arXiv subjects

J. J. Cui

Publications and source records attributed to J. J. Cui.

At least 19 recordsLinked to original sources

arXiv2026

Observation of an Altered $a_{0}(980)$ Line shape in $D^{+} \rightarrow \pi^{+}\eta\eta$

Using $20.3~{\rm fb}^{-1}$ of $e^+e^-$ collision data collected with the BESIII detector at $\sqrt{s}=3.773~{\rm GeV}$, we perform the first amplitude analysis of the decay $D^+\to\pi^+\eta\eta$. The intermediate process $D^+\to a_0(980)^+\eta$, $a_0(980)^+\to\pi^+\eta$, is observed as the only significant component in the amplitude analysis, and its branching fraction is measured to be $(3.67\pm0.12_{\rm stat}\pm0.06_{\rm syst})\times10^{-3}$. The $\pi^+\eta$ mass spectrum associated with $a_0(980)^+\eta$ production exhibits a line shape that differs substantially from those observed in $D_{(s)}\to a_0(980)\pi$ and $D^0\to a_0(980)^-e^+\nu_e$ decays. We examine several conventional descriptions of the $a_0(980)$ amplitude, including Flatt\'e, dispersively modified Flatt\'e, $T$-matrix, and $K$-matrix parameterizations. With reference $a_0(980)$ parameters, neither these models nor their extensions including additional small resonant or non-resonant amplitudes reproduce the observed line shape satisfactorily. When the $a_0(980)$ parameters are allowed to float, satisfactory fits can be obtained, but the pole mass is driven well above the $K\bar K$ threshold, inconsistent with the near-threshold character of the $a_0(980)$. The results reveal a tension between fit quality and the physical pole position in conventional direct-production amplitude models.

hep-ex↗

arXiv2026

Multi-channel joint analysis of the exotic charmonium-like state $T_{c\bar{c}}(4020)$

This paper reports the first multi-channel joint analysis to identify the properties of the exotic charmonium-like state $T_{c\bar{c}}(4020)$ via the electron-positron annihilation process $e^{+}e^{-}\to\pi^{+}T_{c\bar{c}}(4020)^{-}+c.c$. A partial wave analysis is performed simultaneously in three decay channels $T_{c\bar{c}}(4020)^{-}\to {D}^{*0}D^{*-}$, $\pi^{-}J/\psi$, and $\pi^{-}h_{c}$, based on data samples taken at $\sqrt{s}=4.395$ and $4.416\,\mathrm{GeV}$ with an integrated luminosity of $1598.9\,\mathrm{pb}^{-1}$ collected with the BESIII detector operating on the BEPCII collider. For the first time, the spin-parity of the $T_{c\bar{c}}(4020)^{-}$ is determined to be $J^{P}=1^{+}$ with a significance $11.7\sigma$. Pole positions are extracted on the Riemann sheets with three branch points in the complex energy plane. Furthermore, the relative branching fractions are obtained as $\mathcal{B}[T_{c\bar{c}}(4020)^{-}\to\pi^{-}J/\psi]/\mathcal{B}[T_{c\bar{c}}(4020)^{-}\to{D}^{*0}D^{*-}]=(3.6\pm0.6\pm1.6)\times10^{-3}$ and $\mathcal{B}[T_{c\bar{c}}(4020)^{-}\to\pi^{-}h_{c}]/\mathcal{B}[T_{c\bar{c}}(4020)^{-}\to{D}^{*0}D^{*-}]=(8.9\pm1.3\pm2.3)\times10^{-2}$, where the first uncertainties are statistical, and the second are systematic.

hep-ex↗

arXiv2026

Search for the reaction channel $e^+ e^- \to \eta\eta\,J/\psi$ and the isospin partner of the $Z_c(3900)$ at center-of-mass energies $\sqrt{s} = 4.226-4.950$ GeV

We search for the reaction channel $e^+ e^- \to \eta\eta\,J/\psi$ in a data sample with center-of-mass energies from 4.226 to 4.950~GeV, which was collected by the BESIII detector operating at the Beijing Electron Positron Collider (BEPCII). The data analysis is performed with two different methods, exclusively and semi-inclusively, which enabling a comparison and combination of the results. Only in a few cases a statistical significance of the cross sections with more than $3\sigma$ is observed with one of the methods. Only at 4.750~GeV the significance of the cross section measurement is 8.9$\sigma$ (observation) with the exclusive analysis and 3.4$\sigma$ (evidence) with the semi-inclusive analysis. Therefore, the corresponding upper limits of the cross section at the 90% confidence level are determined. The energy dependent results show clear deviations from the the line shape expected from three-body phase space alone. Since the statistical significance for almost all center-of-mass energies is low, the upper limits for the reaction channel $e^+ e^- \to \eta\eta\,J/\psi$ also serve as limits for the existence of a possible isospin partner to the charmonium-like isospin triplet $Z_{\rm c}(3900)$ which decays to $J/\psi \eta$.

hep-ex↗

arXiv2025

Study of $\bar{K}^*(892)^0 \eta$ and $K_S^0 a_0(980)^0$ in the $D^{0} \to K_{S}^{0}\pi^0\eta$ decay

We perform an amplitude analysis of the decay $D^0 \to K_S^0 \pi^0 \eta$ and measure its absolute branching fraction to be $(1.016 \pm 0.013_{\text {stat.}} \pm 0.014_{\text {syst.}})\%$. The analysis utilizes $20.3~\mathrm{fb}^{-1}$ of $e^{+}e^{-}$ collision data collected at a center-of-mass energy of 3.773~GeV with the BESIII detector. The branching fraction of the intermediate process $D^0 \rightarrow \bar{K}^*(892)^0 \eta$ is determined to be $(0.73 \pm 0.05_{\text {stat.}} \pm 0.03_{\text {syst.}}) \%$, which is $5 \sigma$ smaller than the result measured in $D^0 \to K^- \pi^+ \eta$ by the Belle experiment. As a result, the magnitudes of the $W$-exchange and QCD-penguin exchange amplitudes are found to be less than half of their current estimations. Furthermore, we determine $\mathcal{B}(D^0\to K_S^0a_0(980)^0, a_0(980)^0\to \pi^0\eta) = (9.88\pm 0.37_{\rm stat.}\pm 0.42_{\rm syst.})\times10^{-3}$, with a precision improved by a factor of 4.5 compared to the world average.

hep-ex↗

arXiv2025

Measurement of the branching fraction of $\eta \to \mu^+ \mu^-$ and search for $\eta \to e^+ e^-$

We analyze the decay of $\eta\rightarrow \ell^+\ell^-(\ell=e, \mu)$ via $J/\psi\rightarrow\gamma\eta'$ and $\eta'\rightarrow\pi^+\pi^-\eta$, based on (10087 $\pm$ 44) $\times$ 10$^{6}$ $J/\psi$ events collected with the BESIII detector at the BEPCII storage rings. The branching fraction of $\eta\rightarrow\mu^+ \mu^-$ is measured to be $(5.8 \pm 1.0_{\rm stat} \pm 0.2_{\rm syst}) \times 10^{-6}$, which is consistent with the previous measurements and theoretical expectations. In addition, no significant $\eta\to e^+e^-$ signal is observed in the $e^+ e^-$ invariant mass spectrum, and an improved upper limit of ${\cal B}(\eta \to e^+ e^-) < 2.2 \times 10^{-7}$ is set at 90\% confidence level.

hep-ex↗

arXiv2025

Experimental study of the reaction $\Xi^{0}n\rightarrow\Lambda\Lambda X$ using $\Xi^{0}$-nucleus scattering

Using $(10087\pm44)\times10^{6}$$J/\psi$ events collected with the BESIII detector operating at the BEPCII storage ring in $2009$, $2012$, $2018$, and $2019$, we perform a search for the reaction $\Xi^0n\rightarrow\Lambda\Lambda X$, where $X$ denotes any additional final particles. Given the highly suppressed phase space for producing extra pions, the $X$ consists of either nothing or a photon, corresponding to the processes $\Xi^0 n \rightarrow \Lambda\Lambda$ and $\Xi^{0}n\rightarrow\Lambda\Sigma^0\rightarrow\Lambda\Lambda\gamma$. The $\Xi^0$ comes from the decay of $J/\psi\rightarrow\Xi^0\bar{\Xi}^0$, while the neutron originates from material of the beam pipe. A signal is observed for the first time with a statistical significance of 6.4$\sigma$. The cross section for the reaction $\Xi^0+{^9\rm{Be}}\rightarrow\Lambda+\Lambda+X$ is measured to be $(43.6\pm10.5_{\text{stat}}\pm11.1_{\text{syst}})$ mb at $P_{\Xi^0}\approx0.818$ GeV/$c$, where the first uncertainty is statistical and the second systematic. No significant $H$-dibaryon signal is observed in the $\Lambda\Lambda$ final state.

hep-ex↗

arXiv2025

Evidence for the semileptonic decays $\Lambda_c^{+} \to \Sigma^{\pm} \pi^{\mp} e^+ \nu_e$

Using $4.5\, fb^{-1}$ of $e^+e^-$ collision data collected by the BESIII detector at center-of-mass energies between $4.600$ and $4.699\,GeV$, we search for the semileptonic decays $\Lambda_c^{+} \to \Sigma^{+} \pi^{-} e^+ \nu_e$ and $\Lambda_c^{+} \to \Sigma^{-} \pi^{+} e^+ \nu_e$ for the first time. Assuming their branching fractions are equal under isospin symmetry, evidence for $\Lambda_c^{+} \to \Sigma^{\pm} \pi^{\mp} e^+ \nu_e$ is reported with a significance of $3.6\sigma$. The corresponding branching fraction is measured to be $\mathcal{B}(\Lambda_c^{+} \to \Sigma^\pm\pi^\mp e^+\nu_e) = (7.7^{+2.5}_{-2.3_{\rm stat.}}\pm1.3_{\rm syst.})\times 10^{-4}$, which is consistent with quark model predictions within two standard deviations.

hep-ex↗

arXiv2025

Measurement of the hyperon weak radiative decay $\Xi^0\to\gamma\Sigma^0$ at BESIII

The hyperon weak radiative decay $\Xi^0\to\gamma\Sigma^0$ is measured via the process $J/\psi\to\Xi^0\bar\Xi^0$. The absolute branching fraction of $\Xi^0\to\gamma\Sigma^0$ is determined to be $(3.69\pm 0.21_{\text{stat}}\pm0.12_{\text{syst}})\times 10^{-3}$, based on $(10.087\pm 0.044)\times 10^{9}$ $J/\psi$ events collected with the BESIII detector operating at the BEPCII collider. The decay asymmetry parameter is measured, with a complete angular analysis of the cascade decay chain, to be $\alpha_{\gamma} = -0.807\pm 0.095_{\text{stat}}\pm 0.011_{\text{syst}}$.

hep-ex↗

arXiv2025

Search for the charmonium weak decay $J/\psi\to\bar{D}^0\bar{K}^{*0}+{\rm c.c.}$

Based on a sample of $(10087\pm44)\times10^6$ $J/\psi$ events collected at the center-of-mass energy $\sqrt{s}$ = 3.0969 GeV with the BESIII detector, we search for the charmonium rare weak decay $J/\psi\to\bar{D}^0\bar{K}^{*0}+{\rm c.c.}$. No significant signal is observed, and the upper limit on its decay branching fraction at the 90% confidence level is set as $1.4\times10^{-7}$, improving the sensitivity of the previous best limit by an order of magnitude.

hep-ex↗

arXiv2025

Measurement of Born Cross Sections and Effective Form Factors of $e^+e^-\to Ω^{-}\barΩ^{+}$ from$\sqrt{s}$ = 3.7 to 4.7 GeV

Using $e^+e^-$ collision data corresponding to an integrated luminosity of 22.7 fb$^{-1}$, collected at center-of-mass energies between 3.7 and 4.7 GeV with the BESIII detector at the BEPCII storage ring, we measure the energy-dependent Born cross sections of $e^+e^-\to Ω^{-}\barΩ^+$ and the effective form factors of the $Ω^-$ baryon. The analysis employs a single baryon tagging method, and the results are consistent with theoretical predictions, providing critical constraints on the electromagnetic structure of the $Ω^-$ hyperon. No significant signal of charmonium or charmonium-like states decaying to $Ω^{-}\barΩ^+$ is observed in the investigated energy range.

hep-ex↗

arXiv2025

Observation of Charmonium $h_{c}$ Radiative Decays to Multiple Light Hadrons and the Tensor State $f_2(1270)$

Using $ψ(3686)\rightarrow π^{0} h_{c}$ decays from a data sample of $(27.12\pm0.14)\times10^{8}$ $ψ(3686)$ events collected by the BESIII detector at the BEPCII collider, $h_c$ radiative decays to $γπ^{+}π^{-},~γπ^{+}π^{-}η,~\gamma2(π^{+}π^{-})$, and $γp\bar{p}$ are observed for the first time, each with a significance greater than $5σ$. The corresponding branching fractions are measured. Furthermore, intermediate states below 2.8 GeV/$c^{2}$ are investigated, leading to the first observation of the decay process of $h_c\rightarrowγf_{2}(1270)\rightarrowγπ^{+}π^{-}$ with a significance of $5.5\,σ$. This observation represents the first instance of $h_c$ radiative decay to a tensor state.

hep-ex↗

arXiv2025

Amplitude analysis and branching fraction measurement of the decay $D^0 \to K^0_S\pi^0\pi^0$

An amplitude analysis of the decay $D^0 \to K_S^0 \pi^0 \pi^0$ is performed to determine the relative magnitudes and phases of different intermediate processes. The analysis uses $e^+e^-$ collision data collected at the center-of-mass energy of 3.773 GeV by the BESIII detector corresponding to an integrated luminosity of 20.3 $\rm fb^{-1}$. The absolute branching fraction of $D^0 \to K^0_S \pi^0 \pi^0$ is measured to be $(1.026 \pm 0.008_{\rm{stat.}} \pm 0.009_{\rm{syst.}}) \%$. The dominant intermediate process is $D^0 \to \bar{K}^{*}(892)^{0}(\to K^0_S \pi^0) \pi^0$, with a branching fraction of $(4.10\pm0.10_{\rm{stat.}}\pm0.07_{\rm{syst.}})\times 10^{-3}$.

hep-ex↗

arXiv2025

Measurements of the absolute branching fractions of the doubly Cabibbo-suppressed decays $D^+\to K^+π^0$, $D^+\to K^+η$ and $D^+\to K^+η^{\prime}$

Using $20.3\,\rm fb^{-1}$ of $e^+e^-$ collision data collected at a center-of-mass energy of 3.773\,GeV with the BESIII detector, we present the measurements of the absolute branching fractions of the doubly Cabibbo-suppressed decays $D^+\to K^+π^0$, $D^+\to K^+η$ and $ D^+ \to K^+ η^{\prime}$ with the double-tag method, with significantly improved precision compared to the previous measurements. The statistical significance of each signal decay exceeds $10σ$. The branching fractions are determined to be ${\mathcal B}(D^+\to K^+ π^0) = (1.45 \pm 0.06 \pm 0.08)\times 10^{-4}$, ${\mathcal B}(D^+\to K^+ η) = (1.17 \pm 0.10 \pm 0.03)\times 10^{-4}$ and ${\mathcal B}(D^+\to K^+ η^{\prime}) = (1.88 \pm 0.15 \pm 0.11)\times 10^{-4}$, where the first uncertainties are statistical and the second systematic. The branching fractions of $D^+\to K^+η$ and $ D^+ \to K^+ η^{\prime}$ are consistent with the world average values. The reported branching fraction of $D^+\to K^+π^0$ deviates with the world average value by 3$σ$.

hep-ex↗

arXiv2025

First observation of $Λ_{c}(2595)^{+} \to Λ^{+}_{c}π^0π^0$ and $Λ_{c}(2625)^{+}\to Λ^{+}_{c}π^0π^0$

By analysing $e^+e^-$ annihilation data corresponding to an integrated luminosity of 368.48~pb$^{-1}$ collected at the centre-of-mass energies of $\sqrt{s} = 4.918$ and $4.951$~GeV with the BESIII detector, we report the first observation of $Λ_{c}(2595)^{+}$ and $Λ_{c}(2625)^{+}\to Λ^{+}_{c}π^0π^0$ with statistical significances of 7.9$σ$ and 11.8$σ$, respectively. The branching fractions of $Λ_{c}(2595)^{+}$ and $Λ_{c}(2625)^{+}\to Λ^{+}_{c}π^0π^0$ are measured to be $(59.5 \pm 11.1_{\rm stat.} \pm 7.9_{\rm syst.}) \%$ and $(41.0 \pm 5.2_{\rm stat.} \pm 3.3_{\rm syst.}) \%$, respectively. The absolute branching fraction of $Λ_{c}(2595)^{+}$ is consistent with the expectation of the mechanism referred to as the threshold effect, proposed for the strong decays of $Λ_{c}(2595)^{+}$ within uncertainty.

hep-ex↗

arXiv2025

Measurements of absolute branching fractions of $D^{0(+)}\to KKKπ$ decays

Using an $e^+e^-$ sample of $20.3\,\rm fb^{-1}$ collected at the center-of-mass energy $\sqrt{s}=$ 3.773 GeV with the BESIII detector, we report measurements of several four-body hadronic decays of the $D$ mesons. The absolute branching fractions are determined to be ${\mathcal B}(D^0\to K^0_S K^+K^-π^0 )=( 18.4^{+2.6}_{-2.5}\pm 2.4)\times 10^{-5}$, ${\mathcal B}(D^0\to K^0_S K^0_S K^-π^+ )=( 12.9^{+1.7}_{-1.6}\pm 2.5)\times 10^{-5}$, ${\mathcal B}(D^0\to K^0_S K^0_S K^+π^-)=(5.7^{+1.2}_{-1.1}\pm 1.3)\times 10^{-5}$, ${\mathcal B}(D^0\to K^+K^-K^-π^+ )=(17.4^{+1.8}_{-1.7}\pm { 2.2})\times 10^{-5}$, and ${\mathcal B}(D^+\to K^0_S K^+K^-π^+)=(13.8^{+2.4}_{-2.2}\pm 2.5)\times 10^{-5}$. Furthermore, significant $ϕ$ signals are found in the decay channels involving $K^+K^-$ pair, and the corresponding branching fractions are measured as ${\mathcal B}(D^0\to ϕK^0_Sπ^0 )=( 22.7^{+5.4}_{-5.1}\pm 3.7)\times 10^{-5}$, ${\mathcal B}(D^0\to ϕK^-π^+ )=(25.2^{+3.5}_{-3.3}\pm 4.6)\times 10^{-5}$, ${\mathcal B}(D^+\to ϕK^0_Sπ^+)=(16.5 ^{+6.0}_{-5.3}\pm 2.6 )\times 10^{-5}$. The branching fractions of $D^0\to K^0_S K^+K^-π^0$, $D^0\to ϕK^0_Sπ^0$, and $D^+\to ϕK^0_S π^+$ are measured for the first time, and those of $D^0\to K^0_S K^0_SK^-π^+$, $D^0\to K^0_S K^0_SK^+π^-$, $D^0\to K^+K^-K^-π^+$, $D^0\to ϕK^-π^+$, and $D^+\to K^0_S K^+K^-π^+$ are measured with improved precision. The first uncertainties are statistical and the second are systematic.

hep-ex↗

arXiv2025

Observation of $D^+\to K^0_Sπ^0μ^+ν_μ$, Test of Lepton Flavor Universality and First Angular Analysis of $D^+\to \bar{K}^\ast(892)^0\ell^+ν_\ell$

We report a study of the semileptonic decays $D^+\to K_S^0π^0\ell^+ν_\ell$ ($\ell = e, μ$) based on $20.3\,\mathrm{fb}^{-1}$ of $e^+e^-$ collision data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector. The $D^+\to K_S^0π^0μ^+ν_μ$ decay is observed for the first time, with a branching fraction of $(0.896\pm0.017_{\rm stat}\pm0.008_{\rm syst})\%$, and the branching fraction of $D^+\to K_S^0π^0e^+ν_e$ is determined with the improved precision as $(0.943\pm0.012_{\rm stat}\pm0.010_{\rm syst})\%$. From the analysis of the dynamics, we observe that the dominant $\bar{K}^\ast(892)^0$ component is accompanied by an $S$-wave contribution, which accounts for $(7.10 \pm 0.68_{\rm stat} \pm 0.41_{\rm syst})\%$ of the total decay rate of the $μ^+$ channel and $(6.39 \pm 0.17_{\rm stat} \pm 0.14_{\rm syst})\%$ of the $e^+$ channel. Assuming a single-pole dominance parameterization, the hadronic form factor ratios are extracted to be $r_V=V(0)/A_1(0)=1.42 \pm\, 0.03_{\rm stat} \pm\, 0.02_{\rm syst}$ and $r_2=A_2(0)/A_1(0)=0.75 \pm\, 0.03_{\rm stat} \pm\, 0.01_{\rm syst}$. Based on the first comprehensive angular and the decay-rate $CP$ asymmetry analysis, the full set of averaged angular and $CP$ asymmetry observables are measured as a function of the momentum-transfer squared; they are consistent with expectations from the Standard Model. No evidence for violation of $μ-e$ lepton-flavor universality is observed in either the full range or the five chosen bins of momentum-transfer squared.

hep-ex↗

arXiv2025

Study of $ϕ\to K\bar{K}$ and $K_{S}^{0}-K_{L}^{0}$ Asymmetry in the Amplitude Analysis of $D_{s}^{+} \to K_{S}^{0}K_{L}^{0}π^{+}$ Decays

Using $e^+e^-$ annihilation data corresponding to a total integrated luminosity of 7.33 $\rm fb^{-1}$ collected at center-of-mass energies between 4.128 and 4.226~GeV with the BESIII detector, we provide the first amplitude analysis and absolute branching fraction measurement of the hadronic decay $D_{s}^{+} \to K_{S}^{0}K_{L}^{0}π^{+}$. The branching fraction of $D_{s}^{+} \to K_{S}^{0}K_{L}^{0}π^{+}$ is determined to be $(1.86\pm0.06_{\rm stat}\pm0.03_{\rm syst})\%$. Combining the $\mathcal{B}[D_{s}^{+} \to ϕ(\to K_{S}^0K_{L}^0) π^+]$ obtained in this work and the world average of $\mathcal{B}[D_{s}^{+} \to ϕ(\to K^+K^-) π^+]$, we measure the relative branching fraction $\mathcal{B}(ϕ\to K_S^0K_L^0)/\mathcal{B}(ϕ\to K^+K^-)$=($0.593 \pm 0.023_{\rm stat} \pm 0.014_{\rm syst} \pm 0.016_{ϕπ}$), where the third error is due to the uncertainty of the $\mathcal{B}(D_s^+ \to ϕπ^+,ϕ\to K^+K^-)$. Our result deviates from the Particle Data Group value by more than 3$σ$. Furthermore, the asymmetry of the branching fractions of $D^+_s\to K_{S}^0K^{*}(892)^{+}$ and $D^+_s\to K_{L}^0K^{*}(892)^{+}$, $\frac{\mathcal{B}[D_{s}^{+} \to K_{S}^0K^{*}(892)^{+}]-\mathcal{B}[D_{s}^{+} \to K_{L}^0K^{*}(892)^{+}]}{\mathcal{B}[D_{s}^{+} \to K_{S}^0K^{*}(892)^{+}]+\mathcal{B}[D_{s}^{+} \to K_{L}^0K^{*}(892)^{+}]}$, is determined to be $(-14.5\pm 5.1_{\rm stat}\pm 1.8_{\rm syst})\%$.

hep-ex↗

arXiv2025

Single Inclusive $π^\pm$ and $K^\pm$ Production in $e^+e^-$ Annihilation at center-of-mass Energies from 2.000 to 3.671GeV

Using data samples with a total integrated luminosity of 253 $\rm pb^{-1}$ collected by the BESIII detector operating at the BEPCII collider, the differential cross-sections of inclusive $π^\pm$ and $K^\pm$ production, as a function of momentum and normalized by the total hadronic cross-section, are measured at center-of-mass energies from 2.000 to 3.671 GeV. The measured $π^{\pm}$ cross sections are consistent with the previously reported $π^{0}$ cross-sections by BESIII, while the $K^{\pm}$ cross sections are systematically higher than the $K^0_S$ cross sections by a factor of approximately 1.4. These new results are in agreement with state-of-the-art QCD analyses at next-to-next-to-leading order accuracy, particularly in the large hadron momentum region at energy scales down to 3 GeV. These findings support the validity of isospin symmetry in parton fragmentation processes.

hep-ex↗