10 research outputs found

    A Performance Analysis Framework for WiFi/WiMAX Heterogeneous Metropolitan Networks Based on Cross-Layer Design

    Get PDF
    The communication between network nodes within different protocol domains is often regarded simply as a black box with unknown configuration conditions in the path. We address network heterogeneity using a white box approach and focus on its interconnection processes. To achieve this purpose, a Performance Analysis Framework (PAF) is proposed which is composed of the formalization of the latter using process algebra (PA) and the corresponding teletraffic performance models. In this contribution, we target the IEEE 802.16 and IEEE 802.11 protocols. For the teletraffic models, we extend previous models for such scenario with the inclusion of the following protocol operational parameters (metrics): bit error rate (BER), packet error ratio (PER), and packet length (pl). From the framework teletraffic models, the optimal packet length (OPL), end to end throughput, delay, and packet loss are obtained. The PAF outperforms previous modeling solutions in terms of delay and throughput relative to NS3 simulation results. </jats:p

    Molecular characterization of a patient with 3p deletion syndrome and a review of the literature

    No full text
    3p deletion syndrome is a rare disorder involving developmental delay, dysmorphic physical features, and growth retardation. Molecular mapping of several cases in the literature have identified a critical region on chromosome 3p26. We present a child patient with characteristic features of 3p deletion syndrome and a de novo unbalanced translocation involving chromosomes 3 and 13. Fine mapping of this rearrangement using fluorescence in situ hybridization (FISH) and array-based comparative genomic hybridization (aCGH) revealed an unbalanced abnormality including a 4.5 Mb terminal deletion of chromosome 3p, telomeric to ITPR1 on 3p26.2, which was not previously identified with routine cytogenetic analysis. In addition, these investigations confirmed and refined the boundaries of a 26.5 Mb deletion of chromosome 13. This study confirms the minimal candidate region for 3p deletion syndrome, provides further evidence implicating haploinsufficiency of CNTN4 in the disorder, and demonstrates the utility of high-resolution investigations of rare chromosomal rearrangements. © 2008 Wiley-Liss, Inc

    Observation of triple J/ψ meson production in proton-proton collisions

    No full text
    Protons consist of three valence quarks, two up-quarks and one down-quark, held together by gluons and a sea of quark-antiquark pairs. Collectively, quarks and gluons are referred to as partons. In a proton-proton collision, typically only one parton of each proton undergoes a hard scattering – referred to as single-parton scattering – leaving the remainder of each proton only slightly disturbed. Here, we report the study of double- and triple-parton scatterings through the simultaneous production of three J/ψ mesons, which consist of a charm quark-antiquark pair, in proton-proton collisions recorded with the CMS experiment at the Large Hadron Collider. We observed this process – reconstructed through the decays of J/ψ mesons into pairs of oppositely charged muons – with a statistical significance above five standard deviations. We measured the inclusive fiducial cross-section to be 272−104+141(stat)±17(syst)fb, and compared it to theoretical expectations for triple-J/ψ meson production in single-, double- and triple-parton scattering scenarios. Assuming factorization of multiple hard-scattering probabilities in terms of single-parton scattering cross-sections, double- and triple-parton scattering are the dominant contributions for the measured process

    Search for new Higgs bosons via same-sign top quark pair production in association with a jet in proton-proton collisions at s=13TeV

    No full text
    A search is presented for new Higgs bosons in proton-proton (pp) collision events in which a same-sign top quark pair is produced in association with a jet, via the pp→tH/A→ttc‟ and pp→tH/A→ttu‟ processes. Here, H and A represent the extra scalar and pseudoscalar boson, respectively, of the second Higgs doublet in the generalized two-Higgs-doublet model (g2HDM). The search is based on pp collision data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 138fb−1. Final states with a same-sign lepton pair in association with jets and missing transverse momentum are considered. New Higgs bosons in the 200–1000 GeV mass range and new Yukawa couplings between 0.1 and 1.0 are targeted in the search, for scenarios in which either H or A appear alone, or in which they coexist and interfere. No significant excess above the standard model prediction is observed. Exclusion limits are derived in the context of the g2HDM

    Search for new heavy resonances decaying to WW, WZ, ZZ, WH, or ZH boson pairs in the all-jets final state in proton-proton collisions at s=13TeV

    No full text
    A search for new heavy resonances decaying to WW, WZ, ZZ, WH, or ZH boson pairs in the all-jets final state is presented. The analysis is based on proton-proton collision data recorded by the CMS detector in 2016–2018 at a centre-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 138fb−1. The search is sensitive to resonances with masses between 1.3 and 6TeV, decaying to bosons that are highly Lorentz-boosted such that each of the bosons forms a single large-radius jet. Machine learning techniques are employed to identify such jets. No significant excess over the estimated standard model background is observed. A maximum local significance of 3.6 standard deviations, corresponding to a global significance of 2.3 standard deviations, is observed at masses of 2.1 and 2.9 TeV. In a heavy vector triplet model, spin-1 Zâ€Č and Wâ€Č resonances with masses below 4.8TeV are excluded at the 95% confidence level (CL). These limits are the most stringent to date. In a bulk graviton model, spin-2 gravitons and spin-0 radions with masses below 1.4 and 2.7TeV, respectively, are excluded at 95% CL. Production of heavy resonances through vector boson fusion is constrained with upper cross section limits at 95% CL as low as 0.1fb

    Study of azimuthal anisotropy of ϒ(1S) mesons in pPb collisions at sNN = 8.16 TeV

    No full text
    The azimuthal anisotropy of Image 1 mesons in high-multiplicity proton-lead collisions is studied using data collected by the CMS experiment at a nucleon-nucleon center-of-mass energy of 8.16TeV. The Image 1 mesons are reconstructed using their dimuon decay channel. The anisotropy is characterized by the second Fourier harmonic coefficients, found using a two-particle correlation technique, in which the Image 1 mesons are correlated with charged hadrons. A large pseudorapidity gap is used to suppress short-range correlations. Nonflow contamination from the dijet background is removed using a low-multiplicity subtraction method, and the results are presented as a function of Image 1 transverse momentum. The azimuthal anisotropies are smaller than those found for charmonia in proton-lead collisions at the same collision energy, but are consistent with values found for Image 1 mesons in lead-lead interactions at a nucleon-nucleon center-of-mass energy of 5.02 TeV

    Measurement of the ttÂŻ charge asymmetry in events with highly Lorentz-boosted top quarks in pp collisions at s=13 TeV

    No full text
    The measurement of the charge asymmetry in top quark pair events with highly Lorentz-boosted top quarks decaying to a single lepton and jets is presented. The analysis is performed using proton-proton collisions at s=13TeV with the CMS detector at the LHC and corresponding to an integrated luminosity of 138 fb−1. The selection is optimized for top quarks produced with large Lorentz boosts, resulting in nonisolated leptons and overlapping jets. The top quark charge asymmetry is measured for events with a tt¯ invariant mass larger than 750 GeV and corrected for detector and acceptance effects using a binned maximum likelihood fit. The measured top quark charge asymmetry of (0.42−0.69+0.64)% is in good agreement with the standard model prediction at next-to-next-to-leading order in quantum chromodynamic perturbation theory with next-to-leading-order electroweak corrections. The result is also presented for two invariant mass ranges, 750–900 and >900GeV

    Measurement of the Bs0→Ό+Ό− decay properties and search for the B0â€Żâ†’â€ŻÎŒ+Ό− decay in proton-proton collisions at s=13TeV

    Get PDF
    Measurements are presented of the Bs0→Ό+Ό− branching fraction and effective lifetime, as well as results of a search for the B0→Ό+Ό− decay in proton-proton collisions at s=13TeV at the LHC. The analysis is based on data collected with the CMS detector in 2016–2018 corresponding to an integrated luminosity of 140fb−1. The branching fraction of the Bs0→Ό+Ό− decay and the effective Bs0 meson lifetime are the most precise single measurements to date. No evidence for the B0→Ό+Ό− decay has been found. All results are found to be consistent with the standard model predictions and previous measurements

    Measurements of azimuthal anisotropy of nonprompt D0 mesons in PbPb collisions at sNN=5.02TeV

    No full text
    Measurements of the elliptic (v2) and triangular (v3) azimuthal anisotropy coefficients are presented for Image 1 mesons produced in Image 2 hadron decays (nonprompt Image 1 mesons) in lead-lead collisions at sNN=5.02TeV. The results are compared with previously published charm meson anisotropies measured using prompt Image 1 mesons. The data were collected with the CMS detector in 2018 with an integrated luminosity of 0.58nb−1. Azimuthal anisotropy is sensitive to the interactions of quarks with the hot and dense medium created in heavy ion collisions. Comparing results for prompt and nonprompt Image 1 mesons can assist in understanding the mass dependence of these interactions. The nonprompt results show lower magnitudes of v2 and v3 and weaker dependences on the meson transverse momentum and collision centrality than those found for prompt Image 1 mesons. The results are in agreement with theoretical predictions that include a mass dependence in the interactions of quarks with the medium

    Strategies and performance of the CMS silicon tracker alignment during LHC Run 2

    No full text
    The strategies for and the performance of the CMS silicon tracking system alignment during the 2015–2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios
    corecore