250 research outputs found

    Electroacupuncture for psychogenic erectile dysfunction: A resting-state functional magnetic resonance imaging study exploring the alteration of fractional amplitude of low frequency fluctuation

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    BackgroundPsychogenic erectile dysfunction (PED) can seriously affect emotional and marital wellbeing. Electroacupuncture (EA) seems an effective method for treating PED. However, the central mechanisms underlying PED and the beneficial effects of EA treatment are unclear. The purpose of this study was to explore the central mechanisms of PED and to examine the impact of EA on erectile function.MethodsWe recruited 14 PED patients and 14 matched normal controls (NCs). PED patients underwent twice rs-fMRI scans, respectively, pre- and post-treatment. The NCs only completed one rs-fMRI scan. We used the fractional amplitude of low frequency fluctuation (fALFF) to compare spontaneous neural activity between the PED patients and NCs, and to examine the differences between the pre- and post-EA treatment scans in the PED patients.ResultsScores on the IIEF5, QEQ, and SEAR improved after EA treatment. Compared with the NCs, PED patients showed increased fALFF in the right posterior cingulate cortex (PCC), right dorsolateral prefrontal cortex (DLPFC), right supplementary motor area (SMA), and left middle occipital gyrus. Most of these regions are closely implicated in sexual inhibition. The results of the correlation analysis results indicated that the fALFF of the right PCC was negatively correlated with IIEF5 scores. After treatment, fALFF values were substantially lower in the left triangular part of the inferior frontal gyrus, right DLPFC, right SMA, bilateral PCC and the orbital part of the middle frontal gyrus, and higher in the left middle temporal gyrus and left caudate nucleus. These regions mainly belong to the default mode network (DMN), executive control network and primary sensory motor network. The results of the correlation analysis indicated a positive association between the changes in IIEF5 score and changes in the fALFF value in the right PCC after EA treatment.ConclusionIn conclusion, our study highlights that PED patients have abnormal patterns of activity in the right PCC, right DLPFC, and right SMA mainly involved in the DMN, executive central network, and sensory motor network which could lead to a higher levels of sexual inhibition. EA might regulate the process of sexual inhibition to improve erection function in PED patients probably by modulating spontaneous brain activity in the DMN, executive central network, and sensory motor network

    Search for Bc+π+μ+μB_c^+\to\pi^+\mu^+\mu^- decays and measurement of the branching fraction ratio B(Bc+ψ(2S)π+)/B(Bc+J/ψπ+){\cal B}(B_c^+\to\psi(2S)\pi^+)/{\cal B}(B_c^+\to J/\psi \pi^+)

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    International audienceThe first search for nonresonant Bc+π+μ+μB_c^+\to\pi^+\mu^+\mu^- decays is reported. The analysis uses proton-proton collision data collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9 fb1^{-1}. No evidence for an excess of signal events over background is observed and an upper limit is set on the branching fraction ratio B(Bc+π+μ+μ)/B(Bc+J/ψπ+)<2.1×104{\cal B}(B_c^+\to\pi^+\mu^+\mu^-)/{\cal B}(B_c^+\to J/\psi \pi^+) < 2.1\times 10^{-4} at 90%90\% confidence level. Additionally, an updated measurement of the ratio of the Bc+ψ(2S)π+B_c^+\to\psi(2S)\pi^+ and Bc+J/ψπ+B_c^+\to J/\psi \pi^+ branching fractions is reported. The ratio B(Bc+ψ(2S)π+)/B(Bc+J/ψπ+){\cal B}(B_c^+\to\psi(2S)\pi^+)/{\cal B}(B_c^+\to J/\psi \pi^+) is measured to be 0.254±0.018±0.003±0.0050.254\pm 0.018 \pm 0.003 \pm 0.005, where the first uncertainty is statistical, the second systematic, and the third is due to the uncertainties on the branching fractions of the leptonic J/ψJ/\psi and ψ(2S)\psi(2S) decays. This measurement is the most precise to date and is consistent with previous LHCb results

    Helium identification with LHCb

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    International audienceThe 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 pppp collision data at s=13TeV\sqrt{s}=13\,{\rm TeV} recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5fb15.5\,{\rm fb}^{-1}. A total of around 10510^5 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50%50\% with a corresponding background rejection rate of up to O(1012)\mathcal O(10^{12}). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

    Charge-dependent curvature-bias corrections using a pseudomass method

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    International audienceMomentum 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\sqrt{s}=13 TeV during 2016, 2017 and 2018. The biases are determined using Zμ+μZ\to\mu^+\mu^- decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10410^{-4} GeV1^{-1} level, improves the Zμ+μZ\to\mu^+\mu^- mass resolution by roughly 20% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass

    Measurement of J/ψJ/\psi-pair production in pppp collisions at s=13\sqrt{s}=13 TeV and study of gluon transverse-momentum dependent PDFs

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    The production cross-section of J/ψJ/\psi pairs in proton-proton collisions at a centre-of-mass energy of s=13\sqrt{s}=13 TeV is measured using a data sample corresponding to an integrated luminosity of 4.2 fb1^{-1} collected by the LHCb experiment. The measurement is performed with both J/ψJ/\psi mesons in the transverse momentum range 0<pT<140 < p_{\text{T}}<14 GeV/cc and rapidity range 2.0<y<4.52.0 < y < 4.5. The cross-section of this process is measured to be 16.36±\pm0.28(stat)±\pm0.88(syst) nb. The contributions from single-parton scattering and double-parton scattering are separated based on the dependence of the cross-section on the absolute rapidity difference Δy\Delta y between the two J/ψJ/\psi mesons. The effective cross-section of double-parton scattering is measured to be σeff=\sigma_{\text{eff}}=13.1±\pm1.8(stat)±\pm2.3(syst) mb. The distribution of the azimuthal angle ϕCS\phi_{\text{CS}} of one of the J/ψJ/\psi mesons in the Collins-Soper frame and the pTp_{\text{T}}-spectrum of the J/ψJ/\psi pairs are also measured for the study of the gluon transverse-momentum dependent distributions inside protons. The extracted values of cos2ϕCS\langle\cos2\phi_{\text{CS}}\rangle and cos4ϕCS\langle\cos4\phi_{\text{CS}}\rangle are consistent with zero, but the presence of azimuthal asymmetry at a few percent level is allowed.The production cross-section of J/ψJ/\psi pairs in proton-proton collisions at a centre-of-mass energy of s=13\sqrt{s}=13 TeV is measured using a data sample corresponding to an integrated luminosity of 4.2 fb1^{-1} collected by the LHCb experiment. The measurement is performed with both J/ψJ/\psi mesons in the transverse momentum range 0<pT<140<p_{\text{T}}<14 GeV/cc and rapidity range 2.0<y<4.52.0<y<4.5. The cross-section of this process is measured to be 16.36±\pm0.28(stat)±\pm0.88(syst) nb. The contributions from single-parton scattering and double-parton scattering are separated based on the dependence of the cross-section on the absolute rapidity difference Δy\Delta y between the two J/ψJ/\psi mesons. The effective cross-section of double-parton scattering is measured to be σeff=\sigma_{\text{eff}}=13.1±\pm1.8(stat)±\pm2.3(syst) mb. The distribution of the azimuthal angle ϕCS\phi_{\text{CS}} of one of the J/ψJ/\psi mesons in the Collins-Soper frame and the pTp_{\text{T}}-spectrum of the J/ψJ/\psi pairs are also measured for the study of the gluon transverse-momentum dependent distributions inside protons. The extracted values of cos2ϕCS\langle\cos2\phi_{\text{CS}}\rangle and cos4ϕCS\langle\cos4\phi_{\text{CS}}\rangle are consistent with zero, but the presence of azimuthal asymmetry at a few percent level is allowed

    Study of charmonium production via the decay to ppˉp\bar{p} at s=13TeV\sqrt{s} = 13 TeV

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    International audienceCharmonium production cross-section in proton-proton collisions is measured at the centre-of-mass energy s=13TeV\sqrt{s}=13\,TeV using decays to ppˉp\bar{p} final state. The study is performed using a data sample corresponding to an integrated luminosity of 2.2fb12.2\,{fb}^{-1} collected in 2018 with the LHCbLHCb detector. The production cross-section of the ηc\eta_c meson is measured in a rapidity range of 2.0<y<4.02.0 < y < 4.0 and in a transverse momentum range of 5.0<pT<20.0GeV/c5.0 < p_{T} < 20.0\,{GeV/\it{c}}, which is extended compared with previous LHCbLHCb analyses. The differential cross-section is measured in bins of pTp_{T} and, for the first time, of yy. Upper limits, at 90% and 95% confidence levels, on the ηc(2S)\eta_c(2S) and hc(1P)h_c(1P) prompt production cross-sections are determined for the first time

    Measurements of the branching fraction ratio B(ϕμ+μ)/B(ϕe+e)\cal{B}(\phi \to \mu^+\mu^-)/\cal{B}(\phi \to e^+e^-) with charm meson decays

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    International audienceMeasurements of the branching fraction ratio B(ϕμ+μ)/B(ϕe+e){\cal{B}(\phi \to \mu^+ \mu^-)/\cal{B}(\phi\to e^+e^-)} with Ds+π+ϕ{D_{s}^{+} \to \pi^{+} \phi} and D+π+ϕ{D^{+} \to \pi^{+} \phi} decays, denoted RϕπsR^{s}_{\phi \pi} and RϕπdR^{d}_{\phi \pi}, are presented. The analysis is performed using a dataset corresponding to an integrated luminosity of 5.4fb1\,\rm{fb}^{-1} of pppp collision data collected with the LHCb experiment. The branching fractions are normalised with respect to the B+K+J/ψ(e+e){B^{+} \to K^{+} J/\psi(\to e^+e^-)} and B+K+J/ψ(μ+μ){B^{+} \to K^{+} J/\psi(\to \mu^+\mu^-)} decay modes. The combination of the results yields Rϕπ=1.022±0.012(stat)±0.048(syst). R_{\phi \pi} = 1.022 \pm 0.012 \,({\rm stat}) \, \pm 0.048 \,({\rm syst}). The result is compatible with previous measurements of the ϕ+\phi \to \ell^{+}\ell^{-} branching fractions and predictions based on the Standard Model

    Helium identification with LHCb

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    International audienceThe 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 pppp collision data at s=13TeV\sqrt{s}=13\,{\rm TeV} recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5fb15.5\,{\rm fb}^{-1}. A total of around 10510^5 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50%50\% with a corresponding background rejection rate of up to O(1012)\mathcal O(10^{12}). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

    Observation of the decays B(s)0Ds1(2536)K±B_{(s)}^{0}\to D_{s1}(2536)^{\mp}K^{\pm}

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    International audienceThis paper reports the observation of the decays B(s)0Ds1(2536)K±B_{(s)}^{0}\to D_{s1}(2536)^{\mp}K^{\pm} using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9fb19\,\mathrm{fb}^{-1}. The branching fractions of these decays are measured relative to the normalisation channel B0D0K+KB^{0}\to \overline{D}^{0}K^{+}K^{-}. The Ds1(2536)D_{s1}(2536)^{-} meson is reconstructed in the D(2007)0K\overline{D}^{*}(2007)^{0}K^{-} decay channel and the products of branching fractions are measured to be B(Bs0Ds1(2536)K±)×B(Ds1(2536)D(2007)0K)=(2.49±0.11±0.12±0.25±0.06)×105,\mathcal{B}(B_{s}^{0}\to D_{s1}(2536)^{\mp}K^{\pm})\times\mathcal{B}(D_{s1}(2536)^{-}\to\overline{D}^{*}(2007)^{0}K^{-})=(2.49\pm0.11\pm0.12\pm0.25\pm0.06)\times 10^{-5}, B(B0Ds1(2536)K±)×B(Ds1(2536)D(2007)0K)=(0.510±0.021±0.036±0.050)×105.\mathcal{B}(B^{0}\to D_{s1}(2536)^{\mp}K^{\pm})\times\mathcal{B}(D_{s1}(2536)^{-}\to\overline{D}^{*}(2007)^{0}K^{-}) = (0.510\pm0.021\pm0.036\pm0.050)\times 10^{-5}. The first uncertainty is statistical, the second systematic, and the third arises from the uncertainty of the branching fraction of the B0D0K+KB^{0}\to \overline{D}^{0}K^{+}K^{-} normalisation channel. The last uncertainty in the Bs0B_{s}^{0} result is due to the limited knowledge of the fragmentation fraction ratio, fs/fdf_{s}/f_{d}. The significance for the Bs0B_{s}^{0} and B0B^{0} signals is larger than 10σ10\,\sigma. The ratio of the helicity amplitudes which governs the angular distribution of the Ds1(2536)D(2007)0KD_{s1}(2536)^{-}\to\overline{D}^{*}(2007)^{0}K^{-} decay is determined from the data. The ratio of the SS- and DD-wave amplitudes is found to be 1.11±0.15±0.061.11\pm0.15\pm 0.06 and its phase 0.70±0.09±0.040.70\pm0.09\pm 0.04 rad, where the first uncertainty is statistical and the second systematic
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