| 1. |
- Ablikim, M., et al.
(author)
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Amplitude analysis of the pi(0)pi(0) system produced in radiative J/psi decays
- 2015
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In: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:5
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Journal article (peer-reviewed)abstract
- An amplitude analysis of the pi(0)pi(0) system produced in radiative J/psi decays is presented. In particular, a piecewise function that describes the dynamics of the pi(0)pi(0) system is determined as a function of M pi(0)pi(0) from an analysis of the (1.311 +/- 0.011) x 10(9) J/psi decays collected by the BESIII detector. The goal of this analysis is to provide a description of the scalar and tensor components of the pi(0)pi(0) 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/psi -> pi(0)pi(0) is determined to be (1.15 +/- 0.05) x 10(-3), where the uncertainty is systematic only and the statistical uncertainty is negligible.
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| 2. |
- Ablikim, M., et al.
(author)
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An improved limit for Gamma(ee) of X(3872) and Gamma(ee) measurement of psi(3686)
- 2015
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In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 749, s. 414-420
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Journal article (peer-reviewed)abstract
- Using the data sets taken at center-of-mass energies above 4 GeV by the BESIII detector at the BEPCII storage ring, we search for the reaction e(+)e(-) -> gamma(ISR) X(3872) -> gamma(ISR)pi(+)pi(-) J/psi via the Initial State Radiation technique. The production of a resonance with quantum numbers J(PC) = 1(++) such as the X(3872) via single photon e(+)e(-) annihilation is forbidden, but is allowed by a next-to-leading order box diagram. We do not observe a significant signal of X(3872), and therefore give an upper limit for the electronic width times the branching fraction Gamma B-X(3872)(ee)(X(3872) -> pi(+)pi(-) J/psi) < 0.13 eVat the 90% confidence level. This measurement improves upon existing limits by a factor of 46. Using the same final state, we also measure the electronic width of the psi(3686) to be Gamma(psi)(ee)(3686) ee = 2213 +/- 18(stat) +/- 99(sys) eV.
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| 3. |
- Ablikim, M., et al.
(author)
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Confirmation of a charged charmoniumlike state Z(c)(3885)(-/+) in e(+)e(-) -> pi(+/-) (D(D)over-bar*)(-/+) with double D tag
- 2015
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In: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:9
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Journal article (peer-reviewed)abstract
- We present a study of the process e(+)e(-) -> pi(+/-) (D (D) over bar*)(-/+) using data samples of 1092 pb(-1) at root s = 4.23 GeV and 826 pb(-1) at root s = 4.26 GeV collected with the BESIII detector at the BEPCII storage ring. With full reconstruction of the D meson pair and the bachelor pi(+) in the final state, we confirm the existence of the charged structure Z(c) (3885)(-/+) in the (D (D) over bar*)(-/+) system in the two isospin processes e(+)e(-) -> pi(+DD)-D-0*(-) and e(+)e(-) -> pi+D-D*(0). By performing a simultaneous fit, the statistical significance of Zc(3885)(-/+) signal is determined to be greater than 10 sigma, and its pole mass and width are measured to be M-pole = (3881.7 +/- 1.6(stat) +/- 1.6(syst)) MeV/c(2) and Gamma(pole) = (26.6 +/- 2.0(stat) +/- 2.1(syst)) MeV, respectively. The Born cross section times the (D (D) over bar*)(-/+) branching fraction (sigma(e(+)e(-) -> pi(+/-)Z(c)(3885)(-/+)) x Br(Z(c)(3885)(-/+) -> (D (D) over bar*)(-/+) )) is measured to be (141.6 +/- 7.9(stat) +/- 12.3(syst)) pb at root s = 4.23 GeV and (108.4 +/- 6.9(stat) +/- 8.8(syst)) pb at root s = 4.26 GeV. The polar angular distribution of the pi(+) - Z(c)(3885)(-/+) system is consistent with the expectation of a quantum number assignment of J(P) = 1(+) for Z(c)(3885)(-/+).
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| 4. |
- Ablikim, M., et al.
(author)
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Evidence for e(+)e(-)->gamma chi c1,2 at center-of-mass energies from 4.009 to 4.360 GeV
- 2015
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In: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 39:4
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Journal article (peer-reviewed)abstract
- Using data samples collected at center-of-mass energies of root s=4.009, 4.230, 4.260, and 4.360 GeV with the BESIII detector operating at the BEPCII collider, we perform a search for the process e(+)e(-)->gamma chi(cJ) (J=0, 1, 2) and find evidence for e(+)e(-)->gamma chi(c1) and e(+)e(-)->gamma chi(c2) with statistical significances of 3.0 sigma and 3.4 sigma, respectively. The Born cross sections sigma(B)(e(+)e(-)->gamma chi(cJ)), as well as their upper limits at the 90% confidence level (C.L.) are determined at each center-of-mass energy.
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| 5. |
- Ablikim, M., et al.
(author)
-
Measurement of B(psi(3770) -> gamma chi(c1)) and search for psi(3770) -> gamma chi(c2)
- 2015
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In: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:9
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Journal article (peer-reviewed)abstract
- We report a measurement of the branching fraction for psi(3770) -> gamma chi(c1) and search for the transition psi(3770) -> gamma chi(c2) based on 2.92 fb(-1) of e(+)e(-) data accumulated at root s = 3.773 GeV with the BESIII detector at the BEPCII collider. We measure B(psi(3770) -> gamma chi(c1)) = (2.48 +/- 0.15 +/- 0.23) x 10(-3), which is the most precise measurement to date. The upper limit on the branching fraction of psi(3770) -> gamma chi(c2) at a 90% confidence level is B(psi(3770) -> gamma chi(c2)) < 0.64 x 10(-3). The corresponding partial widths are Gamma(psi(3770) -> gamma chi(c1)) = (67.5 +/- 4.1 +/- 6.7)keV and Gamma(psi(3770) -> gamma chi(c2)) < 17.4 keV.
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| 6. |
- Ablikim, M., et al.
(author)
-
Measurement of the Absolute Branching Fraction for Lambda(+)(c) -> Lambda e(+)nu(e)
- 2015
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 115:22
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Journal article (peer-reviewed)abstract
- We report the first measurement of the absolute branching fraction for Lambda(+)(c) -> Lambda e(+)nu(e). This measurement is based on 567 pb(-1) of e(+)e(-) annihilation data produced at root s = 4.599 GeV, which is just above the Lambda(+)(c)Lambda(-)(c) threshold. The data were collected with the BESIII detector at the BEPCII storage rings. The branching fraction is determined to be B(Lambda(+)(c) -> Lambda e(+)nu(e)) = [3.63 +/- 0.38(stat) +/- 0.20(syst)] %, representing a significant improvement in precision over the current indirect determination. As the branching fraction for Lambda(+)(c) -> Lambda e(+)nu(e) is the benchmark for those of other Lambda(+)(c) semileptonic channels, our result provides a unique test of different theoretical models, which is the most stringent to date.
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| 7. |
- Ablikim, M., et al.
(author)
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Measurement of the branching fractions of D-s(+) -> eta ' X and D-s(+) -> eta 'rho(+) in e(+)e(-) -> Ds+Ds-
- 2015
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In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 750, s. 466-474
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Journal article (peer-reviewed)abstract
- We study D-s(+) decays to final states involving the eta' with a 482 pb(-1) data sample collected at root s = 4.009 GeV with the BESIII detector at the BEPCII collider. We measure the branching fractions B(D-s(+) -> eta'X) = (8.8 +/- 1.8 +/- 0.5)% and B(D-s(+) > eta'rho(+)) = (5.8 +/- 1.4 +/- 0.4)% where the first uncertainty is statistical and the second is systematic. In addition, we estimate an upper limit on the non-resonant branching ratio B(D-s(+) -> eta'pi(+)pi(0)) < 5.1% at the 90% confidence level. Our results are consistent with CLEO's recent measurements and help to resolve the disagreement between the theoretical prediction and CLEO's previous measurement of B(D-s(+) -> eta'rho(+)).
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| 8. |
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| 9. |
- Ablikim, M., et al.
(author)
-
Measurement of the form factors in the decay D+ → ωe+νe and search for the decay D+ → ϕe+νe
- 2015
-
In: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 92:7
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Journal article (peer-reviewed)abstract
- Using 2.92 fb−1 of electron-positron annihilation data collected at a center-of-mass energy of √s=3.773 GeV with the BESIII detector, we present an improved measurement of the branching fraction B(D+ → ωe+νe)=(1.63±0.11±0.08)×10−3. The parameters defining the corresponding hadronic form factor ratios at zero momentum transfer are determined for the first time; we measure them to be rV=1.24±0.09±0.06 and r2=1.06±0.15±0.05. The first and second uncertainties are statistical and systematic, respectively. We also search for the decay D+ → ϕe+νe. An improved upper limit B(D+ → ϕe+νe)<1.3×10−5 is set at 90% confidence level.
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| 10. |
- Ablikim, M., et al.
(author)
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Measurement of the matrix elements for the decays eta -> pi(+)pi(-)pi(0) and eta/eta ' -> pi(0)pi(0)pi(0)
- 2015
-
In: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:1
-
Journal article (peer-reviewed)abstract
- Based on a sample of 1.31 x 10(9) J/psi events collected with the BESIII detector at the BEPCII collider, Dalitz plot analyses of selected 79,625 eta -> pi(+)pi(-)pi(0) events, 33,908 eta -> pi(0)pi(0)pi(0) events, and 1,888 eta' -> pi(0)pi(0)pi(0) events are performed. The measured matrix elements of eta -> pi(+)pi(-)pi(0) are in reasonable agreement with previous measurements. The Dalitz plot slope parameters of eta -> pi(0)pi(0)pi(0) and eta' -> pi(0)pi(0)pi(0) are determined to be -0.055 +/- 0.014 +/- 0.004 and -0.640 +/- 0.046 +/- 0.047, respectively, where the first uncertainties are statistical and the second systematic. Both values are consistent with previous measurements, while the precision of the latter one is improved by a factor of 3. Final state interactions are found to have an important role in those decays.
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