arXiv subjects

P. T. Ge

Publications and source records attributed to P. T. Ge.

At least 163 records · Page 9Linked to original sources

arXiv2022

Search for the decay $h_c\rightarrowπ^0J/ψ$

A search for the decay $h_c\rightarrowπ^0J/ψ$ is performed using a sample of $h_c$ produced in the reaction $e^+e^-\rightarrowπ^+π^-h_c$. The data samples were collected with the BESIII detector at center-of-mass energies between 4.189 and 4.437 GeV, corresponding to a total integrated luminosity of 11 fb$^{-1}$. No significant signal is observed. Upper limits on the branching ratio $\mathcal{B}(h_c\rightarrowπ^0J/ψ)/\mathcal{B}(h_c\rightarrowγη_c\rightarrowγK^+K^-π^0)$ and on the branching fraction $\mathcal{B}(h_c\rightarrowπ^0J/ψ)$ are determined to be $7.5\times10^{-2}$ and $4.7\times10^{-4}$ at $90\%$ confidence level, respectively. The latter is derived from the former using the measured branching fraction of the normalization channel. This is the first determination of the upper limit of the decay $h_c\rightarrowπ^0J/ψ$.

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arXiv2022

Search for new hadronic decays of $h_{c}$ and observation of $h_{c}\to p\bar{p}η$

A search for the hadronic decays of the $h_{c}$ meson to the final states $p\bar{p}π^{+}π^{-}π^{0}$, $p\bar{p}η$, and $p\bar{p}π^0$ via the process $ψ(3686) \to π^{0}{h_c}$ is performed using $(4.48\pm0.03)\times10^{8}$ $ψ(3686)$ events collected with the BESIII detector. The decay channel $h_{c}\to p\bar{p}η$ is observed for the first time with a significance greater than $5σ$ and a branching fraction of $\left( {6.41 \pm 1.74 \pm 0.53 \pm 1.00} \right) \times {10^{ -4}}$, where the uncertainties are statistical, systematic, and that from the branching fraction of $ψ(3686)\toπ^{0}h_{c}$. Strong evidence for the decay ${h_c} \to p\bar{p}{π^+}{π^-}{π^0}$ is found with a significance of $4.9σ$ and a branching fraction of $\left( {3.84 \pm 0.83 \pm0.69} \pm 0.58 \right) \times {10^{ - 3}}$. The significances include systematic uncertainties. No clear signal of the decay $h_c\to p\bar{p}π^{0}$ is found, and an upper limit of $6.59\times 10^{-4}$ on its branching fraction is set at the 90% confidence level.

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arXiv2022

Amplitude analysis and branching fraction measurement of $D_{s}^{+} \to K^-K^+π^+π^+π^-$

Using $e^{+}e^{-}$ annihilation data corresponding to a total integrated luminosity of $6.32$ fb$^{-1}$ collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay $D^+_s \to K^-K^+π^+π^+π^-$ and determine the relative fractions and phases of different intermediate processes. Absolute branching fraction of $D^+_s\to K^-K^+π^+π^+π^-$ decay is measured to be ($6.60\pm0.47_{\rm stat.}\pm0.35_{\rm syst.})\times 10^{-3}$. The dominant intermediate process is $D_{s}^{+} \to a_1(1260)^+ϕ, ϕ\to K^-K^+, a_1(1260)^+\to ρπ^+, ρ\toπ^+π^-$, with a branching fraction of $(5.16\pm0.41_{\rm stat.}\pm0.27_{\rm syst.})\times 10^{-3}$.

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arXiv2022

Measurement of the branching fraction of the doubly Cabibbo-suppressed decay $D^0\to K^+π^-π^0$ and search for $D^0\to K^+π^-π^0π^0$

Using $2.93\,\rm fb^{-1}$ of $e^+e^-$ collision data collected at a center-of-mass energy of 3.773\,GeV with the BESIII detector, we present a measurement of the branching fraction of the doubly Cabibbo-suppressed (DCS) decay $D^0\to K^+π^-π^0$ and a search for the DCS decay $D^0\to K^+π^-π^0π^0$. The branching fraction of $D^0\to K^+π^-π^0$ is determined to be $[3.13^{+0.60}_{-0.56}({\rm stat}) \pm 0.09({\rm syst})] \times 10^{-4}$. No signal is observed for $D^0\to K^+π^-π^0π^0$ and an upper limit of $3.6 \times 10^{-4}$ is set on the branching fraction at the 90\% C.L. We combine these results with the world-average branching fractions of their counterpart Cabibbo-favored decays to determine the ratios of the doubly Cabibbo-suppressed over the Cabibbo-favored branching fractions, ${\mathcal B}(D^0\to K^+π^-π^0)/{\mathcal B}(D^0\to K^-π^+π^0)=(0.22\pm 0.04)\%$~and ${\mathcal B}(D^0\to K^+π^-π^0π^0)/{\mathcal B}(D^0\to K^-π^+π^0π^0)<0.40\%$ at the 90\% C.L., which correspond to $(0.75\pm 0.14)\tan^{4} θ_C$~and $1.37\times \tan^{4} θ_C$, respectively, where $θ_C$ is the Cabibbo angle.

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arXiv2022

Measurement of the $D \to K^-π^+π^+π^-$ and $D \to K^-π^+π^0$ coherence factors and average strong-phase differences in quantum-correlated ${D\bar{D}}$ decays

The decays $D\to K^-π^+π^+π^-$ and $D \to K^-π^+π^0$ are studied in a sample of quantum-correlated $D\bar{D}$ pairs produced through the process $e^+e^- \to ψ(3770) \to D\bar{D}$, exploiting a data set collected by the BESIII experiment that corresponds to an integrated luminosity of 2.93 fb$^{-1}$. Here $D$ indicates a quantum superposition of a $D^0$ and a $\bar{D}^0$ meson. By reconstructing one neutral charm meson in a signal decay, and the other in the same or a different final state, observables are measured that contain information on the coherence factors and average strong-phase differences of each of the signal modes. These parameters are critical inputs in the measurement of the angle $γ$ of the Unitarity Triangle in $B^- \to DK^-$ decays at the LHCb and Belle II experiments. The coherence factors are determined to be $R_{K3π}=0.52^{+0.12}_{-0.10}$ and $R_{Kππ^0}=0.78 \pm 0.04$, with values for the average strong-phase differences that are $δ_D^{K3π}=\left(167^{+31}_{-19}\right)^\circ$ and $δ_D^{Kππ^0}=\left(196^{+14}_{-15}\right)^\circ$, where the uncertainties include both statistical and systematic contributions. The analysis is re-performed in four bins of the phase-space of the $D \to K^-π^+π^+π^-$ to yield results that will allow for a more sensitive measurement of $γ$ with this mode, to which the BESIII inputs will contribute an uncertainty of around 6$^\circ$.

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arXiv2022

Measurement of the cross section of $e^{+}e^{-}\toηπ^{+}π^{-}$ at center-of-mass energies from 3.872 GeV to 4.700 GeV

Using data samples with an integrated luminosity of 19 fb$^{-1}$ at twenty-eight center-of-mass energies from 3.872 GeV to 4.700 GeV collected with the BESIII detector at the BEPCII electron--positron collider, the process $e^{+}e^{-}\toηπ^{+}π^{-}$ and the intermediate process $e^{+}e^{-}\toηρ^{0}$ are studied for the first time. The Born cross sections are measured. No significant resonance structure is observed in the cross section lineshape.

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arXiv2022

Measurement of $Λ$ baryon polarization in $e^+e^-\rightarrowΛ\barΛ$ at $\sqrt{s} = 3.773$ GeV

Using a data sample of $ψ(3770)$ events collected with the BESIII detector at BEPCII corresponding to an integrated luminosity of 2.9 fb$^{-1}$, we report a measurement of $Λ$ spin polarization in $e^+e^-\rightarrowΛ\barΛ$ at $\sqrt{s} = 3.773$ GeV. The significance of polarization is found to be 2$σ$ including the systematic uncertainty, which implies a zero phase between the transition amplitudes of the $Λ\barΛ$ helicity states. This phase can be interpreted in terms of psionic form factors, and is determined to be $ΔΦ^Ψ$ = $Φ^Ψ_{E} - Φ^Ψ_{M}$ = $(71^{+66}_{-46}$ $\pm$ 5)$^{\circ}$. Similarly, the ratio between the form factors is found to be $R^ψ$ = $|G^Ψ_{E}/G^Ψ_{M}|$ = $0.48^{+0.12}_{-0.07}$ $\pm$ 0.04. The first uncertainties are statistical and the second systematic.

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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

First measurement of polarizations in the decay $D^0 \to ωϕ$

Using a data sample corresponding to an integrated luminosity of 2.93 fb$^{-1}$ collected at a center-of-mass energy $\sqrt{s}=3.773$ GeV by the BESIII detector, the decay $D^0 \toωϕ$ is observed for the first time. The branching fraction is measured to be $(6.48 \pm 0.96 \pm 0.40)\times 10^{-4}$ with a significance of $6.3 σ$, where the first and second uncertainties are statistical and systematic, respectively. An angular analysis reveals that the $ϕ$ and $ω$ mesons from the $D^0 \to ωϕ$ decay are transversely polarized. The $95\%$ confidence level upper limit on longitudinal polarization fraction is set to be less than $0.24$, which is inconsistent with current theoretical expectations and challenges our understanding of the underlying dynamics in charm meson decays.

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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

Cross sections for the reactions $e^+e^-\rightarrow K^+K^-π^+π^-(π^0)$, $K^+K^-K^+K^-(π^0)$, $π^+π^-π^+π^-(π^0)$, $p\bar{p}π^+π^-(π^0)$ in the energy region between 3.773 and 4.600 GeV

Using the data samples collected in the energy range from 3.773 to 4.600 GeV with the BESIII detector at the BEPCII collider, we measure the dressed cross sections as a function of center-of-mass energy for $e^+e^-\rightarrow K^+K^-π^+π^-(π^0)$, $K^+K^-K^+K^-(π^0)$, $π^+π^-π^+π^-(π^0)$, and $p\bar{p}π^+π^-(π^0)$. The cross sections for $e^+e^-\rightarrow K^+K^-K^+K^-π^0$, $p\bar{p}π^+π^-(π^0)$ are the first measurements. Cross sections for the other five channels are much more precise than previous results in this energy region. We also search for charmonium and charmonium-like resonances, such as the $Y(4230)$, decaying into the same final states. We find evidence of the $ψ(4040)$ decaying to $π^+π^-π^+π^-π^0$ with a statistical significance of $3.6σ$. Upper limits are provided for other decays since no clear signals are observed.

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arXiv2021

Observation of the Decay $D^0\to ρ^-μ^+ν_μ$

By analyzing an $e^+e^-$ annihilation data sample corresponding to an integrated luminosity of $2.93~\mathrm{fb}^{-1}$ collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, we measure the branching fraction of the $D^0\to ρ^- μ^+ν_μ$ decay for the first time. We obtain ${\mathcal B}_{D^0\to ρ^- μ^+ν_μ}=(1.35\pm0.09_{\rm stat}\pm0.09_{\rm syst})\times 10^{-3}$. Using the world average of ${\mathcal B}_{D^0\to ρ^- e^+ν_e}$, we find a branching fraction ratio of ${\mathcal B}_{D^0\to ρ^- μ^+ν_μ}/{\mathcal B}_{D^0\to ρ^- e^+ν_e}=0.90\pm0.11$, which agrees with the theoretical expectation of lepton flavor universality within the uncertainty. Combining the world average of ${\mathcal B}_{D^+\to ρ^0 μ^+ ν_μ}$ and the lifetimes of $D^{0(+)}$, we obtain a partial decay width ratio of $Γ_{D^0\to ρ^- μ^+ ν_μ}/(2Γ_{D^+\to ρ^0 μ^+ ν_μ}) = 0.71\pm0.14$, which is consistent with the isospin symmetry expectation of one within $2.1σ$. For the reported values of ${\mathcal B}_{D^0\to ρ^- μ^+ν_μ}/{\mathcal B}_{D^0\to ρ^- e^+ν_e}$ and $Γ_{D^0\to ρ^- μ^+ ν_μ}/2Γ_{D^+\to ρ^0 μ^+ ν_μ}$, the uncertainty is the quadratic sum of the statistical and systematic uncertainties.

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arXiv2021

Measurement of the cross section for $e^{+}e^{-}\rightarrowΛ\barΛ$ and evidence of the decay $ψ(3770)\rightarrowΛ\barΛ$

The Born cross section of the process $e^{+}e^{-}\rightarrowΛ\barΛ$ is measured at 33 center-of-mass energies between 3.51 and 4.60 GeV using data corresponding to the total integrated luminosity of 20.0 fb$^{-1}$ collected with the BESIII detector at the BEPCII collider. Describing the energy dependence of the cross section requires a contribution from the $ψ(3770)\rightarrowΛ\barΛ$ decay, which is fitted with a significance of 4.6-4.9$σ$ including the systematic uncertainty. The lower bound on its branching fraction is $2.4\times10^{-6}$ at the 90% confidence level (C.L.), at least an order of magnitude larger than expected from predictions using a scaling based on observed electronic widths. This result indicates the importance of effects from vector charmonium(-like) states when interpreting data in terms of e.g., electromagnetic structure observables. The data do not allow for definite conclusions on the interplay with other vector charmonium(-like) states, and we set 90% C.L.upper limits for the products of their electronic widths and the branching fractions.

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