The dynamical holographic QCD method for hadron physics and QCD matter

Abstract

In this paper we present a short overview on the dynamical holographic QCD method for hadron physics and QCD matter. The 5-dimensional dynamical holographic QCD model is constructed in the graviton-dilaton-scalar framework with the dilaton background field Φ and the scalar field X dual to the gluon condensate and the chiral condensate operator thus can represent the gluodynamics (linear confinement) and chiral dynamics (chiral symmetry breaking), respectively. The dilaton background field and the scalar field are a function of the 5th dimension, which plays the role of the energy scale, in this way, the DhQCD model can resemble the renormalization group from ultraviolet (UV) to infrared (IR). By solving the Einstein equation, the metric structure at IR is automatically deformed by the nonperturbative gluon condensation and chiral condensation in the vacuum. We review the results on the hadron spectra including the glueball spectra, the light/heavy meson spectra, as well as on QCD phase transitions, and thermodynamical as well as transport properties in the framework of the dynamical holographic QCD model.

The glueball spectrum with $N_f=4$ light fermions

“…[8] are presented in brown colour in Figure 11. [6,[35][36][37] as well as the quenched results from [8].…”

Thermoelectric Transport in Holographic Quantum Matter under Shear Strain

“…Inserting ( 21) and evaluating at the horizon u = u h , both currents in (20) are thus given by their values at the black hole horizon, which in turn are fixed by E i and ζ i . 8 Finally, we are able to obtain all DC conductivities via (1). More explicitly, with the notation…”

“…The behavior of nonlinear elastic response is encoded in the potential W (X, Z). To be specific, we take two benchmark models with monomial potentials W (X, Z) = X 3 and W (X, Z) = X 1 4 Z 7 8 . The stress-strain curves are shown in Fig.…”

“…It is clear that the thermal conductivity bound can be significantly lowered. By fitting the numerical data for Ω > 5, one finds C 0 ∝ e −Ω/2 ∝ 1/ε where we have used (8). Thus, the violation of the thermal conductivity bound (35) can be driven by the shear deformation.…”

“…Interesting applications of holography can be found, e.g. in some recent reviews [2][3][4][5][6][7][8].…”