276 research outputs found

    Search for the decay J/ψ→γ+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+π−J/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 7.0×10−7\times 10^{-7} at the 90\% confidence level

    Observation of a structure in e+e−→ϕη′e^+e^- \to \phi \eta^{\prime} at s\sqrt{s} from 2.05 to 3.08 GeV

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    The process e+e−→ϕη′e^{+}e^{-} \to \phi \eta^{\prime} has been studied for the first time in detail using data sample collected with the BESIII detector at the BEPCII collider at center of mass energies from 2.05 to 3.08 GeV. A resonance with quantum numbers JPC=1−−J^{PC}=1^{--} is observed with mass MM = (2177.5 ±\pm 4.8 (stat) ±\pm 19.5 (syst)) MeV/c2{ \it{c}^{\mathrm{2}}} and width Γ\Gamma = (149.0 ±\pm 15.6 (stat) ±\pm 8.9 (syst)) MeV with a statistical significance larger than 10σ\sigma. The observed structure could be identified with the ϕ(2170)\phi(2170), then the ratio of partial width between the ϕη′\phi \eta^{\prime} by BESIII and ϕη\phi \eta by BABAR is (BϕηRΓeeR)/(Bϕη′RΓeeR)\mathcal{B}^{R}_{\phi \eta}\Gamma^{R}_{ee})/{(\mathcal{B}^{R}_{\phi \eta^{\prime}}\Gamma^{R}_{ee})} = 0.23 ±\pm 0.10 (stat) ±\pm 0.18 (syst), which is smaller than the prediction of the ssˉgs\bar{s}g hybrid models by several orders of magnitude

    Cross section measurement of e+e−→pp¯η and e+e−→pp¯ω at center-of-mass energies between 3.773 GeV and 4.6 GeV

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    Based on 14.7 fb-1 of e+e- annihilation data collected with the BESIII detector at the BEPCII collider at 17 different center-of-mass energies between 3.7730 GeV and 4.5995 GeV, Born cross sections of the two processes e+e-→pp¯η and e+e-→pp¯ω are measured for the first time. No indication of resonant production through a vector state V is observed, and upper limits on the Born cross sections of e+e-→V→pp¯η and e+e-→V→pp¯ω at the 90% confidence level are calculated for a large parameter space in resonance masses and widths. For the current world average parameters of the ψ(4230) of m=4.2187 GeV/c2 and Γ=44 MeV, we find upper limits on resonant production of the pp¯η and pp¯ω final states of 7.5 pb and 10.4 pb at the 90% CL, respectively

    Search for New Hadronic Decays of hch_c and Observation of hc→K+K−π+π−π0h_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 hc→K+K−π+π−π0h_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(hc→K+K−π+π−π0)=(3.3±0.6±0.6)×10−3\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 hc→π+π−π0ηh_c\rightarrow \pi^{+} \pi^{-} \pi^{0} \eta and hc→KS0K±π∓π+π−h_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(hc→π+π−π0η)=(7.2±1.8±1.3)×10−3\mathcal{B}(h_c\rightarrow \pi^{+} \pi^{-} \pi^{0} \eta ) =(7.2 \pm 1.8 \pm 1.3)\times 10^{-3} (<1.8×10−2)(< 1.8 \times 10^{-2}) and B(hc→KS0K±π∓π+π−)=(2.8±0.9±0.5)×10−3\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} (<4.7×10−3)(<4.7\times 10^{-3}). Upper limits on the branching fractions for the final states hc→K+K−π0h_c \rightarrow K^{+}K^{-}\pi^{0}, K+K−ηK^{+}K^{-}\eta, K+K−π+π−ηK^{+}K^{-}\pi^{+}\pi^{-}\eta, 2(K+K−)π02(K^{+}K^{-})\pi^{0}, K+K−π0ηK^{+}K^{-}\pi^{0}\eta, KS0K±π∓K^{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

    Measurement of the e+e−→Σ0Σ¯0 cross sections at center-of-mass energies from 2.3864 to 3.0200 GeV

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    Amplitude analysis and branching fraction measurement of D+s → K+K− π +

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    We report an amplitude analysis and branching fraction measurement of D+- s → K+K−π+- decay using a data sample of 3.19 fb−1 recorded with BESIII detector at a center-of-mass energy of 4.178 GeV. We perform a model-independent partial wave analysis in the low KþK− mass region to determine the K+K−S-wave line shape, followed by an amplitude analysis of our very pure high-statistics sample. With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be B(D+ s → K+K−π+-) = (5.47 pm 0.08stat pm 0.13sys)

    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~fb−1^{-1} e+e−e^+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 D0→K+K−π0π0D^0\to K^+K^-\pi^0\pi^0, D0→KS0KS0π+π−D^0\to K^0_SK^0_S\pi^+\pi^-, D0→KS0K−π+π0D^0\to K^0_SK^-\pi^+\pi^0, D0→KS0K+π−π0D^0\to K^0_SK^+\pi^-\pi^0, D+→K+K−π+π0D^+\to K^+K^-\pi^+\pi^0, D+→KS0K+π0π0D^+\to K^0_SK^+\pi^0\pi^0, D+→KS0K−π+π+D^+\to K^0_SK^-\pi^+\pi^+, D+→KS0K+π+π−D^+\to K^0_SK^+\pi^+\pi^-, and D+→KS0KS0π+π0D^+\to K^0_SK^0_S\pi^+\pi^0. The decays D0→K+K−π0π0D^0\to K^+K^-\pi^0\pi^0, D0→KS0K−π+π0D^0\to K^0_SK^-\pi^+\pi^0, D0→KS0K+π−π0D^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 D0→KS0KS0π+π−D^0\to K^0_SK^0_S\pi^+\pi^-, D+→K+K−π+π0D^+\to K^+K^-\pi^+\pi^0, D+→KS0K−π+π+D^+\to K^0_SK^-\pi^+\pi^+, and D+→KS0K+π+π−D^+\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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