453 results match your criteria: "Institute of Nuclear Research[Affiliation]"

Measurements of the associated production of a W boson and a charm ( ) quark in proton-proton collisions at a centre-of-mass energy of 8 are reported. The analysis uses a data sample corresponding to a total integrated luminosity of 19.7 collected by the CMS detector at the LHC.

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A search for pairs of Higgs bosons produced via gluon and vector boson fusion is presented, focusing on the four b quark final state. The data sample consists of proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, and corresponds to an integrated luminosity of 138  fb^{-1}. No deviation from the background-only hypothesis is observed.

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Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks (t) and Higgs bosons (H). The analysis is based on data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 137  fb^{-1}. No significant excess above the background prediction is observed.

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Multiparticle azimuthal correlations of prompt D^{0} mesons are measured in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=5.02  TeV. For the first time, a four-particle cumulant method is used to extract the second Fourier coefficient of the azimuthal distribution (v_{2}) of D^{0} mesons as a function of event centrality and the D^{0} transverse momentum.

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A search for resonances decaying into a W boson and a radion, where the radion decays into two W bosons, is presented. The data analyzed correspond to an integrated luminosity of 138  fb^{-1} recorded in proton-proton collisions with the CMS detector at sqrt[s]=13  TeV. One isolated charged lepton is required, together with missing transverse momentum and one or two massive large-radius jets, containing the decay products of either two or one W bosons, respectively.

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Article Synopsis
  • A search for exclusive two-photon production via photon exchange in proton-proton collisions was conducted using data from the LHC in 2016, focusing on events with intact protons.
  • The analysis aimed to select events with a diphoton invariant mass above 350 GeV, ensuring both protons remained intact to minimize interference from strong interactions.
  • No events meeting the criteria were found, which allowed researchers to set new limits on two anomalous four-photon coupling parameters, revealing |ζ_{1}|<2.9×10^{-13} GeV^{-4} and |ζ_{2}|<6.0×10^{-13} GeV^{-4} at a 95% confidence level.
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The B_{c}^{+} meson is observed for the first time in heavy ion collisions. Data from the CMS detector are used to study the production of the B_{c}^{+} meson in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV, via the B_{c}^{+}→(J/ψ→μ^{+}μ^{-})μ^{+}ν_{μ} decay.

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Using a data sample of proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of , the and decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to and , where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of and mesons, .

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A search for low-mass dilepton resonances in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via a pair of beyond the standard model particles, or one such particle and a boson. The search uses proton-proton collision data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 137 , at a center-of-mass energy .

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The potential of accelerator-based techniques as an analytical tool for forensics: The case of coffee.

Forensic Sci Int

June 2022

LII - Ion Implantation Laboratory, Institute of Physics, Federal University of Rio Grande do Sul (UFRGS), Av Bento Gonçalves 9500, CP 15051, CEP 91501-970 Porto Alegre, RS, Brazil; Graduate Program on Materials Science, Federal University of Rio Grande do Sul (UFRGS), Av Bento Gonçalves 9500, CEP 91501-970 Porto Alegre, RS, Brazil. Electronic address:

We discuss how different accelerator-based techniques can be employed synergistically as a powerful analytical tool for forensic studies of foodstuff. Brazilian and Jamaican coffees were chosen as a showcase due to its popularity and potential risk of adulteration and/or falsification. Comprehensive characterization of major and trace elements, age since production and compound contents were achieved using different techniques, including PIXE (Particle-Induced X-ray Emission), FTIR (Fourier Transform Infrared), and AMS-C (Accelerator Mass Spectrometry - Radiocarbon Analysis).

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The spectra measurements of charged hadrons produced in the shower of a parton originating in the same hard scattering with a leptonically decaying Z boson are reported in lead-lead nuclei (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Both Pb-Pb and pp data sets are recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 1.

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Article Synopsis
  • - The Borexino detector at Laboratori Nazionali del Gran Sasso successfully measured sub-MeV solar neutrinos using Cherenkov radiation and a technique linking photon hits to the Sun's position.
  • - In the energy range of 0.54 to 0.74 MeV, they detected 10,887 solar neutrinos from a total of 19,904 events, indicating a neutrino interaction rate consistent with standard solar model predictions.
  • - This groundbreaking measurement showcases the use of directional Cherenkov information in liquid scintillator detectors, paving the way for future hybrid methods that utilize both Cherenkov and scintillation signals in neutrino research.
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A search for dark matter in the form of strongly interacting massive particles (SIMPs) using the CMS detector at the LHC is presented. The SIMPs would be produced in pairs that manifest themselves as pairs of jets without tracks. The energy fraction of jets carried by charged particles is used as a key discriminator to suppress efficiently the large multijet background, and the remaining background is estimated directly from data.

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Measurements of the inclusive and differential fiducial cross sections of the Higgs boson are presented, using the τ lepton decay channel. The differential cross sections are measured as functions of the Higgs boson transverse momentum, jet multiplicity, and transverse momentum of the leading jet in the event, if any. The analysis is performed using proton-proton collision data collected with the CMS detector at the LHC at a center-of-mass energy of 13  TeV and corresponding to an integrated luminosity of 138  fb^{-1}.

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A search for new long-lived particles decaying to leptons using proton-proton collision data produced by the CERN LHC at is presented. Events are selected with two leptons (an electron and a muon, two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10 and are not required to form a common vertex.

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The first evidence for X(3872) production in relativistic heavy ion collisions is reported. The X(3872) production is studied in lead-lead (Pb-Pb) collisions at a center-of-mass energy of sqrt[s_{NN}]=5.02  TeV per nucleon pair, using the decay chain X(3872)→J/ψπ^{+}π^{-}→μ^{+}μ^{-}π^{+}π^{-}.

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A search for long-lived particles (LLPs) produced in decays of standard model (SM) Higgs bosons is presented. The data sample consists of 137  fb^{-1} of proton-proton collisions at sqrt[s]=13  TeV, recorded at the LHC in 2016-2018. A novel technique is employed to reconstruct decays of LLPs in the end cap muon detectors.

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The first measurements of diboson production cross sections in proton-proton interactions at a center-of-mass energy of 5.02 TeV are reported. They are based on data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 302  pb^{-1}.

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A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 at the CERN LHC, corresponding to an integrated luminosity of 137 collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented.

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The measurement of the luminosity recorded by the CMS detector installed at LHC interaction point 5, using proton-proton collisions at in 2015 and 2016, is reported. The absolute luminosity scale is measured for individual bunch crossings using beam-separation scans (the van der Meer method), with a relative precision of 1.3 and 1.

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A search is presented for a heavy vector resonance decaying into a boson and the standard model Higgs boson, where the boson is identified through its leptonic decays to electrons, muons, or neutrinos, and the Higgs boson is identified through its hadronic decays. The search is performed in a Lorentz-boosted regime and is based on data collected from 2016 to 2018 at the CERN LHC, corresponding to an integrated luminosity of 137 . Upper limits are derived on the production of a narrow heavy resonance , and a mass below 3.

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A search for charged Higgs bosons produced in vector boson fusion processes and decaying into vector bosons, using proton-proton collisions at at the LHC, is reported. The data sample corresponds to an integrated luminosity of 137 collected with the CMS detector. Events are selected by requiring two or three electrons or muons, moderate missing transverse momentum, and two jets with a large rapidity separation and a large dijet mass.

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This paper presents new sets of parameters ("tunes") for the underlying-event model of the event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in , and are obtained from a fit to minimum-bias data collected by the CMS experiment at , 7, and . The tunes are based on the NNPDF 3.

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Collinear (small-angle) and large-angle, as well as soft and hard radiations are investigated in three-jet and  + two-jet events collected in proton-proton collisions at the LHC. The normalized production cross sections are measured as a function of the ratio of transverse momenta of two jets and their angular separation. The measurements in the three-jet and  + two-jet events are based on data collected at a center-of-mass energy of 8 , corresponding to an integrated luminosity of 19.

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Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 , corresponding to an integrated luminosity of 35.9 , are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model.

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