Internal structure of light mesons using the power law wave function

TL;DR

This study models the internal structure of light mesons using power-law wave functions, calculating various distribution functions and form factors, and comparing results with experimental data.

Contribution

It introduces a spin-improved power-law wave function approach to analyze light mesons and computes their distribution functions and form factors with evolution equations.

Findings

41% of momentum carried by quarks at 16 GeV^2

Vector form factors agree with experimental data

Charge radii are 0.668 fm (pion) and 0.704 fm (kaon)

Abstract

In this paper, we study the internal structure of light pseudoscalar mesons using spin improved power-law wave functions. We choose the pion and the kaon for our work. We use the standard quark-quark correlation functions to calculate the distribution amplitudes (DAs), parton distribution functions (PDFs), transverse momentum dependent parton distribution functions (TMDs), and generalized parton distribution functions (GPDs) at zero skewness and form factors. We present all the above distribution functions through the overlap of light-front wave functions (LFWFs). We use leading-order Efremov-Radyushkin-Brodsky-Lepage (ERBL) equations for DAs and next-to-leading-order (NLO) Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) equations for PDFs to evolve them to higher scales. We find that only 41\% of the longitudinal momentum fraction is carried by the quark and antiquark of both pion and kaon at 16~GeV$^2$. The vector form factors for both the pion and the kaon are found to be in good agreement with experimental data. Similarly, the electromagnetic charge radii are found to be 0.668~fm and 0.704~fm for the pion and kaon, respectively.