The gauge/gravity duality is used in order to construct effective holographic models that describ... more The gauge/gravity duality is used in order to construct effective holographic models that describe strongly coupled QCD. Assuming Nf << Nc, a holographic model is built that describes the physics of the meson sector of strong interactions, such as chiral symmetry breaking, chiral symmetry restoration above confinement/deconfinement phase transition and the meson mass spectrum. This model is also used to study the transverse part of the vector-axial vector flavor current correlator in the presence of weak external electric field, which is important for the calculation of the two-loop electroweak radiative corrections to the muon anomalous magnetic moment. It is then generalized to describe the spectrum of QCD in the Veneziano limit of large Nf and Nc but at fixed x = Nf Nc . The main results include discrete and gapped spectrum for x < xc, where xc is the conformal transition point. As x ! xc all the parameters of the theory with non trivial mass dimension approach zero foll...
Abstract: We consider a holographic model of QCD in the Veneziano limit of a large number of colo... more Abstract: We consider a holographic model of QCD in the Veneziano limit of a large number of colors Nc and flavors Nf but fixed x = Nf/Nc (V-QCD). The model exhibits a first order deconfined but chirally broken transition, followed by a second order chirally restored transition in the µ − T plane for a range of plausible holographic parameters. We study the quasi-normal mode spectrum, and derive the pertinent vector and axial spectral functions across the transition regions. The pole masses, susceptibilities, diffusion constants and electric conductivity are also discussed. In particular, the pole masses are found to survive the deconfining transition, to quickly dissolve in the the chirally restored phase by developing substantial widths. The flavor electric conductivities arise sharply in the transition region. The flavor susceptibility is shown to be consistent with the one derived from bulk thermodynamics. ar X iv
The gauge/gravity duality is used in order to construct effective holographic models that describ... more The gauge/gravity duality is used in order to construct effective holographic models that describe strongly coupled QCD. Assuming Nf << Nc, a holographic model is built that describes the physics of the meson sector of strong interactions, such as chiral symmetry breaking, chiral symmetry restoration above confinement/deconfinement phase transition and the meson mass spectrum. This model is also used to study the transverse part of the vector-axial vector flavor current correlator in the presence of weak external electric field, which is important for the calculation of the two-loop electroweak radiative corrections to the muon anomalous magnetic moment. It is then generalized to describe the spectrum of QCD in the Veneziano limit of large Nf and Nc but at fixed x = Nf Nc . The main results include discrete and gapped spectrum for x < xc, where xc is the conformal transition point. As x ! xc all the parameters of the theory with non trivial mass dimension approach zero foll...
Abstract: We consider a holographic model of QCD in the Veneziano limit of a large number of colo... more Abstract: We consider a holographic model of QCD in the Veneziano limit of a large number of colors Nc and flavors Nf but fixed x = Nf/Nc (V-QCD). The model exhibits a first order deconfined but chirally broken transition, followed by a second order chirally restored transition in the µ − T plane for a range of plausible holographic parameters. We study the quasi-normal mode spectrum, and derive the pertinent vector and axial spectral functions across the transition regions. The pole masses, susceptibilities, diffusion constants and electric conductivity are also discussed. In particular, the pole masses are found to survive the deconfining transition, to quickly dissolve in the the chirally restored phase by developing substantial widths. The flavor electric conductivities arise sharply in the transition region. The flavor susceptibility is shown to be consistent with the one derived from bulk thermodynamics. ar X iv
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