Radiative Transitions for the Ground and Excited Charmonia States

In this work, we have investigated the physical properties like decay constants, radiative transitions, decay widths, and branching ratios for the ground and radially excited charmonia states. For the numerical calculations, we have adopted the light-front quark model (LFQM). We have studied $\chi_{c0}\rightarrow J{/}\psi+\gamma $ and $\psi(2S)\rightarrow\chi_{c0}+\gamma$, $h_c(1P)\rightarrow\eta_c(1S)+\gamma $, and $\eta_c(2S)\rightarrow h_c(1P)+\gamma $ transitions in this work. We have also demonstrated the behavior of the transition form factors (TFFs) for the $h_c(1P)\rightarrow\eta_c(1S)+\gamma $ and $\psi(2S)\rightarrow\chi_{c0}+\gamma$ decays in this model. Using the TFFs results, we have calculated the decay widths and branching ratios for these transitions. Our numerical results of decay constants, decay widths, and branching ratios are overall in good agreement with available experimental, theoretical and lattice simulation data.