Publications by authors named "Odorici F"

The exclusive photoproduction of meson states from protons, (with ), is studied in ultraperipheral Pb collisions at a centre-of-mass energy per nucleon pair of . The measurement is performed using the decay mode, with data collected by the CMS experiment corresponding to an integrated luminosity of 32.6 .

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An experimental campaign aiming to investigate the effects of innovative nanostructured targets based on Ag nanowires on laser energy absorption in the ns time domain has been carried out at the Laser Energy for Nuclear Science laboratory of INFN-LNS in Catania. The tested targets were realized at INFN-Bologna by anodizing aluminium sheets in order to obtain layers of porous Al2O3 of different thicknesses, on which nanowires of various metals are grown by electro-deposition with different heights. Targets were then irradiated by using a Nd:YAG laser at different pumping energies.

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Different electron guns based on cold- or hot-cathode technologies have been developed since 2009 at INFN for operating within ECR plasma chambers as sources of auxiliary electrons, with the aim of boosting the source performances by means of a higher plasma lifetime and density. Their application to microwave discharge ion sources, where plasma is not confined, has required an improvement of the gun design, in order to "screen" the cathode from the plasma particles. Experimental tests carried out on a plasma reactor show a boost of the plasma density, ranging from 10% to 90% when the electron guns are used, as explained by plasma diffusion models.

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The production of jets associated to bottom quarks is measured for the first time in PbPb collisions at a center-of-mass energy of 2.76 TeV per nucleon pair. Jet spectra are reported in the transverse momentum (p(T)) range of 80-250  GeV/c, and within pseudorapidity |η|<2.

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Results are presented from a search for the rare decays Bs(0)→μ+ μ- and B(0)→μ+ μ- in pp collisions at sqrt[s]=7 and 8 TeV, with data samples corresponding to integrated luminosities of 5 and 20  fb(-1), respectively, collected by the CMS experiment at the LHC. An unbinned maximum-likelihood fit to the dimuon invariant mass distribution gives a branching fraction B(Bs(0)→μ+ μ-)=(3.0(-0.

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The first observation of the associated production of a single top quark and a W boson is presented. The analysis is based on a data set corresponding to an integrated luminosity of 12.2 fb(-1) of proton-proton collisions at sqrt[s] = 8 TeV recorded by the CMS experiment at the LHC.

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Article Synopsis
  • A study was conducted measuring the production rates of W and Z bosons in proton-proton collisions at a collision energy of 8 TeV, using data from the CMS detector.
  • The results indicated a total inclusive cross-section for W bosons of 12.21 nb and for Z bosons of 1.15 nb, with small associated uncertainties.
  • These findings are consistent with advanced theoretical predictions and represent the first measurement of these bosons at this energy level in such collisions.
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Spin correlations and polarization in the top quark-antiquark system are measured using dilepton final states produced in pp collisions at the LHC at sqrt[s]=7  TeV. The data correspond to an integrated luminosity of 5.0  fb(-1) collected with the CMS detector.

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Article Synopsis
  • * Data was collected using the CMS detector at the LHC, involving 19.7 fb(-1) of proton-proton collisions at 8 TeV.
  • * The results show no excess events compared to standard model predictions, indicating no evidence for flavor-changing neutral currents, and a branching fraction greater than 0.05% is excluded at a 95% confidence level.
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  • A search was conducted for heavy partners of the top quark with a charge of 5/3, using data from the CMS experiment which had an integrated luminosity of 19.5 fb(-1) at a collision energy of 8 TeV.
  • No significant excess above the anticipated background was found, leading to the exclusion of top-quark partners with masses under 800 GeV at a 95% confidence level, assuming these partners decay only to tW.
  • This study provides the first limit on such particles from the Large Hadron Collider (LHC) and offers a stricter constraint compared to previous findings.
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Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top quark (the top squark) and the Higgs boson (Higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets.

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Article Synopsis
  • The study measures the production cross section of top quark-antiquark pairs in proton-proton collisions at the LHC, specifically looking at how this varies with the number of jets produced.
  • It utilizes data from both dilepton and lepton+jets decay channels, analyzing events with an integrated luminosity of 5.0 fb⁻¹.
  • Results indicate that the observed data aligns well with predictions made by quantum chromodynamics, showing no significant discrepancies.
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A search for invisible decays of Higgs bosons is performed using the vector boson fusion and associated ZH production modes. In the ZH mode, the Z boson is required to decay to a pair of charged leptons or a [Formula: see text] quark pair. The searches use the 8 [Formula: see text] pp collision dataset collected by the CMS detector at the LHC, corresponding to an integrated luminosity of up to 19.

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Measurements are reported of the WZ and ZZ production cross sections in proton-proton collisions at [Formula: see text][Formula: see text] in final states where one Z boson decays to b-tagged jets. The other gauge boson, either W or Z, is detected through its leptonic decay (either [Formula: see text], [Formula: see text] or [Formula: see text], [Formula: see text], or [Formula: see text]). The results are based on data corresponding to an integrated luminosity of 18.

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A study of color coherence effects in pp collisions at a center-of-mass energy of 7[Formula: see text] is presented. The data used in the analysis were collected in 2010 with the CMS detector at the LHC and correspond to an integrated luminosity of 36 pb[Formula: see text]. Events are selected that contain at least three jets and where the two jets with the largest transverse momentum exhibit a back-to-back topology.

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Spectra of identified charged hadrons are measured in pPb collisions with the CMS detector at the LHC at [Formula: see text]. Charged pions, kaons, and protons in the transverse-momentum range [Formula: see text]-1.7[Formula: see text] and laboratory rapidity [Formula: see text] are identified via their energy loss in the silicon tracker.

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Article Synopsis
  • - The mass of the top quark is determined using data from candidate events featuring at least six jets, collected by the CMS detector during proton-proton collisions at [Formula: see text] TeV in 2011, totaling an integrated luminosity of 3.54 [Formula: see text].
  • - Each event undergoes a kinematic fit of the jets to a [Formula: see text] hypothesis to accurately reconstruct the mass.
  • - The final measurement for the top-quark mass is reported as [Formula: see text] GeV, which is further refined by combining it with earlier measurements from different decay modes by CMS, resulting in a combined mass of [Formula: see text] GeV.
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  • * A data-driven isolation template method was employed to accurately determine the prompt diphoton yield, specifically focusing on photons with transverse energies above certain thresholds.
  • * The results, including cross sections as a function of various parameters, are compared against theoretical predictions from quantum chromodynamics (QCD) at different order levels to assess their alignment with experimental data.
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A search for anomalous production of events with three or more isolated leptons and bottom-quark jets produced in pp collisions at √s=8 TeV is presented. The analysis is based on a data sample corresponding to an integrated luminosity of 19.5 fb(-1) collected by the CMS experiment at the LHC in 2012.

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Article Synopsis
  • - The study examines unusual production of top quark-antiquark pairs from proton-proton collisions at a high energy level (√s=8 TeV), utilizing data from the CMS detector at the LHC.
  • - A total of 19.7 fb(-1) of data was analyzed, and the results show that the observed mass spectrum aligns with predictions made by the standard model of particle physics.
  • - For the first time, limitations on production cross sections and branching fractions are set, exploring specific new physics models that have not been addressed by previous precise measurements.
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An inclusive search is presented for new heavy particle pairs produced in √s=7 TeV proton-proton collisions at the LHC using 4.7±0.1 fb(-1) of integrated luminosity.

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Article Synopsis
  • The study reports the first measurements of vector-boson production associated with a top quark-antiquark pair during proton-proton collisions at a center-of-mass energy of 7 TeV, using data from the CMS detector at the LHC from 2011.
  • Two analysis channels were employed: a trilepton analysis for ttZ events and a same-sign dilepton analysis for ttV events (where V can be W or Z).
  • The measured cross sections are σ(ttZ) = 0.28 pb and σ(ttV) = 0.43 pb, both significant at over 3 standard deviations, and they align with theoretical predictions within the stated uncertainties.
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A search for the pair production of a heavy, narrow resonance decaying into two jets has been performed using events collected in sqrt[s] = 7 TeV pp collisions with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 5.0 fb(-1).

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A study is presented of the mass and spin-parity of the new boson recently observed at the LHC at a mass near 125 GeV. An integrated luminosity of 17.3 fb(-1), collected by the CMS experiment in proton-proton collisions at center-of-mass energies of 7 and 8 TeV, is used.

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The polarizations of the Υ(1S), Υ(2S), and Υ(3S) mesons are measured in proton-proton collisions at sqrt[s] = 7 TeV, using a data sample of Υ(nS) → μ +μ- decays collected by the CMS experiment, corresponding to an integrated luminosity of 4.9 fb(-1). The dimuon decay angular distributions are analyzed in three different polarization frames.

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