Proton Structure Functions from an AdS/QCD model with a deformed background

形变AdS/QCD、介子质量谱与DCE：仍为更重共振态留有余地

Deformed AdS/QCD, mesonic mass spectra, and DCE: Still a margin for heavier resonances

在形变AdS/QCD软墙模型中结合DCE和PDG数据，预测了超出PDG汇总表的更重介子共振态质量谱，为遗漏的候选粒子提供了新线索。

Proton and neutron form factors from deformed gravity/gauge duality

In this work, we study the electric and magnetic Sachs form factors for proton and neutron by using a deformed gravity/gauge model. We describe holographically baryons as well as gauge bosons which are ruled by the parameters $k_{B}$ and $k_γ$, associated with confinement and kinematical energy scales, respectively. Then, we construct the interaction action and calculate the electric and magnetic form factors for the proton and the neutron, and their electromagnetic sizes. The obtained results are compatible with those found in the literature from experimental and theoretical data.

Holographic Model for Hadrons in Deformed AdS5 Background

Several physical quantities of light hadrons are examined by a new holographic model of QCD, which is the modified version of the one proposed by Erlich et al. defined on AdS${}_5$. In our model, AdS${}_5$ is deformed by a non-trivial bulk scalar, this is corresponding to adding the mass term of the adjoint fermions to the 4d SYM theory dual to the gravity on AdS${}_5$. We find that this deformation should be taken to be rather small, but its important effects are also seen.

Heavy quark potential and QCD beta function from a deformed $AdS_5$ model

We show that in a deformed ${\rm AdS}_5$ model with an explicit infrared cutoff included in the logarithmic correction $-c_0\log[(z_{IR}-z)/z_{IR}]$, the heavy quark Cornell potential can be fitted very well, the corresponding beta-function agrees with the QCD beta-function at 2-loop level reasonably well, and its dual dilaton potential is bounded from below in infrared. The results are compared with those in the Andreev-Zakharov model and the Pirner-Galow model.

Entropic destruction of heavy quarkonium from a deformed $AdS_5$ model

In this paper, we study the destruction of heavy quarkonium due to the entropic force in a deformed $AdS_5$ model. The effects of the deformation parameter on the inter-distance and the entropic force are investigated. The influence of the deformation parameter on the quarkonium dissociation is analyzed. It is shown that the inter-distance increases in the presence of the deformation parameter. In addition, the deformation parameter has the effect of decreasing the entropic force. This results imply that the quarkonium dissociates harder in a deformed AdS background than that in an usual AdS b…

Holographic description of glueballs in a deformed AdS-dilaton background

We investigate the mass spectra of scalar and vector glueballs in the so-called bottom-up approach of the AdS/QCD correspondence. The holographic model of QCD includes a static dilaton background field. We study the constraints on the masses coming from perturbing the dilaton field and the geometry of the bulk.

Properties of protons in nuclear medium with AdS/QCD model with a quadratic modified dilaton

A modified version of the usual soft wall quadratic dilaton, a dilaton which catches the variation of the proton mass inside nucleons in the nuclear medium is used. With this dilaton, called nuclear dilaton, we have calculated the electromagnetic form factors and magnetic moments associated with the in-medium proton following the AdS/QCD prescription.

Logarithmic correction in the deformed ${\rm AdS}_5$ model to produce the heavy quark potential and QCD beta function

We stude the \textit{holographic} QCD model which contains a quadratic term $ -σz^2$ and a logarithmic term $-c_0\log[(z_{IR}-z)/z_{IR}]$ with an explicit infrared cut-off $z_{IR}$ in the deformed ${\rm AdS}_5$ warp factor. We investigate the heavy quark potential for three cases, i.e, with only quadratic correction, with both quadratic and logarithmic corrections and with only logarithmic correction. We solve the dilaton field and dilation potential from the Einstein equation, and investigate the corresponding beta function in the G{ü}rsoy -Kiritsis-Nitti (GKN) framework. Our studies show tha…

Heavy quark potential from deformed $AdS_5$ models

In this paper, we investigate the heavy quark potential in some holographic QCD models. The calculation relies on a modified renormalization scheme mentioned in a previous work of Albacete et al. After studying the heavy quark potential in Pirner-Galow model and Andreev-Zakharov model, we extend the discussion to a general deformed $AdS_5$ case. It is shown that the obtained potential is negative definite for all quark-antiquark separations, differs from that using the usual renormalization scheme.

Drag force on a moving heavy quark with deformed string configuration

To study drag force on a moving heavy quark through a plasma, we use a deformed AdS space-time, in which deformation parameter $c$ describes non-conformality in AdS/QCD. In this case the quark is mapped to a probe string in the AdS space. Considering probable contribution of deformation parameter in the probe string, we apply a general form of c-dependent string ansatz in the drag force computation. Then we find the acceptable value of this parameter as it satisfies QCD calculations. Using this result, we also discuss diffusion constant which is in agreement with phenomenological result for no…

Pion form factor from an AdS deformed background

We consider a bottom-up AdS/QCD model with a conformal exponential deformation $e^{k\,z^2}$ on a Lorentz invariant AdS background. In this model, we assume the conformal dimension associated with the operator that creates pions at the boundary as $Δ=3$. Regarding the infrared scale related to photon field $k_γ$, we analyze two cases: constant and depending on the transferred momentum $q$. In these two cases, we computed the electromagnetic pion form factor as well as the pion radius. We compare our results with experimental data as well as other theoretical (holographic and non-holographic) mo…

Drag Force, Jet Quenching, and AdS/QCD

In this note, two important transport observables in the RHIC experiment, relaxation time constant and jet quenching parameter, are calculated from an AdS/QCD model. A quark moving in the viscous medium such as the Quark-Gluon-Plasma is modelled by an open string whose end point travels on the boundary of a deformed AdS_5 black hole. The correction introduced via the deformed AdS_5 is believed to help us better understand the data which is expected to be measured in the RHIC.

Generalized Parton Distributions for the Proton in AdS/QCD

We present a study of proton GPDs in both momentum and position spaces using proton wavefunction obtained from AdS/ QCD. Here we consider the soft wall model. The results are compared with a phenomenological model of proton GPDs.

Proton Decay Constraints on Low Scale AdS/CFT Unification

Dark matter candidates and proton decay in a class of models based on the AdS/CFT correspondence are discussed. We show that the present bound on the proton decay lifetime is inconsistent with ${\cal N} = 1$ SUSY, and strongly constrains ${\cal N} = 0$ non-SUSY, low scale trinification type unification of orbifolded AdS$\otimes S^5$ models.

Dynamical electro-weak symmetry breaking from deformed AdS: vector mesons and effective couplings

We study a modification of the five-dimensional description of dynamical electro-weak symmetry breaking inspired by the AdS/CFT correspondence. Conformal symmetry is broken in the low-energy region near the IR brane by a power-law departure from the pure AdS background. Such a modification--while not spoiling the identification of the IR brane with the scale of confinement-- has a dramatic effect on both the coupling of the first composite states to the standard model currents and their self-couplings. Chiral symmetry breaking can take place at a scale larger than the IR cut-off. This study sh…