Demonstration of the event identification capabilities of the NEXT-White detector

In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a 228Th calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of 71.6 ± 1.5 stat± 0.3 sys% for a background acceptance of 20.6 ± 0.4 stat± 0.3 sys% is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies. [Figure not available: see fulltext.

Radiogenic backgrounds in the NEXT double beta decay experiment

Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity- induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterráneo de Canfranc with xenon depleted in 136Xe are analyzed to derive a total background rate of (0.84±0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT collaboration. A spectral fit to this model yields the specific contributions of 60Co, 40K, 214Bi and 208Tl to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25±0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5σ after 1 year of data taking. The background measurement in a Qββ±100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75±0.12) events. [Figure not available: see fulltext.]

Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield

High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe–He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by ∼ 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures. [Figure not available: see fulltext.]

Energy calibration of the NEXT-White detector with 1% resolution near Q ββ of 136Xe

Excellent energy resolution is one of the primary advantages of electroluminescent high-pressure xenon TPCs. These detectors are promising tools in searching for rare physics events, such as neutrinoless double-beta decay (ββ0ν), which require precise energy measurements. Using the NEXT-White detector, developed by the NEXT (Neutrino Experiment with a Xenon TPC) collaboration, we show for the first time that an energy resolution of 1% FWHM can be achieved at 2.6 MeV, establishing the present technology as the one with the best energy resolution of all xenon detectors for ββ0ν searches. [Figure not available: see fulltext.

Short-term prognosis of polypharmacy in elderly patients treated in emergency departments: results from the EDEN project

Background: Polypharmacy is a growing phenomenon among elderly individuals. However, there is little information about the frequency of polypharmacy among the elderly population treated in emergency departments (EDs) and its prognostic effect. This study aims to determine the prevalence and short-term prognostic effect of polypharmacy in elderly patients treated in EDs. Methods: A retrospective analysis of the Emergency Department Elderly in Needs (EDEN) project's cohort was performed. This registry included all elderly patients who attended 52 Spanish EDs for any condition. Mild and severe polypharmacy was defined as the use of 5-9 drugs and >10 drugs, respectively. The assessed outcomes were ED revisits, hospital readmissions, and mortality 30 days after discharge. Crude and adjusted logistic regression analyses, including the patient's comorbidities, were performed. Results: A total of 25,557 patients were evaluated [mean age: 78 (IQR: 71-84) years]; 10,534 (41.2%) and 5678 (22.2%) patients presented with mild and severe polypharmacy, respectively. In the adjusted analysis, mild polypharmacy and severe polypharmacy were associated with an increase in ED revisits [odds ratio (OR) 1.13 (95% confidence interval (CI): 1.04-1.23) and 1.38 (95% CI: 1.24-1.51)] and hospital readmissions [OR 1.18 (95% CI: 1.04-1.35) and 1.36 (95% CI: 1.16-1.60)], respectively, compared to non-polypharmacy. Mild and severe polypharmacy were not associated with increased 30-day mortality [OR 1.05 (95% CI: 0.89-2.26) and OR 0.89 (95% CI: 0.72-1.12)], respectively. Conclusion: Polypharmacy was common among the elderly treated in EDs and associated with increased risks of ED revisits and hospital readmissions 10 drugs. In these patients comorbidities were associated with an increase in the number of drugs. In the patients with severe polypharmacy (>10 drugs), diuretics were the most frequently drugs prescribed, followed by antihypertensives and statins. The results obtained indicate that polypharmacy is a frequent phenomenon among the elderly population treated in Emergency departments, being antihypertensives the most frequently used drugs in this population. Those patients who takes >10 drugs have a higher risk of new visits to the emergency room and hospital readmissions in short term period

Sensitivity of a tonne-scale NEXT detector for neutrinoless double beta decay searches

The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta decay of Xe-136 using high-pressure xenon gas TPCs with electroluminescent amplification. A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of neutrinoless double-beta decay decay better than 1E27 years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.Comment: 22 pages, 11 figure

Reporte de Mercados Financieros - Tercer trimestre de 2022

El Banco de la Republica genera información para la toma de decisiones, la rendición de cuentas y la difusión al público. En particular, el Reporte de Mercados Financieros está enmarcado dentro del principio de difusión al público y contribuye a cumplir con el servicio que presta el Banco de ofrecer información e investigación económica de calidad. En línea con lo anterior, este reporte busca proveer al público un análisis general del comportamiento y las tendencias de los mercados financieros nacionales e internacionales. Adicionalmente, el reporte señala los principales factores que permiten explicar el comportamiento de dichos mercados así como sus interacciones. El reporte también presenta una descripción de los principales cambios en política monetaria y decisiones de los bancos centrales a nivel mundial. Durante el tercer trimestre de 2022 (3T22), continuaron las mayores presiones inflacionarias, lo que incidió en las expectativas de un mayor ritmo de contracción monetaria junto a los temores de una posible recesión económica a nivel global. Además, el conflicto entre Rusia y Ucrania, así como las tensiones entre EE.UU y China, las medidas adoptadas por las autoridades de este último país para contener la pandemia y diversos eventos idiosincráticos presionaron a los mercados financieros. Así, durante el periodo se observó un aumento de las tasas de interés, menores precios en el mercado de commodities y de renta variable y un fortalecimiento del dólar a nivel global soportado por el endurecimiento de las condiciones monetarias globales y las expectativas de mayores ajustes de tasas de política monetaria por la FED. Las monedas de una muestra de países emergentes se debilitaron ante el descenso de los precios de commodities y factores idiosincráticos. En Colombia, lo datos de actividad económica continuaron evidenciando un buen dinamismo y llevaron a mejoras en las perspectivas de crecimiento económico para este año. No obstante, se observó un deterioro en los índices de confianza del consumidor y empresarial. El desempeño de los activos financieros locales estuvo influenciado por el entorno global y las políticas económicas que adelante el nuevo gobierno. El peso colombiano presento la mayor depreciación en comparación con sus pares de la región durante el 3T22, influenciado por el contexto internacional, la caída de los precios del petróleo y factores locales. La TRM registro un máximo histórico. El mercado de deuda pública presentó una desvalorización en línea con lo observado en los títulos de la mayoría de los países de la región y con el comportamiento de los Tesoros en EE.UU. Las desvalorizaciones pudieron estar contenidas por los flujos de demanda por parte de inversionistas extranjeros durante este periodo. Durante el trimestre, la Junta Directiva del Banco de la República (JDBR) aumento su tasa de interés en 250 puntos básicos (de 7,50% a 10,00%) ante el aumento de las presiones inflacionarias. En esta edición, el documento se divide en ocho secciones, siendo esta introducción la primera. La sección dos presenta un resumen ejecutivo del documento. En la sección tres se presenta una descripción de los hechos más importantes en el entorno económico internacional. Posteriormente, en la sección cuatro se presenta el comportamiento de los principales indicadores de percepción del riesgo a nivel local. En la sección cinco se describe el mercado cambiario a nivel global y local. En la sección seis se presenta un análisis del mercado monetario y de renta fija. Adicionalmente, en la sección siete se describe el comportamiento del mercado primario de deuda privada local y finalmente, en la sección ocho se analiza el comportamiento de los mercados accionarios. En esta edición se incluyen tres recuadros: 1. Mercado de derivados peso-dólar en Colombia 2. Estimación de la prima a término de las tasas OIS 3. Análisis del beta de la tasa de cambi

Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−

The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions