Decay constants in AdS/QCD: a different approach

TL;DR

This paper revisits the holographic calculation of decay constants in AdS/QCD, proposing a new boundary-dependent expression and demonstrating its consistency and equivalence to traditional methods across various models.

Contribution

It introduces a novel boundary-based formula for decay constants in AdS/QCD, improving the understanding of holographic correlators and their boundary behavior.

Findings

The new decay constant expression depends on boundary mode values.

The approach is consistent with existing AdS/QCD models.

It is shown to be equivalent to the standard holographic prescription.

Abstract

The holographic recipe for the calculation of decay constants is revisited. Starting from the holographic 2-point function and using the fact that normalizable bulk modes scale as $z^{\Delta-S}$, with $S$ the spin, we can obtain a consistent expression that depends on the value of the mode at the boundary, not the derivative. We apply our decay constant expression to other AdS/QCD (static and dynamic) models proving its consistency. We also demonstrated that our approach is equivalent to the usual holographic prescription.