Selected issues on justification of holographic approach to QCD

TL;DR

This paper discusses foundational issues in bottom-up holographic models of QCD, suggesting they can be viewed as an alternative to QCD sum rules and proposing a method to incorporate chiral symmetry breaking into these models.

Contribution

It highlights the theoretical limitations of holographic QCD models and offers a new approach to include chiral symmetry breaking scale.

Findings

Holographic models can be interpreted as an alternative language for QCD sum rules.

A general recipe for incorporating chiral symmetry breaking scale is proposed.

Spectroscopic aspects do not necessarily rely on AdS/CFT prescriptions.

Abstract

Some problems with theoretical foundations of bottom-up holographic models are briefly discussed. It is pointed out that the spectroscopic aspects of these models in principle do not require the AdS/CFT prescriptions and may be interpreted as just an alternative language expressing the phenomenology of QCD sum rules in the large-Nc limit. A general recipe for incorporation of the chiral symmetry breaking scale into the soft-wall holographic models is proposed.