We calculate theD^0-D^-0 mixing parameter y in the factorization-assisted topological-amplitude（FAT）approach, considering contributions from D^0→PP, PV, and VV modes, where P（V） stands for a pseudoscalar（vector...We calculate theD^0-D^-0 mixing parameter y in the factorization-assisted topological-amplitude（FAT）approach, considering contributions from D^0→PP, PV, and VV modes, where P（V） stands for a pseudoscalar（vector） meson. The D^0→PP and PV decay amplitudes are extracted in the FAT approach, and the D^0→VV decay amplitudes with final states in the longitudinal polarization are estimated via the parameter set for D^0→PV. It is found that the VV contribution to y, being of order of 10-4, is negligible, and that the PP and PV contributions amount only up to y_（PP＋PV） =（0.21±0.07）%, a prediction more precise than those previously obtained in the literature,and much lower than the experimental data yexp =（0.61 ±0.08）%. We conclude that D^0 meson decays into other two-body and multi-particle final states are relevant to the evaluation of y, so it is difficult to understand it fully in an exclusive approach.展开更多
The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, Ξ;and Ξ;, which should be...The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, Ξ;and Ξ;, which should be helpful for experimental searches for these particles. The long-distance contributions are first studied in the doubly heavy baryon decays, and found to be significantly enhanced. Comparing all the processes, Ξ;→Λ;K;π;π;andΞ;π;are the most favorable decay modes for experiments to search for doubly heavy baryons.展开更多
The doubly charmed baryon■cc++was recently observed by LHCb via the decay processes of■cc++→∧+cK^(-)π^(+)π^(+)and■c+π^(+).These discovery channels were successfully predicted in a framework in which the short-...The doubly charmed baryon■cc++was recently observed by LHCb via the decay processes of■cc++→∧+cK^(-)π^(+)π^(+)and■c+π^(+).These discovery channels were successfully predicted in a framework in which the short-distance contributions are calculated under the factorization hypothesis and the long-distance contributions are estimated using the rescattering mechanism for the final-state-interaction effcts.In this paper,we illustrate the above framework in detail by systematic studies on the tw o-body baryonic decays Bcc→BcP involving the doubly charmed baryons Bcc=(■cc++,■cc++,Ωcc+),the singly charmed baryons Bc=(B3,B6)and the light pseudoscalar mesons P=(π,K,η1,8).展开更多
基金Supported by National Natural Science Foundation of China(11347027,11505083,11375208,11521505,1162113100,11235005,U1732101)Ministry of Science and Technology of R.O.C.(MOST-104-2112-M-001-037-MY3)DFG Forschergruppe FOR 1873"Quark Flavour Physics and Effective Field Theories"
文摘We calculate theD^0-D^-0 mixing parameter y in the factorization-assisted topological-amplitude（FAT）approach, considering contributions from D^0→PP, PV, and VV modes, where P（V） stands for a pseudoscalar（vector） meson. The D^0→PP and PV decay amplitudes are extracted in the FAT approach, and the D^0→VV decay amplitudes with final states in the longitudinal polarization are estimated via the parameter set for D^0→PV. It is found that the VV contribution to y, being of order of 10-4, is negligible, and that the PP and PV contributions amount only up to y_（PP＋PV） =（0.21±0.07）%, a prediction more precise than those previously obtained in the literature,and much lower than the experimental data yexp =（0.61 ±0.08）%. We conclude that D^0 meson decays into other two-body and multi-particle final states are relevant to the evaluation of y, so it is difficult to understand it fully in an exclusive approach.
基金Supported by National Natural Science Foundation of China(11505083,11505098,11647310,11575110,11375208,11521505,11621131001,11235005,11447032,U1732101)Natural Science Foundation of Shanghai(15DZ2272100)
文摘The existence of doubly heavy flavor baryons has not been well established experimentally so far. In this Letter we systematically investigate the weak decays of the doubly charmed baryons, Ξ;and Ξ;, which should be helpful for experimental searches for these particles. The long-distance contributions are first studied in the doubly heavy baryon decays, and found to be significantly enhanced. Comparing all the processes, Ξ;→Λ;K;π;π;andΞ;π;are the most favorable decay modes for experiments to search for doubly heavy baryons.
基金the National Natural Science Foundation of China(11775117,U1732101,11975112)National Key Research and Development Program of China(2020YFA0406400)。
文摘The doubly charmed baryon■cc++was recently observed by LHCb via the decay processes of■cc++→∧+cK^(-)π^(+)π^(+)and■c+π^(+).These discovery channels were successfully predicted in a framework in which the short-distance contributions are calculated under the factorization hypothesis and the long-distance contributions are estimated using the rescattering mechanism for the final-state-interaction effcts.In this paper,we illustrate the above framework in detail by systematic studies on the tw o-body baryonic decays Bcc→BcP involving the doubly charmed baryons Bcc=(■cc++,■cc++,Ωcc+),the singly charmed baryons Bc=(B3,B6)and the light pseudoscalar mesons P=(π,K,η1,8).
