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BESIII collaboration

Publications and source records attributed to BESIII collaboration.

16 recordsLinked to original sources
arXiv2026

Search for the rare decays of $D\to h(h^{(')})e^{+}e^{-}$

We search for 15 rare decays of $D$ mesons to hadrons accompanied by an electron-positron pair $D\to h(h^{(')})e^{+}e^{-}$, based on 20.3 fb$^{-1}$ of $e^+ e^-$ collision data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector at BEPCII. No significant signals are observed, and the corresponding upper limits on the branching fractions at the 90\% confidence level are determined. The sensitivities of the results are at the level of $10^{-6}$ $\sim$ $10^{-7}$. The upper limits on the branching fractions for the $D^+\to \rho^{+} e^+ e^-$, $D^+\to K^{*+} e^+ e^-$, $D^0\to K_S^0 K_S^0 e^+ e^-$, $D^0\to \pi^0 \pi^0 e^+ e^-$ and $D^0\to \eta^{\prime} e^+ e^-$ decay channels are measured for the first time. For the $D^0\to \pi^0 e^+ e^-$, $D^0\to \eta e^+ e^-$, $D^0\to \omega e^+ e^-$, $D^0\to K_S^0 e^+ e^-$, $D^+\to \pi^+ \pi^0 e^+ e^-$, $D^+\to K^+ \pi^0 e^+ e^-$, $D^+\to \pi^+ K_S^0 e^+ e^-$ and $D^+\to K^+ K_S^0 e^+ e^-$ decay channels, the upper limits on the branching fractions are determined, with an improvement of at least a factor of four compared to previous searches. The upper limits on the branching fractions for the $D^0\to \rho^{0} e^+ e^-$ and $D^0\to \phi e^+ e^-$ decay channels are set at $0.7 \times 10^{-6}$ and $4.6 \times 10^{-6}$, respectively.

hep-ex↗
arXiv2023

Study of the $e^+e^- \to \pi^{+}\pi^{-}\omega$ process at center-of-mass energies between 4.0 and 4.6 GeV

Using $15.6$ $\rm fb^{-1}$ of $e^+e^-$ collision data collected at twenty-four center-of-mass energies from $4.0$ to $4.6$ GeV with the BESIII detector, the helicity amplitudes of the process $e^+e^-\to \pi^{+}\pi^{-}\omega$ are analyzed for the first time. Born cross section measurements of two-body intermediate resonance states with statistical significance greater than 5$\sigma$ are presented, such as $f_{0}(500)$, $f_{0}(980)$, $f_{2}(1270)$, $f_{0}(1370)$, $b_{1}(1235)^{\pm}$, and $\rho(1450)^{\pm}$. In addition, evidence of a resonance state in $e^+e^-\to \pi^+\pi^-\omega$ production is found. The mass of this state obtained by line shape fitting is about 4.2 GeV/$c^2$, which is consistent with the production of $\psi(4160)$ or $Y(4220)$.

hep-ex↗
arXiv2020

Inclusive charged and neutral particle multiplicity distributions in $\chi_{cJ}$ and $J/\psi$ decays

Using a sample of 106 million $\psi(3686)$ decays, $\psi(3686) \to \gamma \chi_{cJ} (J = 0, 1, 2)$ and $\psi(3686) \to \gamma \chi_{cJ}, \chi_{cJ} \to \gamma J/\psi$ $(J = 1, 2)$ events are utilized to study inclusive $\chi_{cJ} \to$ anything, $\chi_{cJ} \to$ hadrons, and $J/\psi \to$ anything distributions, including distributions of the number of charged tracks, electromagnetic calorimeter showers, and $\pi^0$s, and to compare them with distributions obtained from the BESIII Monte Carlo simulation. Information from each Monte Carlo simulated decay event is used to construct matrices connecting the detected distributions to the input predetection "produced" distributions. Assuming these matrices also apply to data, they are used to predict the analogous produced distributions of the decay events. Using these, the charged particle multiplicities are compared with results from MARK I. Further, comparison of the distributions of the number of photons in data with those in Monte Carlo simulation indicates that G-parity conservation should be taken into consideration in the simulation.

hep-ex↗
arXiv2018

Search for the rare decay of $ψ(3686) \rightarrow Λ_c^+ \overline{p} e^+ e^- + c.c.$ at BESIII

Based on a data sample of $(448.1\pm2.9)\times10^6~ψ(3686)$ decays collected with the BESIII experiment, a search for the flavor changing neutral current transition $ψ(3686)\rightarrow Λ_c^+ \overline{p} e^+ e^- + c.c.$ is performed for the first time. No signal candidates are observed and the upper limit on the branching fraction of $ψ(3686)\rightarrow Λ_c^+ \overline{p} e^+ e^-$ is determined to be $1.7\times10^{-6}$ at the 90\% confidence level. The result is consistent with expectations from the Standard Model, and no evidence for new physics is found.

hep-ex↗
arXiv2018

Search for $ψ(3686)\to γη_c(η(1405))\to γπ^{+}π^{-}π^{0}$

Using a sample of $448.1\times10^{6}$ $ψ(3686)$ events collected with the BESIII detector, a search for the isospin violating decay $η_{c}\toπ^{+}π^{-}π^{0}$ via $ψ(3686)\toγη_{c}$ is presented. No signal is observed, and the upper limit on $\mathcal{B}(ψ(3686)\to γη_{c}\to γπ^{+}π^{-}π^{0} )$ is determined to be $1.6\times10^{-6}$ at the $90\%$ confidence level. In addition, a search for $η(1405)\to f_{0}(980)π^{0}$ in $ψ(3686)$ radiative decays is performed. No signal is observed, and the branching fraction $\mathcal{B}(ψ(3686)\toγη(1405)\to γf_{0}(980)π^{0}\toγπ^+π^-π^0 )$ is calculated to be less than $ 5.0\times10^{-7}$ at the $90\%$ confidence level.

hep-ex↗
arXiv2017

Measurement of Singly Cabibbo Suppressed Decays $Λ_c^{+}\to pπ^{+}π^{-}$ and $Λ_c^{+}\to pK^{+}K^{-}$

Using 567 $pb^{-1}$ of data collected with the BESIII detector at a center-of-mass energy of $\sqrt{s}=$ 4.599 $GeV$, near the $Λ_{c}^{+}Λ_{c}^{-}$ threshold, we study the singly Cabibbo-suppressed decays $Λ_c^{+}\to pπ^{+}π^{-}$ and $Λ_c^{+}\to pK^{+}K^{-}$. By normalizing with respect to the Cabibbo-favored decay $Λ_c^{+}\to pK^{-}π^{+}$, we obtain ratios of branching fractions: $\frac{\mathcal{B}(Λ_c^{+}\to pπ^{+}π^{-})}{\mathcal{B}(Λ_c^{+}\to pK^{-}π^{+})}$ = $(6.70 \pm 0.48 \pm 0.25)\%$, $\frac{\mathcal{B}(Λ_c^{+}\to pϕ)}{\mathcal{B}(Λ_c^{+}\to pK^{-}π^{+})}$ = $(1.81 \pm 0.33 \pm 0.13)\%$, and $\frac{\mathcal{B}(Λ_c^{+}\to pK^{+}K^{-}_{\text{non-}ϕ})}{\mathcal{B}(Λ_c^{+}\to pK^{-}π^{+})}$ = $(9.36 \pm 2.22 \pm 0.71)\times10^{-3}$, where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay $Λ_c^{+}\to pπ^{+}π^{-}$ is observed for the first time, and the precision of the branching fraction for $Λ_c^{+}\to pK^{+}K^{-}_{\text{non-}ϕ}$ and $Λ_c^{+}\to pϕ$ is significantly improved.

hep-ex↗
arXiv2017

Search for the rare decay $D^+ \to D^0 e^+ν_e$

We search for the rare decay $D^+\to D^0 e^+ν_{e}$, using a data set with an integrated luminosity of 2.93 $\rm fb^{-1}$ collected at $\sqrt{s}=3.773$ GeV with the BESIII detector operating at the BEPCII storage rings. No signals are observed. We set the upper limit on the branching fraction for $D^+\to D^0 e^+ν_e$ to be $1.0\times 10^{-4}$ at the 90\% confidence level.

hep-ex↗
arXiv2017

Observation of $e^{+}e^{-} \to ηh_{c}$ at center-of-mass energies from 4.085 to 4.600 GeV

We observe for the first time the process $e^{+}e^{-} \rightarrow ηh_c$ with data collected by the BESIII experiment. Significant signals are observed at the center-of-mass energy $\sqrt{s}=4.226$ GeV, and the Born cross section is measured to be $(9.5^{+2.2}_{-2.0} \pm 2.7)$ pb. Evidence for $ηh_c$ is observed at $\sqrt{s}=4.358$ GeV with a Born cross section of $(10.0^{+3.1}_{-2.7} \pm 2.6)$ pb, and upper limits on the production cross section at other center-of-mass energies between 4.085 and 4.600 GeV are determined.

hep-ex↗
arXiv2017

Branching fraction measurements of $ψ(3686) \to γχ_{cJ}$

Using a sample of 106 million $ψ(3686)$ decays, the branching fractions of $ψ(3686) \to γχ_{c0}, ψ(3686) \to γχ_{c1}$, and $ψ(3686) \to γχ_{c2}$ are measured with improved precision to be $(9.389 \pm 0.014 \pm 0.332)\,\%$, $(9.905 \pm 0.011 \pm 0.353)\,\% $, and $(9.621 \pm 0.013 \pm 0.272)\,\% $, respectively, where the first uncertainties are statistical and the second ones are systematic. The product branching fractions of $ψ(3686) \to γχ_{c1}, χ_{c1} \to γJ/ψ$ and $ψ(3686) \to γχ_{c2}, χ_{c2} \to γJ/ψ$ and the branching fractions of $χ_{c1} \to γJ/ψ$ and $χ_{c2} \to γJ/ψ$ are also presented.

hep-ex↗
arXiv2015

Observation of a neutral charmoniumlike state $Z_c(4025)^0$ in $e^{+} e^{-} \to (D^{*} \bar{D}^{*})^{0} π^0$

We report a study of the process $e^{+} e^{-} \to (D^{*} \bar{D}^{*})^{0} π^0$ using $e^+e^-$ collision data samples with integrated luminosities of $1092 \rm{pb}^{-1}$ at $\sqrt{s}=4.23 \rm{GeV}$ and $826 \rm{pb}^{-1}$ at $\sqrt{s}=4.26 \rm{GeV}$ collected with the BESIII detector at the BEPCII storage ring. We observe a new neutral structure near the $(D^{*} \bar{D}^{*})^{0}$ mass threshold in the $π^0$ recoil mass spectrum, which we denote as $Z_{c}(4025)^{0}$. Assuming a Breit-Wigner line shape, its pole mass and pole width are determined to be $(4025.5^{+2.0}_{-4.7}\pm3.1) \rm{MeV}/c^2$ and $(23.0\pm 6.0\pm 1.0) \rm{MeV}$, respectively. The Born cross sections of $e^{+}e^{-}\to Z_{c}(4025)^{0} π^0\to (D^{*} \bar{D}^{*})^{0}π^0$ are measured to be $(61.6\pm8.2\pm9.0) \rm{pb}$ at $\sqrt{s}=4.23 \rm{GeV}$ and $(43.4\pm8.0\pm5.4) \rm{pb}$ at $\sqrt{s}=4.26 \rm{GeV}$. The first uncertainties are statistical and the second are systematic.

hep-ex↗
arXiv2015

An Improved Limit for Gamma_ee of X(3872) and Gamma_ee Measurement of psi(3686)

Using the data sets taken at center-of-mass energies above 4 GeV by the BESIII detector at the BEPCII storage ring, we search for the reaction e+e- -> gamma_ISR X(3872) -> gamma_ISR pi+pi-J/psi via the Initial State Radiation technique. The production of a resonance with quantum numbers J^PC = 1^++ such as the X(3872) via single photon e+e- annihilation is forbidden, but is allowed by a next-to-leading order box diagram. We do not observe a significant signal of X(3872), and therefore give an upper limit for the electronic width times the branching fraction Gamma_ee^X(3872)Br(X(3872) -> pi+pi-Jψ) < 0.13 eV at the 90% confidence level. This measurement improves upon existing limits by a factor of 46. Using the same final state, we also measure the electronic width of the psi(3686) to be Gamma_ee^psi(3686) = 2231 +- 18 +- 99 eV.

hep-ex↗
arXiv2015

Search for the weak decays $J/ψ\to D^{(*)}_{s}eν_{e}$

Using a sample of $2.25\times 10^8$ $J/ψ$ events collected with the BESIII detector at the BEPCII collider, we search for the $J/ψ$ semi-leptonic weak decay $J/ψ\to D^{-}_{s} e^{+}ν_{e}+c.c.$ with a much higher sensitivity than previous searches. We also perform the first search for $J/ψ\to D^{*-}_{s} e^{+}ν_{e}+c.c.$ No significant excess of a signal above background is observed in either channel. At the $90\%$ confidence level, the upper limits are determined to be $\mathcal{B}(J/ψ\to D^{-}_{s}e^{+}ν_{e}+c.c.)<1.3\times10^{-6}$ and $\mathcal{B}(J/ψ\to {D^{*}_{s}}^{-}e^{+}ν_{e}+c.c.)<1.8\times10^{-6}$, respectively. Both are consistent with Standard Model predictions.

hep-ex↗
arXiv2014

Observation of a charged charmoniumlike structure in $e^+e^- \to (D^{*} \bar{D}^{*})^{\pm} π^\mp$ at $\sqrt{s}=4.26$GeV

We study the process $e^+e^- \to (D^{*} \bar{D}^{*})^{\pm} π^\mp$ at a center-of-mass energy of 4.26GeV using a 827pb$^{-1}$ data sample obtained with the BESIII detector at the Beijing Electron Positron Collider. Based on a partial reconstruction technique, the Born cross section is measured to be $(137\pm9\pm15)$pb. We observe a structure near the $(D^{*} \bar{D}^{*})^{\pm}$ threshold in the $π^\mp$ recoil mass spectrum, which we denote as the $Z^{\pm}_c(4025)$. The measured mass and width of the structure are $(4026.3\pm2.6\pm3.7)$MeV/c$^2$ and $(24.8\pm5.6\pm7.7)$MeV, respectively. Its production ratio $\frac{σ(e^+e^-\to Z^{\pm}_c(4025)π^\mp \to (D^{*} \bar{D}^{*})^{\pm} π^\mp)}{σ(e^+e^-\to (D^{*} \bar{D}^{*})^{\pm} π^\mp)}$ is determined to be $0.65\pm0.09\pm0.06$. The first uncertainties are statistical and the second are systematic.

hep-ex↗
arXiv2014

Observation of $e^{+} e^{-} \to γX(3872)$ at BESIII

With data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies from 4.009 to 4.420 GeV, the process $e^{+} e^{-} \to γX(3872)$ is observed for the first time with a statistical significance of $6.3σ$. The measured mass of the $X(3872)$ is ($3871.9\pm 0.7_{\rm stat.}\pm 0.2_{\rm sys.}$) MeV/$c^2$, in agreement with previous measurements. Measurements of the product of the cross section $σ[e^{+} e^{-} \to γX(3872)]$ and the branching fraction $\mathcal{B}[X(3872) \to π^{+} π^{-} J/ψ]$ at center-of-mass energies 4.009, 4.229, 4.260, and 4.360 GeV are reported. Our measurements are consistent with expectations for the radiative transition process $Y(4260) \to γX(3872)$.

hep-ex↗
arXiv2013

Observation of the decay $ψ(3686)$ $\rightarrow$ $Λ\barΣ^{\pm}π^{\mp}+c.c.$

Using a sample of $1.06\times10^{8}$ $ψ(3686)$ events collected with the BESIII detector, we present the first observation of the decays of $ψ(3686)$ $\rightarrow$ $Λ\barΣ^{+}π^{-}+c.c.$ and $ψ(3686)$ $\rightarrow$ $Λ\barΣ^{-}π^{+}+c.c.$. The branching fractions are measured to be $\mathcal{B}(ψ(3686) \rightarrow Λ\barΣ^{+}π^{-} + c.c.)=(1.40\pm 0.03 \pm 0.13)\times10^{-4}$ and $\mathcal{B}(ψ(3686) \rightarrow Λ\barΣ^{-}π^{+}+c.c.)=(1.54\pm 0.04 \pm 0.13)\times10^{-4}$, where the first errors are statistical and the second ones systematic.

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