Skyrmion properties from holographic instantons of large size

TL;DR

This paper investigates baryon properties using holographic instantons in the Skyrme model, demonstrating that large instantons effectively describe low-energy baryons and improve upon previous results without fine-tuning parameters.

Contribution

It introduces a method to use large holographic instantons to accurately model baryon properties, enhancing the Skyrme model's predictive power without parameter fine-tuning.

Findings

Large instantons are necessary to match the physical axial coupling.

Predictions for baryon quantities are significantly improved.

The approach reproduces results from full instanton quantization.

Abstract

Based on the intanton approximation of Skyrmion and recent progresses on the holographic approach, we study baryon properties using Skyrmions generated from holographic instantons. First we employ Atiyah and Manton's early observation to show that the instanton approximation gives the correct infrared behavior for the Skyrmion solution, and thus those of the electromagnetic form factors of the nucleon. We then use Skyrmions generated from flat-space instanton solutions to study various baryon properties, treating the instanton size as an arbitrary variable. It is found that, a large instanton size is required to reproduce the physical axial coupling. From such an instanton configuration, the predictions for other baryon quantities in the Skyrme model improve the original results quite a lot. Some of the results reproduce those by quantizing the full instanton solution, while no fine-tuning of the mesonic parameters are needed. From these we conclude that the baryons in the low energy region can be effectively described by large instantons.