# Peripheral transverse densities of the baryon octet from chiral effective field theory and dispersion analysis

## TL;DR

This paper calculates the peripheral transverse charge and magnetization densities of octet baryons using chiral effective field theory and dispersion analysis, providing insights into their internal structure at large distances.

## Contribution

It introduces a novel combination of relativistic chiral EFT and dispersion analysis to compute baryon densities, extending into the rho meson mass region with a new N/D method.

## Key findings

- Peripheral densities are successfully computed for octet baryons.
- Uncertainties and quark flavor decompositions are estimated.
- The method can be extended to other baryon form factors and GPD moments.

## Abstract

The baryon electromagnetic form factors are expressed in terms of two-dimensional densities describing the distribution of charge and magnetization in transverse space at fixed light-front time. We calculate the transverse densities of the spin-1/2 flavor-octet baryons at peripheral distances b = O(M_\pi^{-1}) using methods of relativistic chiral effective field theory (\chi EFT) and dispersion analysis. The densities are represented as dispersive integrals over the imaginary parts of the form factors in the timelike region (spectral functions). The isovector spectral functions on the two-pion cut t > 4 M_\pi^2 are calculated using relativistic \chi EFT including octet and decuplet baryons. The \chi EFT calculations are extended into the \rho meson mass region using an N/D method that incorporates the pion electromagnetic form factor data. The isoscalar spectral functions are modeled by vector meson poles. We compute the peripheral charge and magnetization densities in the octet baryon states, estimate the uncertainties, and determine the quark flavor decomposition. The approach can be extended to baryon form factors of other operators and the moments of generalized parton distributions.