded and transcribed verbatim. Framework analysis was used to analyse the data and interpret the core concepts from the interviews. Results Nine parents participated in the study. None of the children received the appropriate emergency dental care within the timeframe identified by national and international guidelines. The core themes that emerged following the analysis were knowledge, access and emotion. Discussion & Conclusions The parents who were interviewed for this study had poor knowledge of what to do in the event of a tooth avulsion injury. This lack of knowledge directly impaired their ability to navigate emergency dental care for their child. They described their upset and distress following their child's injury, but also feelings of frustration and disappointment in relation to the emergency care their child received. There is a need to develop appropriate support and clinical pathways to enable parents to rapidly access appropriate and timely care for their child following a complex dental trauma

    Position and energy-resolved particle detection using phonon-mediated microwave kinetic inductance detectors

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    We demonstrate position and energy-resolved phonon-mediated detection of particle interactions in a silicon substrate instrumented with an array of microwave kinetic inductance detectors (MKIDs). The relative magnitude and delay of the signal received in each sensor allow the location of the interaction to be determined with ≲ 1mm resolution at 30 keV. Using this position information, variations in the detector response with position can be removed, and an energy resolution of σ_E = 0.55 keV at 30 keV was measured. Since MKIDs can be fabricated from a single deposited film and are naturally multiplexed in the frequency domain, this technology can be extended to provide highly pixelized athermal phonon sensors for ∼1 kg scale detector elements. Such high-resolution, massive particle detectors would be applicable to rare-event searches such as the direct detection of dark matter, neutrinoless double-beta decay, or coherent neutrino-nucleus scattering

    Research into the Impact of School Leadership on Pupil Outcomes: Policy and Research Contexts

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    This paper extends the introduction to the authors’ study of successful school leadership and how it influences pupil outcomes begun in the Editorial introduction. Critical to an appreciation especially of the external validity of their results is an understanding of the policy context in which the English leaders in their study found themselves; this is a policy context dominated by concerns for external accountability and increases in the academic performance of pupils. In addition to describing this context, the paper summarises the conceptual and methodological framework that guided the early stage of their research and outlines their mixed-methods research design

    Development of microwave superconducting microresonators for neutrino mass measurement in the HOLMES framework

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    The European Research Council has recently funded HOLMES, a project with the aim of performing a calorimetric measurement of the electron neutrino mass measuring the energy released in the electron capture decay of 163Ho. The baseline for HOLMES are microcalorimeters coupled to Transition Edge Sensors (TESs) read out with rf-SQUIDs, for microwave multiplexing purposes. A promising alternative solution is based on superconducting microwave resonators, that have undergone rapid development in the last decade. These detectors, called Microwave Kinetic Inductance Detectors (MKIDs), are inherently multiplexed in the frequency domain and suitable for even larger-scale pixel arrays, with theoretical high energy resolution and fast response. The aim of our activity is to develop arrays of microresonator detectors for X-ray spectroscopy and suitable for the calorimetric measurement of the energy spectra of 163Ho. Superconductive multilayer films composed by a sequence of pure Titanium and stoichiometric TiN layers show many ideal properties for MKIDs, such as low loss, large sheet resistance, large kinetic inductance, and tunable critical temperature TcT_c. We developed Ti/TiN multilayer microresonators with TcT_c within the range from 70 mK to 4.5 K and with good uniformity. In this contribution we present the design solutions adopted, the fabrication processes and the characterization results

    Semi-leptonic Octet Baryon Weak Axial-Vector Form Factors in the Chiral Constitutent Quark Model

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    The weak vector and axial-vector form factors have been investigated for the semi-leptonic octet baryon decays in the chiral constituent quark model with configuration mixing (\chiCQM_{config}). The effects of SU(3) symmetry breaking and configuration mixing have also been investigated and the results are not only in good agreement with existing experimental data but also show improvement over other phenomenological models.Comment: 5 pages, 2 tables. Presented at the 18th International Spin Physics Symposium, University of Virginia, USA, October 6-11, 200

    The brightest pure-H ultracool white dwarf

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    We report the identification of LSR J0745+2627 in the United Kingdom InfraRed Telescope Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) as a cool white dwarf with kinematics and age compatible with the thick-disk/halo population. LSR J0745+2627 has a high proper motion (890 mas/yr) and a high reduced proper motion value in the J band (H_J=21.87). We show how the infrared-reduced proper motion diagram is useful for selecting a sample of cool white dwarfs with low contamination. LSR J0745+2627 is also detected in the Sloan Digital Sky Survey (SDSS) and the Wide-field Infrared Survey Explorer (WISE). We have spectroscopically confirmed this object as a cool white dwarf using X-Shooter on the Very Large Telescope. A detailed analysis of its spectral energy distribution reveals that its atmosphere is compatible with a pure-H composition model with an effective temperature of 3880+-90 K. This object is the brightest pure-H ultracool white dwarf (Teff<4000 K) ever identified. We have constrained the distance (24-45 pc), space velocities and age considering different surface gravities. The results obtained suggest that LSR J0745+2627 belongs to the thick-disk/halo population and is also one of the closest ultracool white dwarfs.Comment: 5 pages, 7 figures, accepted for publication in A&A Letter
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