543 Search Results

Using $(2712.4\pm 14.3)\times {10}^6$ $\psi \left(3686\right)$ events collected with the BESIII detector at BEPCII, a partial wave analysis of the decay $\psi \left(3686\right)\to \varphi \eta {\eta }^{\prime }$ is performed with the covariant tensor approach. In addition to the established states $h_1(1900$ ) and $\varphi \left(2170\right)$ , an axial-vector state with a mass near $more »$ 2.3     GeV / c 2 is observed for the first time. Its mass and width are measured to be $2316\pm 9_{\mathrm{stat}}\pm 30_{\mathrm{syst}}\mathrm{MeV}/c^2$ and $89\pm 15_{\mathrm{stat}}\pm 26_{\mathrm{syst}}\mathrm{MeV}$ , respectively. The product branching fractions of $\mathcal{B}\left[\psi \right(3686)\to X(2300\left){\eta }^{\prime }\right]\mathcal{B}\left[X\right(2300)\to \varphi \eta ]$ and $\mathcal{B}\left[\psi \right(3686)\to X(2300\left)\eta \right]\mathcal{B}\left[X\right(2300)\to \varphi {\eta }^{\prime }]$ are determined to be $(4.8\pm {1.3}_{\mathrm{stat}}\pm {0.7}_{\mathrm{syst}})\times {10}^{-6}$ and $(2.2\pm {0.7}_{\mathrm{stat}}\pm {0.7}_{\mathrm{syst}})\times {10}^{-6}$ , respectively. The branching fraction $\mathcal{B}\left[\psi \right(3686)\to \varphi \eta {\eta }^{\prime }]$ is measured for the first time to be ( $3.14\pm 0.17_{\mathrm{stat}}\pm 0.24_{\mathrm{syst}})\times {10}^{-5}$ . The first uncertainties are statistical and the second are systematic. Published by the American Physical Society 2025« less

Based on $(2712.4\pm 14.1)\times {10}^6$ $\psi \left(3686\right)$ decays collected with the BESIII detector, we have observed, for the first time, the hadronic decays of S- and P-wave charmonium states into $2\left({\pi }^{+}{\pi }^{-}\right)\eta$ via radiative transitions from $\psi \left(3686\right)$ . The branching fraction of the decay ${\eta }_c\left(1S\right)\to 2({\pi }^{+}{\pi }^{more »}$ − ) η has a significant dependence on the interference pattern between ${\eta }_c\left(1S\right)$ and non- ${\eta }_c\left(1S\right)$ processes. We measure it in both the destructive and constructive interference scenarios for the first time. The mass and width of the ${\eta }_c\left(1S\right)$ are measured to be $M=(2984.14\pm 0.13\pm 0.38)\mathrm{MeV}/c^2$ and $\mathrm{\Gamma }=(28.82\pm 0.11\pm 0.82)\mathrm{MeV}$ , respectively. Clear signals for the decays of the ${\chi }_{cJ}(J=0,1,2)$ and the ${\eta }_c\left(2S\right)$ to $2\left({\pi }^{+}{\pi }^{-}\right)\eta$ are also observed for the first time, and the corresponding branching fractions are measured. The ratio of the branching fractions between the ${\eta }_c\left(2S\right)$ and ${\eta }_c\left(1S\right)$ decays is significantly lower than the theoretical prediction, which might suggest different dynamics in their decays. Published by the American Physical Society 2025« less

The inclusive cross sections of prompt $J/\psi$ and $\psi \left(3686\right)$ production are measured at center-of-mass energies from 3.808 to 4.951 GeV. The dataset used is $22{\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ annihilation data collected with the BESIII detector operating at the BEPCII storage ring. The results obtained are in agreement with the previous BESIII measurements of exclusive $J/\psi$ and $\psi \left(3686\right)$ production. The average values obtainedmore » for the cross sections measured in the center-of-mass energy ranges from 4.527 to 4.951 GeV for $J/\psi$ and from 4.843 to 4.951 GeV for $\psi \left(3686\right)$ , where the impact of known resonances is negligible, are $14.0\pm 1.7\pm 3.1\mathrm{pb}$ and $15.3\pm 3.0\mathrm{pb}$ , respectively. For $J/\psi$ , the first and the second uncertainties are statistical and systematic, respectively. For $\psi \left(3686\right)$ , the uncertainty is total. These values are useful for testing charmonium production models. Published by the American Physical Society 2025« less

We measure the Born cross section for the reaction 𝑒⁺⁢𝑒⁻→ 𝜂⁢ℎ_𝑐 from $$\sqrt{𝑠}$$ = 4.129 to 4.600 GeV using datasets collected by the BESIII detector running at the BEPCII collider. A resonant structure in the cross-section line shape near 4.200 GeV is observed with a statistical significance of 7⁢𝜎. The parameters of this resonance are measured to be 𝑀 = 4188.8 ± 4.7 ± 8.0 MeV/𝑐² and Γ = 49 ± 16 ± 19 MeV, where the first uncertainties are statistical and the second systematic.

Based on $(10.09\pm 0.04)\times {10}^{9}J/\psi$ events collected with the BESIII detector operating at the BEPCII collider, a partial wave analysis of the decay $J/\psi \to \varphi {\pi }^0\eta$ is performed. We observe for the first time two new structures on the $\varphi \eta$ invariant mass distribution, with significances exceeding $27\sigma$ and $13\sigma$ ; the first with $J^{\mathrm{PC}}=1^{more »}$ + − , mass $\mathrm{M}=(1908\pm 6(\mathrm{stat}\left){}_{-4}^{+8}\right(\mathrm{sys}\left)\right)\mathrm{MeV}/c^2$ , and width $\mathrm{\Gamma }=(175\pm 13(\mathrm{stat}\left){}_{-16}^{+7}\right(\mathrm{sys}\left)\right)\mathrm{MeV}$ , the second with $J^{\mathrm{PC}}=1^{--}$ , mass $\mathrm{M}=(1992\pm 12(\mathrm{stat}\left){}_{-6}^{+15}\right(\mathrm{sys}\left)\right)\mathrm{MeV}/c^2$ , and width $\mathrm{\Gamma }=(132\pm 22(\mathrm{stat}\left){}_{-4}^{+17}\right(\mathrm{sys}\left)\right)\mathrm{MeV}$ . These measurements provide important input for the strangeonium spectrum. In addition, the $f_0\left(980\right)-a_0(980{)}^0$ mixing signal in $J/\psi \to \varphi f_0\left(980\right)\to \varphi a_0(980{)}^0$ and the corresponding electromagnetic decay $J/\psi \to \varphi a_0(980{)}^0$ are measured with improved precision, providing crucial information to understand the nature of $a_0(980{)}^0$ and $f_0\left(980\right)$ . Published by the American Physical Society 2024« less

We report the precise measurements of the cross section of $e^{+}{e}^{-}\to \text{hadrons}$ at center-of-mass energies from 3.645 to 3.871 GeV. We thereby perform the most precise study of the cross sections and find a complex system composed of three resonances of $\mathcal{R}\left(3760\right)$ , $\mathcal{R}\left(3780\right)$ , and $\mathcal{R}\left(3810\right)$ . For the first time, we measure the $\mathcal{R}\left(3810\right)$ electronicmore » width to be $(19.4\pm 7.4\pm 12.1)\mathrm{eV}$ . For the $\mathcal{R}\left(3760\right)$ resonance, we measure the mass to be $(3751.9\pm 3.8\pm 2.8)\mathrm{MeV}/c^2$ , the total width to be $(32.8\pm 5.8\pm 8.7)\mathrm{MeV}$ , and the electronic width to be $(184\pm 75\pm 86)\mathrm{eV}$ . For the $\mathcal{R}\left(3780\right)$ resonance, we measure its mass to be $(3778.7\pm 0.5\pm 0.3)\mathrm{MeV}/c^2$ , total width to be $(20.3\pm 0.8\pm 1.7)\mathrm{MeV}$ , and electronic width to be $(265\pm 67\pm 83)\mathrm{eV}$ . Forty-seven years ago, the $\psi \left(3770\right)$ resonance was discovered, and was subsequently interpreted as the $1{}^3{D}_1$ -wave dominant state of charmonium. However, our analysis of the total-hadron cross sections indicates that the $\psi \left(3770\right)$ is not a single state, but a complex system composed of the $\mathcal{R}\left(3760\right)$ , $\mathcal{R}\left(3780\right)$ , and $\mathcal{R}\left(3810\right)$ resonances. Among these, we interpret the $\mathcal{R}\left(3780\right)$ is a resonance dominated by the $1{}^3{D}_1$ charmonium state. Published by the American Physical Society 2024« less

Using $7.33{\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected by the BESIII detector at center-of-mass energies in the range of $\sqrt{s}=4.128–4.226\mathrm{GeV}$ , we search for the rare decays $D_s^{+}\to h^{+}\left(h^0\right)e^{+}$ e − , where $h$ represents a kaon or pion. By requiring the $e^{+}{e}^{-}$ invariant mass to be consistent with a $\varphi \left(1020\right)$ , $0.98<M\left(e^{+}{e}^{-}\right)<1.04\mathrm{GeV}/c^2$ , the decay $D_s^{+}\to {\pi }^{+}\varphi$ , $\varphi \to e^{+}{e}^{-}$ is observed with a statistical significance of $7.8\sigma$ , and evidence for the decay $D_s^{+}\to {\rho }^{+}\varphi$ , $\varphi \to e^{+}{e}^{-}$ is found for the first time with a statistical significance of $4.4\sigma$ . The decay branching fractions are measured to be $\mathcal{B}(D_s^{+}\to {\pi }^{+}\varphi ,\varphi \to e^{+}{e}^{-})=(1.17_{-0.21}^{+0.23}\pm 0.03)\times {10}^{-5}$ , and $\mathcal{B}(D_s^{+}\to {\rho }^{+}\varphi ,\varphi \to e^{+}{e}^{-})=(2.44_{-0.62}^{+0.67}\pm 0.16)\times {10}^{-5}$ , where the first uncertainties are statistical and the second systematic. No significant signals for the three four-body decays of $D_s^{+}\to {\pi }^{+}{\pi }^0{e}^{+}{e}^{-}$ , $D_s^{+}\to K^{+}{\pi }^0{e}^{+}{e}^{-}$ , and $D_s^{+}\to K_S^0{\pi }^{+}{e}^{+}{e}^{-}$ are observed. For $D_s^{+}\to {\pi }^{+}{\pi }^0{e}^{+}{e}^{-}$ , the $\varphi$ mass region is vetoed to minimize the long-distance effects. The 90% confidence level upper limits set on the branching fractions of these decays are in the range of $\left(7.0–8.1\right)\times {10}^{-5}$ . Published by the American Physical Society 2024« less

Abstract By analyzinge⁺e⁻annihilation data corresponding to an integrated luminosity of 2.93 fb⁻¹collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, the first observation of the semileptonic decays$$$$ {D}^0\to {K}_S^0{\pi}^{-}{\pi}^0{e}^{+}{\nu}_e $$$$ $D^0\to K_S^0{\pi }^{-}{\pi }^0{e}^{+}{\nu }_e$ and$$$$ {D}^{+}\to {K}_S^0{\pi}^{+}{\pi}^{-}{e}^{+}{\nu}_e $$$$ $D^{+}\to K_S^0{\pi }^{+}{\pi }^{-}{e}^{+}{\nu }_e$ is reported. In the hypothesis that all events correspond toK₁(1270) decays, the branching fractions are measured to be$$$$ \mathcal{B}\left({D}^0\to {K}_1{(1270)}^{-}\left(\to {K}_S^0{\pi}^{-}{\pi}^0\right){e}^{+}{\nu}_e\right)=\left({1.69}_{-0.46}^{+0.53}\pm 0.15\right)\times {10}^{-4} $$$$ $B\left(D^0\to K_1{\left(1270\right)}^{-}\left(\to K_S^{more »}\right)\right)$ 0 π− π0 e+ ν e = 1.69 − 0.46 + 0.53 ± 0.15 ×10 − 4 and$$$$ \mathcal{B}\left({D}^{+}\to {\overline{K}}_1{(1270)}^0\left(\to {K}_S^0{\pi}^{+}{\pi}^{-}\right){e}^{+}{\nu}^e\right)=\left({1.47}_{-0.40}^{+0.45}\pm 0.14\right)\times {10}^{-4} $$$$ $B\left(D^{+}\to {\overline{K}}_1{\left(1270\right)}^0\left(\to K_S^0{\pi }^{+}{\pi }^{-}\right)e^{+}{\nu }^e\right)=\left({1.47}_{-0.40}^{+0.45}\pm 0.14\right)\times {10}^{-4}$ with statistical significance of 5.4σand 5.6σ, respectively. When combined with measurements of theK₁(1270)→ K⁺π⁻πdecays, the absolute branching fractions are determined to be$$$$ \mathcal{B}\left({D}^0\to {K}_1{(1270)}^{-}{e}^{+}{\nu}_e\right)=\left({1.08}_{-0.13-0.10}^{+0.14+0.08}\pm 0.21\right)\times {10}^{-3} $$$$ $B\left(D^0\to K_1{\left(1270\right)}^{-}{e}^{+}{\nu }_e\right)=\left({1.08}_{-0.13-0.10}^{+0.14+0.08}\pm 0.21\right)\times {10}^{-3}$ and$$$$ \mathcal{B}\left({D}^{+}\to {\overline{K}}_1{(1270)}^0{e}^{+}{\nu}_e\right)=\left({1.70}_{-0.23}^{+0.26}\pm 0.13\pm 0.35\right)\times {10}^{-3} $$$$ $B\left(D^{+}\to {\overline{K}}_1{\left(1270\right)}^0{e}^{+}{\nu }_e\right)=\left({1.70}_{-0.23}^{+0.26}\pm 0.13\pm 0.35\right)\times {10}^{-3}$ . The first and second uncertainties are statistical and systematic, respectively, and the third uncertainties originate from the assumed branching fractions of theK₁(1270)→ Kππdecays.« less

Using a sample of about 10 billion $J/\psi$ events with the BESIII detector, we search for the weak decays of $J/\psi \to {\overline{D}}^0{\pi }^0+\mathrm{c}.\mathrm{c}.$ , $J/\psi \to {\overline{D}}^0\eta +\mathrm{c}.\mathrm{c}.$ , $J/\psi more »$ → D ¯ 0 ρ 0 + c . c . , $J/\psi \to D^{-}{\pi }^{+}+\mathrm{c}.\mathrm{c}.$ , and $J/\psi \to D^{-}{\rho }^{+}+\mathrm{c}.\mathrm{c}.$ . Since no significant signal is observed, we set the upper limits of the branching fractions of these decays to be $\mathcal{B}(J/\psi \to {\overline{D}}^0{\pi }^0+\mathrm{c}.\mathrm{c}.)<4.7\times {10}^{-7}$ , $\mathcal{B}(J/\psi \to {\overline{D}}^0\eta +\mathrm{c}.\mathrm{c}.)<6.8\times {10}^{-7}$ , $\mathcal{B}(J/\psi \to {\overline{D}}^0{\rho }^0+\mathrm{c}.\mathrm{c}.)<5.2\times {10}^{-7}$ , $\mathcal{B}(J/\psi \to D^{-}{\pi }^{+}+\mathrm{c}.\mathrm{c}.)<7.0\times {10}^{-8}$ , and $\mathcal{B}(J/\psi \to D^{-}{\rho }^{+}+\mathrm{c}.\mathrm{c}.)<6.0\times {10}^{-7}$ at the 90% confidence level. Published by the American Physical Society 2024« less

Using data samples collected with the BESIII detector at the BEPCII collider at center-of-mass energies ranging from 3.80 to 4.95 GeV, corresponding to an integrated luminosity of $20{\mathrm{fb}}^{-1}$ , a measurement of Born cross sections for the $e^{+}{e}^{-}\to D^0{\overline{D}}^0$ and $D^{+}{D}^{-}$ processes is presented with unprecedented precision. Many clear peaks in the line shape of $e^{+}{more »}^{}$ e − → D 0 D ¯ 0 and $D^{+}{D}^{-}$ around the mass range of $G\left(3900\right)$ , $\psi \left(4040\right)$ , $\psi \left(4160\right)$ , $Y\left(4260\right)$ , and $\psi \left(4415\right)$ , etc., are foreseen. These results offer crucial experimental insights into the nature of hadron production in the open-charm region. Published by the American Physical Society 2024« less