AdS/QCD at the correlator level

TL;DR

This paper compares two AdS/QCD models' predictions for scalar glueball correlators with QCD data, revealing their complementary insights into nonperturbative QCD physics and testing the influence of UV dynamics.

Contribution

It provides a detailed analysis of the hard-wall and soft-wall AdS/QCD models at the correlator level, highlighting their respective strengths and limitations in describing nonperturbative QCD phenomena.

Findings

Both models encode different aspects of nonperturbative QCD.

OPE Wilson coefficients challenge the impact of UV dynamics on holographic predictions.

Models show complementary features aligning with lattice and theoretical QCD results.

Abstract

We derive and analyze predictions of both the hard-wall and dilaton soft-wall AdS/QCD approximations for the scalar glueball correlator and decay constants. We confront the results with QCD information from the lattice, the operator product expansion (OPE), a hypothetical UV gluon mass associated with the short-distance behavior of the heavy-quark potential, and a low-energy theorem based on the anomalous dilatational Ward identity. Both duals turn out to encode complementary aspects of the above, nonperturbative QCD physics. The OPE Wilson coefficients, in particular, are shown to provide a challenging testing ground for the impact of the strongly coupled holographic UV dynamics on dual gravity predictions.