| 1. |
- Ablikim, M., et al.
(author)
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Amplitude analysis of the π$^0$π$^0$ system produced in radiative J/ψ decays
- 2016
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In: PHYSICAL REVIEW D. - 2470-0010. ; 93:3
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Journal article (peer-reviewed)abstract
- An amplitude analysis of the π0π0 system produced in radiative J/ψ decays is presented. In particular, a piecewise function that describes the dynamics of the π0π0 system is determined as a function of Mπ0π0 from an analysis of the (1.311±0.011)×109 J/ψ decays collected by the BESIII detector. The goal of this analysis is to provide a description of the scalar and tensor components of the π0π0 system while making minimal assumptions about the properties or number of poles in the amplitude. Such a model-independent description allows one to integrate these results with other related results from complementary reactions in the development of phenomenological models, which can then be used to directly fit experimental data to obtain parameters of interest. The branching fraction of J/ψ→γπ0π0 is determined to be (1.15±0.05)×10-3, where the uncertainty is systematic only and the statistical uncertainty is negligible.
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| 2. |
- Ablikim, M., et al.
(author)
-
Measurement of azimuthal asymmetries in inclusive charged dipion production in $e^+e^-$ annihilations at $\sqrt{s}$ = 3.65 GeV
- 2016
-
In: PHYSICAL REVIEW LETTERS. - 0031-9007 .- 1079-7114. ; 116:4
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Journal article (peer-reviewed)abstract
- We present a measurement of the azimuthal asymmetries of two charged pions in the inclusive process $e^+e^-\rightarrow \pi\pi X$ based on a data set of 62 $\rm{pb}^{-1}$ at the center-of-mass energy $\sqrt{s}=3.65$ GeV collected with the BESIII detector. These asymmetries can be attributed to the Collins fragmentation function. We observe a nonzero asymmetry, which increases with increasing pion momentum. As our energy scale is close to that of the existing semi-inclusive deep inelastic scattering experimental data, the measured asymmetries are important inputs for the global analysis of extracting the quark transversity distribution inside the nucleon and are valuable to explore the energy evolution of the spin-dependent fragmentation function.
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| 3. |
- Ablikim, M., et al.
(author)
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Measurement of the center-of-mass energies at BESIII via the di-muon process
- 2016
-
In: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 40:6
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Journal article (peer-reviewed)abstract
- From 2011 to 2014, the BESIII experiment collected about 5 fb$^{-1}$ data at center-of-mass energies around 4 GeV for the studies of the charmonium-like and higher excited charmonium states. By analyzing the di-muon process $e^{+}e^{-}\rightarrow\gamma_{\rm ISR/FSR}\mu^{+}\mu^{-}$, the center-of-mass energies of the data samples are measured with a precision of 0.8 MeV. The center-of-mass energy is found to be stable for most of time during the data taking.
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| 4. |
- Ablikim, M., et al.
(author)
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Measurement of the $D\to K^-\pi^+$ strong phase difference in $\psi(3770)\to D^0\overline{D}{}^0$
- 2014
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In: PHYSICS LETTERS B. - : Elsevier BV. - 0370-2693. ; 734
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Journal article (peer-reviewed)abstract
- We study $D^0\overline{D}{}^0$ pairs produced in $e^+e^-$ collisions at $\sqrt{s}=3.773$ GeV using a data sample of 2.92 fb$^{-1}$ collected with the BESIII detector. We measure the asymmetry $\mathcal{A}^{CP}_{K\pi}$ of the branching fractions of $D \to K^-\pi^+$ in $CP$-odd and $CP$-even eigenstates to be $(12.7\pm1.3\pm0.7)\times10^{-2}$. $\mathcal{A}^{CP}_{K\pi}$ can be used to extract the strong phase difference $\delta_{K\pi}$ between the doubly Cabibbo-suppressed process $\overline{D}{}^{0}\to K^-\pi^+$ and the Cabibbo-favored process $D^0\to K^- \pi^+$. Using world-average values of external parameters, we obtain $\cos\delta_{K\pi} = 1.02\pm0.11\pm0.06\pm0.01$. Here, the first and second uncertainties are statistical and systematic, respectively, while the third uncertainty arises from the external parameters. This is the most precise measurement of $\delta_{K\pi}$ to date.
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| 5. |
- Ablikim, M., et al.
(author)
-
Observation of $e^+e^− → γX$(3872) at BESIII
- 2014
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In: PHYSICAL REVIEW LETTERS. - 1079-7114. ; 112:9
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Journal article (peer-reviewed)abstract
- 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 $e^{+} e^{-} \to \gamma X(3872)$ is observed for the first time with a statistical significance of $6.3\sigma$. 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 $\sigma[e^{+} e^{-} \to \gamma X(3872)]$ and the branching fraction $\mathcal{B}[X(3872) \to \pi^{+} \pi^{-} J/\psi]$ 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 $Y(4260) \to \gamma X(3872)$.
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| 6. |
- Ablikim, M., et al.
(author)
-
Observation of electromagnetic Dalitz decays J/\psi \to P e^+e^-
- 2014
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In: PHYSICAL REVIEW D. - 2470-0010 .- 1550-7998 .- 1550-2368. ; 89:9
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Journal article (peer-reviewed)abstract
- Based on a sample of (225.3\pm2.8)\times 10^{6} J/\psi events collected with the BESIII detector, the electromagnetic Dalitz decays of J/\psi \to P e^+e^-(P=\eta'/\eta/\pi^0) are studied. By reconstructing the pseudoscalar mesons in various decay modes, the decays J/\psi \to \eta' e^+e^-, J/\psi \to \eta e^+e^- and J/\psi \to \pi^0 e^+e^- are observed for the first time. The branching fractions are determined to be \mathcal{B}(J/\psi\to \eta' e^+e^-) = (5.81\pm0.16\pm0.31)\times10^{-5}, \mathcal{B}(J/\psi\to \eta e^+e^-) = (1.16\pm0.07\pm0.06)\times10^{-5}, and \mathcal{B}(J/\psi\to \pi^0 e^+e^-)=(7.56\pm1.32\pm0.50)\times10^{-7}, where the first errors are statistical and the second ones systematic.
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| 7. |
- Ablikim, M., et al.
(author)
-
Precision measurements of $B(D^+ \rightarrow \mu^+ \nu_{\mu})$, the pseudoscalar decay constant $f_{D^+}$, and the quark mixing matrix element $|V_{\rm cd}|$
- 2014
-
In: PHYSICAL REVIEW D. - 2470-0010 .- 1550-7998 .- 1550-2368. ; 89:5
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Journal article (peer-reviewed)abstract
- We report a measurement of the branching fraction $B(D^+ \rightarrow \mu^+ \nu_{\mu}) = [3.71 \pm 0.19 (\rm stat) \pm 0.06 (\rm sys)]\times 10^{-4}$ based on 2.92 ${\rm fb^{-1}}$ of data accumulated at $\sqrt{s}=3.773$ GeV with the BESIII detector at the BEPCII collider. This measurement, in conjunction with the Cabibbo-Kobayashi-Maskawa matrix element $|V_{\rm cd}|$ determined from a global Standard Model fit, implies a value for the weak decay constant $f_{D^+}=(203.2 \pm 5.3 \pm 1.8)$ MeV. Additionally, using this branching fraction measurement together with a Lattice QCD prediction for $f_{D^+}$, we find $|V_{\rm cd}|=0.2210\pm 0.0058 \pm 0.0047$. In either case, these are the most precise results for these quantities to date.
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| 8. |
- Ablikim, M., et al.
(author)
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Search for a light CP-odd Higgs boson in radiative decays of J/psi
- 2016
-
In: PHYSICAL REVIEW D. - 2470-0010. ; 93:5
-
Journal article (peer-reviewed)abstract
- We search for a light Higgs boson A(0) in the fully reconstructed decay chain of J/psi -> gamma A(0), A(0)-> mu(+)mu(-) using (225.0 +/- 2.8) x 10(6) J/psi events collected by the BESIII experiment. The A(0) is a hypothetical CP-odd light Higgs boson predicted by many extensions of the Standard Model including two spin-0 doublets plus an extra singlet. We find no evidence for A(0) production and set 90% confidence-level upper limits on the product branching fraction B(J/psi -> gamma A(0)) x B(A(0)-> mu(+)mu(-)) in the range of (2.8-495.3) x 10(-8) for 0.212 <= mA(0) <= 3.0 GeV/c(2). The new limits are five times below our previous results, and the nature of the A(0) is constrained to be mostly singlet.
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| 9. |
- Ablikim, M., et al.
(author)
-
Study of J/Psi -> p(p)over-bar phi at BESIII
- 2016
-
In: PHYSICAL REVIEW D. - 2470-0010. ; 93:5
-
Journal article (peer-reviewed)abstract
- Using a data sample of 1.31×109 J/ψ events accumulated with the BESIII detector, the decay J/ψ→pp¯ϕ is studied via two decay modes, ϕ→KS0KL0 and ϕ→K+K-. The branching fraction of J/ψ→pp¯ϕ is measured to be B(J/ψ→pp¯ϕ)=[5.23±0.06(stat)±0.33(syst)]×10-5, which agrees well with a previously published measurement, but with a significantly improved precision. No evident enhancement near the pp¯ mass threshold, denoted as X(pp¯), is observed, and the upper limit on the branching fraction of J/ψ→X(pp¯)ϕ→pp¯ϕ is determined to be B(J/ψ→X(pp¯)ϕ→pp¯ϕ)<2.1×10-7 at the 90% confidence level.
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| 10. |
- Ablikim, M., et al.
(author)
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Study of psi decays to the Xi(-)(Xi)over-bar(+) and Sigma(1385)(-/+)(Sigma)over-bar(1385)(+/-) final states
- 2016
-
In: PHYSICAL REVIEW D. - 2470-0010. ; 93:7
-
Journal article (peer-reviewed)abstract
- We study the decays of the charmonium resonances J/psi and psi(3686) to the final states Xi(-)(Xi) over bar (+), S(1385)(-/+)(Sigma) over bar (1385)(+/-) based on a single baryon tag method using data samples of (223.7 +/- 1.4) x 10(6) J/psi and (106.4 +/- 0.9) x 10(6) psi(3686) events collected with the BESIII detector at the BEPCII collider. The decay psi(3686) -> Sigma(1385)(-/+)(Sigma) over bar (1385)(+/-) is observed for the first time, and the measurements of the other processes, including the branching fractions and angular distributions, are in good agreement with, and much more precise than, the previously published results. Additionally, the ratios B(psi(3686)->Xi(-)(Xi) over bar (+))/B(J/psi ->Xi(-)(Xi) over bar (+)), B(psi(3686)->Sigma(1385)(-)(Sigma) over bar (1385)(+))/B(J/psi ->Sigma(1385)(-)(Sigma) over bar (1385)(+)) and B(psi(3686)->Sigma(1385)(+)(Sigma) over bar (1385)(-))/B(J/psi ->Sigma(1385)(+)(Sigma) over bar (1385)(-)) are detetmind
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