Year: 2008
Type: article
Abstract: I derive and systematically analyze scalar glueball correlation functions in both the hard-wall and dilaton soft-wall approximations to holographic QCD. The dynamical content of the holographic correlators is uncovered by examining their spectral density and by relating them to the operator product expansion, a dilatational low-energy theorem and a recently suggested two-dimensional power correction associated with the short-distance behavior of the heavy-quark potential. This approach provides holographic estimates for the three lowest-dimensional gluon condensates or alternatively their Wilson coefficients, the two leading moments of the instanton size distribution in the QCD vacuum and an effective UV gluon mass. A remarkable complementarity between the nonperturbative physics of the hard- and soft-wall correlators emerges, and their ability to describe detailed QCD results can be assessed quantitatively. I further provide the first holographic estimates for the decay constants of the ${0}^{++}$ glueball and its excitations. The hard-wall background turns out to encode more of the relevant QCD physics, and its prediction ${f}_{S}\ensuremath{\simeq}0.8--0.9\text{ }\text{ }\mathrm{GeV}$ for the phenomenologically important ground-state decay constant agrees inside errors with recent QCD sum rule and lattice results.
Author: Hilmar Forkel
Institutions: Instituto Tecnológico de Aeronáutica, Heidelberg University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2062486609