Form factors and generalized parton distributions of heavy quarkonia in basis light front quantization

Lekha Adhikari,Yang Li,James P Vary,Meijian Li

doi:10.1103/physrevc.99.035208

Abstract

We calculate the electromagnetic (charge, magnetic and quadrupole) form factors and the associated static moments of heavy quarkonia (charmonia and bottomonia) using the Basis Light Front Quantization (BLFQ) approach. For this work, we adopt light front wavefunctions (LFWFs) generated by a holographic QCD confining potential and a one-gluon exchange interaction with fixed coupling. We compare our BLFQ results with the limiting case of a single BLFQ basis state description of heavy quarkonia and with other available results. These comparisons provide insights into relativistic effects. Using the same LFWFs generated in the BLFQ approach, we also present the generalized parton distributions (GPDs) for selected mesons including those for radially excited mesons such as $\psi^\prime$ and $\Upsilon^\prime$. Our GPD results establish the foundation within BLFQ for further investigating hadronic structure such as probing the spin structure of spin-one hadrons in the off-forward limit.

Highlights

Exploring the electromagnetic (EM) properties of spin-one hadrons has been of great interest because it provides insight into the spin-sensitive structure and the internal dynamics of the hadrons
Hadronic form factors (FFs) serve as one important tool to understand the structure of bound states in quantum chromodynamics (QCD)
We present the EM FFs and the associated static moments, the charge radii, magnetic moments, and the quadrupole moments, for a selection of heavy quarkonia

Summary

INTRODUCTION

Exploring the electromagnetic (EM) properties of spin-one hadrons has been of great interest because it provides insight into the spin-sensitive structure and the internal dynamics of the hadrons. We are motivated by the feasibility of experiments to investigate the hadronic structure of the (pseudo)scalar and vector meson GPDs in the forward limit (zero momentum transfer limit). Such measurements provide connections with unpolarized parton distributions [31]. We adopt the BLFQ approach which is developed for solving bound-state problems in quantum field theory [20,41,42] This approach provides easy conversion between the transverse coordinates and momentum space [21,43], and connects mass spectroscopy with other observables [20,44].

FORM FACTORS AND GENERALIZED PARTON DISTRIBUTIONS FOR SPIN-ONE HADRONS ON THE

FORMALISM

RESULTS AND DISCUSSION

The EM FFs and the associated static moments

Generalized parton distributions

SUMMARY AND OUTLOOK