| 1. |
- Ablikim, M., et al.
(author)
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Amplitude analysis of D+-> K-S(0)pi(+)pi(+)pi(-)
- 2019
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In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:7
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Journal article (peer-reviewed)abstract
- The decay D+-> K-S(0)pi(+)pi(+)pi(-) is studied with an amplitude analysis using a data set of 2.93 fb(-1) of e(+)e(-) collisions at the psi(3770) peak accumulated by the BESIII detector. Intermediate states and nonresonant components, and their relative fractions and phases, have been determined. The significant amplitudes, which contribute to the model that best fits the data, are composed of five quasitwo-body decays K(S)(0)a(1)(1260)(+), (K) over bar (1)(1270)(0)pi(+) (K) over bar (1)(1400)(0)pi(+), (K) over bar (1)(1650)(0)pi(+), and (K) over bar (1460)(0)pi(+), a three-body decay K-S(0)pi(+)rho(0), as well as a nonresonant component K-S(0)pi(+)pi(+)pi(-). The dominant amplitude is K(S)(0)a(1)(1260)(+), with a fit fraction of (40.3 +/- 2.1 +/- 2.9)%, where the first and second uncertainties are statistical and systematic, respectively.
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| 2. |
- Ablikim, M., et al.
(author)
-
Complete Measurement of the Λ Electromagnetic Form Factors
- 2019
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 123:12
-
Journal article (peer-reviewed)abstract
- The exclusive process e(+)e(-) -> Lambda(Lambda) over bar, with Lambda -> p pi(-) and (Lambda) over bar -> (p) over bar pi(+), has been studied at root s = 2.396 GeV for measurement of the timelike Lambda electric and magnetic form factors, G(E) and G(M). A data sample, corresponding to an integrated luminosity of 66.9 pb(-1), was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R = vertical bar G(E)/G(M)vertical bar and, for the first time for any baryon, the relative phase Delta Phi = Phi(E) - Phi(M). The resulting values are R = 0.96 +/- 0.14(stat) +/- 0.02(syst) and Phi(F) = 37 degrees +/- 12 degrees (stat) +/- 6 degrees (syst), respectively. These are obtained using the recently established and most precise value of the asymmetry parameter alpha(Lambda) = 0.750 +/- 0.010 measured by BESIII. In addition, the cross section is measured with unprecedented precision to be sigma = 118.7 +/- 5.3(stat) +/- 5.1(syst) pb, which corresponds to an effective form factor of vertical bar G vertical bar = 0.123 +/- 0.003(stat) +/- 0.003(syst). The contribution from two-photon exchange is found to be negligible. Our result enables the first complete determination of baryon timelike electromagnetic form factors.
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| 3. |
- Ablikim, M., et al.
(author)
-
Cross section measurement of e(+) e(-) -> eta ' J/psi from root S=4.178 to 4.600 GeV
- 2020
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In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 101:1
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Journal article (peer-reviewed)abstract
- The cross section of the process e(+) e(-) -> eta ' J/ psi is measured at center-of-mass (c.m.) energies from root S = 4.178 to 4.600 GeV using data samples corresponding to a total integrated luminosity of 11 fb(-1) collected with the BESIII detector operating at the BEPCII storage ring. The dependence of the cross section on root S shows an enhancement around 4.2 GeV. While the shape of the cross section cannot be fully explained with a single psi(4160) or psi(4260) state, a coherent sum of the two states does provide a reasonable description of the data.
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| 4. |
- Ablikim, M., et al.
(author)
-
Cross section measurements of e+e- -> K+ K- K+ K- and ΦK+ K- at center-of-mass energies from 2.10 to 3.08 GeV
- 2019
-
In: Physical Review D. - 2470-0010 .- 2470-0029. ; 100:3
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Journal article (peer-reviewed)abstract
- We measure the Born cross sections of the process e(+)e(-) -> K+ K- K+ K- at center-of-mass (c.m.) energies, root s, between 2.100 and 3.080 GeV. The data were collected using the BESIII detector at the BEPCII collider. An enhancement at root s = 2.232 GeV is observed, very close to the e(+)e(-) -> Lambda(Lambda) over bar production threshold. A similar enhancement at the same c.m. energy is observed in the e(+)e(-) -> phi K+ K- cross section. The energy dependence of the K+ K- K+ K- and phi K+ K- cross sections differs significantly from that of e(+)e(-) -> phi pi(+)pi(-).
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| 5. |
- Ablikim, M., et al.
(author)
-
Cross section measurements of e(+) e(-) -> omega chi(c0) from root s=4.178 to 4.278 GeV
- 2019
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In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:9
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Journal article (peer-reviewed)abstract
- The cross section of the process e(+)e(-) -> omega chi(C0) is measured at center -of -mass energies from root s = 4.178 to 4.278 GeV using a data sample of 7 fb(-1) collected with the BESIII detector operating at the BEPCII storage ring. The dependence of the cross section on root s shows a resonant structure with mass of (4218.5 +/- 1.6(stat) +/- 4.0(syst)) MeV/c(2) and width of (28.2 +/- 3.9(stat) +/- 1.6(syst)) MeV, respectively. This observation confirms and improves upon the result of a previous study. The angular distribution of the e(+) e(-) ->omega chi(C0) process is extracted for the first time.
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| 6. |
- Ablikim, M., et al.
(author)
-
Direct Measurement of the Branching Fractions B(psi(3686) -> J/psi X) and B(psi(3770) -> J/psi X), and Observation of the State R(3760) in e(+)e(-) -> J/psi X
- 2021
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In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 127:8
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Journal article (peer-reviewed)abstract
- We report a measurement of the observed cross sections of e(+)e(-) -> J/psi X based on 3.21 fb(-1) of data accumulated at energies from 3.645 to 3.891 GeV with the BESIII detector operated at the BEPCII collider. In analysis of the cross sections, we measured the decay branching fractions of B(psi(3686 -> J/psi X) = (64.4 +/- 0.6 +/- 1.6)% and B(psi(3770) -> J/psi X) = (0.5 +/- 0.2 +/- 0.1)% for the first time. The energy-dependent line shape of these cross sections cannot be well described by two Breit-Wigner (BW) amplitudes of the expected decays psi(3686) -> J/psi X and psi(3770) -> J/psi X. Instead, it can be better described with one more BW amplitude of the decay R(3760) -> J/psi X. Under this assumption, we extracted the R(3760) mass M-R(3760) = 3766.2 +/- 3.8 +/- 0.4 MeV/c(2), total width Gamma(tot)(R(3760)) = 22.2 +/- 5.9 +/- 1.4 MeV, and product of leptonic width and decay branching fraction Gamma(ee)(R(3760)) B[R(3760) -> J/psi X] = (79.4 +/- 85.5 +/- 11.7) eV. The significance of the R(3760) is 5.3 sigma. The first uncertainties of these measured quantities are from fits to the cross sections and second systematic.
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| 7. |
- Ablikim, M., et al.
(author)
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First observation of the decay chi(cJ) -> Sigma(+)(p)over-barK(S)(0)+ c.c. (J=0,1,2)
- 2019
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 100:9
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Journal article (peer-reviewed)abstract
- Using E1 radiative transitions psi(3686) -> gamma chi(cJ) from a sample of (448.1 +/- 2.9) x 10(6) psi(3686) events collected with the BESIII detector, the decays chi(cJ) -> Sigma(+)(p) over barK(S)(0) + c.c.(J = 0,1,2) are studied. The decay branching fractions are measured to be B(chi(c0) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (3.52 +/- 0.19 +/- 0.21) x 10(-4), B(chi(c1) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (1.53 +/- 0.10 +/- 0.08) x 10(-4), and B(chi(c2) -> Sigma(+)(p) over barK(S)(0) + c.c.) = (8.25 +/- 0.83 +/- 0.49) x 10(-5), where the first and second uncertainties are the statistical and systematic ones, respectively. No evident intermediate resonances arc observed in the studied processes.
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| 8. |
- Ablikim, M., et al.
(author)
-
First Observation of the Direct Production of the χc1 in e+e− Annihilation
- 2022
-
In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 129:12
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Journal article (peer-reviewed)abstract
- We study the direct production of the JPC=1++ charmonium state χc1(1P) in electron-positron annihilation by carrying out an energy scan around the mass of the χc1(1P). The data were collected with the BESIII detector at the BEPCII collider. An interference pattern between the signal process e+e−→χc1(1P)→γJ/ψ→γμ+μ− and the background processes e+e−→γISRJ/ψ→γISRμ+μ− and e+e−→γISRμ+μ− is observed by combining all the data samples. The χc1(1P) signal is observed with a significance of 5.1σ. This is the first observation of a C-even state directly produced in e+e− annihilation. The electronic width of the χc1(1P) resonance is determined to be Γee=(0.12+0.13−0.08) eV, which is of the same order of magnitude as theoretical calculations.
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| 9. |
- Ablikim, M., et al.
(author)
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First observations of h(c )-> hadrons
- 2019
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In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:7
-
Journal article (peer-reviewed)abstract
- Based on (4.48 +/- 0.03) x 10(8) Psi(3686) events, collected with the BESIII detector at the BEPCII storage ring, five h(c) hadronic decays are searched for via the process Psi(3686) -> pi(0)h(c). Three of them, h(c) -> p (p) over bar pi(+)pi(-) , pi(+)pi(-)pi(0 )and 2(pi(+)pi(-))pi(0) are observed for the first time with significances of 7.4 sigma, 4.6 sigma, and 9.1 sigma, and their branching fractions are determined to be (2.89 +/- 0.32 +/- 0.55) x 10(-3), (1.60 +/- 0.40 +/- 0.32) x 10(-3), and (7.44 +/- 0.94 +/- 1.52) x 10(-3), respectively, where the first uncertainties are statistical and the second systematic. No significant signal is observed for the other two decay modes, and the corresponding upper limits of the branching fractions are determined to be B(h(c) -> 3(pi(+)pi(-))pi(0)) < 8.7 x 10(-3) and B(h(c) -> K+K-pi(+)pi(-) ) < 5.8 x 10(-4) at the 90% confidence level.
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| 10. |
- Ablikim, M., et al.
(author)
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Future Physics Programme of BESIII *
- 2020
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In: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 44:4
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Journal article (peer-reviewed)abstract
- There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESIII and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESIII, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESIII during the remaining operation period of BEPCII. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCII to higher luminosity.
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