Decays of both η and η＇ provide very useful information in our understanding of low-energy QCD, and experimental signatures for these decays would be extremely helpful at BES-III. The rare decays of the η and η＇...Decays of both η and η＇ provide very useful information in our understanding of low-energy QCD, and experimental signatures for these decays would be extremely helpful at BES-III. The rare decays of the η and η＇ mesons could serve as a low-energy test of the Standard Model and its beyond. The sensitivities of the measurements of η and η＇ decays are discussed at BES-III, in which the η and η＇ mesons are produced in the ψ decays.展开更多
The recent observations of the purely leptonic decay Ds＋→μ＋νμ and τ＋ντ at CLEO-c and B factory may allow a possible contribution from a charged Higgs boson. One such measurement of the decay constant fD. dif...The recent observations of the purely leptonic decay Ds＋→μ＋νμ and τ＋ντ at CLEO-c and B factory may allow a possible contribution from a charged Higgs boson. One such measurement of the decay constant fD. differs from the most precise unquenched lattice QCD calculation by a level of 4 σ. Meanwhile, the measured ratio, BR（Ds＋→μ＋νμ）/BR（D＋→μ＋νμ）, is larger than the standard model prediction at a 2.0σ level. We discuss that the precise measurement of the ratio BR（Ds＋→μ＋νμ）/BR（D＋→μ＋νμ） at BES-Ⅲ will shed light on the presence of new intermediate particles by comparing the data with the theoretical predictions, especially, the predictions of high precise unquenched lattice QCD calculations.展开更多
基金Supported by National Natural Science Foundation of China (10575108, 10521003, 10735080, 10821063, 10835001)100 Talents Program of CAS and Knowledge Innovation Project of CAS (U-612 and U-530 (IHEP))
文摘Decays of both η and η＇ provide very useful information in our understanding of low-energy QCD, and experimental signatures for these decays would be extremely helpful at BES-III. The rare decays of the η and η＇ mesons could serve as a low-energy test of the Standard Model and its beyond. The sensitivities of the measurements of η and η＇ decays are discussed at BES-III, in which the η and η＇ mesons are produced in the ψ decays.
基金Supported by National Natural Science Foundation of China (10575108,10521003, 10735080)100 Talents Program of CAS,and Knowledge Innovation Project of CAS (U-612, U-530 (IHEP))
文摘The recent observations of the purely leptonic decay Ds＋→μ＋νμ and τ＋ντ at CLEO-c and B factory may allow a possible contribution from a charged Higgs boson. One such measurement of the decay constant fD. differs from the most precise unquenched lattice QCD calculation by a level of 4 σ. Meanwhile, the measured ratio, BR（Ds＋→μ＋νμ）/BR（D＋→μ＋νμ）, is larger than the standard model prediction at a 2.0σ level. We discuss that the precise measurement of the ratio BR（Ds＋→μ＋νμ）/BR（D＋→μ＋νμ） at BES-Ⅲ will shed light on the presence of new intermediate particles by comparing the data with the theoretical predictions, especially, the predictions of high precise unquenched lattice QCD calculations.
