Spectroscopy of excited quarkonium states in the light-front quark model

TL;DR

This paper explores various excited states of heavy quarkonium mesons using the light-front quark model, providing new insights into their electromagnetic and structural properties, especially for the less-studied 3S and 1P states.

Contribution

It extends the light-front quark model analysis to radially excited 3S and orbitally excited 1P states of heavy quarkonia, including detailed calculations of form factors, charge radii, and wave functions.

Findings

Calculated electromagnetic form factors, charge radii, and decay constants for excited quarkonium states.

Provided detailed 3D wave functions illustrating nodal structures of excited states.

Enhanced understanding of the structure of 3S and 1P quarkonium states.

Abstract

We have investigated the ground state ($1S$), radially excited states ($2S$) and ($3S$) along with the orbitally excited state ($1P$) for the heavy charmonia ($c \bar c$) and bottomonia ($b \bar b$) mesons in the light-front quark model (LFQM). The light-front wave functions have been successful in explaining various physical properties of meson states in the past, especially for the $1S$ and $2S$ states. However, studies regarding the radially excited state $3S$ and orbitally excited state $1P$ have hardly been pursued before. In this study, we take up these two excited states and investigate the electromagnetic form factors (EMFFs), charge radii, decay constants, parton distribution functions (PDFs) and the distribution amplitudes (DAs) for the quarkonia system. For the sake of completeness, we have also included the study of the ground and the first excited states of quarkonia mesons. We have also illustrated the 3D wave functions for the radially excited states in order to study their nodal structures.