We calculate the branching ratio of B → J/ψπ0 with a mixed formalism that combines the QCDimproved factorization and the perturbative QCD approaches.The result is consistent with experimental data.The quite small p...We calculate the branching ratio of B → J/ψπ0 with a mixed formalism that combines the QCDimproved factorization and the perturbative QCD approaches.The result is consistent with experimental data.The quite small penguin contribution in B → J/ψπ0 decay can be calculated with this method.We suggest two methods to extract the weak phase β.One is through the dependence of the mixing induced CP asymmetry SJ/ψπ0 on the weak phase β,the other is from the relation of the total asymmetry ACP with the weak phase β.Our results show that the deviation ΔSJ/ψπ0 of the mixing induced CP asymmetry from sin（-2β） is of O（10-3） and has much less uncertainty.The above O（10-3） deviation can provide a good reference for identifying new physics.展开更多
Weak radiative hyperon decays,important to test the strong interaction and relevant in searches for beyond the standard model physics,have remained puzzling both experimentally and theoretically for a long time.The re...Weak radiative hyperon decays,important to test the strong interaction and relevant in searches for beyond the standard model physics,have remained puzzling both experimentally and theoretically for a long time.The recently updated branching fraction and first measurement of the asymmetry parameter of Λ→nγ by the BESIII Collaboration further exacerbate the issue,as none of the existing predictions can describe the data.We show in this work that the covariant baryon chiral perturbation theory,with constraints from the latest measurements of hyperon non-leptonic decays,can well describe the BESIII data.The predicted branching fraction and asymmetry parameter for Ξ→Σγ are also in agreement with the experimental data.We note that a more precise measurement of the asymmetry parameter,which is strongly constrained by chiral symmetry and related with that of Σ→pγ,is crucial to test Hara’s theorem.We further predict the branching fraction and asymmetry parameter of Σ~0→nγ,whose future measurement can serve as a highly nontrivial check on our understanding of weak radiative hyperon decays and on the covariant baryon chiral perturbation theory.展开更多
文摘We calculate the branching ratio of B → J/ψπ0 with a mixed formalism that combines the QCDimproved factorization and the perturbative QCD approaches.The result is consistent with experimental data.The quite small penguin contribution in B → J/ψπ0 decay can be calculated with this method.We suggest two methods to extract the weak phase β.One is through the dependence of the mixing induced CP asymmetry SJ/ψπ0 on the weak phase β,the other is from the relation of the total asymmetry ACP with the weak phase β.Our results show that the deviation ΔSJ/ψπ0 of the mixing induced CP asymmetry from sin（-2β） is of O（10-3） and has much less uncertainty.The above O（10-3） deviation can provide a good reference for identifying new physics.
基金supported in part by the National Natural Science Foundation of China (11735003, 11975041, and11961141004)support from the National Natural Science Foundation of China (12147145)+2 种基金support from the National Natural Science Foundation of China (12105006)Project funded by China Postdoctoral Science Foundation (2021M700343)China Postdoctoral Science Foundation (2021M690008)
文摘Weak radiative hyperon decays,important to test the strong interaction and relevant in searches for beyond the standard model physics,have remained puzzling both experimentally and theoretically for a long time.The recently updated branching fraction and first measurement of the asymmetry parameter of Λ→nγ by the BESIII Collaboration further exacerbate the issue,as none of the existing predictions can describe the data.We show in this work that the covariant baryon chiral perturbation theory,with constraints from the latest measurements of hyperon non-leptonic decays,can well describe the BESIII data.The predicted branching fraction and asymmetry parameter for Ξ→Σγ are also in agreement with the experimental data.We note that a more precise measurement of the asymmetry parameter,which is strongly constrained by chiral symmetry and related with that of Σ→pγ,is crucial to test Hara’s theorem.We further predict the branching fraction and asymmetry parameter of Σ~0→nγ,whose future measurement can serve as a highly nontrivial check on our understanding of weak radiative hyperon decays and on the covariant baryon chiral perturbation theory.
