563 research outputs found

    Light sterile neutrino sensitivity of 163Ho experiments

    Get PDF
    We explore the sensitivity of 163^{163}Ho electron capture experiments to neutrino masses in the standard framework of three-neutrino mixing and in the framework of 3+1 neutrino mixing with a sterile neutrino which mixes with the three standard active neutrinos, as indicated by the anomalies found in short-baseline neutrino oscillations experiments. We calculate the sensitivity to neutrino masses and mixing for different values of the energy resolution of the detectors, of the unresolved pileup fraction and of the total statistics of events, considering the expected values of these parameters in the two planned stages of the ECHo project (ECHo-1k and ECHo-1M). We show that an extension of the ECHo-1M experiment with the possibility to collect 101610^{16} events will be competitive with the KATRIN experiment. This statistics will allow to explore part of the 3+1 mixing parameter space indicated by the global analysis of short-baseline neutrino oscillation experiments. In order to cover all the allowed region, a statistics of about 101710^{17} events will be needed.Comment: 11 page

    Emerging frustration effects in ferromagnetic Ce_2[Pd_{1-x}Ag_x]_2In alloys

    Full text link
    Magnetic and thermal properties of Ferromagnetic (FM) Ce_{2.15}(Pd_{1-x}Ag_x)_{1.95}In_{0.9} alloys were studied in order to determine the Quantum Critical Point (QCP) at T_C => 0. The increase of band electrons produced by Pd/Ag substitution depresses T_C(x) from 4.1K down to T_C(x=0.5)=1.1K, with a QCP extrapolated to x_{QCP}~ 0.6. Magnetic susceptibility from T>30K indicates an effective moment slightly decreasing from \mu_{eff}=2.56\mu_B to 2.4\mu_B at x=0.5. These values and the paramagnetic temperature \theta_P~ -10K exclude significant Kondo screening effects. The T_C(x) reduction is accompanied by a weakening of the FM magnetization and the emergence of a specific heat C_m(T) anomaly at T*~ 1K, without signs of magnetism detected from AC-susceptibility. The magnetic entropy collected around 4K (i.e. the T_C of the x=0 sample) practically does not change with Ag concentration: S_m(4K)~ 0.8 Rln2, suggesting a progressive transfer of FM degrees of freedom to the non-magnetic (NM) component. No antecedent was found concerning any NM anomaly emerging from a FM system at such temperature. The origin of this anomaly is attributed to an 'entropy bottleneck' originated in the nearly divergent power law dependence for T>T*.Comment: 5 pages, 4 figures, Int. Conf. ICM 201

    MRI/TRUS data fusion for brachytherapy

    Full text link
    BACKGROUND: Prostate brachytherapy consists in placing radioactive seeds for tumour destruction under transrectal ultrasound imaging (TRUS) control. It requires prostate delineation from the images for dose planning. Because ultrasound imaging is patient- and operator-dependent, we have proposed to fuse MRI data to TRUS data to make image processing more reliable. The technical accuracy of this approach has already been evaluated. METHODS: We present work in progress concerning the evaluation of the approach from the dosimetry viewpoint. The objective is to determine what impact this system may have on the treatment of the patient. Dose planning is performed from initial TRUS prostate contours and evaluated on contours modified by data fusion. RESULTS: For the eight patients included, we demonstrate that TRUS prostate volume is most often underestimated and that dose is overestimated in a correlated way. However, dose constraints are still verified for those eight patients. CONCLUSIONS: This confirms our initial hypothesis

    Clinical Impact of Mediterranean Diet Adherence before and after Bariatric Surgery: A Narrative Review

    Get PDF
    The population suffering from obesity is rapidly increasing all over the world. Bariatric surgery has shown to be the treatment of choice in patients with severe obesity. A Mediterranean diet has long been acknowledged to be one of the healthiest dietary patterns associated with a lower incidence of many chronic diseases. The aim of the present narrative review is to summarize the existing research on the clinical impact of a Mediterranean diet before and after bariatric surgery, focusing on its effects on weight loss and improvement in comorbidities. Although the current knowledge is limited, this information could add value and emphasize the importance of adopting a Mediterranean diet before and after bariatric surgery

    First Calorimetric Measurement of OI-line in the Electron Capture Spectrum of 163^{163}Ho

    Full text link
    The isotope 163^{163}Ho undergoes an electron capture process with a recommended value for the energy available to the decay, QECQ_{\rm EC}, of about 2.5 keV. According to the present knowledge, this is the lowest QECQ_{\rm EC} value for electron capture processes. Because of that, 163^{163}Ho is the best candidate to perform experiments to investigate the value of the electron neutrino mass based on the analysis of the calorimetrically measured spectrum. We present for the first time the calorimetric measurement of the atomic de-excitation of the 163^{163}Dy daughter atom upon the capture of an electron from the 5s shell in 163^{163}Ho, OI-line. The measured peak energy is 48 eV. This measurement was performed using low temperature metallic magnetic calorimeters with the 163^{163}Ho ion implanted in the absorber. We demonstrate that the calorimetric spectrum of 163^{163}Ho can be measured with high precision and that the parameters describing the spectrum can be learned from the analysis of the data. Finally, we discuss the implications of this result for the Electron Capture 163^{163}Ho experiment, ECHo, aiming to reach sub-eV sensitivity on the electron neutrino mass by a high precision and high statistics calorimetric measurement of the 163^{163}Ho spectrum.Comment: 5 pages, 3 figure

    Structural reorganization in a hydrogen-bonded organic framework

    Get PDF
    Self-recognition of 3,3′,5,5′-azobenzenetetracarboxylic acid drives the formation of a grid-like anionic hydrogen-bonded framework with channels occupied by organic cations. This supramolecular solid is capable of reorganizing its connectivity in the presence of specific guests into a different crystalline architecture by sequential dissolution and recrystallization
    • …
    corecore