The construction of BESⅢ detector has been finished and the data taking is under plan. Some physics topics on charmonium decays at BESIII experiment are discussed in this paper. The measurement of properties of ηc a...The construction of BESⅢ detector has been finished and the data taking is under plan. Some physics topics on charmonium decays at BESIII experiment are discussed in this paper. The measurement of properties of ηc and η′c at BESⅢ is discussed and the expected precision of the measurement is estimated based on BOSS. Also the XcJ decay and the measurement of hyperon decay parameters are mentioned.展开更多
By analyzing existing data on pseudoscalar charmonium decays,we obtain the ratio of the branching fractions of η_(c)(2S) and η_(c) decays into ten different final states with light hadrons.For the first time,we test...By analyzing existing data on pseudoscalar charmonium decays,we obtain the ratio of the branching fractions of η_(c)(2S) and η_(c) decays into ten different final states with light hadrons.For the first time,we test the two existing theoretical predictions of these decays and find that the experimental data are significantly different from both of them.The lack of observation of any decay mode with higher rate in η_(c)(2S)than in η_(c) decays suggests very unusual decay dynamics in pseudoscalar charmonium decays to be identified.We also report the first model-independent evaluation of the partial width of η_(c)(2S)→yy(2.21^(+0.88)_(-0.64)keV)and improve determination of that of η_(c)→yy(5.43^(+0.41)_(-0.38)KeV).The latter shows a tension with the most recent lattice QCD calculation.展开更多
Amplitudes for φ（2S） sequential decays into 2（π^＋π^-）pp^-γ via XCJ are constructed in effective coupling scheme. A Mote-Carlo simulation is carried out to study angular distributions of the decayed particles ...Amplitudes for φ（2S） sequential decays into 2（π^＋π^-）pp^-γ via XCJ are constructed in effective coupling scheme. A Mote-Carlo simulation is carried out to study angular distributions of the decayed particles in laboratory system. The results can be taken as a reference for measuring the decay of XCJ into at BESⅡ/BEPC in the near future.展开更多
Using ～ 14 × 10^6 ψ（2S） and ～ 58 × 10^ J/ ψ data collected at BES Ⅱ/BEPC, the branching fraction of ψ（2S）→Ω-Ω^＋ is measured with about 5a statistical significance. The A electric dipole and ∧...Using ～ 14 × 10^6 ψ（2S） and ～ 58 × 10^ J/ ψ data collected at BES Ⅱ/BEPC, the branching fraction of ψ（2S）→Ω-Ω^＋ is measured with about 5a statistical significance. The A electric dipole and ∧ decay parameter are studied using the decay J/ψ →∧∧→ ppπ^＋π^-. Using （106±3）× 10^6 ψ（2S） decays collected at BESⅢ/BEPC Ⅱ, we have obtained some interesting physics results. The branching fractions of XcJ→π^0π^0, ηη are measured with precision improved. The mass and width of he（l^1P1） state, together with the branching fractions of Br（ψ（2S） →π^0hc） and Br（hc →γηc） are the first measurements. Surprisingly, the decays of Xc1→φφ, ωω, and ωφ are firstly observed in BESⅢ data.展开更多
基金National Natural Science Foundation of China(10491303)100 Talents Program of CAS(U-25)
文摘The construction of BESⅢ detector has been finished and the data taking is under plan. Some physics topics on charmonium decays at BESIII experiment are discussed in this paper. The measurement of properties of ηc and η′c at BESⅢ is discussed and the expected precision of the measurement is estimated based on BOSS. Also the XcJ decay and the measurement of hyperon decay parameters are mentioned.
基金Supported in part by National Key Research and Development Program of China(2020YFA0406301)National Natural Science Foundation of China(NSFC)(11961141012,11835012,11521505)。
文摘By analyzing existing data on pseudoscalar charmonium decays,we obtain the ratio of the branching fractions of η_(c)(2S) and η_(c) decays into ten different final states with light hadrons.For the first time,we test the two existing theoretical predictions of these decays and find that the experimental data are significantly different from both of them.The lack of observation of any decay mode with higher rate in η_(c)(2S)than in η_(c) decays suggests very unusual decay dynamics in pseudoscalar charmonium decays to be identified.We also report the first model-independent evaluation of the partial width of η_(c)(2S)→yy(2.21^(+0.88)_(-0.64)keV)and improve determination of that of η_(c)→yy(5.43^(+0.41)_(-0.38)KeV).The latter shows a tension with the most recent lattice QCD calculation.
基金the National Natural Science Foundation of China under
文摘Amplitudes for φ（2S） sequential decays into 2（π^＋π^-）pp^-γ via XCJ are constructed in effective coupling scheme. A Mote-Carlo simulation is carried out to study angular distributions of the decayed particles in laboratory system. The results can be taken as a reference for measuring the decay of XCJ into at BESⅡ/BEPC in the near future.
基金Supported by National Natural Science Foundation of China (10491300,10225524,10225525,10425523,10625524,10521003,10821063,10825524)Chinese Academy of Sciences (KJ 95T-03)+2 种基金100 Talents Program of CAS (U-11,U-24,U-25)Knowledge Innovation Project of CAS (U-602,U-34 (IHEP))National Natural Science Foundation of China (10225522 (Tsinghua University))
文摘Using ～ 14 × 10^6 ψ（2S） and ～ 58 × 10^ J/ ψ data collected at BES Ⅱ/BEPC, the branching fraction of ψ（2S）→Ω-Ω^＋ is measured with about 5a statistical significance. The A electric dipole and ∧ decay parameter are studied using the decay J/ψ →∧∧→ ppπ^＋π^-. Using （106±3）× 10^6 ψ（2S） decays collected at BESⅢ/BEPC Ⅱ, we have obtained some interesting physics results. The branching fractions of XcJ→π^0π^0, ηη are measured with precision improved. The mass and width of he（l^1P1） state, together with the branching fractions of Br（ψ（2S） →π^0hc） and Br（hc →γηc） are the first measurements. Surprisingly, the decays of Xc1→φφ, ωω, and ωφ are firstly observed in BESⅢ data.
