Heavy quarkonium 2S states in light-front quark model

Understand

We study the charmonium 2S states $\psi'$ and $\eta_c'$, and the bottomonium 2S states $\Upsilon'$ and $\eta_b'$, using the light-front quark model and the 2S state wave function of harmonic oscillator as the approximation of the 2S quarkonium wave function.

• The decay constants, transition form factors and masses of these mesons are calculated and compared with experimental data.
• Predictions of quantities such as Br$(\psi' \to \gamma \eta_c')$ are made.
• The 2S wave function may help us learn more about the structure of these heavy quarkonia.