12 research outputs found

    Olfactory and gustatory dysfunction in patients with autoimmune encephalitis

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    OBJECTIVE: To test the hypothesis that olfactory (OF) and gustatory function (GF) is disturbed in patients with autoimmune encephalitides (AE). METHODS: The orthonasal OF was tested in 32 patients with AE and 32 age- and sex-matched healthy controls (HC) with the standardized Threshold Discrimination Identification (TDI) score. This validated olfactory testing method yields individual scores for olfactory threshold (T), odor discrimination (D), and identification (I), along with a composite TDI score. The GF was determined by the Taste Strip Test (TST). RESULTS: Overall, 24/32 (75%) of patients with AE, but none of 32 HC (p < 0.001) had olfactory dysfunction in TDI testing. The results of the threshold, discrimination and identification subtests were significantly reduced in patients with AE compared to HC (all p < 0.001). Assessed by TST, 5/19 (26.3%) of patients with AE, but none of 19 HC presented a significant limitation in GF (p < 0.001). The TDI score was correlated with the subjective estimation of the olfactory capacity on a visual analog scale (VAS; r(s) = 0.475, p = 0.008). Neither age, sex, modified Rankin Scale nor disease duration were associated with the composite TDI score. CONCLUSIONS: This is the first study investigating OF and GF in AE patients. According to unblinded assessment, patients with AE have a reduced olfactory and gustatory capacity compared to HC, suggesting that olfactory and gustatory dysfunction are hitherto unrecognized symptoms in AE. Further studies with larger number of AE patients would be of interest to verify our results

    Helium identification with LHCb

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    The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

    Measurement of forward charged hadron flow harmonics in peripheral PbPb collisions at √sNN = 5.02 TeV with the LHCb detector

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    Flow harmonic coefficients, v n , which are the key to studying the hydrodynamics of the quark-gluon plasma (QGP) created in heavy-ion collisions, have been measured in various collision systems and kinematic regions and using various particle species. The study of flow harmonics in a wide pseudorapidity range is particularly valuable to understand the temperature dependence of the shear viscosity to entropy density ratio of the QGP. This paper presents the first LHCb results of the second- and the third-order flow harmonic coefficients of charged hadrons as a function of transverse momentum in the forward region, corresponding to pseudorapidities between 2.0 and 4.9, using the data collected from PbPb collisions in 2018 at a center-of-mass energy of 5.02 TeV . The coefficients measured using the two-particle angular correlation analysis method are smaller than the central-pseudorapidity measurements at ALICE and ATLAS from the same collision system but share similar features

    Curvature-bias corrections using a pseudomass method

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    Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using Z→μ + μ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z→μ + μ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass

    Measurement of the DD^* longitudinal polarization in B0Dτ+ντB^0 \to D^{* -}\tau^+\nu_{\tau} decays  

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    The longitudinal polarization fraction of the DD^* meson is measured in B0Dτ+ντB^0 \to D^{* -}\tau^+\nu_{\tau} decays, where the τ\tau lepton decays to three charged pions and a neutrino, using proton-proton collision data collected by the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV and corresponding to an integrated luminosity of 5 fb1^{-1}. The DD^* polarization fraction FLDF_L^{D^*} is measured in two q2q^2 regions, below and above 7 GeV2^2/c4^4, where q2q^2 is defined as the squared invariant mass of the τντ\tau\nu_{\tau} system. The FLDF_L^{D^*} values are measured to be 0.51±0.07±0.030.51 \pm 0.07 \pm 0.03 and 0.35±0.08±0.020.35 \pm 0.08 \pm 0.02 for the lower and higher q2q^2 regions, respectively. The first uncertainties are statistical and the second systematic. The average value over the whole q2q^2 range is: FLD=0.43±0.06±0.03.F_L^{D^*} = 0.43 \pm 0.06 \pm 0.03. These results are compatible with the Standard Model predictions.The longitudinal polarization fraction of the DD^{*} meson is measured in B0Dτ+ντB^0\to D^{*-}\tau^{+}\nu_{\tau} decays, where the τ\tau lepton decays to three charged pions and a neutrino, using proton-proton collision data collected by the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV and corresponding to an integrated luminosity of 5 fb1^{-1}. The DD^{*} polarization fraction FLDF_{L}^{D^{*}} is measured in two q2q^{2} regions, below and above 7 GeV2/c4^{2}/c^{4}, where q2q^{2} is defined as the squared invariant mass of the τντ\tau\nu_{\tau} system. The FLDF_{L}^{D^{*}} values are measured to be 0.51±0.07±0.030.51 \pm 0.07 \pm 0.03 and 0.35±0.08±0.020.35 \pm 0.08 \pm 0.02 for the lower and higher q2q^{2} regions, respectively. The first uncertainties are statistical and the second systematic. The average value over the whole q2q^{2} range is: FLD=0.43±0.06±0.03.F_{L}^{D^{*}} = 0.43 \pm 0.06 \pm 0.03. These results are compatible with the Standard Model predictions

    Measurement of the DD^{*} longitudinal polarization in B0Dτ+ντB^0\to D^{*-}\tau^{+}\nu_{\tau} decays

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    International audienceThe longitudinal polarization fraction of the DD^{*} meson is measured in B0Dτ+ντB^0\to D^{*-}\tau^{+}\nu_{\tau} decays, where the τ\tau lepton decays to three charged pions and a neutrino, using proton-proton collision data collected by the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV and corresponding to an integrated luminosity of 5 fb1^{-1}. The DD^{*} polarization fraction FLDF_{L}^{D^{*}} is measured in two q2q^{2} regions, below and above 7 GeV2/c4^{2}/c^{4}, where q2q^{2} is defined as the squared invariant mass of the τντ\tau\nu_{\tau} system. The FLDF_{L}^{D^{*}} values are measured to be 0.51±0.07±0.030.51 \pm 0.07 \pm 0.03 and 0.35±0.08±0.020.35 \pm 0.08 \pm 0.02 for the lower and higher q2q^{2} regions, respectively. The first uncertainties are statistical and the second systematic. The average value over the whole q2q^{2} range is: FLD=0.43±0.06±0.03.F_{L}^{D^{*}} = 0.43 \pm 0.06 \pm 0.03. These results are compatible with the Standard Model predictions

    Measurement of the DD^{*} longitudinal polarization in B0Dτ+ντB^0\to D^{*-}\tau^{+}\nu_{\tau} decays

    No full text
    International audienceThe longitudinal polarization fraction of the DD^{*} meson is measured in B0Dτ+ντB^0\to D^{*-}\tau^{+}\nu_{\tau} decays, where the τ\tau lepton decays to three charged pions and a neutrino, using proton-proton collision data collected by the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV and corresponding to an integrated luminosity of 5 fb1^{-1}. The DD^{*} polarization fraction FLDF_{L}^{D^{*}} is measured in two q2q^{2} regions, below and above 7 GeV2/c4^{2}/c^{4}, where q2q^{2} is defined as the squared invariant mass of the τντ\tau\nu_{\tau} system. The FLDF_{L}^{D^{*}} values are measured to be 0.51±0.07±0.030.51 \pm 0.07 \pm 0.03 and 0.35±0.08±0.020.35 \pm 0.08 \pm 0.02 for the lower and higher q2q^{2} regions, respectively. The first uncertainties are statistical and the second systematic. The average value over the whole q2q^{2} range is: FLD=0.43±0.06±0.03.F_{L}^{D^{*}} = 0.43 \pm 0.06 \pm 0.03. These results are compatible with the Standard Model predictions

    Measurement of the DD^{*} longitudinal polarization in B0Dτ+ντB^0\to D^{*-}\tau^{+}\nu_{\tau} decays

    No full text
    International audienceThe longitudinal polarization fraction of the DD^{*} meson is measured in B0Dτ+ντB^0\to D^{*-}\tau^{+}\nu_{\tau} decays, where the τ\tau lepton decays to three charged pions and a neutrino, using proton-proton collision data collected by the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV and corresponding to an integrated luminosity of 5 fb1^{-1}. The DD^{*} polarization fraction FLDF_{L}^{D^{*}} is measured in two q2q^{2} regions, below and above 7 GeV2/c4^{2}/c^{4}, where q2q^{2} is defined as the squared invariant mass of the τντ\tau\nu_{\tau} system. The FLDF_{L}^{D^{*}} values are measured to be 0.51±0.07±0.030.51 \pm 0.07 \pm 0.03 and 0.35±0.08±0.020.35 \pm 0.08 \pm 0.02 for the lower and higher q2q^{2} regions, respectively. The first uncertainties are statistical and the second systematic. The average value over the whole q2q^{2} range is: FLD=0.43±0.06±0.03.F_{L}^{D^{*}} = 0.43 \pm 0.06 \pm 0.03. These results are compatible with the Standard Model predictions

    Measurement of the DD^{*} longitudinal polarization in B0Dτ+ντB^0\to D^{*-}\tau^{+}\nu_{\tau} decays

    No full text
    International audienceThe longitudinal polarization fraction of the DD^{*} meson is measured in B0Dτ+ντB^0\to D^{*-}\tau^{+}\nu_{\tau} decays, where the τ\tau lepton decays to three charged pions and a neutrino, using proton-proton collision data collected by the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV and corresponding to an integrated luminosity of 5 fb1^{-1}. The DD^{*} polarization fraction FLDF_{L}^{D^{*}} is measured in two q2q^{2} regions, below and above 7 GeV2/c4^{2}/c^{4}, where q2q^{2} is defined as the squared invariant mass of the τντ\tau\nu_{\tau} system. The FLDF_{L}^{D^{*}} values are measured to be 0.51±0.07±0.030.51 \pm 0.07 \pm 0.03 and 0.35±0.08±0.020.35 \pm 0.08 \pm 0.02 for the lower and higher q2q^{2} regions, respectively. The first uncertainties are statistical and the second systematic. The average value over the whole q2q^{2} range is: FLD=0.43±0.06±0.03.F_{L}^{D^{*}} = 0.43 \pm 0.06 \pm 0.03. These results are compatible with the Standard Model predictions
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