arXiv subjects

Y. N. Gao

Publications and source records attributed to Y. N. Gao.

281 records · Page 16Linked to original sources

arXiv2022

Measurement of $e^{+}e^{-} \to K^{+}K^{-}π^{0}$ cross section and observation of a resonant structure

Based on $e^{+}e^{-}$ collision data collected by the BESIII detector at the BEPCII collider at center-of-mass energies from 2.000 to 3.080 GeV, a partial-wave analysis is performed for the process $e^{+}e^{-} \to K^{+}K^{-}π^{0}$. The Born cross section of the process $e^{+}e^{-} \to K^{+}K^{-}π^{0}$ and its subprocesses $e^{+}e^{-} \to ϕπ^{0}$, $K^{*}(892)K$ and $K^{*}_{2}(1430)K$ are measured. The results for $e^{+}e^{-} \to K^{+}K^{-}π^{0}$ and $ϕπ^{0}$ are consistent with the BaBar measurements and with improved precision. By analyzing the cross section, of the subprocesses $e^{+}e^{-} \to$ $K^{*}(892)K$ and $K^{*}_{2}(1430)K$, a structure with mass $M_R$ = (2208 $\pm$ 19 $\pm$ 24) MeV/$c^{2}$ and width $Γ_R$ = (168 $\pm$ 24 $\pm$ 39) MeV is observed with a combined statistical significance of 7.6$σ$. The measured resonance parameters suggest it can be identified as the $ϕ(2170)$, thus the results provide valuable input to understand the internal nature of this state.

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arXiv2022

Measurement of the Cross Section for $e^{+}e^{-}\to$ hadrons at Energies from 2.2324 to 3.6710 GeV

Based on electron-positron collision data collected with the BESIII detector operating at the Beijing Electron Positron Collider II storage rings, the value of $R\equivσ(e^{+}e^{-}\to$hadrons)/$σ(e^{+}e^{-}\toμ^{+}μ^{-})$ is measured at 14 center-of-mass energies from 2.2324 to 3.6710 GeV. The resulting uncertainties are less than $3.0\%$, and are dominated by systematic uncertainties.

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arXiv2022

Observation of a state $X(2600)$ in the $π^{+}π^{-}η'$ system in the process $J/ψ\rightarrowγπ^{+}π^{-}η'$

Based on $(10087\pm44)\times10^{6}$ $J/ψ$ events collected with the BESIII detector, the process $J/ψ\rightarrowγπ^{+}π^{-}η'$ is studied using two dominant decay channels of the $η'$ meson, $η'\rightarrowγπ^{+}π^{-}$ and $η'\rightarrowηπ^{+}π^{-},η\rightarrowγγ$. The $X(2600)$ is observed with a statistical significance larger than 20$σ$ in the $π^{+}π^{-}η'$ invariant mass spectrum, and it has a strong correlation to a structure around 1.5$~\mathrm{GeV}$/{\it c}$^{2}$ in the $π^{+}π^{-}$ invariant mass spectrum. A simultaneous fit on the $π^{+}π^{-}η'$ and $π^{+}π^{-}$ invariant mass spectra with the two $η'$ decay modes indicates that the mass and width of the $X(2600)$ state are $2617.8\pm2.1 ^{+18.2}_{-1.9}~\mathrm{MeV}$/{\it c}$^{2}$ and $200\pm8^{+20}_{-17}~\mathrm{MeV}$, respectively. The corresponding branching fractions are measured to be $B(J/ψ\rightarrowγX(2600))\cdot B(X(2600)\rightarrow f_{0}(1500)η')\cdot B(f_{0}(1500)\rightarrowπ^{+}π^{-})$ = ($3.39\pm0.18^{+0.91}_{-0.66})\times10^{-5}$ and $B(J/ψ\rightarrowγX(2600))\cdot B(X(2600)\rightarrow f_{2}^{'}(1525)η')\cdot B(f_{2}^{'}(1525)\rightarrowπ^{+}π^{-})$ = ($2.43\pm0.13^{+0.31}_{-1.11})\times10^{-5}$, where the first uncertainties are statistical, and the second systematic.

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arXiv2022

Search for a $CP$-odd light Higgs boson in $J/ψ\to γA^0$

Using $J/ψ$ radiative decays from 9.0 billion $J/ψ$ events collected by the BESIII detector, we search for di-muon decays of a $CP$-odd light Higgs boson ($A^0$), predicted by many new physics models beyond the Standard Model, including the Next-to-Minimal Supersymmetric Standard Model. No evidence for the $CP$-odd light Higgs production is found, and we set $90\%$ confidence level upper limits on the product branching fraction $\mathcal{B}(J/ψ\to γA^0)\times \mathcal{B}(A^0 \to μ^+μ^-)$ in the range of $(1.2-778.0)\times 10^{-9}$ for $0.212 \le m_{A^0} \le 3.0$ GeV/$c^2$. The new measurement is a 6-7 times improvement over our previous measurement, and is also slightly better than the BaBar measurement in the low-mass region for $\tan β=1$.

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arXiv2022

Observation of the electromagnetic Dalitz decay $D^{\ast 0}\to D^{0}e^{+}e^{-}$

Based on 3.19 fb$^{-1}$ of $e^+e^-$ collision data accumulated at the center-of-mass energy 4.178 GeV with the BESIII detector operating at the BEPCII collider, the electromagnetic Dalitz decay $D^{\ast 0}\to D^{0}e^{+}e^{-}$ is observed for the first time with a statistical significance of $13.2σ$. The ratio of the branching fraction of $D^{\ast 0}\to D^{0}e^{+}e^{-}$ to that of $D^{\ast 0}\to D^{0} γ$ is measured to be $(11.08\pm0.76\pm0.49)\times 10^{-3}$. By using the world average value of the branching fraction of $D^{\ast 0}\to D^{0} γ$, the branching fraction of $D^{\ast 0}\to D^{0}e^{+}e^{-}$ is determined to be $(3.91\pm0.27\pm0.17\pm0.10)\times 10^{-3}$, where the first uncertainty is statistical, the second systematic and the third external branching fractions.

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arXiv2021

Observation of $J/ψ$ Electromagnetic Dalitz Decays to $X(1835)$, $X(2120)$ and $X(2370)$

Using a sample of about 10 billion $J/ψ$ events collected at a center-of-mass energy $\sqrt s = 3.097$ GeV with the BESIII detector, the electromagnetic Dalitz decays $J/ψ\to e^+e^- π^+ π^- η'$, with $η'\toγπ^+ π^-$ and $η'\toπ^+π^-η$, have been studied. The decay $J/ψ\to e^+ e^- X(1835)$ is observed with a significance of $15σ$, and the transition form factor of $J/ψ\to e^+e^-X(1835)$ is presented for the first time. The intermediate states $X(2120)$ and $X(2370)$ are also observed in the $π^+ π^- η'$ invariant mass spectrum with significances of $5.3σ$ and $7.3σ$. The corresponding product branching fractions for $J/ψ\to e^+e^-X$, $X\toπ^+π^-η'$ $(X=X(1835), X(2120)$ and $X(2370))$, are reported.

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arXiv2021

Cross section measurements of the $e^+e^-\to D^{+}D^{-}$ and $e^+e^-\to D^{*+}D^{-}$ processes at center-of-mass energies from 4.085 to 4.600 GeV

The Born cross sections of the $e^+e^-\to D^{*+}D^{*-}$ and $e^+e^-\to D^{*+}D^{-}$ processes are measured using $e^+e^-$ collision data collected with the BESIII experiment at center-of-mass energies from 4.085 to 4.600 GeV, corresponding to an integrated luminosity of $15.7~{\rm fb}^{-1}$. The results are consistent with and more precise than the previous measurements by the Belle, Babar and CLEO collaborations. The measurements are essential for understanding the nature of vector charmonium and charmonium-like states.

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arXiv2021

Study of the Dalitz decay $J/ψ\to e^+e^- η$

We report corrected results on a study of the electromagnetic Dalitz decay $J/ψ\to e^+e^- η$ and search for di-electron decays of a light dark gauge boson ($γ'$) in $J/ψ\to γ' η$ with the two $η$ decay modes $η\rightarrow γγ$ and $η\rightarrow π^+π^-π^0$, using $(1310.6\pm 7.0)\times10^6$ $J/ψ$ events collected with the BESIII detector. In particular we update the measurement of the pole mass of the transition form factor (TFF) of $J/ψ\to e^+e^- η$ to be $Λ= 2.56 \pm 0.04({\rm stat}) \pm 0.03({\rm syst})$ GeV/$c^2$. The branching fraction of $J/ψ\to e^+e^-η$ and the kinetic-mixing strength between the Standard Model photon and $γ'$ are also updated after taking the corrected $Λ$ value into account. The measured branching fraction of $J/ψ\to e^+e^- η$ is updated to be $(1.42 \pm 0.04({\rm stat}) \pm 0.07 ({\rm syst}))\times 10^{-5}$, where the first and second uncertainties are statistical and systematic, respectively.

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arXiv2021

Study of the decay $D_s^+\to K_S^0K_S^0π^+$ and observation an isovector partner to $f_0(1710)$

Using $e^+e^-$ annihilation data corresponding to a total integrated luminosity of 6.32 $\rm fb^{-1}$ collected at center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay $D_{s}^{+} \to K_{S}^{0}K_{S}^{0}π^{+}$ for the first time. An enhancement is observed in the $K_{S}^{0}K_{S}^{0}$ mass spectrum near 1.7 GeV/$c^2$, which was not seen in $D_{s}^{+} \to K^+K^-π^{+}$ in an earlier work, implying the existence of an isospin one partner of the $f_0(1710)$. The branching fraction of the decay $D_{s}^{+}\to K_{S}^{0}K_{S}^{0}π^{+}$ is determined to be $\mathcal{B}(D_{s}^{+} \to K_{S}^{0}K_{S}^{0}π^{+})=(0.68\pm0.04_{\rm stat}\pm0.01_{\rm syst})\%$.

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arXiv2021

Amplitude analysis and branching fraction measurement of the decay $D_{s}^{+} \to π^{+}π^{0}π^{0}$

Using a data set corresponding to an integrated luminosity of 6.32~$\rm fb^{-1}$ recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, an amplitude analysis of the decay $D_{s}^{+} \to π^{+}π^{0}π^{0}$ is performed, and the relative fractions and phases of different intermediate processes are determined. The absolute branching fraction of the decay $D_{s}^{+} \to π^{+}π^{0}π^{0}$ is measured to be $(0.50\pm 0.04_{\text{stat}}\pm 0.02_{\text{syst}})\%$. The absolute branching fraction of the intermediate process $D_{s}^{+} \to f_0(980)π^{+}, f_0(980)\toπ^{0}π^{0}$ is determined to be $(0.21\pm 0.03_{\text{stat}}\pm 0.03_{\text{syst}})\%$.

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arXiv2021

Observation of $ψ(3686)\toΞ(1530)^{0}\barΞ(1530)^{0}$ and $Ξ(1530)^{0}\barΞ^0$

Using $(448.1\pm2.9)\times 10^{6}$ $ψ(3686)$ events collected with the BESIII detector and a single-baryon tagging technique, we present the first observation of the decays $ψ(3686)\toΞ(1530)^{0}\barΞ(1530)^{0}$ and $Ξ(1530)^{0}\barΞ^0$. The branching fractions are measured to be ${\cal{B}}(ψ(3686)\toΞ(1530)^{0}\barΞ(1530)^{0}) = (6.77\pm0.14\pm0.39)\times10^{-5}$ and ${\cal{B}}(ψ(3686)\toΞ(1530)^{0}\barΞ^{0}) = (0.53\pm0.04\pm0.03)\times10^{-5}$. Here, the first and second uncertainties are statistical and systematic, respectively. In addition, the parameter associated with the angular distribution for the decay $ψ(3686)\toΞ(1530)^{0}\barΞ(1530)^0$ is determined to be $α= 0.32\pm0.19\pm0.07$, in agreement with theoretical predictions within one standard deviation.

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