arXiv subjects

Y. Z. Che

Publications and source records attributed to Y. Z. Che.

At least 199 records · Page 11Linked to original sources

arXiv2025

Observation of $χ_{cJ}\to 3K_S^0K^\pmπ^\mp$

By analyzing $(2712.4\pm14.3)\times10^6$ $ψ(3686)$ events collected with the BESIII detector operating at the BEPCII collider, the decays $χ_{c0,1,2} \to 3K_S^0K^\pmπ^\mp$ are observed for the first time with statistical significances greater than $10σ$. The branching fractions of these decays are determined to be $\mathcal{B}(χ_{c0}\to 3K_S^0K^\pmπ^\mp )=(7.95\pm0.50\pm0.65)\times10^{-5},$ $\mathcal{B}(χ_{c1}\to 3K_S^0K^\pmπ^\mp)=(2.62\pm0.08\pm0.19)\times10^{-4},$ and $\mathcal{B}(χ_{c2}\to 3K_S^0K^\pmπ^\mp)=(1.72\pm0.07\pm0.15)\times10^{-4},$ where the first uncertainties are statistical and the second systematic.

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arXiv2025

Observation of an Altered $a_{0}(980)$ Line-shape in $D^{+} \rightarrow π^{+}ηη$ due to the Triangle Loop Rescattering Effect

Using 20.3~${\rm fb}^{-1}$ of $e^{+}e^{-}$ collision data taken with the BESIII detector at the center-of-mass energy 3.773~GeV, we report the first amplitude analysis of the hadronic decay $D^{+} \rightarrow π^{+}ηη$. The intermediate process $D^{+} \to a_{0}(980)^{+}η, a_{0}(980)^{+} \to π^{+}η$ is observed and is found to be the only component and its branching fraction is measured to be $(3.67\pm0.12_{\mathrm{stat.}}\pm 0.06_{\mathrm{syst.}})\times 10^{-3}$. Unlike the $a_{0}(980)$ line-shape observed in the decays of charmed mesons to $a_{0}(980)π$ and in the decay $D^{0} \to a_{0}(980)^{-}e^{+}ν_{e}$, where the low-mass side of the $a_0(980)$ is wider than the high-mass side, the $a_{0}(980)$ line-shape in $D^{+} \to a_{0}(980)^{+}η$ is found to be significantly altered, with the high-mass side being wider than the low-mass side. We establish that the $a_0(980)$ line-shape arises from the triangle loop rescattering of $D^+ \to \bar{K}_0^*(1430)^0K^+ \to a_0(980)^+ η$ and $D^+ \to K_0^*(1430)^+\bar{K}^0 \to a_0(980)^+ η$ with a significance of 5.8$σ$. This is the first experimental confirmation of the triangle loop rescattering effect.

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arXiv2025

Search for the lepton number violation decay $ω\to π^+ π^+ e^-e^- +c.c.$

The lepton number violation decay $ω\to π^+ π^+ e^-e^- +c.c.$ is searched for via $J/ψ\to ωη$ using a data sample of $(1.0087 \pm 0.0044) \times 10^{10}$ $J/ψ$ events collected by the BESIII detector at the BEPCII collider. No significant signal is observed, and the upper limit on the branching fraction of $ω\to π^+ π^+ e^-e^- +c.c.$ at the 90\% confidence level is determined for the first time to be $2.8 \times 10^{-6}$.

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arXiv2025

Measurements of branching fractions of $D^0\to K^- 3π^+2π^-$, $D^0\to K^- 2π^+π^-2π^0$ and $D^+\to K^- 3π^+π^-π^0$

Utilizing $7.9\,\rm fb^{-1}$ of $e^+e^-$ collision data taken with the BESIII detector at the center-of-mass energy of 3.773 GeV, we report the measurements of absolute branching fractions of the hadronic decays $D^0\to K^- 3π^+2π^-$, $D^0\to K^- 2π^+π^-2π^0$ and $D^+\to K^- 3π^+π^-π^0$. The $D^0\to K^- 3π^+2π^-$ decay is measured with improved precision, while the latter two decays are observed with statistical significance higher than $5σ$ for the first time. The absolute branching fractions of these decays are determined to be ${\mathcal B}(D^0\to K^- 3π^+2π^-)=( 1.35\pm 0.23\pm 0.08 )\times 10^{-4}$, ${\mathcal B}(D^0\to K^- 2π^+π^-2π^0)=( 19.0\pm 1.1\pm 1.5)\times 10^{-4}$, and ${\mathcal B}(D^+\to K^- 3π^+π^-π^0)=( 6.57\pm 0.69\pm 0.33)\times 10^{-4}$, where the first uncertainties are statistical and the second systematic.

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arXiv2025

Evidence for Two Excited $Ω^{-}$ Hyperons

Using $e^+e^-$ collision data corresponding to an integrated luminosity of 19,fb$^{-1}$ collected by the BESIII detector at center-of-mass energies ranging from 4.13 to 4.70,GeV, we report the first evidence for a new excited $Ω^{-}$ hyperon, the $Ω(2109)^{-}$, through the process $e^+ e^- \to Ω(2109)^{-} \barΩ^{+} +c.c.$ with a significance of 4.1 $σ$. The mass and width of $Ω(2109)^{-}$ are measured to be $2108.5 \pm 5.2_{\rm stat} \pm 0.9_{\rm syst}\,{\rm MeV}/c^{2}$ and $18.3 \pm 16.4_{\rm stat} \pm 5.7_{\rm syst}\,{\rm MeV}$, respectively. We also present evidence for a new production mechanism for the previously identified $Ω(2012)^-$ via the process $e^+ e^- \to Ω(2012)^{-} \barΩ^{+} +c.c.$ with a significance of 3.5 $σ$.

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arXiv2025

Search for $1^{-+}$ charmonium-like hybrid via $e^{+}e^{-}\rightarrow γη^{(\prime)} η_{c}$ at center-of-mass energies between 4.258 and 4.681 GeV

Using $e^{+}e^{-}$ collision data corresponding to an integrated luminosity of 10.6 fb$^{-1}$ collected at center-of-mass energies between 4.258 and 4.681 GeV with the BESIII detector at the BEPCII collider, we search for the $1^{- +}$ charmonium-like hybrid via $e^{+}e^{-}\rightarrowγηη_{c}$ and $e^{+}e^{-}\rightarrowγη^{\prime}η_{c}$ decays for the first time. No significant signal is observed and the upper limits on the Born cross sections for both processes are set at the 90% confidence level.

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arXiv2025

Updated model-independent measurement of the strong-phase differences between $D^0$ and $\bar{D}^0 \to K^{0}_{S/L}π^+π^-$ decays

The strong-phase differences between $D^0\to K_{S/L}^0π^+π^-$ and $\bar{D}^0\to K_{S/L}^0π^+π^-$ decays are one of the most important inputs in measuring the $C\!P$ violating angle $γ$ via $B^- \to D K^-$ decays. They also play a key role in studies of charm mixing and indirect $C\!P$ violation. In this paper, the strong-phase differences are determined in a model-independent way with quantum-correlated $D^0$-$\bar{D}^0$ decays from 7.93 fb$^{-1}$ of $e^+e^-$ annihilation data at $\sqrt{s}$=3.773 GeV by the BESIII experiment. These results are the most precise to date and are expected to significantly reduce associated uncertainties in determining the $C\!P$ violating angle $γ$ and related charm mixing parameters.

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arXiv2025

Observation of $D\to \bar{K}_{1}(1270)μ^+ν_μ$ and test of lepton flavor universality with $D\to \bar{K}_1(1270) \ell^{+} ν_{\ell}$

By analyzing 7.93 $\rm fb^{-1}$ of $e^+e^-$ collision data collected at the center-of-mass energy of 3.773 GeV with the BESIII detector operated at the BEPCII collider, we report the observation of the semimuonic decays of $D^+\to \bar K_1(1270)^0μ^+ν_μ$ and $D^0\to K_1(1270)^-μ^+ν_μ$ with statistical significances of $12.5σ$ and $6.0σ$, respectively. Their decay branching fractions are determined to be ${\mathcal B}[D^{+}\to \bar{K}_1(1270)^0 μ^{+}ν_μ]=(2.36\pm0.20^{+0.18}_{-0.27}\pm 0.48)\times10^{-3}$ and ${\mathcal B}[D^{0}\to K_1(1270)^{-} μ^{+}ν_μ]=(0.78\pm0.11^{+0.05}_{-0.09}\pm 0.15)\times10^{-3}$, where the first and second uncertainties are statistical and systematic, respectively, and the third originates from the input branching fraction of $\bar K_{1}(1270)^0\to K^- π^+π^0$ or $K_1(1270)^-\to K^-π^+π^-$. Combining our branching fractions with the previous measurements of ${\mathcal B}[D^+\to \bar K_1(1270)^0e^+ν_{e}]$ and ${\mathcal B}[D^0\to K_1(1270)^-e^+ν_{e}]$, we determine the branching fraction ratios to be ${\mathcal B}[D^+\to \bar K_1(1270)^0μ^+ν_μ]/{\mathcal B}[D^+\to \bar K_1(1270)^0e^+ν_{e}]=1.03 \pm 0.14 \substack{+0.11\\-0.15}$ and ${\mathcal B}[D^0\to K_1(1270)^-μ^+ν_μ]/{\mathcal B}[D^0\to K_1(1270)^-e^+ν_{e}]=0.74\pm 0.13 \substack{+0.08\\-0.13}$. Using the branching fractions measured in this work and the world-average lifetimes of the $D^+$ and $D^0$ mesons, we determine the semimuonic partial decay width ratio to be $Γ[D^+\to \bar K_1(1270)^0 μ^+ν_μ]/Γ[D^0\to K_1(1270)^- μ^+ν_μ]=1.22\pm 0.10\substack{+0.06\\-0.09}$, which is consistent with unity as predicted by isospin conservation.

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arXiv2025

Precise measurement of the form factors in $D^0\rightarrow K^(892)^-μ^+ν_μ$ and test of lepton universality with $D^0\rightarrow K^(892)^-\ell^+ν_{\ell}$ decays

We report a study of the semileptonic decay $D^0 \rightarrow \bar{K}^0π^-μ^+ν_μ$ based on a sample of $7.9~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data collected at a center-of-mass energy of 3.773~GeV with the BESIII detector at the BEPCII collider. The branching fraction of the decay is measured for the first time to be $\mathcal{B}(D^0\rightarrow \bar{K}^0π^-μ^+ν_μ) = (1.373 \pm 0.020_{\rm stat} \pm 0.023_{\rm syst})\%$, where the first uncertainty is statistical and the second is systematic. Based on the investigation of the decay dynamics, we find that the decay is dominated by the $K^{*}(892)^-$ resonance with the branching fraction measured to be $\mathcal{B}(D^0\rightarrow K^{*}(892)^-μ^+ν_μ) = (1.948 \pm 0.033_{\rm stat} \pm 0.036_{\rm syst})\%$. We also determine the hadronic form factors for the $D^0\rightarrow K^{*}(892)^-μ^+ν_μ$ decay to be $r_{V} = V(0)/A_1(0) = 1.46 \pm 0.11_{\rm stat} \pm 0.04_{\rm syst}$, $r_{2} = A_2(0)/A_1(0) = 0.71 \pm 0.08_{\rm stat} \pm 0.03_{\rm syst}$, and $A_1(0)=0.609 \pm 0.008_{\rm stat} \pm 0.008_{\rm syst}$, where $V(0)$ is the vector form factor and $A_{1,2}(0)$ are the axial form factors evaluated at $q^2=0$. The $A_1(0)$ is measured for the first time in $D^0\rightarrow K^{*}(892)^-μ^+ν_μ$ decay. Averaging the form-factor parameters that we reported previously in $D^0\rightarrow K^*(892)^-(\rightarrow \bar{K}^0π^-)e^+ν_{e}$ and $D^0\rightarrow K^*(892)^-(\rightarrow K^-π^0)μ^+ν_μ$ decays, we obtain $r_{V}=1.456\pm0.040_{\rm stat}\pm0.016_{\rm syst}$, $r_{2}=0.715\pm0.031_{\rm stat}\pm0.014_{\rm stat}$, and $A_1(0)=0.614\pm0.005_{\rm stat}\pm0.004_{\rm syst}$. This is the most precise determination of the form-factor parameters to date measured in $D\rightarrow K^*(892)$ transition, which provide the most stringent test on various theoretical models.

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arXiv2025

Search for the baryon and lepton number violating decay $J/ψ\to pe^-$ + c.c

Based on $(2712.4\pm 14.3) \times 10^{6} $ ${ψ(3686)}$ events collected by the BESIII detector operating at the BEPCII storage ring, we perform a search for the baryon- and lepton-number violating decay $J/ψ\to pe^{-}+c.c.$ via $ψ(3686) \to π^{+}π^{-}J/ψ$. No significant signal is found. An upper limit on the branching fraction of $\mathcal{B}(J/ψ\to p e^{-}+ c.c.) < 3.1 \times 10^{-8}$ at 90\% confidence level.

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arXiv2025

Observation of the charmonium decay $η_c\toγγ$ in $J/ψ\toγη_c$

Using $(2712.4\pm14.3)\times10^{6}$ $ψ(3686)$ events collected with the BESIII detector at the BEPCII collider, the decay $η_c\toγγ$ in $J/ψ\toγη_c$ is observed. We determine the product branching fraction $\mathcal{B}(J/ψ\toγη_c)\times\mathcal{B}(η_c\toγγ)=(5.23\pm0.26_{\rm{stat.}}\pm0.30_{\rm{syst.}})\times10^{-6}$. This result is consistent with the LQCD calculation $(5.34\pm0.16)\times10^{-6}$ from HPQCD in 2023. By using the world-average values of $\mathcal{B}(J/ψ\toγη_c)$ and the total decay width of $η_c$, the partial decay width $Γ(η_c\toγγ)$ is determined to be $(11.30\pm0.56_{\rm{stat.}}\pm0.66_{\rm{syst.}}\pm1.14_{\rm{ref.}})~\rm{keV}$, which deviates from the corresponding world-average value by $3.4σ$.

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arXiv2025

Evidence of doubly OZI-suppressed decay $η_{c} \to ωϕ$ in the radiative decay $J/ψ\to γη_{c}$

Using a sample of $(10087\pm44) \times 10^{6}$ $J/ψ$ events collected with the BESIII detector at the BEPCII collider, the first evidence for the doubly OZI-suppressed decay $η_{c} \to ωϕ$ is reported with a significance of 4.0$σ$. The branching fraction of $η_{c} \to ωϕ$ is measured to be $\mathcal{B}(η_{c} \to ωϕ) = (3.86 \pm 0.92 \pm 0.62) \times 10^{-5}$, where the first uncertainty is statistical and the second is systematic. This result provides valuable insights into the underlying mechanisms of charmonium decays, particularly for processes such as $η_{c} \to VV$ (where $V$ represents a vector meson).

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arXiv2025

Measurement of the branching fractions of doubly Cabibbo-suppressed $D$ decays

By analyzing $e^+e^-$ collision data collected at the center-of-mass energy of 3.773~GeV with the BESIII detector, corresponding to an integrated luminosity of 20.3~fb$^{-1}$, we measure the branching fractions of the doubly Cabibbo-suppressed (DCS) decays $D^0\to K^+π^-$, $D^0\to K^+π^-π^-π^+$, $D^0\to K^+π^-π^0$, $D^0\to K^+π^-π^0π^0$, $D^+\to K^+π^+π^-$, and $D^+\to K^+K^+K^-$. We also perform the first searches for $D^0\to K^+π^-η$, $D^0\to K^+π^-π^0η$, $D^+\to K^+π^+π^-η$, $D^{+} \to K^{+} \left(π^{+} π^{-} η\right)_{{\rm non}-η^{\prime}}$, and $D^+\to K^+ηη$ and report the first observations and evidence for some of these final states. Combining the measurements with the world averages of the corresponding Cabibbo-favored (CF) decays, the ratios of the DCS/CF branching fractions are obtained. For the $D^{+} \to K^{+} \left(π^{+} π^{-} η\right)_{{\rm non}-η^{\prime}}$ decay, the ratio is significantly larger than the corresponding ratios of the other DCS decays.

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arXiv2025

Observation of the decay $ψ(3686)\rightarrow Σ^{0}\barΣ^{0}ω$

Using a dataset of $(27.12\pm 0.14)\times 10^{8}$ $ψ(3686)$ events collected by the BESIII detector operating at the BEPCII collider, we report the first observation of the decay $ψ(3686)\toΣ^{0}\barΣ^{0}ω$ with a statistical significance of 8.9$σ$. The measured branching fraction is $(1.24 \pm 0.16_{\textrm{stat}} \pm 0.11_{\textrm{sys}}) \times 10^{-5}$, where the first uncertainty is statistical and the second is systematic. Additionally, we investigate potential intermediate states in the invariant mass distributions of $Σ^{0}ω$, $\barΣ^{0}ω$ and $Σ^{0}\barΣ^{0}$. A hint of a resonance is observed in the invariant mass distribution of $M_{Σ^{0}(\barΣ^{0})ω}$, located around 2.06 GeV/$c^2$, with a significance of 2.5$σ$.

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arXiv2025

Stringent test of $CP$ symmetry in $Σ^+$ hyperon decays

The non-leptonic two-body weak decays $Σ^{+} \to p π^{0}$ and $\barΣ^{-} \to \bar{p} π^{0}$ are investigated, utilizing $(1.0087\pm0.0044)\times10^{10}$ $J/ψ$ events and $(2.7124\pm0.0143)\times10^{9}$ $ψ(3686)$ events collected by BESIII experiment. The precision of the weak-decay parameters for the decays $Σ^{+} \to p π^{0}$ ($α_{0}$) and $\barΣ^{-} \to \bar{p} π^{0}$ ($\barα_{0}$) is improved by a factor of three compared to the previous world average. Furthermore, the quantum-entangled $Σ^{+}\barΣ^{-}$ system enables the most precise test of $CP$ symmetry for the decay $Σ^+\to pπ^0$, through the asymmetry observable $A_{CP}=(α_{0}+\barα_{0})/(α_{0}-\barα_{0})$ that is measured to be $-0.0118\pm0.0083_{\rm stat}\pm0.0028_{\rm syst}$. Assuming $CP$ conservation, the average decay parameter is determined to be ${\left< α_{\rm 0}\right>} = (α_0-\barα_0)/2=-0.9869\pm0.0011_{\rm stat}\pm0.0016_{\rm syst}$, which is the most precise measurement of the asymmetry decay parameters in baryon sectors. The angular dependence of the ratio of the polarization of the $Σ^+$ in both $J/ψ$ and $ψ(3686)$ decays is studied for the first time.

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arXiv2025

Measurement of Born cross section of $e^+e^-\toΣ^0\barΣ^0$ at $\sqrt{s} = 3.50-4.95$ GeV

Using $e^+e^-$ collision data collected with the BESIII detector at the BEPCII collider at thirty-two center-of-mass energies from 3.50 to 4.95 GeV, corresponding to an integrated luminosity of 25 $\rm{fb^{-1}}$, we measure the Born cross section of the $e^+e^-\toΣ^0\barΣ^0$ reaction and the effective form factor. No significant charmonium(-like) state, i.e., $ψ(3770)$, $ψ(4040)$, $ψ(4160)$, $ψ(4230)$, $ψ(4360)$, $ψ(4415)$, or $ψ(4660)$, decaying into the $Σ^0\barΣ^0$ final state is observed by fitting the $e^+e^- \to Σ^0\barΣ^0$ dressed cross section. The upper limits for the product of the branching fraction and the electronic partial width at the 90% confidence level are provided for each assumed charmonium(-like) state. In addition, the ratios of the Born cross section and the effective form factor between the $e^+e^-\toΣ^0\barΣ^0$ and the $e^+e^-\toΣ^+\barΣ^-$ reactions are provided, which can be used to validate the prediction of the vector meson dominance model.

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arXiv2025

Search for a $1^{-+}$ molecular state via $e^{+}e^{-} \to γD^{+}_{s} D_{s1}^{-}(2536) +c.c.$

We search, for the first time, for an exotic molecular state with quantum numbers $J^{PC}=1^{-+}$, called $X$, via the process $e^{+}e^{-} \to γD^{+}_{s} D_{s1}^{-}(2536) +c.c.$ using data samples corresponding to a luminosity of $5.8~\mathrm{fb^{-1}}$ across center-of-mass energies from 4.612 to 4.951~GeV, collected with the BESIII detector operating at the BEPCII collider. No statistically significant signal is observed. The upper limits on the product of cross-section and branching fraction $σ({e^{+}e^{-} \to γX}) \times \mathcal{B}(X \to D^{+}_{s} D_{s1}^{-}(2536) +c.c.)$ at 90\% confidence level are reported for each energy point, assuming the $X$ mass to be 4.503~GeV/$c^{2}$ and the width 25, 50, 75, and 100~MeV, respectively.

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arXiv2025

Measurement of the branching fractions of $D^+ \to K^+K^-π^+π^+π^-$, $ϕπ^+π^+π^-$, $K^0_SK^+π^+π^-π^0$, $K^0_SK^+η$, and $K^0_SK^+ω$ decays

Using $20.3~\mathrm{fb}^{-1}$ of $e^+e^-$ collision data collected at a center-of-mass energy of 3.773 GeV with the BESIII detector operating at the BEPCII collider, the branching fractions of three hadronic charm meson decays, $D^+\to ϕπ^+π^+π^-$, $D^+\to K^0_SK^+π^+π^-π^0$, and $D^+\to K^0_SK^+ω$, are measured for the first time to be $(0.54\pm0.19\pm0.02)\times 10^{-4}$, $(2.51\pm0.34\pm0.14)\times 10^{-4}$, and $(2.02\pm0.35\pm0.10)\times 10^{-4}$, respectively. Futhermore, the branching fractions of $D^+\to K^+K^-π^+π^+π^-$ and $D^+\to K^0_SK^+η$ are measured with improved precision, yielding values of $(0.66\pm0.11\pm0.03)\times 10^{-4}$ and $(2.27\pm0.22\pm0.05)\times 10^{-4}$, respectively.

hep-ex↗