Flavor Corrections in the Static Potential in Holographic QCD

TL;DR

This paper investigates how flavor backreaction affects the static potential in holographic QCD models, revealing exponential corrections, screening effects, and modifications to string configurations, supported by numerical analysis and comparison with lattice data.

Contribution

It provides an analytical and numerical study of flavor corrections to the static potential in the Sakai-Sugimoto model with backreacted flavors, highlighting exponential corrections and screening effects.

Findings

Flavor corrections are exponential in long strings.

Static force is reduced due to screening effects.

Backreaction modifies string world-sheets compared to probe limit.

Abstract

We examine the static potential in the presence of flavors in the perturbative backreacted D4/D8 system from localized D8 branes, focusing in particular on the Sakai-Sugimoto model. For the case of long strings we find the flavor corrections to the static potential which are of exponential form. We then investigate shorter Wilson loops and express their energy analytically in terms of the lengths of two neighboring Wilson loops. Moreover, we find that the static force for all the cases in the backreacted background is reduced compared to one in the probe limit, as expected due to screening effects. We also compare the string world-sheets in the two backgrounds and find how they get modified by the backreaction. Our results are supported by numerical computations as well. Finally we discuss our results in comparison with the lattice data and comment on the issue of physical scales which seem to lie at the heart of the reason that obstructs our model at this level to fully describe QCD.