2012/02/21 by Zhi-Guo He, He, Zhi-Guo
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.1202.4775
9 pages, no figures
arxiv created 2012/02/21 · openalex publication_date 2012/02/21 · arxiv updated 2012/02/23 · openalex created_date 2016/09/16 · openalex updated_date 2026/07/28
In this work, we study the radiative decay of heavy quarkonium states by using the effective Lagrangian approach. Firstly, we construct the spin-breaking terms in the effective Lagrangian for the nP↔ mS transitions and determine the some of the coupling constants by fitting the experimental data. Our results show that in χcJ, ψ(2S), Υ(2S), and Υ(3S) radiative decays, the spin-breaking effect is so small that can be ignored. Secondly, we investigate the radiative decay widths of the cc(1D) states and find the if ψ(3770) is a pure 3D1 state its radiative decay into χcJ+γ roughly preserve the heavy-quark spin symmetry, while if it is a S-D mixing state with mixing angel 12∘ the heavy quark-spin symmetry in its radiative decay and in the radiative decay of ψ(3686) will be largely violated. In the end, we show that combining the radiative decay and the light hadron decay of P-wave χbJ(1,2P) can provide another way to extract the information of the color-octet matrix element in the context of non-relativistic QCD (NRQCD) effective theory, and our result is consistent with potential NRQCD hypothesis.