94 research outputs found

    A study of the K+→π0e+νγK^+ \to \pi^0 e^+ \nu \gamma decay

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    A sample of 1.3×1051.3 \times 10^5K+→π0e+νγK^+ \to \pi^0 e^+ \nu \gamma candidates with less than 1% background was collected by the NA62 experiment at the CERN SPS in 2017-2018. Branching fraction measurements are obtained at percent relative precision in three restricted kinematic regions, improving on existing results by a factor larger than two. An asymmetry, possibly related to T-violation, is investigated with no evidence observed within the achieved precision

    Measurement of the K+→π+γγK^+ \to \pi^+ \gamma \gamma decay

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    A sample of 3984 candidates of the K+→π+γγK^+ \to \pi^+ \gamma \gamma decay, with an estimated background of 291±14291 \pm 14 events, was collected by the NA62 experiment at CERN during 2017–2018. In order to describe the observed di-photon mass spectrum, the next-to-leading order contribution in chiral perturbation theory was found to be necessary. The decay branching ratio in the full kinematic range is measured to be (9.61±0.17)×10−79.61 \pm 0.17) \times 10^{−7}. The first search for production and prompt decay of an axion-like particle with gluon coupling in the process K+→π+a,a→γγK^+ \to \pi^+ a, a \to \gamma \gamma is also reported.A sample of 3984 candidates of the K+→π+γγK^+\to\pi^+\gamma\gamma decay, with an estimated background of 291±14291\pm14 events, was collected by the NA62 experiment at CERN during 2017-2018. In order to describe the observed di-photon mass spectrum, the next-to-leading order contribution in chiral perturbation theory was found to be necessary. The decay branching ratio in the full kinematic range is measured to be (9.61±0.17)×10−7(9.61\pm0.17)\times10^{-7}. The first search for production and prompt decay of an axion-like particle with gluon coupling in the process K+→π+aK^+\to\pi^+a, a→γγa\to\gamma\gamma is also reported

    Measurement of the K+→π+γγK^+\to\pi^+\gamma\gamma decay

    No full text
    International audienceA sample of 3984 candidates of the K+→π+γγK^+\to\pi^+\gamma\gamma decay, with an estimated background of 291±14291\pm14 events, was collected by the NA62 experiment at CERN during 2017-2018. In order to describe the observed di-photon mass spectrum, the next-to-leading order contribution in chiral perturbation theory was found to be necessary. The decay branching ratio in the full kinematic range is measured to be (9.61±0.17)×10−7(9.61\pm0.17)\times10^{-7}. The first search for production and prompt decay of an axion-like particle with gluon coupling in the process K+→π+aK^+\to\pi^+a, a→γγa\to\gamma\gamma is also reported

    Antidiabetic Drug Prescription Pattern in Hospitalized Older Patients with Diabetes

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    Objective: To describe the prescription pattern of antidiabetic and cardiovascular drugs in a cohort of hospitalized older patients with diabetes. Methods: Patients with diabetes aged 65 years or older hospitalized in internal medicine and/or geriatric wards throughout Italy and enrolled in the REPOSI (REgistro POliterapuie SIMI—Società Italiana di Medicina Interna) registry from 2010 to 2019 and discharged alive were included. Results: Among 1703 patients with diabetes, 1433 (84.2%) were on treatment with at least one antidiabetic drug at hospital admission, mainly prescribed as monotherapy with insulin (28.3%) or metformin (19.2%). The proportion of treated patients decreased at discharge (N = 1309, 76.9%), with a significant reduction over time. Among those prescribed, the proportion of those with insulin alone increased over time (p = 0.0066), while the proportion of those prescribed sulfonylureas decreased (p < 0.0001). Among patients receiving antidiabetic therapy at discharge, 1063 (81.2%) were also prescribed cardiovascular drugs, mainly with an antihypertensive drug alone or in combination (N = 777, 73.1%). Conclusion: The management of older patients with diabetes in a hospital setting is often sub-optimal, as shown by the increasing trend in insulin at discharge, even if an overall improvement has been highlighted by the prevalent decrease in sulfonylureas prescription

    Search for K+K^+ decays into the π+e+e−e+e−\pi^+e^+e^-e^+e^- final state

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    The first search for ultra-rare K+K^+ decays into the π+e+e−e+e−\pi^+e^+e^-e^+e^- final state is reported, using a dataset collected by the NA62 experiment at CERN in 2017-2018. An upper limit of 1.4×10−81.4\times 10^{-8} at 90% CL is obtained for the branching ratio of the K+→π+e+e−e+e−K^+\to\pi^+e^+e^-e^+e^- decay, predicted in the Standard Model to be (7.2±0.7)×10−11(7.2\pm0.7)\times 10^{-11}. Upper limits at 90% CL are obtained at the level of 10−910^{-9} for the branching ratios of two prompt decay chains involving pair-production of hidden-sector mediators: K+→π+aaK^+\to\pi^+aa, a→e+e−a\to e^+e^- and K+→π+SK^+\to\pi^+S, S→A′A′S\to A^\prime A^\prime, A′→e+e−A^\prime\to e^+e^-. The QCD axion is excluded as a possible explanation of the '17 MeV anomaly'

    Improved calorimetric particle identification in NA62 using machine learning techniques

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    International audienceMeasurement of the ultra-rare K+→π+νν‾ {K}^{+}\to {\pi}^{+}\nu \overline{\nu} decay at the NA62 experiment at CERN requires high-performance particle identification to distinguish muons from pions. Calorimetric identification currently in use, based on a boosted decision tree algorithm, achieves a muon misidentification probability of 1.2 × 10−5^{−5} for a pion identification efficiency of 75% in the momentum range of 15–40 GeV/c. In this work, calorimetric identification performance is improved by developing an algorithm based on a convolutional neural network classifier augmented by a filter. Muon misidentification probability is reduced by a factor of six with respect to the current value for a fixed pion-identification efficiency of 75%. Alternatively, pion identification efficiency is improved from 72% to 91% for a fixed muon misidentification probability of 10−5^{−5}

    A study of the K+→π0e+νγK^+ \to \pi^0 e^+ \nu \gamma decay

    No full text
    International audienceA sample of 1.3×1051.3 \times 10^5K+→π0e+νγK^+ \to \pi^0 e^+ \nu \gamma candidates with less than 1% background was collected by the NA62 experiment at the CERN SPS in 2017-2018. Branching fraction measurements are obtained at percent relative precision in three restricted kinematic regions, improving on existing results by a factor larger than two. An asymmetry, possibly related to T-violation, is investigated with no evidence observed within the achieved precision

    Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

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    Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81 years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16-2.61) and patients with dementia (HR 1.75, 95% CI 1.06-2.90) had a higher risk of death at one year. The Kaplan-Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population

    Measurement of the K+→π+γγK^+\to\pi^+\gamma\gamma decay

    No full text
    International audienceA sample of 3984 candidates of the K+→π+γγK^+\to\pi^+\gamma\gamma decay, with an estimated background of 291±14291\pm14 events, was collected by the NA62 experiment at CERN during 2017-2018. In order to describe the observed di-photon mass spectrum, the next-to-leading order contribution in chiral perturbation theory was found to be necessary. The decay branching ratio in the full kinematic range is measured to be (9.61±0.17)×10−7(9.61\pm0.17)\times10^{-7}. The first search for production and prompt decay of an axion-like particle with gluon coupling in the process K+→π+aK^+\to\pi^+a, a→γγa\to\gamma\gamma is also reported

    Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

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    Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81 years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16-2.61) and patients with dementia (HR 1.75, 95% CI 1.06-2.90) had a higher risk of death at one year. The Kaplan-Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population
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