Publications by authors named "Wittich P"

A study of vector boson scattering in pp collisions at a center-of-mass energy of 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.4  fb(-1) collected with the CMS detector.

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The ratio between the prompt ψ(2S) and J/ψ yields, reconstructed via their decays into μ+ μ-, is measured in Pb-Pb and p-p collisions at sqrt[sNN]=2.76  TeV. The analysis is based on Pb-Pb and p-p data samples collected by CMS at the Large Hadron Collider, corresponding to integrated luminosities of 150  μb(-1) and 5.

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We report a measurement of single top quark production in proton-antiproton collisions at a center-of-mass energy of sqrt[s]=1.96  TeV using a data set corresponding to 7.5  fb(-1) of integrated luminosity collected by the Collider Detector at Fermilab.

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Article Synopsis
  • The study presents measurements of CP-violating asymmetries in the decay of neutral bottom hadrons at the Fermilab Tevatron using upgraded detector technology and a significant dataset.
  • Two specific decay processes were analyzed: Λ(b)⁰ decaying to pπ⁻ and pK⁻, showing no significant asymmetry in their measurements.
  • In contrast, notable CP-violating asymmetries were identified in the decays of B(s)⁰ to K⁻π⁺ and B⁰ to K⁺π⁻, aligning with existing world averages and confirming significant deviations from zero.
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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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We measure the inclusive forward-backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton-antiproton collisions and decaying to final states that contain two charged leptons (electrons or muons). The data are collected with the Collider Detector at Fermilab and correspond to an integrated luminosity of 9.1 fb(-1).

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  • A search was conducted for the production of single top quarks via an s-channel virtual W boson, analyzing events with imbalanced transverse energy, b-tagged jets, and no leptons.
  • This study measured a cross section of 1.12 pb (with uncertainty) for this process, achieving a significance of 1.9 standard deviations.
  • The results were combined with another method involving imbalanced transverse momentum, b-tagged jets, and one lepton, yielding a higher cross section of 1.36 pb and a significance of 4.2 standard deviations.
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We report evidence for s-channel single-top-quark production in proton-antiproton collisions at center-of-mass energy sqrt[s] = 1.96 TeV using a data set that corresponds to an integrated luminosity of 9.4 fb(-1) collected by the Collider Detector at Fermilab.

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We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.

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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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We present a measurement of the ratio of the top-quark branching fractions R=B(t→Wb)/B(t→Wq), where q represents any quark flavor, in events with two charged leptons, imbalance in total transverse energy, and at least two jets. The measurement uses proton-antiproton collision data at center-of-mass energy 1.96 TeV, corresponding to an integrated luminosity of 8.

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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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  • * 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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A search for forbidden and exotic Z boson decays in the diphoton mass spectrum is presented for the first time in hadron collisions, based on data corresponding to 10.0 fb(-1) of integrated luminosity from proton-antiproton collisions at √s = 1.96 TeV collected by the CDF experiment.

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Background: Fractures of the humeral shaft are associated with a profound temporary (and in the elderly sometimes even permanent) impairment of independence and quality of life. These fractures can be treated operatively or non-operatively, but the optimal tailored treatment is an unresolved problem. As no high-quality comparative randomized or observational studies are available, a recent Cochrane review concluded there is no evidence of sufficient scientific quality available to inform the decision to operate or not.

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We measure the time dependence of the ratio of decay rates for D0→K(+)π(-) to the Cabibbo-favored decay D(0)→K(-)π(+). The charge conjugate decays are included. A signal of 3.

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A measurement of the cross section for the production of top quark-antiquark pairs ([Formula: see text]) in association with a vector boson V (W or Z) in proton-proton collisions at [Formula: see text][Formula: see text] is presented. The results are based on a dataset corresponding to an integrated luminosity of 19.5 fb[Formula: see text] recorded with the CMS detector at the LHC.

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Searches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and [Formula: see text], [Formula: see text], and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy [Formula: see text] with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 [Formula: see text].

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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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