1,070 research outputs found

    An Appraisal of Muon Neutrino Disappearance at Short Baseline

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    Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long standing problem of new Physics beyond the Standard Model. The recent measurements of the third mixing angle Ξ13\theta_{13} in the standard mixing oscillation scenario encourage to pursue the still missing results on the leptonic CP violation and the absolute neutrino masses. However, several puzzling and incomplete measurements are in place which deserve an exhaustive evaluation and study. We will report about the present situation of the muon disappearance measurements at small L/EL/E in the context of the current CERN project to revitalize the neutrino field in Europe and the search for sterile neutrinos. We will then illustrate the achievements that a double muon spectrometer can attain in terms of discovery of new neutrino states, performing a newly developed analysis.Comment: 19 pages, 8 figures, to be published in "Advances in High Energy Physics

    Neutrino Physics with Opera

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    Camera traps equipped with macro lenses as a tool for monitoring arboreal small mammals: a case study in an agroecosystem (NE Italy)

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    Despite their increasing use, camera traps as a monitoring tool for arboreal small mammals leave room for further improvements to increase their effectiveness. In the summer of 2023, we conducted a small mammal survey in a wooded area of a lowland agroecosystem in the Veneto region, using standard camera traps equipped with macro lenses for close-up shooting. This camera trap technique made it possible to contact three species of small mammals in the tree-shrub layer: Eurasian red squirrel Sciurus vulgaris, wood mouse Apodemus sylvaticus, and black rat Rattus rattus. The use of macro lenses combined with the standard camera trapping technique made it possible to obtain better quality images and more information even on smaller species compared to more traditional camera traps

    Preliminary Report on the Study of Beam-Induced Background Effects at a Muon Collider

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    Physics at a multi-TeV muon collider needs a change of perspective for the detector design due to the large amount of background induced by muon beam decays. Preliminary studies, based on simulated data, on the composition and the characteristics of the particles originated from the muon decays and reaching the detectors are presented here. The reconstruction performance of the physics processes H→bbˉH\to b\bar b and Z→bbˉZ\to b\bar b has been investigated for the time being without the effect of the machine induced background. A preliminary study of the environment hazard due to the radiation induced by neutrino interactions with the matter is presented using the FLUKA simulation program

    Heavy quarkonium: progress, puzzles, and opportunities

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    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the BB-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

    Observation of J/ψpJ/\psi p resonances consistent with pentaquark states in Λb0→J/ψK−p{\Lambda_b^0\to J/\psi K^-p} decays

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    Observations of exotic structures in the J/ψpJ/\psi p channel, that we refer to as pentaquark-charmonium states, in Λb0→J/ψK−p\Lambda_b^0\to J/\psi K^- p decays are presented. The data sample corresponds to an integrated luminosity of 3/fb acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis is performed on the three-body final-state that reproduces the two-body mass and angular distributions. To obtain a satisfactory fit of the structures seen in the J/ψpJ/\psi p mass spectrum, it is necessary to include two Breit-Wigner amplitudes that each describe a resonant state. The significance of each of these resonances is more than 9 standard deviations. One has a mass of 4380±8±294380\pm 8\pm 29 MeV and a width of 205±18±86205\pm 18\pm 86 MeV, while the second is narrower, with a mass of 4449.8±1.7±2.54449.8\pm 1.7\pm 2.5 MeV and a width of 39±5±1939\pm 5\pm 19 MeV. The preferred JPJ^P assignments are of opposite parity, with one state having spin 3/2 and the other 5/2.Comment: 48 pages, 18 figures including the supplementary material, v2 after referee's comments, now 19 figure

    Differences between cardiogenic shock related to acute decompensated heart failure and acute myocardial infarction

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    The present analysis from the multicentre prospective Altshock-2 registry aims to better define clinical features, in-hospital course, and management of cardiogenic shock complicating acutely decompensated heart failure (ADHF-CS) as compared with that complicating acute myocardial infarction (AMI-CS). All patients with AMI-CS or ADHF-CS enrolled in the Altshock-2 registry between March 2020 and February 2022 were selected. The primary objective was the characterization of ADHF-CS patients as compared with AMI-CS. In-hospital length of stay and mortality were secondary endpoints. One-hundred-ninety of the 238 CS patients enrolled in the aforementioned period were considered for the present analysis: 101 AMI-CS (80% ST-elevated myocardial infarction and 20% non-ST-elevated myocardial infarction) and 89 ADHF-CS. As compared with AMI-CS, ADHF-CS patients were younger [63 (IQR 59-76) vs. 67 (IQR 54-73) years, P = 0.01], but presented with higher creatinine [1.6 (IQR 1.0-2.6) vs. 1.2 (IQR 1.0-1.4) mg/dL, P < 0.001], bilirubin [1.3 (IQR 0.9-2.3) vs. 0.6 (IQR 0.4-1.1) mg/dL, P = 0.01], and central venous pressure values [14 mmHg (IQR 8-12) vs. 10 mmHg (IQR 7-14),P = 0.01]. Norepinephrine was the most common catecholamine used in AMI-CS (79.3%), whereas epinephrine was used more commonly in ADHF-CS (65.5%); 75.8% vs. 46.6% received a temporary mechanical support in AMI-CS and ADHF-CS, respectively (P < 0.001). Length of hospital stay was longer in the latter [28 (IQR 13-48) vs. 17 (IQR 9-29) days, P = 0.001]. Heart replacement therapies were more frequently used in the ADHF-CS group (heart transplantation 13.5% vs. 0% and left ventricular assist device 11% vs. 2%, P < 0.01 and 0.01, respectively). In-hospital mortality was 41.1% (38.6% AMI-CS vs. 43.8% ADHF-CS, P = 0.5). ADHF-CS is characterized by a higher prevalence of end-organ and biventricular dysfunction at presentation, a longer hospital length of stay, and higher need of heart replacement therapies when compared with AMI-CS. In-hospital mortality was similar between the two aetiologies. Our data warrant development of new management protocols focused on CS aetiology

    Measurement of the forward Z boson production cross-section in pp collisions at s=13\sqrt{s} = 13 TeV

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    A measurement of the production cross-section of Z bosons in pp collisions at s=13\sqrt{s} = 13 TeV is presented using dimuon and dielectron final states in LHCb data. The cross-section is measured for leptons with pseudorapidities in the range 2.0η4.52.0 \eta 4.5, transverse momenta pT20p_\text{T} 20 GeV and dilepton invariant mass in the range 60m(ℓℓ)12060 m(\ell\ell) 120 GeV. The integrated cross-section from averaging the two final states is \begin{equation*}\sigma_{\text{Z}}^{\ell\ell} = 194.3 \pm 0.9 \pm 3.3 \pm 7.6\text{ pb,}\end{equation*} where the first uncertainty is statistical, the second is due to systematic effects, and the third is due to the luminosity determination. In addition, differential cross-sections are measured as functions of the Z boson rapidity, transverse momentum and the angular variable ϕη∗\phi^*_\eta

    Fatality rate and predictors of mortality in an Italian cohort of hospitalized COVID-19 patients

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    Clinical features and natural history of coronavirus disease 2019 (COVID-19) differ widely among different countries and during different phases of the pandemia. Here, we aimed to evaluate the case fatality rate (CFR) and to identify predictors of mortality in a cohort of COVID-19 patients admitted to three hospitals of Northern Italy between March 1 and April 28, 2020. All these patients had a confirmed diagnosis of SARS-CoV-2 infection by molecular methods. During the study period 504/1697 patients died; thus, overall CFR was 29.7%. We looked for predictors of mortality in a subgroup of 486 patients (239 males, 59%; median age 71 years) for whom sufficient clinical data were available at data cut-off. Among the demographic and clinical variables considered, age, a diagnosis of cancer, obesity and current smoking independently predicted mortality. When laboratory data were added to the model in a further subgroup of patients, age, the diagnosis of cancer, and the baseline PaO2/FiO2 ratio were identified as independent predictors of mortality. In conclusion, the CFR of hospitalized patients in Northern Italy during the ascending phase of the COVID-19 pandemic approached 30%. The identification of mortality predictors might contribute to better stratification of individual patient risk

    Towards a Muon Collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work.Comment: 118 pages, 103 figure
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