The dilepton invariant mass spectra and integrated branching ratios of the single and double Dalitz decays P→l^＋l^-γ and P→l^＋l^-l^＋l^-（P=π^0,η,η＇;l=e or μ） are predicted by means of a data-driven approac...The dilepton invariant mass spectra and integrated branching ratios of the single and double Dalitz decays P→l^＋l^-γ and P→l^＋l^-l^＋l^-（P=π^0,η,η＇;l=e or μ） are predicted by means of a data-driven approach based on the use of rational approximants applied to π^0,η and η＇ transition form factor experimental data in the space-like region.展开更多
We present measurements of the γγ＊ → π^0 transition form factor for the momentum transfer range Q^2=4-40 GeV^2 and the γγ＊ → ηc transition form factor for the range Q^2=2-50 GeV^2. The current status of meas...We present measurements of the γγ＊ → π^0 transition form factor for the momentum transfer range Q^2=4-40 GeV^2 and the γγ＊ → ηc transition form factor for the range Q^2=2-50 GeV^2. The current status of measurements of the meson-photon transition form factors for the η and η＇ mesons is discussed. The results of the measurement of the ηc mass, total and two-photon widths are also presented.展开更多
With the recent investigations of the g＊g＊-η（＇） transition form factor and mixing scheme, we present an updated study of the radiative decays J/ψ→η（＇）γ in perturbative QCD. The decays are taken as a test ...With the recent investigations of the g＊g＊-η（＇） transition form factor and mixing scheme, we present an updated study of the radiative decays J/ψ→η（＇）γ in perturbative QCD. The decays are taken as a test ground for the g＊g＊-η（＇） transition form factors and the η-η＇ mixing scheme. The form factors are found to be working for glunic η＇ production and the mixing angle is constrained to be φ = 35.1°±1 0.8°.展开更多
BESⅢ合作组最近开始双光子物理研究,主要源于强子light-by-light散射对缪子反常磁矩的贡献有很大不确定性,电磁跃迁形状因子作为实验输入是改善计算精度的需要。在BESⅢ探测器上获得的质心能量3.77 Ge V到4.6Ge V的数据使得我们能够测...BESⅢ合作组最近开始双光子物理研究,主要源于强子light-by-light散射对缪子反常磁矩的贡献有很大不确定性,电磁跃迁形状因子作为实验输入是改善计算精度的需要。在BESⅢ探测器上获得的质心能量3.77 Ge V到4.6Ge V的数据使得我们能够测量轻赝标量介子的跃迁形状因子。在动量转移低于2(Ge V/c)2时单标记技术测量的结果达到前所未有的精确,该区域对于αμ的计算十分重要,并且也首次开始了π介子跃迁形状因子的双标记测量。这是π~0跃迁形状因子模型无关参数化研究的第一步。另外,多介子末态测量也在进行中.展开更多
基金Supported by the FPI scholarship BES-2012-055371(S.G-S)the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya under grant 2014 SGR 1450+3 种基金the Ministerio de Ciencia e Innovación under grant FPA2011-25948,the Ministerio de Economía y Competitividad under grants CICYT-FEDER-FPA 2014-55613-P and SEV-2012-0234the Spanish Consolider-Ingenio 2010 Program CPAN(CSD2007-00042)the European Commission under program FP7-INFRASTRUCTURES-2011-1(283286)Support from the CAS President's International Fellowship Initiative for Young International Scientist(2017PM0031)
文摘The dilepton invariant mass spectra and integrated branching ratios of the single and double Dalitz decays P→l^＋l^-γ and P→l^＋l^-l^＋l^-（P=π^0,η,η＇;l=e or μ） are predicted by means of a data-driven approach based on the use of rational approximants applied to π^0,η and η＇ transition form factor experimental data in the space-like region.
文摘We present measurements of the γγ＊ → π^0 transition form factor for the momentum transfer range Q^2=4-40 GeV^2 and the γγ＊ → ηc transition form factor for the range Q^2=2-50 GeV^2. The current status of measurements of the meson-photon transition form factors for the η and η＇ mesons is discussed. The results of the measurement of the ηc mass, total and two-photon widths are also presented.
基金Supported by National Natural Science Foundation of China (10735080,11075059)
文摘With the recent investigations of the g＊g＊-η（＇） transition form factor and mixing scheme, we present an updated study of the radiative decays J/ψ→η（＇）γ in perturbative QCD. The decays are taken as a test ground for the g＊g＊-η（＇） transition form factors and the η-η＇ mixing scheme. The form factors are found to be working for glunic η＇ production and the mixing angle is constrained to be φ = 35.1°±1 0.8°.
基金Supported by the German Research Foundation DFG under Contract(CRC-1044)
文摘BESⅢ合作组最近开始双光子物理研究,主要源于强子light-by-light散射对缪子反常磁矩的贡献有很大不确定性,电磁跃迁形状因子作为实验输入是改善计算精度的需要。在BESⅢ探测器上获得的质心能量3.77 Ge V到4.6Ge V的数据使得我们能够测量轻赝标量介子的跃迁形状因子。在动量转移低于2(Ge V/c)2时单标记技术测量的结果达到前所未有的精确,该区域对于αμ的计算十分重要,并且也首次开始了π介子跃迁形状因子的双标记测量。这是π~0跃迁形状因子模型无关参数化研究的第一步。另外,多介子末态测量也在进行中.
基金Supported in part by the the Ministerio de Ciencia e Innovación(FPA2011-25948)the Ministerio de Economíia y Competitividad(CICYT-FEDER-FPA 2014-55613-P,SEV-2012-0234)+1 种基金the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya(2014 SGR 1450)the Spanish Consolider-Ingenio 2010Programme CPAN(CSD2007-00042)
