On the $\pi$ and $K$ as $q \bar q$ Bound States and Approximate Nambu-Goldstone Bosons

TL;DR

This paper explores the dual nature of $$ and $$ mesons as quark-antiquark bound states and approximate Nambu-Goldstone bosons, analyzing their masses, wavefunctions, and other properties.

Contribution

It provides a detailed analysis of meson properties highlighting their dual role as bound states and Nambu-Goldstone bosons, with new insights into their mass splittings and wavefunction overlaps.

Findings

Mass splittings between $$ and $ ho$, and between $K$ and $K^*$, are quantitatively analyzed.

Meson wavefunctions and charge radii are characterized, revealing structural details.

Overlap between $K$ and $$ wavefunctions is computed, indicating their internal similarities.

Abstract

We reconsider the two different facets of $\pi$ and $K$ mesons as $q \bar q$ bound states and approximate Nambu-Goldstone bosons. We address several topics, including masses, mass splittings between $\pi$ and $\rho$ and between $K$ and $K^*$, meson wavefunctions, charge radii, and the $K-\pi$ wavefunction overlap.