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
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.
