| 1. |
- Collaboration, The PANDA, et al.
(author)
-
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
- 2016
-
In: European Physical Journal A. - : Springer Publishing Company. - 1434-6001 .- 1434-601X. ; 52:10
-
Journal article (peer-reviewed)abstract
- Simulation results for future measurements of electromagnetic proton form factors at P ¯ ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯ p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.p¯ p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
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| 2. |
- Singh, B., et al.
(author)
-
Feasibility study for the measurement of pi N transition distribution amplitudes at (P)over-barANDA in (P)over-barp -> J/psi pi(0)
- 2017
-
In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:3
-
Journal article (peer-reviewed)abstract
- The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is shown that the measurement can be done at (P) over bar ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.
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| 3. |
- Singh, B., et al.
(author)
-
Study of doubly strange systems using stored antiprotons
- 2016
-
In: Nuclear Physics A. - : Elsevier. - 0375-9474 .- 1873-1554. ; 954, s. 323-340
-
Journal article (peer-reviewed)abstract
- Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Xi(-) -atoms will be feasible and even the production of Omega(-) -atoms will be within reach. The latter might open the door to the vertical bar S vertical bar = 3 world in strangeness nuclear physics, by the study of the hadronic Omega(-) -nucleus interaction. For the first time it will be possible to study the behavior of Xi(+) in nuclear systems under well controlled conditions.
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| 4. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis and branching fraction measurement of D-0 -> K-pi(+)pi(0)pi(0)
- 2019
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 99:9
-
Journal article (peer-reviewed)abstract
- Utilizing the dataset corresponding to an integrated luminosity of 2.93 fb(-1) at root s = 3.773 GeV collected by the BESIII detector, we report the first amplitude analysis and branching fraction measurement of the D-0 -> K- pi(+)pi(0)pi(0) decay. We investigate the substructures and determine the relative fractions and the phases among the different intermediate processes. Our results are used to provide an accurate detection efficiency and allow measurement of B(D-0 -> K- pi(+)pi(0)pi(0)) = (8.86 +/- 0.13(stat) +/- 0.19(syst))%.
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| 5. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis and branching fraction measurement of D-s(+)-> K- K+ pi(+) pi(0)
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:3
-
Journal article (peer-reviewed)abstract
- The first amplitude analysis of the decay D-s(+)-> K- K+ pi(+) pi(0) is presented using the data samples, corresponding to an integrated luminosity of 6.32 fb(-1), collected with the BESIII detector at e(+)e(-) center-of-mass energies between 4.178 and 4.226 GeV. More than 3000 events selected with a purity of 97.5% are used to perform the amplitude analysis, and nine components are found necessary to describe the data.
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| 6. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis and branching-fraction measurement of D-s(+) -> K-S(0)pi(+)pi(0)
- 2021
-
In: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :6
-
Journal article (peer-reviewed)abstract
- By using 6.32 fb(-1) of data collected with the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, we perform an amplitude analysis of the decay D-s(+) -> K-S(0) pi(+)pi(0) and determine the relative fractions and phase differences of different intermediate processes, which include K-S(0) rho(770)(+), K-S(0)rho(1450)(+), K*(892)(0) pi(+), K* (892)(+) pi(0), and K* (1410)(0) pi(+). With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be B(D-s(+) -> K-S(0) pi(+) pi(0)) = (5.43 +/- 0.30(stat) +/- 0.15(syst)) x 10(-3).
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| 7. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis and branching-fraction measurement of D+s → K0SK−π+π
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 103:9
-
Journal article (peer-reviewed)abstract
- Using 6.32 fb−1 of e+e− collision data collected by the BESIII detector at the center-of-mass energies between 4.178 and 4.226 GeV, an amplitude analysis of the D+s → K0SK−π+π+ decays is performed for the first time to determine the intermediate-resonant contributions. The dominant component is the D+s → K∗(892)+¯K∗(892)0 decay with a fraction of (40.6±2.9stat±4.9sys)%. Our results of the amplitude analysis are used to obtain a more precise measurement of the branching fraction of the D+s → K0SK−π+π+ decay, which is determined to be (1.46±0.05stat±0.05sys)%.
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| 8. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis and branching fraction measurement of D+s → K−K+π+π+π−
- 2022
-
In: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :7
-
Journal article (peer-reviewed)abstract
- 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 BE- SIII detector, we perform an amplitude analysis of the decay D-s(+) -> K-K+pi(+)pi(+)pi(-) and de-termine the relative fractions and phases of different intermediate processes. Absolute branch- ing fraction of D-s(+) -> K-K+pi(+)pi(+)pi(-) decay is measured to be (6.60 +/- 0.47(stat). +/- 0.38(syst).) x 10(-3). The dominant intermediate process is D-s(+) -> a(1) (1260)(+)phi,phi -> K- K+, a(1)(1260)(+) -> rho pi(+), rho -> pi(+)pi(-), with a branching fraction of (5.15 +/- 0.41(stat.) +/- 0.32(syst.)) x 10(-3).
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| 9. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis and branching-fraction measurement of D+s → π+π0η′
- 2022
-
In: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :4
-
Journal article (peer-reviewed)abstract
- Using data collected with the BESIII detector in e(+)e(-) collisions at center-of-mass energies between 4.178 and 4.226 GeV and corresponding to 6.32 fb(-1) of integrated luminosity, we report the amplitude analysis and branching-fraction measurement of the D-s(+) -> pi(+)pi(0)eta' decay. We find that the dominant intermediate process is D-s(+) -> rho(+)eta' and the significances of other resonant and nonresonant processes are all less than 3 sigma. The upper limits on the branching fractions of S-wave and P-wave nonresonant components are set to 0.10% and 0.74% at the 90% confidence level, respectively. In addition, the branching fraction of the D-s(+) -> pi(+)pi(0)eta' decay is measured to be (6.15 +/- 0.25(stat.) +/- 0.18(syst.))%, which receives significant contribution only from D-s(+) -> rho(+)eta' according to the amplitude analysis.
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| 10. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis and branching fraction measurement of Ds+ → K+K-π
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:1
-
Journal article (peer-reviewed)abstract
- We report an amplitude analysis and branching fraction measurement of D-s(+) -> K+K-pi(+) decay using a data sample of 3.19 fb(-1) recorded with BESIII detector at a center-of-mass energy of 4.178 GeV. We perform a model-independent partial wave analysis in the low K+K- mass region to determine the K+K- S-wave line shape, followed by an amplitude analysis of our very pure high-statistics sample. With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be B(D-s(+) -> K+K-pi(+)) = (5.47 +/- 0.08(stat) +/- 0.13(sys))%.
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| 11. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis and branching fraction measurement of the decay D+s → K+π+π−
- 2022
-
In: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :8
-
Journal article (peer-reviewed)abstract
- Using 6.32 fb−1 of e+e− collision data 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 → K+π+π− and determine the amplitudes of the various intermediate states. The absolute branching fraction of D+s → K+π+π− is measured to be (6.11 ± 0.18stat. ± 0.11syst.) × 10−3. The branching fractions of the dominant intermediate processes D+s → K+ρ0, ρ0 → π+π− and D+s → K*(892)0π+, K*(892)0 → K+π− are determined to be (1.96 ± 0.19stat. ± 0.23syst.) × 10−3 and (1.85 ± 0.12stat. ± 0.13syst.) × 10−3, respectively. The intermediate resonances f0(500), f0(980), and f0(1370) are observed for the first time in this channel.
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| 12. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis of D+-> K-S(0)pi(+)pi(+)pi(-)
- 2019
-
In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 100:7
-
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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| 13. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis of D0 → K -π+π+π-
- 2017
-
In: Physical Review D. - 2470-0010 .- 2470-0029. ; 95:7
-
Journal article (peer-reviewed)abstract
- We present an amplitude analysis of the decay D0 → K -π+π+π- based on a data sample of 2.93 fb−1 acquired by the BESIII detector at the ψ(3770) resonance. With a nearly background free sample of about 16000 events, we investigate the substructure of the decay and determine the relative fractions and the phases among the different intermediate processes. Our amplitude model includes the two-body decays D0 → ¯K*0ρ0, D0 → K−a+1(1260) and D0 → K−1(1270)π+, the three-body decays D0 →¯K*0π+π− and D0 → K−π+ρ0, as well as the four-body nonresonant decay D0 → K−π+π+π−. The dominant intermediate process is D0 → K−a+1(1260), accounting for a fit fraction of 54.6%.
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| 14. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis of the chi(c1) -> eta pi(+)pi(-) decays
- 2017
-
In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:3
-
Journal article (peer-reviewed)abstract
- Using 448.0 x 10(6) psi(3686) events collected with the BESIII detector, an amplitude analysis is performed for psi(3686) -> gamma chi(c1), chi(c1) ->eta pi(+)pi(-) decays. The most dominant two- body structure observed is a(0)(980)(+/-) pi(-/+); a(0)(980)(+/-) -> eta pi(+/-.) line shape is modeled using a dispersion relation, and a significant nonzero a(0) (980) coupling to the eta'pi channel is measured. We observe chi(c1) -> a(2)(1700)pi production for the first time, with a significance larger than 17 sigma. The production of mesons with exotic quantum numbers, J(PC) = 1(-+), is investigated, and upper limits for the branching fractions chi(c1) -> pi(1)(1400)(+/-)pi(-/+) , chi(c1) -> pi(1)(1600)(+/-)pi(-/+) and chi(c1) -> pi 1(2015)(+/-)pi(-/+) with subsequent pi(1)(X)(+/-) -> eta pi(+/-) decay, are determined.
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| 15. |
- Ablikim, M., et al.
(author)
-
Amplitude Analysis of the Decays eta ' -> pi(+)pi(-)pi(0) and eta' -> pi(0)pi(0)pi(0)
- 2017
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 118:1
-
Journal article (peer-reviewed)abstract
- Based on a sample of 1.31 x 10(9) J/Psi events collected with the BESIII detector, an amplitude analysis of the isospin-violating decays eta' -> pi(+)pi(-)pi(0) and eta' -> pi(0)pi(0)pi(0) is performed. A significant P-wave contribution from eta' -> rho(+/-)eta(-/+) is observed for the first time in eta' -> pi(+)pi(-)pi(0). The branching fraction is determined to be B(eta' -> rho(+/-)pi(-/+)) = (7.44 +/- 0.60 +/- 1.26 +/- 1.84) x 10(-4), where the first uncertainty is statistical, the second systematic, and the third model dependent. In addition to the nonresonant S-wave component, there is a significant sigma meson component. The branching fractions of the combined S-wave components are determined to be B(eta' -> pi(+)pi(-)pi(0))(S) = (37.63 +/- 0.77 +/- 2.22 +/- 4.48) x 10(-4) and B(eta' -> pi(0)pi(0)pi(0)) = (35.22 +/- 0.82 +/- 2.54) x 10(-4), respectively. The latter one is consistent with previous BESIII measurements.
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| 16. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis of the KSKS system produced in radiative J /psi decays
- 2018
-
In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 98:7
-
Journal article (peer-reviewed)abstract
- An amplitude analysis of the KSKS system produced in radiative J/psi decays is performed using the (1310.6 +/- 7.0) x 10(6) nip decays collected by the BESIII detector. Two approaches are presented. A mass-dependent analysis is performed by parametrizing the KSKS invariant mass spectrum as a sum of Breit-aligner line shapes. Additionally, a mass-independent analysis is performed to extract a piecewise function that describes the dynamics of the KSKS system while making minimal assumptions about the properties and number of poles in the amplitude. The dominant amplitudes in the mass-dependent analysis include the f(0)(1710), f(0)(2200), and f(2)'(1525). The mass-independent results, which are made available as input for further studies, are consistent with those of the mass-dependent analysis and are useful for a systematic study of hadronic interactions. The branching fraction of radiative J/psi decays to KSKS is measured to be (8.1 +/- 0.4) x 10(-4), where the uncertainty is systematic and the statistical uncertainty is negligible.
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| 17. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis of the pi(0)pi(0) system produced in radiative J/psi decays
- 2015
-
In: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:5
-
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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| 18. |
- Ablikim, M., et al.
(author)
-
Amplitude analysis of the π$^0$π$^0$ system produced in radiative J/ψ decays
- 2016
-
In: PHYSICAL REVIEW D. - 2470-0010. ; 93:3
-
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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| 19. |
- Ablikim, M., et al.
(author)
-
An improved limit for Gamma(ee) of X(3872) and Gamma(ee) measurement of psi(3686)
- 2015
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 749, s. 414-420
-
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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| 20. |
- Ablikim, M., et al.
(author)
-
Analysis of D+ -> (K)over-bar(0)e(+)nu(e) and D+ -> pi(0)e(+)nu(e) semileptonic decays
- 2017
-
In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 96:1
-
Journal article (peer-reviewed)abstract
- Using 2.93 fb(-1) of data taken at 3.773 GeV with the BESIII detector operated at the BEPCII collider, we study the semileptonic decays D+ -> (K) over bar (0)e(+)nu(e) and D+ -> pi(0)e(+)nu(e). We measure the absolute decay branching fractions B(D+ -> (K) over bar (0)e(+)nu(e)) = (8.60 +/- 0.06 +/- 0.15) x 10(-2) and B(D+ -> pi(0)e(+)nu(e)) = (3.63 +/- 0.08 +/- 0.05) x 10(-3), where the first uncertainties are statistical and the second systematic. We also measure the differential decay rates and study the form factors of these two decays. With the values of |V-cs| and |V-cd| from Particle Data Group fits assuming Cabibbo-Kobayashi-Maskawa (CKM) unitarity, we obtain the values of the form factors at q(2) = 0, f(+)(K)(0) = 0.725 +/- 0.004 +/- 0.012, and f(+)(pi)(0) = 0.622 +/- 0.012 +/- 0.003. Taking input from recent lattice QCD calculations of these form factors, we determine values of the CKM matrix elements |V-cs| = 0.944 +/- 0.005 +/- 0.015 +/- 0.024 and |V-cd| = 0.210 +/- 0.004 +/- 0.001 +/- 0.009, where the third uncertainties are theoretical.
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| 21. |
- Ablikim, M., et al.
(author)
-
Branching fraction measurement of J/ψ→KSKL and search for J/ψ→KSKS
- 2017
-
In: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:11
-
Journal article (peer-reviewed)abstract
- Using a sample of 1.31 x 10(9) J/Psi events collected with the BESIII detector at the BEPCII collider, we study the decays of J/Psi -> KSKL and KSKS. The branching fraction of J/Psi -> KSKL is determined to be B(J/Psi -> KSKL) = (1.93 +/- 0.01 (stat) +/- 0.05 (syst)) x 10(-4), which significantly improves on previous measurements. No clear signal is observed for the J/Psi -> KSKS process, and the upper limit at the 95% confidence level for its branching fraction is determined to be B(J/Psi -> KSKS) < 1.4 x 10(-8), which improves on the previous searches by 2 orders in magnitude and reaches the order of the Einstein-Podolsky-Rosen expectation.
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| 22. |
- Ablikim, M., et al.
(author)
-
Branching fraction measurements of psi (3686) -> gamma chi(cJ)
- 2017
-
In: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:3
-
Journal article (peer-reviewed)abstract
- Using a sample of 106 million psi(3686) decays, the branching fractions of psi(3686) -> gamma chi(c0), psi(3686) -> gamma chi(c1), and psi(3686) -> gamma chi(c2) are measured with improved precision to be (9.389 +/- 0.014 +/- 0.332) %, (9.905 +/- 0.011 +/- 0.353) %, and (9.621 +/- 0.013 +/- 0.272) %, respectively, where the first uncertainties are statistical and the second ones are systematic. The product branching fractions of (psi 3686) -> gamma chi(c1), chi(c1) -> gamma J/psi (3686) -> gamma chi(c2), chi(c2) -> gamma J/psi and the branching fractions of chi(c1) -> gamma J/psi and chi(c2) -> gamma J/psi are also presented.
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| 23. |
- Ablikim, M., et al.
(author)
-
Complete Measurement of the Λ Electromagnetic Form Factors
- 2019
-
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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| 24. |
- Ablikim, M., et al.
(author)
-
Confirmation of a charged charmoniumlike state Z(c)(3885)(-/+) in e(+)e(-) -> pi(+/-) (D(D)over-bar*)(-/+) with double D tag
- 2015
-
In: Physical Review D. - 1550-7998 .- 1550-2368. ; 92:9
-
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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| 25. |
- Ablikim, M., et al.
(author)
-
Cross section measurement of e(+) e(-) -> eta ' J/psi from root S=4.178 to 4.600 GeV
- 2020
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 101:1
-
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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| 26. |
- Ablikim, M., et al.
(author)
-
Cross section measurement of e(+)e(-) -> (KSKL0)-K-0 at root s=2.00-3.08 GeV
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:9
-
Journal article (peer-reviewed)abstract
- The cross sections of the process e(+)e(-) -> (KSKL0)-K-0 are measured at fifteen center-of-mass energies root s from 2.00 to 3.08 GeV with a total integrated luminosity of 582 pb(-1) and using the BESIII detector at the Beijing Electron Positron Collider. The results are found to be consistent with those obtained by BABAR. A resonant structure around 2.2 GeV is observed, with a mass and width of 2273.7 +/- 5.7 +/- 19.3 MeV/c(2) and 86 +/- 44 +/- 51 MeV, respectively, where the first uncertainties are statistical and the second ones are systematic. The product of its radiative width (Gamma(e+e-)) with its branching fraction to (KSKL0)-K-0 (Br-KS0KL0) is 0.9 +/- 0.6 +/- 0.7 eV.
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| 27. |
- Ablikim, M., et al.
(author)
-
Cross section measurement of e(+)e(-) -> p(p)over-bar eta and e(+)e(-) -> p(p)over-bar omega at center-of-mass energies between 3.773 GeV and 4.6 GeV
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:9
-
Journal article (peer-reviewed)abstract
- Based on 14.7 fb(-1) of e(+)e(-) annihilation data collected with the BESIII detector at the BEPCII collider at 17 different center-of-mass energies between 3.7730 GeV and 4.5995 GeV, Born cross sections of the two processes e(+)e(-) -> p (p) over bar eta and e(+)e(-) -> p (p) over bar omega are measured for the first time. No indication of resonant production through a vector state V is observed, and upper limits on the Born cross sections of e(+)e(-) -> p (p) over bar eta and e(+)e(-) -> p (p) over bar omega at the 90% confidence level are calculated for a large parameter space in resonance masses and widths. For the current world average parameters of the psi(4230) of m = 4.2187 GeV=c(2) and Gamma = 44 MeV, we find upper limits on resonant production of the p (p) over bar eta and p (p) over bar omega final states of 7.5 pb and 10.4 pb at the 90% CL, respectively.
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| 28. |
- Ablikim, M., et al.
(author)
-
Cross section measurement of e+e- → π+π-ψ(3686) from √s = 4.0076 GeV to 4.6984 GeV
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:5
-
Journal article (peer-reviewed)abstract
- Using data samples with a total integrated luminosity of 20.1 fb(-1) collected by the BESIII detector operating at the BEPCII collider, the cross section of the process e(+) e(-) -> pi(+) pi(-) psi(3686) is measured at center-of-mass energies between 4.0076 and 4.6984 GeV. The measured cross section is consistent with previous results, and with much improved precision. A fit to the measured energy-dependent cross section, which includes three Breit-Wigner functions and a nonresonant contribution, confirms the existence of the charmonium-like states Y(4220), Y(4390), and Y(4660). This is the first observation of the Y(4660) at the BESIII experiment.
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| 29. |
- 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
-
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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| 30. |
- Ablikim, M., et al.
(author)
-
Cross section measurements of e(+) e(-) -> omega chi(c0) from root s=4.178 to 4.278 GeV
- 2019
-
In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 99:9
-
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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| 31. |
- Ablikim, M., et al.
(author)
-
Cross section measurements of the e(+)e(-) -> D*D+*(-) and e(+)e(-) -> D*D-+(-) processes at center-of-mass energies from 4.085 to 4.600 GeV
- 2022
-
In: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :5
-
Journal article (peer-reviewed)abstract
- The Born cross sections of the e(+)e(-) -> D*D+*(-) and e(+)e(-) -> 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 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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| 32. |
- Ablikim, M., et al.
(author)
-
Cross section measurements of the processes e+e− → ωπ0 and ωη at center-of-mass energies between 3.773 and 4.701 GeV
- 2022
-
In: Journal of High Energy Physics (JHEP). - : Springer Nature. - 1126-6708 .- 1029-8479. ; :7
-
Journal article (peer-reviewed)abstract
- The Born cross sections of the processes e(+)e(-) -> omega pi(0) and e(+)e(-) -> omega eta are measured at center-of-mass energies between 3.773 and 4.701 GeV using a total integrated luminosity of 22.7 fb(-1) collected with the BESIII detector operating at the BEPCII collider. A simple s(-n) dependence for the continuum process can describe the measured Born cross sections. No significant contributions from the psi(4160), Y(4230), Y(4360), psi(4415), Y(4660) resonances are found, which indicates relative small branching fractions for these resonances into the omega pi(0) and omega eta final states.
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| 33. |
- Ablikim, M., et al.
(author)
-
Cross sections for the reactions e+e−→K+K−π+π−(π0), K+K−K+K−(π0), π+π−π+π−(π0), p¯pπ+π−(π0) in the energy region between 3.773 and 4.600 GeV
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:11
-
Journal article (peer-reviewed)abstract
- 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(-) -> K+K- pi(+)pi(-) (pi(0)), K+K-K+K- (pi(0)), pi(+)pi(-) pi(+)pi(-) (pi(0)), and p (p) over bar pi(+)pi(-)(pi(0)). The cross sections for e(+)e(-) -> K+K-K+K- pi(0), p (p) over bar pi(+)pi(-)(pi(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 psi(4040) decaying to pi(+)pi(-) pi(+)pi(-) pi(0) with a statistical significance of 3.6 sigma. Upper limits are provided for other decays since no clear signals are observed.
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| 34. |
- Ablikim, M., et al.
(author)
-
Dalitz plot analysis of the decay ω→π+π−π0
- 2018
-
In: Physical Review D. - 2470-0010 .- 2470-0029. ; 98:11
-
Journal article (peer-reviewed)abstract
- Using a low-background sample of 2.6 x 10(5) J/psi -> omega eta(omega -> pi(+) pi(-) pi(0), eta -> gamma gamma) events, about 5 times larger statistics than previous experiments, we present a Dalitz plot analysis of the decay omega -> pi(+) pi(-) pi(0). It is found that the Dalitz plot distribution differs from the pure P-wave phase space with a statistical significance of 18.9 sigma. The parameters from the fit to data are in reasonable agreement with those without the cross-channel effect within the dispersive framework, which indicates that the cross-channel effect in omega -> pi(+) pi(-) pi(0) is not significant.
|
|
| 35. |
- Ablikim, M., et al.
(author)
-
Dark photon search in the mass range between 1.5 and 3.4 GeV/c
- 2017
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 774, s. 252-257
-
Journal article (peer-reviewed)abstract
- Using a data set of 2.93 fb taken at a center-of-mass energy root s = 3.773 GeV with the BESIII detector at the BEPCII collider, we perform a search for an extra U(1) gauge boson, also denoted as a dark photon. We examine the initial state radiation reactions e(+)e(-) -> e(+)e(-) gamma(ISR) and e(+)e(-) -> mu(+)mu(-) gamma(ISR) for this search, where the dark photon would appear as an enhancement in the invariant mass distribution of the leptonic pairs. We observe no obvious enhancement in the mass range between 1.5 and 3.4 GeV/c(2) and set a 90% confidence level upper limit on the mixing strength of the dark photon and the Standard Model photon. We obtain a competitive limit in the tested mass range.
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| 36. |
- Ablikim, M., et al.
(author)
-
Determination of the absolute branching fractions of D0 → K-e+νe and D+ → K0e+νe
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 104:5
-
Journal article (peer-reviewed)abstract
- Using 2.93 fb(-1) of e(+)e(-) collision data collected with the BESIII detector at a center-of-mass energy of 3.773 GeV, we measure the absolute branching fractions of the decays D-0 -> K(-)e(+)nu(e) and D+ -> (K) over bar (0)e(+)nu(e) to be (3.567 +/- 0.031(stat) +/- 0.025(syst))% and (8.68 +/- 0.14(stat) +/- 0.16(syst))%, respectively. Starting with the process e(+)e(- ) -> D (D) over bar, a new reconstruction method is employed to select events that contain candidates for both D -> (K) over bare(+)nu(e) and (D) over bar -> Ke(-)(nu) over bar (e) decays. The branching fractions reported in this work are consistent within uncertainties with previous BESIII measurements that selected events containing D -> (K) over bare(+)nu(e) and hadronic (D) over bar decays. Combining our results with the lifetimes of the D degrees and D+ mesons and the previous BESIII measurements leads to a ratio of the two decay partial widths of (Gamma) over bar (D0 -> K-e+)(nu e)/(Gamma) over bar (D+ -> (K) over bar 0e+)(nu e) = 1.039 +/- 0.021. This ratio supports isospin symmetry in the D-0 -> K(-)e(+)nu(e) and D+ -> (K) over bar (0)e(+)nu(e) decays within 1.9 sigma.
|
|
| 37. |
- Ablikim, M., et al.
(author)
-
Determination of the number of J/psi events with inclusive J/psi decays
- 2017
-
In: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 41:1
-
Journal article (peer-reviewed)abstract
- A measurement of the number of J/psi events collected with the BESIII detector in 2009 and 2012 is performed using inclusive decays of the J/psi. The number of J/psi events taken in 2009 is recalculated to be (223.7 +/- 1.4) x 10(6), which is in good agreement with the previous measurement, but with significantly improved precision due to improvements in the BESIII software. The number of J/psi events taken in 2012 is determined to be (1086.9 +/- 6.0) x 10(6). In total, the number of J/psi events collected with the BESIII detector is measured to be (1310.6 +/- 7.0) x 10(6), where the uncertainty is dominated by systematic effects and the statistical uncertainty is negligible.
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| 38. |
- Ablikim, M., et al.
(author)
-
Determination of the Pseudoscalar Decay Constant f(Ds)(+) via D-s(+) -> mu(+)nu(mu)
- 2019
-
In: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 122:7
-
Journal article (peer-reviewed)abstract
- Using a 3.19 fb(-1) data sample collected at an e(+)e(-) center-of-mass energy of E-cm = 4.178 GeV with the BESIII detector, we measure the branching fraction of the leptonic decay D-s(+) -> mu(+)nu(mu) to be BDs+ -> mu+nu mu = (5.49 +/- 0.16(stat) +/- 0.15(syst)) x 10(-3). Combining our branching fraction with the masses of the D-s(+) and mu(+) and the lifetime of the D-s(+), we determine f(Ds+)vertical bar V-cs vertical bar = 246.2 +/- 3.6(stat) +/- 3.5(syst) MeV. Using the c -> s quark mixing matrix element vertical bar V-cs vertical bar determined from a global standard model fit, we evaluate the D-s(+) decay constant f(Ds+) = 252.9 +/- 3.7(stat) +/- 3.6(syst) MeV. Alternatively, using the value of f(Ds+) calculated by lattice quantum chromodynamics, we find vertical bar V-cs vertical bar = 0.985 +/- 0.014(stat) +/- 0.014(syst). These values of BDs+ -> mu+nu mu, f(Ds+)vertical bar V-cs vertical bar, f(Ds+) and vertical bar V-cs vertical bar are each the most precise results to date.
|
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| 39. |
- Ablikim, M., et al.
(author)
-
Determination of the Spin and Parity of the Z(c)(3900)
- 2017
-
In: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 119:7
-
Journal article (peer-reviewed)abstract
- The spin and parity of the Z(c)(3900)(+/-) state are determined to be J(P) = 1(+) with a statistical significance larger than 7 sigma over other quantum numbers in a partial wave analysis of the process e(+)e(-) -> pi(+)pi(-) J/psi We use a data sample of 1.92 fb(-1) accumulated at root s = 4.23 and 4.26 GeV with the BESIII experiment. When parametrizing the Z(c)(3900)(+/-) with a Flatte-like formula, we determine its pole mass M-pole = (3881.2 +/- 4.2(stat) +/- 52.7(syst)) MeV/c(2) and pole width Gamma(pole) = (51.8 +/- 4.6(stat) +/- 36.0(syst)) MeV. We also measure cross sections for the process e(+)e(-) -> Z(c)(3900)(+)pi(-) + c.c. -> J/psi pi(+)pi(-) and determine an upper limit at the 90% confidence level for the process e(+)e(-) -> Z(c)(4020)(+)pi(-) + c.c. -> J/psi pi(+)pi(-).
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| 40. |
- Ablikim, M., et al.
(author)
-
Determination of the Λ+c spin via the reaction e+e− → Λc¯Λc
- 2021
-
In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 103:9
-
Journal article (peer-reviewed)abstract
- We report on a comparison of two possible Λ+c spin hypotheses, J=½ and 3/2, via the process e+e− → Λ+c¯Λ−c, using the angular distributions of Λ+c decays into pK0S, Λπ+, Σ0π+, and Σ+π0. The data were recorded at √s=4.6 GeV with the BESIII detector and correspond to an integrated luminosity of 587 pb−1. The Λ+c spin is determined to be J=½, with this value favored over the 3/2 hypothesis with a significance corresponding to more than 6 Gaussian standard deviations.
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| 41. |
- 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
-
In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 127:8
-
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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| 42. |
- Ablikim, M., et al.
(author)
-
Evidence for e(+)e(-)->gamma chi c1,2 at center-of-mass energies from 4.009 to 4.360 GeV
- 2015
-
In: Chinese Physics C. - : IOP Publishing. - 1674-1137 .- 2058-6132. ; 39:4
-
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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| 43. |
- Ablikim, M., et al.
(author)
-
Evidence for the Cusp Effect in η' Decays into ηπ0π0
- 2023
-
In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 130:8
-
Journal article (peer-reviewed)abstract
- Using a sample of 4.3 x 105 eta' -> eta pi 0 pi 0 events selected from the ten billion J=psi event dataset collected with the BESIII detector, we study the decay eta' -> eta pi 0 pi 0 within the framework of nonrelativistic effective field theory. Evidence for a structure at pi+pi- mass threshold is observed in the invariant mass spectrum of pi 0 pi 0 with a statistical significance of around 3.5 sigma, which is consistent with the cusp effect as predicted by the nonrelativistic effective field theory. After introducing the amplitude for describing the cusp effect, the pi pi scattering length combination a0 - a2 is determined to be 0.226 10.060stat 10.013syst, which is in good agreement with theoretical calculation of 0.2644 10.0051.
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| 44. |
- Ablikim, M., et al.
(author)
-
Evidence for the decays of Lambda(+)(C) -> Sigma(+) eta and Sigma(+) eta '
- 2019
-
In: Chinese Physics C. - : IOP PUBLISHING LTD. - 1674-1137 .- 2058-6132. ; 43:8
-
Journal article (peer-reviewed)abstract
- We study the hadronic decays of Lambda(+)(C) to the final states Sigma(+) eta and Sigma(+) eta', using an e(+) e(-) annihilation data sample of 567 pb(-1) taken at a center-of-mass energy of 4.6 GeV with the BESIII detector at the BEPCII collider. We find evidence for the decays Lambda(+)(C) -> Sigma(+) eta and Sigma(+) eta' with statistical significance of and, respectively. Normalizing to the reference decays Lambda(+)(C) -> Sigma(+) pi(0) and Sigma(+) omega, we obtain the ratios of the branching fractions B(Lambda(+)(C) -> Sigma(+) eta)/B(Lambda(+)(C) -> Sigma(+) pi(0)) and B(Lambda(+)(C) -> Sigma(+) eta')/B(Lambda(+)(C) -> Sigma(+) omega) to be 0.35 +/- 0.16 +/- 0.02 and 0.86 +/- 0.34 +/- 0.04, respectively. The upper limits at the 90% confidence level are set to be B(Lambda(+)(C) -> Sigma(+) eta)/B(Lambda(+)(C) -> Sigma(+) pi(0)) < 0.58 and B(Lambda(+)(C) -> Sigma(+) eta')/B(Lambda(+)(C) -> Sigma(+) omega) < 1.2. Using BESIII measurements of the branching fractions of the reference decays, we determine B(Lambda(+)(C) -> Sigma(+) eta) = (0.41 +/- 0.19 +/- 0.05)% (<0.68%) and B(Lambda(+)(C) -> Sigma(+) eta') = (1.34 +/- 0.53 +/- 0.19)% (<1.9%). Here, the first uncertainties are statistical and the second systematic. The obtained branching fraction of Lambda(+)(C) -> Sigma(+) eta is consistent with the previous measurement, and the branching fraction of Lambda(+)(C) -> Sigma(+) eta' is measured for the first time.
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| 45. |
- Ablikim, M., et al.
(author)
-
Evidence for the singly Cabibbo suppressed decay Lambda(+)(c) -> p eta and search for Lambda(+)(c) -> p pi(0)
- 2017
-
In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:11
-
Journal article (peer-reviewed)abstract
- We study the singly Cabibbo suppressed decays Lambda(+)(c) -> p eta and Lambda(+)(c) -> p pi(0) using Lambda(+)(c)(Lambda) over bar (-)(c) pairs produced by e(+)e(-) collisions at a center-of-mass energy of root s = 4.6 GeV. The data sample was collected by the BESIII detector at the BEPCII collider and corresponds to an integrated luminosity of 567 pb(-1). We find the first evidence for the decay Lambda(+)(c) -> p eta with a statistical significance of 4.2 sigma and measure its branching fraction to be B(Lambda(+)(c) -> p eta) = (1.24 +/- 0.28(stat) +/- 0.10(sys)) x 10(-3). No significant Lambda(+)(c) -> p pi(0) signal is observed. We set an upper limit on its branching fraction B(Lambda(+)(c) -> p pi(0)) < 2.7 x 10(-4) at the 90% confidence level.
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| 46. |
- Ablikim, M., et al.
(author)
-
Evidence for e+e−→γηc(1S) at center-of-mass energies between 4.01 and 4.60 GeV
- 2017
-
In: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:5
-
Journal article (peer-reviewed)abstract
- We present first evidence for the process e(+)e(-) -> gamma eta(c)(1S) at six center-of-mass energies between 4.01 and 4.60 GeV using data collected by the BESIII experiment operating at BEPCII. We measure the Born cross section at each energy using a combination of twelve eta(c)(1S) decay channels. We also combine all six energies under various assumptions for the energy-dependence of the cross section. If the process is assumed to proceed via the Y(4260), we measure a peak Born cross section sigma(peak)(e(+)e(-) -> gamma eta(c)(1S)) = 2.11 +/- 0.49 (stat.) +/- 0.36 (syst.) pb with a statistical significance of 4.2 sigma.
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| 47. |
- Ablikim, M., et al.
(author)
-
Evidence of a Resonant Structure in the e(+) e(-) -> pi(+) (DD)-D-0*(-) Cross Section between 4.05 and 4.60 GeV
- 2019
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 122:10
-
Journal article (peer-reviewed)abstract
- The cross section of the process e(+) e(-) -> pi(+) (DD)-D-0*(-) for center-of-mass energies from 4.05 to 4.60 GeV is measured precisely using data samples collected with the BESIII detector operating at the BEPCII storage ring. Two enhancements are clearly visible in the cross section around 4.23 and 4.40 GeV. Using several models to describe the dressed cross section yields stable parameters for the first enhancement, which has a mass of 4228.6 +/- 4.1 +/- 6.3 MeV/c(2) and a width of 77.0 +/- 6.8 +/- 6.3 MeV, where the first uncertainties are statistical and the second ones are systematic. Our resonant mass is consistent with previous observations of the Y(4220) state and the theoretical prediction of a D (D) over bar (1)(2420) molecule. This result is the first observation of Y(4220) associated with an open-charm final state. Fits with three resonance functions with additional Y(4260), Y(4320), Y(4360), psi(4415), or a new resonance do not show significant contributions from either of these resonances. The second enhancement is not from a single known resonance. It could contain contributions from psi(4415) and other resonances, and a detailed amplitude analysis is required to better understand this enhancement.
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| 48. |
- Ablikim, M., et al.
(author)
-
Evidence of Two Resonant Structures in e(+)e(-)->pi(+) pi(-) h(c)
- 2017
-
In: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 118:9
-
Journal article (peer-reviewed)abstract
- The cross sections of e(+)e(-) -> pi(+) pi(-) hc at center-of-mass energies from 3.896 to 4.600 GeVare measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of e(+)e(-) -> pi(+) pi(-) J/psi and e(+)e(-) -> pi(+) pi(-) psi (2S), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e(+)e(-) -> pi(+) pi(-) hc cross sections around 4.22 and 4.39 GeV/c(2), which we call Y(4220)and Y(4390), respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218.4(- 4.5)(vertical bar 5.5) +/- 0.9) MeV/ c(2) and a width of (66.0(- 8.3)(vertical bar 12.3) +/- 0.4) MeV for the Y(4220), and a mass of (4391.5(- 6.8)(+6.3) +/- 1.0) MeV/c(2) and a width of (139.5(- 20.6)(+16.2) +/- 0.6) MeV for the Y(4390), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y(4220) and Y(4390) is 10 sigma over one structure assumption.
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| 49. |
- Ablikim, M., et al.
(author)
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First measurement of e(+)e(-) -> pK(S)(0)(n)over-barK(-) + c.c. above open charm threshold
- 2018
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In: Physical Review D. - 2470-0010 .- 2470-0029. ; 98:3
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Journal article (peer-reviewed)abstract
- The process e(+)e(-) -> pK(S)(0)(n) over barK(-) + c.c. and its intermediate processes are studied for the first time, using data samples collected with the BESIII detector at BEPCII at center-of-mass energies of 3.773, 4.008, 4.226, 4.258, 4.358, 4.416, and 4.600 GeV, with a total integrated luminosity of 7.4 fb(-1). The Born cross section of e(+)e(-) -> pK(S)(0)(n) over barK(-) + c.c. is measured at each center-of-mass energy, but no significant resonant structure in the measured cross-section line shape between 3.773 and 4.600 GeV is observed. No evident structure is detected in the pK(-), nK(S)(0), pK(S)(0), nK(+), p (n) over bar, or (KSK-)-K-0 invariant mass distributions except for Lambda(1520). The Born cross sections of e(+)e(-) -> Lambda(1520)(n) over barK(S)(0) + c.c. and e(+)e(-) -> Lambda(1520)(p) over barK(+) + c.c. are measured, and the 90% confidence level upper limits on the Born cross sections of e(+)e(-) -> Lambda(1520)(Lambda) over bar (1520) are determined at the seven center-of-mass energies. There is an evident difference in line shape and magnitude of the measured cross sections between e(+)e(-) -> Lambda(1520)(-> pK(-))(n) over barK(S)(0) and e(+)e(-) -> pK-(Lambda) over bar (1520)(-> (n) over barK(S)(0)).
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| 50. |
- Ablikim, M., et al.
(author)
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First Measurement of Polarizations in the Decay D-0 -> omega phi
- 2022
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In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 128:1
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Journal article (peer-reviewed)abstract
- Using a data sample corresponding to an integrated luminosity of 2.93 fb(-1) collected at a center-of-mass energy root s = 3.773 GeV by the BESIII detector, the decay D-0 -> omega phi is observed for the first time. The branching fraction is measured to be (6.48 +/- 10.9 +/- 1 0.40) x 10(-4) with a significance of 6.3 sigma, where the first and second uncertainties are statistical and systematic, respectively. An angular analysis reveals that the phi and omega mesons from the D-0 -> omega phi 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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