Gravitational, electromagnetic, and transition form factors of the pion

TL;DR

This paper uses the Spectral Quark Model to analyze the pion's gravitational, electromagnetic, and transition form factors, showing good agreement with lattice and experimental data and revealing a notable relation among the form factors.

Contribution

The paper introduces the Spectral Quark Model's predictions for pion form factors, demonstrating consistency with lattice calculations and experimental results, and uncovers a new relation among the form factors.

Findings

Good agreement with lattice data for gravitational form factor

Consistent predictions with experimental transition form factor data

Discovery of a relation between the three form factors

Abstract

Results of the Spectral Quark Model for the gravitational, electromagnetic, and transition form factors of the pion are discussed. In this model both the parton distribution amplitude and the parton distribution function are flat, in agreement with the transverse lattice calculations at low renormalization scales. The model predictions for the gravitational form factor are compared to the lattice data, with good agreement. We also find a remarkable relation between the three form factors, holding within our model, which besides reproducing the anomaly, provides a relation between radii which is reasonably well fulfilled. Comparison with the CELLO, CLEO, and BaBar data for the transition form factor is also considered.