PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12294/2425
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Browsing PubMed İndeksli Yayınlar Koleksiyonu by Author "Achasov M.N."
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Article Precise Measurement of the E+e- →π+π-J/Ψ Cross Section at Center-of Energies From 3.77 to 4.60 GeV(American Physical Society, 2017) Ablikim M.; Achasov M.N.; Ahmed S.; Ai X.C.; Albayrak O.; Albrecht M.; Zou J.H.The cross section for the process e+e-→π+π-J/ψ is measured precisely at center-of-mass energies from 3.77 to 4.60 GeV using 9 fb-1 of data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in a fit to the cross section. The first resonance has a mass of (4222.0±3.1±1.4) MeV/c2 and a width of (44.1±4.3±2.0) MeV, while the second one has a mass of (4320.0±10.4±7.0) MeV/c2 and a width of (101.4-19.7+25.3±10.2) MeV, where the first errors are statistical and second ones are systematic. The first resonance agrees with the Y(4260) resonance reported by previous experiments. The precision of its resonant parameters is improved significantly. The second resonance is observed in e+e-→π+π-J/ψ for the first time. The statistical significance of this resonance is estimated to be larger than 7.6σ. The mass and width of the second resonance agree with the Y(4360) resonance reported by the BABAR and Belle experiments within errors. Finally, the Y(4008) resonance previously observed by the Belle experiment is not confirmed in the description of the BESIII data. © 2017 American Physical Society.Article Precision Study of Η′ →γπ+π- Decay Dynamics(American Physical Society, 2018) Ablikim M.; Achasov M.N.; Ahmed S.; Ai X.C.; Albayrak O.; Albrecht M.; Zou J.H.Using a low background data sample of 9.7×105 J/ψ→γη′, η′→γπ+π- events, which are 2 orders of magnitude larger than those from the previous experiments, recorded with the BESIII detector at BEPCII, the decay dynamics of η′→γπ+π- are studied with both model-dependent and model-independent approaches. The contributions of ω and the ρ(770)-ω interference are observed for the first time in the decays η′→γπ+π- in both approaches. Additionally, a contribution from the box anomaly or the ρ(1450) resonance is required in the model-dependent approach, while the process specific part of the decay amplitude is determined in the model-independent approach. .
