Heavy quarkonium 2S states in light-front quark model

TL;DR

This paper employs the light-front quark model with harmonic oscillator wave functions to analyze the properties of 2S heavy quarkonium states, providing theoretical predictions and comparisons with experimental data.

Contribution

It introduces a method to approximate 2S quarkonium wave functions using harmonic oscillators within the light-front model, enabling detailed calculations of decay constants and transition form factors.

Findings

Calculated decay constants and masses align with experimental data.

Predicted branching ratios for radiative decays.

Provided insights into the structure of heavy quarkonia.

Abstract

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.