493 research outputs found

    Association of antioxidants use with the risk of dementia among community-dwelling adults in the United Kingdom biobank

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    BackgroundData regarding the association between antioxidant supplementation and incident dementia are limited.MethodsWe included 494,632 adults (54.5% females) aged 40–71 years at baseline from the United Kingdom Biobank in the final analysis. Incident dementia was ascertained using hospital inpatient and death records up to January 2021.ResultsOver a median follow-up of 11.9 years, 7,128 new cases of all-cause dementia, 2,772 cases of Alzheimer’s disease, and 1,397 cases of vascular dementia were recorded. The hazard ratio (95% CI) for incident dementia associated with zinc supplementation was 0.84 (0.74–0.96), and the association remained significant after adjusting for all confounders (0.84 (0.74–0.96)). In the full model, zinc supplementation was associated with a reduced risk of Alzheimer’s disease [HR (95% CI): 0.71 (0.57–0.88)]. There was no significant association between zinc supplementation and the risk of vascular dementia. No significant associations with incident dementia were observed for other antioxidant supplementation. The association between zinc supplementation and incident dementia was significant among individuals with [HR (95% CI): 0.34 (0.15–0.77)] and without cataract [0.87 (0.77–0.99)] but it was stronger among those with cataract (p value for interaction = 0.0271).ConclusionOur findings suggest that zinc supplementation may help reduce the risk of all-cause dementia and Alzheimer’s disease in middle-aged or older adults, especially among those with cataracts

    Observation of ηcωω\eta_c\to\omega\omega in J/ψγωωJ/\psi\to\gamma\omega\omega

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    Using a sample of (1310.6±7.0)×106(1310.6\pm7.0)\times10^6 J/ψJ/\psi events recorded with the BESIII detector at the symmetric electron positron collider BEPCII, we report the observation of the decay of the (11S0)(1^1 S_0) charmonium state ηc\eta_c into a pair of ω\omega mesons in the process J/ψγωωJ/\psi\to\gamma\omega\omega. The branching fraction is measured for the first time to be B(ηcωω)=(2.88±0.10±0.46±0.68)×103\mathcal{B}(\eta_c\to\omega\omega)= (2.88\pm0.10\pm0.46\pm0.68)\times10^{-3}, where the first uncertainty is statistical, the second systematic and the third is from the uncertainty of B(J/ψγηc)\mathcal{B}(J/\psi\to\gamma\eta_c). The mass and width of the ηc\eta_c are determined as M=(2985.9±0.7±2.1)M=(2985.9\pm0.7\pm2.1)\,MeV/c2c^2 and Γ=(33.8±1.6±4.1)\Gamma=(33.8\pm1.6\pm4.1)\,MeV.Comment: 13 pages, 6 figure

    Observation and study of the decay J/ψϕηηJ/\psi\rightarrow\phi\eta\eta'

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    We report the observation and study of the decay J/ψϕηηJ/\psi\rightarrow\phi\eta\eta' using 1.3×1091.3\times{10^9} J/ψJ/\psi events collected with the BESIII detector. Its branching fraction, including all possible intermediate states, is measured to be (2.32±0.06±0.16)×104(2.32\pm0.06\pm0.16)\times{10^{-4}}. We also report evidence for a structure, denoted as XX, in the ϕη\phi\eta' mass spectrum in the 2.02.12.0-2.1 GeV/c2c^2 region. Using two decay modes of the η\eta' meson (γπ+π\gamma\pi^+\pi^- and ηπ+π\eta\pi^+\pi^-), a simultaneous fit to the ϕη\phi\eta' mass spectra is performed. Assuming the quantum numbers of the XX to be JP=1J^P = 1^-, its significance is found to be 4.4σ\sigma, with a mass and width of (2002.1±27.5±21.4)(2002.1 \pm 27.5 \pm 21.4) MeV/c2c^2 and (129±17±9)(129 \pm 17 \pm 9) MeV, respectively, and a product branching fraction B(J/ψηX)×B(Xϕη)=(9.8±1.2±1.7)×105\mathcal{B}(J/\psi\rightarrow\eta{}X)\times{}\mathcal{B}(X\rightarrow\phi\eta')=(9.8 \pm 1.2 \pm 1.7)\times10^{-5}. Alternatively, assuming JP=1+J^P = 1^+, the significance is 3.8σ\sigma, with a mass and width of (2062.8±13.1±7.2)(2062.8 \pm 13.1 \pm 7.2) MeV/c2c^2 and (177±36±35)(177 \pm 36 \pm 35) MeV, respectively, and a product branching fraction B(J/ψηX)×B(Xϕη)=(9.6±1.4±2.0)×105\mathcal{B}(J/\psi\rightarrow\eta{}X)\times{}\mathcal{B}(X\rightarrow\phi\eta')=(9.6 \pm 1.4 \pm 2.0)\times10^{-5}. The angular distribution of J/ψηXJ/\psi\rightarrow\eta{}X is studied and the two JPJ^P assumptions of the XX cannot be clearly distinguished due to the limited statistics. In all measurements the first uncertainties are statistical and the second systematic.Comment: 10 pages, 6 figures and 4 table

    Observation of Ds+pnˉD^+_s\rightarrow p\bar{n} and confirmation of its large branching fraction

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    The baryonic decay Ds+pnˉD^+_s\rightarrow p\bar{n} is observed, and the corresponding branching fraction is measured to be (1.21±0.10±0.05)×103(1.21\pm0.10\pm0.05)\times10^{-3}, where the first uncertainty is statistical and second systematic. The data sample used in this analysis was collected with the BESIII detector operating at the BEPCII e+ee^+e^- double-ring collider with a center-of-mass energy of 4.178~GeV and an integrated luminosity of 3.19~fb1^{-1}. The result confirms the previous measurement by the CLEO Collaboration and is of greatly improved precision, which may deepen our understanding of the dynamical enhancement of the W-annihilation topology in the charmed meson decays

    Evidence of a resonant structure in the e+eπ+D0De^+e^-\to \pi^+D^0D^{*-} cross section between 4.05 and 4.60 GeV

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    The cross section of the process e+eπ+D0De^+e^-\to \pi^+D^0D^{*-} for center-of-mass energies from 4.05 to 4.60~GeV is measured precisely using data samples collected with the BESIII detector operating at the BEPCII storage ring. Two enhancements are clearly visible in the cross section around 4.23 and 4.40~GeV. Using several models to describe the dressed cross section yields stable parameters for the first enhancement, which has a mass of 4228.6 \pm 4.1 \pm 6.3 \un{MeV}/c^2 and a width of 77.0 \pm 6.8 \pm 6.3 \un{MeV}, where the first uncertainties are statistical and the second ones are systematic. Our resonant mass is consistent with previous observations of the Y(4220)Y(4220) state and the theoretical prediction of a DDˉ1(2420)D\bar{D}_1(2420) molecule. This result is the first observation of Y(4220)Y(4220) associated with an open-charm final state. Fits with three resonance functions with additional Y(4260)Y(4260), Y(4320)Y(4320), Y(4360)Y(4360), ψ(4415)\psi(4415), or a new resonance, do not show significant contributions from either of these resonances. The second enhancement is not from a single known resonance. It could contain contributions from ψ(4415)\psi(4415) and other resonances, and a detailed amplitude analysis is required to better understand this enhancement

    Search for the decay J/ψγ+invisibleJ/\psi\to\gamma + \rm {invisible}

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    We search for J/ψJ/\psi radiative decays into a weakly interacting neutral particle, namely an invisible particle, using the J/ψJ/\psi produced through the process ψ(3686)π+πJ/ψ\psi(3686)\to\pi^+\pi^-J/\psi in a data sample of (448.1±2.9)×106(448.1\pm2.9)\times 10^6 ψ(3686)\psi(3686) decays collected by the BESIII detector at BEPCII. No significant signal is observed. Using a modified frequentist method, upper limits on the branching fractions are set under different assumptions of invisible particle masses up to 1.2  GeV/c2\mathrm{\ Ge\kern -0.1em V}/c^2. The upper limit corresponding to an invisible particle with zero mass is 7.0×107\times 10^{-7} at the 90\% confidence level

    First observations of hch_c \to hadrons

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    Based on (4.48±0.03)×108(4.48 \pm 0.03) \times 10^{8} ψ(3686)\psi(3686) events collected with the BESIII detector, five hch_c hadronic decays are searched for via process ψ(3686)π0hc\psi(3686) \to \pi^0 h_c. Three of them, hcppˉπ+πh_c \to p \bar{p} \pi^+ \pi^-, π+ππ0\pi^+ \pi^- \pi^0, and 2(π+π)π02(\pi^+ \pi^-) \pi^0 are observed for the first time, with statistical significances of 7.4σ\sigma, 4.9σ4.9\sigma, and 9.1σ\sigma, and branching fractions of (2.89±0.32±0.55)×103(2.89\pm0.32\pm0.55)\times10^{-3}, (1.60±0.40±0.32)×103(1.60\pm0.40\pm0.32)\times10^{-3}, and (7.44±0.94±1.56)×103(7.44\pm0.94\pm1.56)\times10^{-3}, respectively, where the first uncertainties are statistical and the second systematic. No significant signal is observed for the other two decay modes, and the corresponding upper limits of the branching fractions are determined to be B(hc3(π+π)π0)<8.7×103B(h_c \to 3(\pi^+ \pi^-) \pi^0)<8.7\times10^{-3} and B(hcK+Kπ+π)<5.8×104B(h_c \to K^+ K^- \pi^+ \pi^-)<5.8\times10^{-4} at 90% confidence level.Comment: 17 pages, 16 figure

    Measurements of Weak Decay Asymmetries of Λc+pKS0\Lambda_c^+\to pK_S^0, Λπ+\Lambda\pi^+, Σ+π0\Sigma^+\pi^0, and Σ0π+\Sigma^0\pi^+

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    Using e+eΛc+Λˉce^+e^-\to\Lambda_c^+\bar\Lambda_c^- production from a 567 pb1^{-1} data sample collected by BESIII at 4.6 GeV, a full angular analysis is carried out simultaneously on the four decay modes of Λc+pKS0\Lambda_c^+\to pK_S^0, Λπ+\Lambda \pi^+, Σ+π0\Sigma^+\pi^0, and Σ0π+\Sigma^0\pi^+. For the first time, the Λc+\Lambda_c^+ transverse polarization is studied in unpolarized e+ee^+e^- collisions, where a non-zero effect is observed with a statistical significance of 2.1σ\sigma. The decay asymmetry parameters of the Λc+\Lambda_c^+ weak hadronic decays into pKS0pK_S^0, Λπ+\Lambda\pi^+, Σ+π0\Sigma^+\pi^0 and Σ0π+\Sigma^0\pi^+ are measured to be 0.18±0.43(stat)±0.14(syst)0.18\pm0.43(\rm{stat})\pm0.14(\rm{syst}), 0.80±0.11(stat)±0.02(syst)-0.80\pm0.11(\rm{stat})\pm0.02(\rm{syst}), 0.57±0.10(stat)±0.07(syst)-0.57\pm0.10(\rm{stat})\pm0.07(\rm{syst}), and 0.73±0.17(stat)±0.07(syst)-0.73\pm0.17(\rm{stat})\pm0.07(\rm{syst}), respectively. In comparison with previous results, the measurements for the Λπ+\Lambda\pi^+ and Σ+π0\Sigma^+\pi^0 modes are consistent but with improved precision, while the parameters for the pKS0pK_S^0 and Σ0π+\Sigma^0\pi^+ modes are measured for the first time
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