518 research outputs found

    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

    Precise Measurements of Branching Fractions for Ds+D_s^+ Meson Decays to Two Pseudoscalar Mesons

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    We measure the branching fractions for seven Ds+D_{s}^{+} two-body decays to pseudo-scalar mesons, by analyzing data collected at s=4.1784.226\sqrt{s}=4.178\sim4.226 GeV with the BESIII detector at the BEPCII collider. The branching fractions are determined to be B(Ds+K+η)=(2.68±0.17±0.17±0.08)×103\mathcal{B}(D_s^+\to K^+\eta^{\prime})=(2.68\pm0.17\pm0.17\pm0.08)\times10^{-3}, B(Ds+ηπ+)=(37.8±0.4±2.1±1.2)×103\mathcal{B}(D_s^+\to\eta^{\prime}\pi^+)=(37.8\pm0.4\pm2.1\pm1.2)\times10^{-3}, B(Ds+K+η)=(1.62±0.10±0.03±0.05)×103\mathcal{B}(D_s^+\to K^+\eta)=(1.62\pm0.10\pm0.03\pm0.05)\times10^{-3}, B(Ds+ηπ+)=(17.41±0.18±0.27±0.54)×103\mathcal{B}(D_s^+\to\eta\pi^+)=(17.41\pm0.18\pm0.27\pm0.54)\times10^{-3}, B(Ds+K+KS0)=(15.02±0.10±0.27±0.47)×103\mathcal{B}(D_s^+\to K^+K_S^0)=(15.02\pm0.10\pm0.27\pm0.47)\times10^{-3}, B(Ds+KS0π+)=(1.109±0.034±0.023±0.035)×103\mathcal{B}(D_s^+\to K_S^0\pi^+)=(1.109\pm0.034\pm0.023\pm0.035)\times10^{-3}, B(Ds+K+π0)=(0.748±0.049±0.018±0.023)×103\mathcal{B}(D_s^+\to K^+\pi^0)=(0.748\pm0.049\pm0.018\pm0.023)\times10^{-3}, where the first uncertainties are statistical, the second are systematic, and the third are from external input branching fraction of the normalization mode Ds+K+Kπ+D_s^+\to K^+K^-\pi^+. Precision of our measurements is significantly improved compared with that of the current world average values

    Protocol for a national, mixed-methods knowledge, attitudes and practices survey on non-communicable diseases

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    Background Mongolia is undergoing rapid epidemiological transition with increasing urbanisation and economic development. The lifestyle and health of Mongolians are changing as a result, shown by the 2005 and 2009 STEPS surveys (World Health Organization's STEPwise Approach to Chronic Disease Risk Factor Surveillance) that described a growing burden of Non-Communicable Diseases and injuries (NCDs). This study aimed to assess, describe and explore the knowledge, attitudes and practices of the Mongolian adult population around NCDs in order to better understand the drivers and therefore develop more appropriate solutions to this growing disease burden. In addition, it aimed to provide data for the evaluation of current public health programs and to assist in building effective, evidence-based health policy. Methods/design This national survey consisted of both quantitative and qualitative methods. A quantitative household-based questionnaire was conducted using a nationally representative sample of 3854 rural and urban households. Participants were selected using a multi-stage cluster sampling technique in 42 regions across Mongolia, including rural and urban sites. Permanent residents of sampled households were eligible for recruitment, if aged between 15-64 years. This quantitative arm was then complemented and triangulated with a qualitative component: twelve focus group discussions focusing on diet, exercise and alcohol consumption. Discussions took place in six sites across the country, facilitated by local, trained health workers. These six sites were chosen to reflect major Mongolian cultural and social groups. Discussion KAP surveys are well represented in the literature, but studies that aim to explore the knowledge, attitudes and practices of a population around NCDs remain scarce. This is despite the growing number of national epidemiological surveys, such as STEPS, which aim to quantify the burden of these diseases but do not explore the level of population-based awareness, understanding, risk-perception and possible motivation for change. Therefore this paper will contribute to building a knowledge base of NCD KAP survey methodology for future use in epidemiology and research worldwide

    Measurement of the inclusive branching fraction for ψ(3686)→KS 0+anything

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    Using 5.9 pb−1 of e+e− annihilation data collected at center-of-mass energies from 3.640 to 3.701 GeV with the BESIII detector at the BEPCII Collider, we measure the observed cross sections of e+e−→KS0X (where X=anything). From a fit to these observed cross sections with the sum of continuum and ψ(3686) and J/ψ Breit-Wigner functions and considering initial state radiation and the BEPCII beam energy spread, we obtain for the first time the product of ψ(3686) leptonic width and inclusive decay branching fraction Γψ(3686)eeB(ψ(3686)→KS0X)=(373.8±6.7±20.0) eV, and assuming Γψ(3686)ee is (2.33±0.04) keV from PDG value, we measure B(ψ(3686)→KS0X)=(16.04±0.29±0.90)%, where the first uncertainty is statistical and the second is systematic

    Amplitude analysis of Ds+π+ππ+D_s^{+} \rightarrow \pi^{+} \pi^{-} \pi^{+}

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    Utilizing the data set corresponding to an integrated luminosity of 3.193.19 fb1^{-1} collected by the BESIII detector at a center-of-mass energy of 4.178 GeV, we perform an amplitude analysis of the Ds+π+ππ+D_s^+\to\pi^+\pi^-\pi^+ decay. The sample contains 13,797 candidates with a signal purity of \sim80%. The amplitude and phase of the contributing ππ\pi\pi S{\cal S} wave are measured based on a quasi-model-independent approach, along with the amplitudes and phases of the P{\cal P} and D{\cal D} waves parametrized by Breit-Wigner models. The fit fractions of different intermediate decay channels are also reported.Comment: 14 pages, 6 figure

    Corrigendum to “Measurement of the e+e− → π+π− cross section between 600 and 900 MeV using initial state radiation” [Phys. Lett. B 753 (2016) 629–638]

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    In Ref. [1] the BESIII collaboration published a cross section measurement of the process e+e−→π+π− in the energy range between 600 and 900 MeV. In this corrigendum, we report a corrected evaluation of the statistical errors in terms of a fully propagated covariance matrix. The correction also yields a reduced statistical uncertainty for the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon, which now reads as aμππ,LO(600−900MeV)=(368.2±1.5stat±3.3syst)×10−10. The central values of the cross section measurement and of aμππ,LO, as well as the systematic uncertainties remain unchanged

    Observation of the electromagnetic Dalitz decay D∗0 →d0e+e-

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    Search for the reaction e+e−→χcJπ+π− and a charmoniumlike structure decaying to χcJπ± between 4.18 and 4.60 GeV

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    We search for the process e+e-→χcJπ+π- (J=0, 1, 2) and for a charged charmoniumlike state in the χcJπ± subsystem. The search uses datasets collected with the BESIII detector at the BEPCII storage ring at center-of-mass energies between 4.18 GeV and 4.60 GeV. No significant χcJπ+π- signals are observed at any center-of-mass energy, and thus upper limits are provided which also serve as limits for a possible charmoniumlike structure in the invariant χcJπ± mass

    Search for New Hadronic Decays of hch_c and Observation of hcK+Kπ+ππ0h_c\rightarrow K^{+}K^{-}\pi^{+}\pi^{-}\pi^{0}

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    Ten hadronic final states of the hch_c decays are investigated via the process ψ(3686)π0hc\psi(3686)\rightarrow \pi^0 h_c, using a data sample of (448.1±2.9)×106(448.1 \pm 2.9) \times 10^6 ψ(3686)\psi(3686) events collected with the BESIII detector. The decay channel hcK+Kπ+ππ0h_c\rightarrow K^{+}K^{-}\pi^{+}\pi^{-}\pi^{0} is observed for the first time with a significance of 6.0σ6.0 \sigma. The corresponding branching fraction is determined to be B(hcK+Kπ+ππ0)=(3.3±0.6±0.6)×103\mathcal{B}(h_c\rightarrow K^{+}K^{-}\pi^{+}\pi^{-}\pi^{0}) =(3.3 \pm 0.6 \pm 0.6)\times 10^{-3} (the first uncertainty is statistical and the second systematical). Evidence for the decays hcπ+ππ0ηh_c\rightarrow \pi^{+} \pi^{-} \pi^{0} \eta and hcKS0K±ππ+πh_c\rightarrow K^{0}_{S}K^{\pm}\pi^{\mp}\pi^{+}\pi^{-} is found with a significance of 3.6σ3.6 \sigma and 3.8σ3.8 \sigma, respectively. The corresponding branching fractions (and upper limits) are obtained to be B(hcπ+ππ0η)=(7.2±1.8±1.3)×103\mathcal{B}(h_c\rightarrow \pi^{+} \pi^{-} \pi^{0} \eta ) =(7.2 \pm 1.8 \pm 1.3)\times 10^{-3} (<1.8×102)(< 1.8 \times 10^{-2}) and B(hcKS0K±ππ+π)=(2.8±0.9±0.5)×103\mathcal{B}(h_c\rightarrow K^{0}_{S}K^{\pm}\pi^{\mp}\pi^{+}\pi^{-}) =(2.8 \pm 0.9 \pm 0.5)\times 10^{-3} (<4.7×103)(<4.7\times 10^{-3}). Upper limits on the branching fractions for the final states hcK+Kπ0h_c \rightarrow K^{+}K^{-}\pi^{0}, K+KηK^{+}K^{-}\eta, K+Kπ+πηK^{+}K^{-}\pi^{+}\pi^{-}\eta, 2(K+K)π02(K^{+}K^{-})\pi^{0}, K+Kπ0ηK^{+}K^{-}\pi^{0}\eta, KS0K±πK^{0}_{S}K^{\pm}\pi^{\mp}, and ppˉπ0π0p\bar{p}\pi^{0}\pi^{0} are determined at a confidence level of 90\%.Comment: 10 pages, 2 figure

    Measurements of the absolute branching fractions of D0(+)KKˉππD^{0(+)}\to K\bar K\pi\pi decays

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    Based on 2.93~fb1^{-1} e+ee^+e^- collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report the measurements of the absolute branching fractions of D0K+Kπ0π0D^0\to K^+K^-\pi^0\pi^0, D0KS0KS0π+πD^0\to K^0_SK^0_S\pi^+\pi^-, D0KS0Kπ+π0D^0\to K^0_SK^-\pi^+\pi^0, D0KS0K+ππ0D^0\to K^0_SK^+\pi^-\pi^0, D+K+Kπ+π0D^+\to K^+K^-\pi^+\pi^0, D+KS0K+π0π0D^+\to K^0_SK^+\pi^0\pi^0, D+KS0Kπ+π+D^+\to K^0_SK^-\pi^+\pi^+, D+KS0K+π+πD^+\to K^0_SK^+\pi^+\pi^-, and D+KS0KS0π+π0D^+\to K^0_SK^0_S\pi^+\pi^0. The decays D0K+Kπ0π0D^0\to K^+K^-\pi^0\pi^0, D0KS0Kπ+π0D^0\to K^0_SK^-\pi^+\pi^0, D0KS0K+ππ0D^0\to K^0_SK^+\pi^-\pi^0, D+KS0KS0π+π0D^+\to K^0_SK^0_S\pi^+\pi^0, and D+KS0K+π0π0D^+\to K^0_SK^+\pi^0\pi^0 are observed for the first time. The branching fractions of the decays D0KS0KS0π+πD^0\to K^0_SK^0_S\pi^+\pi^-, D+K+Kπ+π0D^+\to K^+K^-\pi^+\pi^0, D+KS0Kπ+π+D^+\to K^0_SK^-\pi^+\pi^+, and D+KS0K+π+πD^+\to K^0_SK^+\pi^+\pi^- are measured with improved precision compared to the world-average values.Comment: 11 pages, 5 figure
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