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"Soffi, Livia"
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Data from Emergency Medical Service Activities: A Novel Approach to Monitoring COVID-19 and Other Infectious Diseases
Background: Italy, particularly the northern region of Lombardy, has experienced very high rates of COVID-19 cases and deaths. Several indicators, i.e., the number of new positive cases, deaths and hospitalizations, have been used to monitor virus spread, but all suffer from biases. The aim of this study was to evaluate an alternative data source from Emergency Medical Service (EMS) activities for COVID-19 monitoring. Methods: Calls to the emergency number (112) in Lombardy (years 2015–2022) were studied and their overlap with the COVID-19 pandemic, influenza and official mortality peaks were evaluated. Modeling it as a counting process, a specific cause contribution (i.e., COVID-19 symptoms, the “signal”) was identified and enucleated from all other contributions (the “background”), and the latter was subtracted from the total observed number of calls using statistical methods for excess event estimation. Results: A total of 6,094,502 records were analyzed and filtered for respiratory and cardiological symptoms to identify potential COVID-19 patients, yielding 742,852 relevant records. Results show that EMS data mirrored the time series of cases or deaths in Lombardy, with good agreement also being found with seasonal flu outbreaks. Conclusions: This novel approach, combined with a machine learning predictive approach, could be a powerful public health tool to signal the start of disease outbreaks and monitor the spread of infectious diseases.
Journal Article
Search for new exotic particles decaying to photons with the CMS experiment at the LHC
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The results of searches for physics beyond the standard model with photons in the final state are presented. Events were collected at center-of-mass energies of 7 and 8 TeV in proton-proton collisions during the first run of the LHC data taking between 2011 and 2015 and analyzed with the general-purpose detector of the Compact Muon Solenoid experiment. A search for long-lived particles which decay to photons is first presented. This is the first search at CMS which exploits information of the time measurement made with the CMS electromagnetic calorimeter to identify displaced photons. A model-independent search for new heavy scalars in the diphoton final state is also described. The search, covering the mass range between 150 GeV and 850 GeV, is extended to resonances with natural width up to 10% of the mass. Results obtained in both searches significantly extend previous searches results in terms of mass, width and lifetime ranges.
Journal Article
Measurements of inclusive and differential cross sections for top quark production in association with a Z boson in proton-proton collisions at $\\sqrt{s}$ = 13 TeV
Measurements are presented of inclusive and differential cross sections for Z boson associated production of top quark pairs ($\\mathrm{t\\bar{t}}$Z) and single top quarks (tZq or tWZ). The data were recorded in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. Events with three or more leptons, electrons or muons, are selected and a multiclass deep neural network is used to separate three event categories, the $\\mathrm{t\\bar{t}}$Z and tWZ processes, the tZq process, and the backgrounds. A profile likelihood approach is used to unfold the differential cross sections, to account for systematic uncertainties, and to determine the correlations between the two signal categories in one global fit. The inclusive cross sections for a dilepton invariant mass between 70 and 110 GeV are measured to be 1.14 $\\pm$ 0.07 pb for the sum of $\\mathrm{t\\bar{t}}$Z and tWZ, and 0.81 $\\pm$ 0.10 pb for tZq, in good agreement with theoretical predictions.
Journal Article
Measurement of differential ZZ + jets production cross sections in pp collisions at $ \\sqrt{s} $ = 13 TeV
Diboson production in association with jets is studied in the fully leptonic final states, pp → (Z/γ$^{*}$)(Z/γ$^{*}$) + jets → 2ℓ2ℓ′ + jets, (ℓ, ℓ′ = e or μ) in proton-proton collisions at a center-of-mass energy of 13 TeV. The data sample corresponds to an integrated luminosity of 138 fb$^{−1}$ collected with the CMS detector at the LHC. Differential distributions and normalized differential cross sections are measured as a function of jet multiplicity, transverse momentum p$_{T}$, pseudorapidity η, invariant mass and ∆η of the highest-p$_{T}$ and second-highest-p$_{T}$ jets, and as a function of invariant mass of the four-lepton system for events with various jet multiplicities. These differential cross sections are compared with theoretical predictions that mostly agree with the experimental data. However, in a few regions we observe discrepancies between the predicted and measured values. Further improvement of the predictions is required to describe the ZZ+jets production in the whole phase space.
Journal Article
Correction: del Re et al. Data from Emergency Medical Service Activities: A Novel Approach to Monitoring COVID-19 and Other Infectious Diseases. Diagnostics 2025, 15 , 181
In the original publication [...].
Journal Article
A deep neural network to search for new long-lived particles decaying to jets
A tagging algorithm to identify jets that are significantly displaced from the proton-proton (pp) collision region in the CMS detector at the LHC is presented. Displaced jets can arise from the decays of long-lived particles (LLPs), which are predicted by several theoretical extensions of the standard model. The tagger is a multiclass classifier based on a deep neural network, which is parameterised according to the proper decay length cτ0 of the LLP. A novel scheme is defined to reliably label jets from LLP decays for supervised learning. Samples of pp collision data, recorded by the CMS detector at a centre-of-mass energy of 13 TeV, and simulated events are used to train the neural network. Domain adaptation by backward propagation is performed to improve the simulation modelling of the jet class probability distributions observed in pp collision data. The potential performance of the tagger is demonstrated with a search for long-lived gluinos, a manifestation of split supersymmetric models. The tagger provides a rejection factor of 10 000 for jets from standard model processes, while maintaining an LLP jet tagging efficiency of 30%-80% for gluinos with 1 mm≤cτ0≤ 10 m. The expected coverage of the parameter space for split supersymmetry is presented.
Journal Article
Search for light bosons in decays of the 125 GeV Higgs boson in proton-proton collisions at sqrt(s) = 8 TeV
A search is presented for decays beyond the standard model of the 125 GeV Higgs bosons to a pair of light bosons, based on models with extended scalar sectors. Light boson masses between 5 and 62.5 GeV are probed in final states containing four tau leptons, two muons and two b quarks, or two muons and two tau leptons. The results are from data in proton-proton collisions corresponding to an integrated luminosity of 19.7 inverse-femtobarns, accumulated by the CMS experiment at the LHC at a center-of-mass energy of 8 TeV. No evidence for such exotic decays is found in the data. Upper limits are set on the product of the cross section and branching fraction for several signal processes. The results are also compared to predictions of two-Higgs-doublet models, including those with an additional scalar singlet.
Journal Article
Measurement of the inclusive energy spectrum in the very forward direction in proton-proton collisions at sqrt(s)=13 TeV
The differential cross section for inclusive particle production as a function of energy in proton-proton collisions at a center-of-mass energy of 13 TeV is measured in the very forward region of the CMS detector. The measurement is based on data collected with the CMS apparatus at the LHC, and corresponds to an integrated luminosity of 0.35 inverse microbarns. The energy is measured in the CASTOR calorimeter, which covers the pseudorapidity region -6.6
Journal Article
Search for associated production of a Z boson with a single top quark and for tZ flavour-changing interactions in pp collisions at sqrt(s) = 8 TeV
A search for the production of a single top quark in association with a Z boson is presented, both to identify the expected standard model process and to search for flavour-changing neutral current interactions. The data sample corresponds to an integrated luminosity of 19.7 inverse-femtobarns recorded by the CMS experiment at the LHC in proton-proton collisions at sqrt(s) = 8 TeV. Final states with three leptons (electrons or muons) and at least one jet are investigated. An events yield compatible with tZq standard model production is observed, and the corresponding cross section is measured to be sigma( p p -> t Z q -> l nu b l+ l- q ) = 10 +8/-7 fb with a significance of 2.4 standard deviations. No presence of flavour-changing neutral current production of tZq is observed. Exclusion limits at 95% confidence level on the branching fractions of a top quark decaying to a Z boson and an up or a charm quark are found to be B( t -> Z u ) < 0.022% and B( t -> Z c ) < 0.049%.
Journal Article
Measurement of electroweak-induced production of W gamma with two jets in pp collisions at sqrt(s)=8 TeV and constraints on anomalous quartic gauge couplings
A measurement of electroweak-induced production of W gamma and two jets is performed, where the W boson decays leptonically. The data used in the analysis correspond to an integrated luminosity of 19.7 inverse femtobarns collected by the CMS experiment in sqrt(s)=8 TeV proton-proton collisions produced at the LHC. Candidate events are selected with exactly one muon or electron, missing transverse momentum, one photon, and two jets with large rapidity separation. An excess over the hypothesis of the standard model without electroweak production of W gamma with two jets is observed with a significance of 2.7 standard deviations, corresponding to an upper limit on the electroweak signal strength of 4.3 times the standard model expectation at 95% confidence level. The cross section measured in the fiducial region is 10.8 +/- 4.1 (stat) +/- 3.4 (syst) +/- 0.3 (lum) fb, which is consistent with the standard model electroweak prediction. The total cross section for W gamma in association with two jets in the same fiducial region is measured to be 23.2 +/- 4.3 (stat) +/- 1.7 (syst) +/- 0.6 (lum) fb, which is consistent with the standard model prediction from the combination of electroweak- and quantum chromodynamics-induced processes. No deviations are observed from the standard model predictions and experimental limits on anomalous quartic gauge couplings f[M,0-7]/\\Lambda^4, f[T,0-2]/\\Lambda^4, and f[T,5-7]/\\Lambda^4 are set at 95% confidence level.
Journal Article