Title：Wave-Packet Effects: A Solution for Isospin Anomalies in Vector-Meson Decay
Time：2023/12/04 (Mon.) 12:30
Place：Webex online

Abstract：
There is a long-standing anomaly in the ratio of the decay width for psi(3770)->D0D0bar to that for psi(3770)->D+D− at the level of 9.5sigma. A similar anomaly exists for the ratio of phi(1020)→K0LK0S to phi(1020)->K+K− at 2.1sigma. In this study, we reassess the anomaly through the lens of Gaussian wave-packet formalism. Our comprehensive calculations include the localization of the overlap of the wave packets near the mass thresholds as well as the composite nature of the initial-state vector mesons. The results align within ~1sigma confidence level with the Particle Data Group's central values for a physically reasonable value of the form-factor parameter, indicating a resolution to these anomalies. We also check the deviation of a wave-packet resonance from the Briet-Wigner shape and find that wide ranges of the wave-packet size are consistent with the experimental data. This talk is based on arXiv:2308.09933 (Eur.Phys.J.C 83 (2023) 10, 978).