| 1801. |
- Ablikim, M., et al.
(author)
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Measurement of the Cross Section for e+e- -> Hadrons at Energies from 2.2324 to 3.6710 GeV
- 2022
-
In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 128:6
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Journal article (peer-reviewed)abstract
- 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 equivalent to sigma(e(+)e(-)-> hadrons)/sigma(e(+)e(-) -> mu(+)mu(-)) 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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| 1802. |
- Ablikim, M., et al.
(author)
-
Measurement of the cross section for e(+)e(-) -> Lambda(Lambda)over-bar and evidence of the decay psi(3770) -> Lambda(Lambda)over-bar
- 2021
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In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:9
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Journal article (peer-reviewed)abstract
- The Born cross section of the process e(+)e(-) ->Lambda(Lambda) over bar over line 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 psi(3770) -> Lambda(Lambda) over bar decay, which is fitted with a significance of 4.6 - 4.9 sigma including the systematic uncertainty. The lower bound on its branching fraction is 2.4 x 10(-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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| 1803. |
- Ablikim, M., et al.
(author)
-
Measurement of the Cross Section for e(+)e(-) -> Xi(-)Xi(+)and Observation of an Excited Xi Baryon
- 2020
-
In: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 124:3
-
Journal article (peer-reviewed)abstract
- Using a total of 11.0 fb(-1) of e(+)e(-) collision data with center-of-mass energies between 4.009 and 4.6 GeV and collected with the BESIII detector at BEPCII, we measure fifteen exclusive cross sections and effective form factors for the process e(+)e(-) -> Xi(-)Xi(+) by means of a single baryon-tag method. After performing a fit to the dressed cross section of e(+)e(-)-> Xi(-)Xi(+) no significant psi(4230) or psi(4260) resonance is observed in the Xi(-)Xi(+) final states, and upper limits at the 90% confidence level on T B-ee for the processes psi(4230)psi/(4260) -> Xi(-)Xi(+) are determined. In addition, an excited Xi baryon at 1820 MeV/c(2) is observed with a statistical significance of 6.2-6.5 sigma by including the systematic uncertainty, and the mass and width are measured to be M = (1825.5 +/- 4.7 +/- 4.7) MeV/c(2) and Gamma = (17.0 +/- 15.0 +/- 7.9) MeV, which confirms the existence of the J(P) =3-/2 state Xi (1820).
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| 1804. |
- Ablikim, M., et al.
(author)
-
Measurement of the cross section of e+e− → ηπ+π− at center-of-mass energies from 3.872 GeV to 4.700 GeV
- 2022
-
In: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :12
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Journal article (peer-reviewed)abstract
- 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− → ηπ+π− and the intermediate process e+e− → ηρ0 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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| 1805. |
- Ablikim, M., et al.
(author)
-
Measurement of the D → K−π+π+π− and D → K−π+π0 coherence factors and average strong-phase differences in quantum-correlated D‾D decays
- 2021
-
In: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :5
-
Journal article (peer-reviewed)abstract
- The decays D → K−π+π+π− and D → K−π+π0 are studied in a sample of quantum-correlated D¯D pairs produced through the process e+e− → ψ(3770) → D¯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 D0 and a 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− → DK− decays at the LHCb and Belle II experiments. The coherence factors are determined to be RK3π = 0.52+0.12−0.10 and RKππ0 = 0.78 ± 0.04, with values for the average strong-phase differences that are δK3πD=(167+31−19)∘ and δKππ0D=(196+14−15)∘, where the uncertainties include both statistical and systematic contributions. The analysis is re-performed in four bins of the phase-space of the D → 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°.
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| 1806. |
- Ablikim, M., et al.
(author)
-
Measurement of the doubly Cabibbo-suppressed decay D+→K+π+π−π0 with semileptonic tags
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:7
-
Journal article (peer-reviewed)abstract
- We propose a new semileptonic tag method to study the doubly Cabibbo-suppressed D decay in psi(3770) -> D (D) over bar reaction. Utilizing the dataset corresponding to an integrated luminosity of 2.93 fb(-1) at a center-of-mass energy of 3.773 GeV collected by the BESIII detector, we determine the branching fraction for D+ -> K+pi(+)pi(-)pi(0) to be (1.03 +/- 0.12(stat) +/- 0.06(syst)) x 10(-3), in which the contributions from narrow intermediate resonances, D+ -> K+eta, D+ -> K+omega, and D+ -> K+phi have been excluded. Combining the world average of the branching fraction of D+ -> K+pi(+)pi(-)pi(0), we determine B(D+ -> K+pi(+)pi(-)pi(0))/B(D+ -> K+pi(+)pi(-)pi(0)) = (1.65 +/- 0.21)%, corresponding to (5.73 +/- 0.73) tan(4)theta(c), where theta(c) is the Cabibbo mixing angle. These results are consistent with our previous measurement with hadronic tags but are significantly larger than other doubly Cabibbo-suppressed decays in the charm sector.
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| 1807. |
- Ablikim, M., et al.
(author)
-
Measurement of the Dynamics of the Decays D-s(+ )-> eta(('))e(+)nu(e)
- 2019
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In: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 122:12
-
Journal article (peer-reviewed)abstract
- Using e(+)e(-) annihilation data corresponding to an integrated luminosity of 3.19 fb(-1) collected at a center-of-mass energy of 4.178 GeV with the BESIII detector, we measure the absolute branching fractions BDs+->eta e+nu e = (2.323 +/- 0.063(stat) +/- 0.063(syst))% and BDs+->eta'e+nu e = (0.824 +/- 0.073(stat) +/- 0.027(syst))% via a tagged analysis technique, where one D-s is fully reconstructed in a hadronic mode. Combining these measurements with previous BESIII measurements of B-D+->eta(')e+(nu e),the eta - eta' mixing angle in the quark flavor basis is determined to be phi(P) = (40.1 +/- 2.1(stat) +/- 0.7(syst))degrees. From the first measurements of the dynamics of Ds+ -> eta(')e(+)nu(e) decays, the products of the hadronic form factors f(+)(eta('))(0) and the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cs vertical bar are determined with different form factor parametrizations. For the two-parameter series expansion, the results are f(+)(eta) (0) vertical bar V-cs vertical bar = 0.4455 +/- 0.0053(stat) +/- 0.0044(syst) and f(+)(eta)' (0) vertical bar V-cs vertical bar and = 0.477 +/- 0.049(stat) +/- 0.011(syst).
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| 1808. |
- Ablikim, M., et al.
(author)
-
Measurement of the e(+) e(-) -> omega pi(0)pi(0) cross section at center-of-mass energies from 2.0 to 3.08 GeV
- 2022
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In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 105:3
-
Journal article (peer-reviewed)abstract
- The cross section of the process e(+)e(-) -> omega pi(0)pi(0) is measured at nineteen center-of-mass energies from 2.0 to 3.08 GeV using data collected with the BESIII detector at the BEPCII storage ring. A resonant structure around 2.20 GeV is observed with statistical significance larger than 5 sigma. Using a coherent fit to the cross section line shape, the mass and width are determined to be M = 2222 +/- 7 +/- 2 MeV/c(2) and Gamma = 59 +/- 30 +/- 6 MeV, respectively, where the first uncertainties are statistical and the second ones are systematic.
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| 1809. |
- Ablikim, M., et al.
(author)
-
Measurement of the e(+) e(-) -> pi(+)pi(-) J/psi cross section in the vicinity of 3.872 GeV
- 2023
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 107:3
-
Journal article (peer-reviewed)abstract
- We report a measurement of the cross section for the process e(+)e(-) -> pi(+)pi(-)J/psi around the X(3872) mass in search for the direct formation of e(+)e(-) -> X(3872) through the two-photon fusion process. No enhancement of the cross section is observed at the X(3872) peak and an upper limit on the product of electronic width and branching fraction of X(3872) -> pi(+)pi(-) J/psi is determined to be Gamma(ee) x B(X(3872) -> pi(+)pi(-) J/psi) <7.5 x 10(-3) eV at 90% confidence level under an assumption of total width of 1.19 +/- 0.21 MeV. This is an improvement of a factor of about 17 compared to the previous limit. Furthermore, using the latest result of B(X(3872) -> pi(+)pi(-) J/psi), an upper limit on the electronic width Fee of X(3872) is obtained to be <0.32 eV at the 90% confidence level.
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| 1810. |
- Ablikim, M., et al.
(author)
-
Measurement of the e(+)e(-) -> Sigma(0)(Sigma)over-bar(0) cross sections at center-of-mass energies from 2.3864 to 3.0200 GeV
- 2022
-
In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 831
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Journal article (peer-reviewed)abstract
- The Born cross sections of e(+)e(-) -> Sigma(0)(Sigma) over bar (0) are measured at center-of-mass energies from 2.3864 to 3.0200 GeV using data samples with an integrated luminosity of 328.5 pb(-1) collected with the BESIII detector operating at the BEPCII collider. The analysis makes use of a novel reconstruction method for energies near production threshold, while a single-tag method is employed at other center-of-mass energies. The measured cross sections are consistent with earlier results from BaBar, with a substantially improved precision. The cross-section lineshape can be well described by a perturbative QCD-driven energy function. In addition, the effective form factors of the Sigma(0) baryon are determined. The results provide precise experimental input for testing various theoretical predictions. (C) 2022 The Author(s). Published by Elsevier B.V.
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