The vector dominance of the electromagnetic form factors both for mesons and baryons arises naturally in holographic QCD, where both the number of colors and the 't Hooft coupling are taken to be very large, offering a bona-fide derivation of the notion of vector dominance. The crucial ingredient for this is the infinite tower of vector mesons in the approximations made which share features that are characteristic of the quenched approximation in lattice QCD. We approximate the infinite sum by contributions from the lowest four vector mesons of the tower which turn out to saturate the charge and magnetic moment sum rules within a few percent and compute them totally free of unknown parameters for momentum transfers Q^2 less than 1GeV^2. We identify certain observables that can be reliably computed within the approximations and others that are not, and discuss how the improvement of the latter can enable one to bring holographic QCD closer to QCD proper.
The Cheshire cat principle emerges naturally from the holographic approach of the nucleon in terms of a bulk instanton. The cat hides in the holographic direction. I briefly review the one-nucleon problem in the holographic limit.
Recent developments in holography have provided a new vista to the nucleon composition. A strongly coupled core nucleon tied with vector mesons emerge in line with the Cheshire cat principle. The cat is found to hide in the holographic direction. We discuss the one, two and many baryon problem in this context and point at the striking similarities between the holographic results and recent lattice simulations at strong coupling.
We calculate the low energy constants of four-nucleon interactions in an effective chiral Lagrangian in holographic QCD. We start with a D4-D8 model to obtain meson-nucleon interactions and then integrate out massive mesons to obtain the four-nucleon interactions in 4D. We end up with two low energy constants at the leading order and seven of them at the next leading order, which is consistent with the effective chiral Lagrangian. The values of the low energy constants are evaluated with the first five Kaluza-Klein resonances.
We introduce the strong CP-violation in the framework of AdS/QCD model and calculate the electric dipole moments of nucleons as well as the CP-violating pion-nucleon coupling. Our holographic estimate of the electric dipole moments gives for the neutron d_n=1.08 X 10^{-16} theta (e cm), which is comparable with previous estimates. We also predict that the electric dipole moment of the proton should be precisely the minus of the neutron electric dipole moment, thus leading to a new sum rule on the electric dipole moments of baryons.
Using ideas from Light Front Holography, we discuss the calculation of the nucleon helicity-independent generalized parton distributions of quarks in the zero skewness case.
We investigate masses and coupling constants of mesons and nucleons within a hard wall model of holographic QCD in a unified approach. We first examine an appropriate form of fermionic solutions by restricting the mass coupling for the five dimensional bulk fermions and bosons. We then derive approximated analytic solutions for the nucleons and the corresponding masses in a small mass coupling region. In order to treat meson and nucleon properties on the same footing, we introduce the same infrared (IR) cut in such a way that the meson-nucleon coupling constants, i.e., g_{pi NN} and g_{rho NN}…
We study nucleon-to-delta electromagnetic transition form factors and relations between them within the framework of holographic dual model of QCD proposed by Sakai and Sugimoto. In this setup, baryons appear as topological solitons of the five dimensional holographic gauge theory that describes a tower of mesons and their interactions. We find a relativistic extension of the nucleon-delta-vector meson interaction vertices and use these to calculate transition form factors from holographic QCD. We observe that at low momentum transfer, magnetic dipole, electric and Coulomb quadrupole form fact…
We develope the holographic mean field theory approach in a bottom-up holographic QCD model including baryons and scalar mesons in addition to vector mesons and pions. We study the effect of parity doubling structure of baryons at non-zero density to the equation of state between the chemical potential and the baryon number density. We first show that we can adjust the amount of nucleon mass coming from the chiral symmetry breaking by changing the boundary value of the five-dimensional baryon fields. Then, introducing the mean field for the baryon fields, we calculate the equation of state bet…
Based on the chiral perturbation theory (ChPT) with the hidden local symmetry, we propose a methodology to calculate the large $N_c$ corrections in the holographic QCD (HQCD). As an example, we apply the method to an HQCD model recently proposed by Sakai and Sugimoto. We show that the $ρ$-$π$-$π$ coupling becomes in good agreement with the experiment due to the $1/N_c$-subleading corrections.
The analysis on nucleon structure functions at small Bjorken $x$ in the framework of holographic QCD is presented. In the model setup, the complicated nonperturbative interaction between the virtual photon and the target nucleon is described via the Pomeron exchange, which corresponds to the reggeized graviton exchange in the AdS space. We show that our calculations for both $F_2$ and $F_L$ structure functions are in agreement with the experimental data measured at HERA.
We derive a two-parameter formula for the electromagnetic form factors of the nucleon described as an instanton by "integrating out" all KK modes other than the lowest mesons from the infinite-tower of vector mesons in holographic QCD while preserving hidden local symmetry for the resultant vector fields. With only two parameters, the proton Sachs form factors can be fit surprisingly well to the available experimental data for momentum transfers $Q^2\lsim 0.5$ GeV$^2$ with $χ^2$/dof $\lsim 2$, indicating the importance of an infinite tower in the soliton structure of the nucleon. The predictio…
We study the physics with finite nuclear density in the framework of AdS/QCD with holographic baryon field included. Based on a mean field type approach, we introduce the nucleon density as a bi-fermion condensate of the lowest mode of the baryon field and calculate the density dependence of the chiral condensate and the nucleon mass. We observe that the chiral condensate as well as the mass of nucleon decrease with increasing nuclear density. We also consider the mass splitting of charged vector mesons in iso-spin asymmetric nuclear matter.
We discuss unpolarized neutrino- and anti-neutrino-nucleon deep inelastic scattering (DIS) using a chiral doublet of baryonic sources with explicit symmetry breaking, in a slice of AdS$_5$ with both a hard and soft wall. We explicitly derive the direct and transition form factors for the vector and axial-vector currents for the holographic dual of a proton and neutron. We use them to derive the s-channel structure functions for neutrino and anti-neutrino scattering on a proton and neutron in bulk. The t-channel contributions stemming from the Pomeron and Reggeon exchanges are also evaluated ex…
Origin of the nucleon gravitational form factor $B_N(t)$: Exposition in light-front holographic QCD
University of Science and Technology of China（中国科学技术大学）；Indian Institute of Technology Kanpur（坎普尔印度理工学院）；Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所）；School of Nuclear Science and Technology, University of Chinese Academy of Sciences（中国科学院大学核科学与技术学院）
We derive a two-parameter formula for the electromagnetic form factors of the nucleon described as an instanton by "integrating out" all KK modes other than the lowest mesons from the infinite-tower of vector mesons in holographic QCD while preserving hidden local symmetry for the resultant vector fields. With only two parameters, the proton Sachs form factors can be fit surprisingly well to the available experimental data for momentum transfers $Q^2\lsim 0.5$ GeV$^2$ with $χ^2$/dof $\lsim 2$. We interpret this agreement as indicating the importance of an infinite tower in the soliton structur…
In the framework of constituent quark model, the effect of hidden color channels on the nucleon-nucleon ($NN$) interaction is studied. By adjusting the color confinement strength between the hidden color channels and color singlet channels and/or between the hidden color channels and hidden color channels, the experimental data of $S$ to $I$ partial-wave phase shifts of $NN$ scattering can be fitted well. The results show that the hidden color channel coupling might be important in producing the intermediate-range attraction of $NN$ interaction. The deuteron properties and dibaryon candidates …
We analyze the decay modes of the three $[\frac 12\frac 12^-]_{S=0,1}$ and $[\frac 12\frac 32^-]_{S=1}$ non-strange pentaquarks with hidden charm and bottom, predicted by holographic QCD in the heavy quark limit. In leading order, the pentaquarks %are composed of heavy-light mesons in bulk bound to an instanton core. They are degenerate and stable by heavy quark symmetry. At next to leading order, the spin interactions lift the degeneracy and cause the pentaquarks to decay. We show that the open charm (bottom) decay modes dwarf the hidden charm (bottom) ones, with total widths that are consist…
We investigate the hadron-hadron total cross sections at high energies in the framework of holographic QCD. In our model setup, the involved strong interaction is described by the Brower-Polchinski-Strassler-Tan Pomeron exchange kernel, and the two form factors are obtained from the bottom-up AdS/QCD models. We show that the resulting nucleon-nucleon total cross section is consistent with the experimental data recently measured by the TOTEM collaboration at the LHC. As examples to see the general versatility of the model, we also present our analysis on the pion-nucleon and pion-pion cases, wh…
The D-term is one of the conserved charges of hadrons defined as the forward limit of the gravitational form factor $D(t)$. We calculate the nucleon's D-term in a holographic QCD model in which the nucleon is described as a soliton in five dimensions. We show that the form factor $D(t)$ is saturated by the exchanges of infinitely many $0^{++}$ and $2^{++}$ glueballs dual to transverse-traceless metric fluctuations on the Wick rotated AdS$_7$ black hole geometry. We refer to this phenomenon as `glueball dominance', in perfect analogy to the vector meson dominance of the electromagnetic form fac…
We use light-front Holography to estimate the valence quark and the meson cloud contributions to the nucleon axial form factor. The free couplings of the holographic model are determined by the empirical data and by the information extracted from lattice QCD. The holographic model provides a good description of the empirical data when we consider a meson cloud mixture of about 30\% in the physical nucleon state. The estimate of the valence quark contribution to the nucleon axial form factor compares well with the lattice QCD data for small pion masses. Our estimate of the meson cloud contribut…
We analyze static properties of nucleons in the two flavor holographic QCD model of Sakai and Sugimoto described effectively by a five-dimensional U(2) Yang-Mills theory with the Chern-Simons term on a curved background. The baryons are represented in this model as a soliton, which at a time slice is approximately the BPST instanton with a fixed size. First, we construct a chiral current in four dimensions from the Noether current of local gauge transformations which are non-vanishing on the boundaries of the extra dimension. We examine this chiral current for nucleons with quantized collectiv…
We discuss gauge mediation in the case where the hidden sector is strongly coupled but, via the gauge-gravity correspondence, admits a weakly-coupled description in terms of a warped higher-dimensional spacetime. In this framework, known as holographic gauge mediation, the visible-sector gauge group is realized in the gravitational description by probe D-branes and the non-supersymmetric state by normalizable perturbations to the geometry. Using the formalism of general gauge mediation, supersymmetry-breaking soft terms in the visible sector can be related to the two-point functions of the hid…
The infinite tower of vector mesons encoded in holographic dual QCD bring drastic changes to the soliton structure of the nucleon. The nucleon is given by a point-like instanton in 5D surrounded by a vector meson cloud with the vector dominance restored by the infinite tower. I discuss the possible relevance of this structure in hot and dense hadronic matter.
We develop a previously proposed gauge-invariant method to integrate out infinite tower of Kaluza-Klein (KK) modes of vector and axialvector mesons in a class of models of holographic QCD (HQCD). The HQCD is reduced by our method to the chiral perturbation theory with the hidden local symmetry (HLS) having only the lowest KK mode identified as the HLS gauge boson. We take the Sakai-Sugimoto model as a concrete HQCD, and completely determine the ${\cal O} (p^4)$ terms as well as the ${\cal O}(p^2)$ terms from the DBI part and the anomaly-related (intrinsic parity odd) gauge-invariant terms from…
The diffractive photoproduction of $J/Ψ$ on a nucleon, is mostly due to gluonic exchanges at all $\sqrt{s}$. In holographic QCD (large number of colors and strong $^\prime$t Hooft coupling), these exchanges are captured by gravitons near threshold, and their Reggeized Pomeron form asymptotically. We revisit our holographic analysis of the A and D gravitational form factors in light of the new lattice data, and use them to refine our predictions for the photoproduction of $J/Ψ$ near threshold, and the comparison to the GlueX data. We use these results to estimate the scalar and mass radii of th…
The superconformal algebraic approach to hadronic physics is used to construct a semiclassical effective theory for nucleons which incorporates essential nonperturbative dynamical features, such as the emergence of a confining scale and the Regge resonance spectrum. Relativistic bound-state equations for nucleons follow from the extension of superconformal quantum mechanics to the light front and its holographic embedding in a higher dimensional gravity theory. Superconformal algebra has been used elsewhere to describe the connections between the light mesons and baryons, but in the present co…
The analysis on the hadron-hadron scattering at high energies in the framework of holographic QCD is presented. Combining the Pomeron exchange kernel and the hadron-Pomeron couplings which are obtained from the bottom-up AdS/QCD models, we calculate the total cross sections. Our calculation for the nucleon-nucleon scattering is consistent with the experimental data including the recent ones measured by the TOTEM collaboration at the LHC. Within the framework, one can consider other processes involving other hadrons. As examples to show this feature of the model, the resulting total cross secti…
We present our analysis on high energy hadron-hadron scattering in the framework of the holographic QCD. Combining the Brower-Polchinski-Strassler-Tan Pomeron exchange kernel and gravitational form factors of the involved hadrons which are obtained by using the bottom-up AdS/QCD models in the five-dimensional AdS space, we calculate the total cross sections at high energies. We show that our calculations for the nucleon-nucleon scattering agree with the experimental data including the recent ones taken by the TOTEM collaboration at the LHC. The present framework is applicable to any high energ…
In the holographic model of QCD, baryons are chiral solitons sourced by D4 flavor instantons in bulk of size 1/\sqrtλ with λ=g^2*N_c. Using the ADHM construction we explicit the exact two-instanton solution in bulk. We use it to construct the core NN potential to order N_c/λ. The core sources meson fields to order \sqrt{N_c/λ} which are shown to contribute to the NN interaction to order N_c/λ. In holographic QCD, the NN interaction splits into a small core and a large cloud contribution in line with meson exchange models. The core part of the interaction is repulsive in the central, spin and t…
We overview a holographic QCD based on the D4-D8 string theory model, with emphasis on baryons and nucleon-meson interactions thereof. Baryons are realized as holographic images of Skyrmions, but with much qualitative changes. This allows us to derive, without adjustable parameters, couplings of baryons to the entire tower of spin one mesons and also to pseudoscalar mesons. We find some surprisingly good match against empirical values for nucleons, in particular. Tensor couplings to all axial-vectors and iso-singlet vectors all vanish, while, for $ρ$ mesons, tensor couplings are found to be do…
We present in this talk a recent investigation on a unified approach within the framework of a hard-wall model of AdS/QCD. We first study a theoretical inconsistency in existing models. In order to remove this inconsistency, we propose a unified approach in which the mesons and the nucleons are treated on the same footing, the same infrared (IR) cutoff being employed in both fermionic and bosonic sectors. We also suggest a possible way of improving the model by introducing a five-dimensional anomalous dimension.
Baryonic matter is studied in the Skyrme model by taking into account the roles of $π,$ $ρ$, and $ω$ mesons through the hidden local symmetry up to $\mathcal{O}(p^4)$ terms including the homogeneous Wess-Zumino (hWZ) terms. Using the master formulas for the low energy constants derived from holographic QCD models the skyrmion matter properties can be quantitatively calculated with the input values of the pion decay constant $f_π$ and the vector meson mass $m_ρ^{}$. We find that the hWZ terms are responsible for the repulsive interactions of the $ω$ meson. In addition, the self-consistently inc…
We present a comprehensive analysis of the spacelike nucleon electromagnetic form factors and their flavor decomposition within the framework of light-front holographic QCD. We show that the inclusion of the higher Fock components $\ket {qqqq\bar{q}}$ has a significant effect on the spin-flip elastic Pauli form factor and almost zero effect on the spin-conserving Dirac form factor. We present light-front holographic QCD results for the proton and neutron form factors at any momentum transfer range, including asymptotic predictions, and show that our results agree with the available experimenta…
We construct spin-improved holographic light front wavefunctions for the nucleons (viewed as quark-diquark systems) and use them to successfully predict their electromagnetic Sachs form factors, their electromagnetic charge radii, as well as the axial form factor, charge and radius of the proton. The confinement scale is the universal mass scale of light-front holography, previously extracted from spectroscopic data for light hadrons. With the Dirac and Pauli form factors normalized using the quark counting rules and the measured anomalous magnetic moments respectively, the masses of the quark…
We briefly review and expand our recent analysis for all three invariant A,B,D gravitational form factors of the nucleon in holographic QCD. They compare well to the gluonic gravitational form factors recently measured using lattice QCD simulations. The holographic A-term is fixed by the tensor $T=2^{++}$ (graviton) Regge trajectory, and the D-term by the difference between the tensor $T=2^{++}$ (graviton) and scalar $S=0^{++}$ (dilaton) Regge trajectories. The B-term is null in the absence of a tensor coupling to a Dirac fermion in bulk. A first measurement of the tensor form factor A-term is…
We study a self-bound dense object in the hard wall model. We consider a spherically symmetric dense object which is characterized by its radial density distribution and non-uniform but spherically symmetric chiral condensate. For this we analytically solve the partial differential equations in the hard wall model and read off the radial coordinate dependence of the density and chiral condensate according to the AdS/CFT correspondence. We then attempt to describe nucleon density profiles of a few nuclei within our framework and observe that the confinement scale changes from a free nucleon to …
In this paper, minimal coupling constants of meson-$Δ$ baryon and meson-nucleon to $Δ$ baryon transition have been investigated in the AdS/QCD soft-wall model at finite temperature limits. Initially, the right and left profile functions of $Δ$ baryons have been calculated using the Rarita-Schwinger field in this model. After this, coupling constants have been written by taking into account the profile functions of thermal hadrons according to the zero-temperature case. Then, the temperature dependence graphs are plotted for strong couplings $g_{ρΔΔ}(T)$, $g_{a_{1} ΔΔ}(T)$ and $g_{ρN Δ}(T)$. As…
In this manuscript, a unified approach to hadron physics from holographic point of view is described. After introduction of a general setup for meson-nucleon system based on the bottom-up approach of QCD (AdS/QCD), as an illustration, we specifically examine meson-nucleon couplings. This is an example of the notion we call "holographic unification" in hadron physics.
By adopting the nonlinear realization of chiral symmetry, a holographic model for the baryon octet is proposed. The mass spectra of the baryon octet and their low-lying excited states are calculated, which show good consistency with experiments. The couplings of pion to nucleons are derived in two gauges and are shown to be equivalent with each other. It also shows that only derivative couplings of pion to nucleons appear in this holographic model. The coupling constant is then calculated.
We develop a previously proposed gauge-invariant method to integrate out infinite towers of vector and axialvector mesons arising as Kaluza-Klein (KK) modes in a class of holographic models of QCD (HQCD). We demonstrate that HQCD can be reduced to the chiral perturbation theory (ChPT) with the hidden local symmetry (HLS) (so-called HLS-ChPT) having only the lowest KK mode identified as the HLS gauge boson, and the Nambu-Goldstone bosons. The ${\cal O} (p^4)$ terms in the HLS-ChPT are completely determined by integrating out infinite towers of vector/axialvector mesons in HQCD: Effects of highe…
We present analyses on nucleon structure functions at the small Bjorken-$x$ in the framework of holographic QCD. In this study, we improve the description of the target nucleon in the current setup of the holographic model by introducing a soft-wall AdS/QCD model, in which the AdS geometry is smoothly cut off at IR. Combining the improved Pomeron-nucleon coupling and the wave function of the 5D U(1) vector field with the BPST Pomeron exchange kernel, then we obtain the structure functions. Here we focus on the nonperturbative kinematical region, where $10^{-6} \leq x \leq 10^{-2}$ and $0.1 \le…
We present a study of flavor structures of transverse charge and anomalous magnetization densities for both unpolarized and transversely polarized nucleons. We consider two different models for the electromagnetic form factors in holographic QCD. The flavor form factors are obtained by decomposing the Dirac and Pauli form factors for nucleons using the charge and isospin symmetry. The results are compared with two standard phenomenological parametrizations.
Holographic soft-wall model is successful in the phenomenology of hadrons. Here with the use of generalized parton distributions (GPDs) obtained from AdS/QCD, perturbative effects are entered into the formalism. Perturbations are incorporated in the formalism through the evolution of GPDs according to the DGLAP like equations. Evolved proton GPDs are compared with a phenomenological model to show that we can get good improvements of the holographic model. It seems that combining the holographic soft-wall model with perturbative effects to some extent, gives the correct physics of GPDs.
In this talk we discuss the formation of exotic hadrons with hidden charm arising from three-body interactions. To be more specific, in the strangeness sector, we predict the existence of a mesonic state, $K^*(4307)$, which is dynamically generated from the three-body interactions of the $KD\bar{D}^*$ system, has mass around $4307$ MeV and quantum numbers $I(J^P) = 1/2\,(1^-)$. In the baryonic sector, we predict the existence of $N^*$ states, which are generated from the three-body interactions of the $ND\bar{D}^*$ system, with masses around $4400\sim 4600$ MeV, widths of $2\sim 20$ MeV and po…
We compute nuclear force in a holographic model of QCD on the basis of a D4-D8 brane configuration in type IIA string theory. Repulsive core of nucleons is quite important in nuclear physics, but its origin has not been well-understood in strongly-coupled QCD. We find that string theory via gauge/string duality deduces this repulsive core at short distance between nucleons. Since baryons in the model are realized as solitons given by Yang-Mills instanton configuration on flavor D8-branes, ADHM construction of two instantons probes well the nucleon interaction at short scale, which provides the…
We revisit the electromagnetic form factors of the proton and neutron in the original-minimal soft-wall holographic QCD, which has only two parameters, i.e., the mass scale $κ$ and the twist parameter of the nucleon $τ$. We first fix $τ=3$ by the hard scattering rule, and extract $κ=0.402~\text{GeV}$ from the world data (including the Mainz A1 data) of the Sachs magnetic form factor of the proton $G_M^p$. We then predict among others, the charge radius of the proton to be $\bf{r_{p}=0.831\,\pm\,0.008\,\,\text{fm}}$, in perfect agreement with the recent charge radius of the proton measured by t…
We propose a simple prescription for including low-energy weak-interactions into the framework of holographic QCD, based on the standard AdS/CFT dictionary of double-trace deformations. As our proposal enables us to calculate various electro-weak observables involving strongly coupled QCD, it opens a new perspective on phenomenological applications of holographic QCD. We illustrate efficiency and usefulness of our method by performing a few exemplar calculations; neutron beta decay, charged pion weak decay, and meson-nucleon parity non-conserving (PNC) couplings. The idea is general enough to …
Nuclear effects in deep inelastic scattering at low$-x$ are phenomenologically described changing the typical dynamical and/or kinematical scales characterizing the free nucleon case. In a holographic approach, this rescaling is an analytical property of the computed structure function $F_2(x,Q^2)$. This function is given by the sum of a conformal term and of a contribution due to quark confinement, depending on IR hard-wall parameter $z_0$ and on the mean square distances, related to a parameter $Q^\prime$, among quarks and gluons in the target. The holographic structure function per nucleon …
In this presentation we discuss the generation of hadrons with an exotic quark content and hidden charm emerging from three-body interactions. To be more specific, we have studied the $KD\bar{D}^*/K\bar D D^*$ and $ND\bar{D}^*/N\bar{D}D^*$ systems and predicted states generated from the respective three-body dynamics. In the case of the $KD\bar{D}^*/K\bar D D^*$ system we predict the formation of a meson state with mass around $4307$ MeV and quantum numbers $I(J^P) = 1/2(1^-)$, $K^*(4307)$, and from the study of the $ND\bar{D}^*/N\bar{D}D^*$ system we found $N^*$ states with masses in the rang…
The phenomenological sum-rule-based approach is used to discuss the quark composition dependence of some static electroweak characteristics of baryons.The role of nonvalence degrees of freedom (the sea partons and/or peripheral meson currents) is shown to be important to select and make use of the relevant symmetry parametrization of baryon observables.The implications of the baryon magnetic moment analysis for estimation of the $Δ$q values of the spin-dependent DIS on nucleons, the contribution of hidden strangeness to the nucleon magnetic moment and to the quark-line-rule violating $ϕπ$ - pr…
We study compact star made of degenerate hidden sector nucleons which will be a candidate for cold dark matter. A hidden sector like QCD is considered, and as the low energy effective theory we take (hidden sector) $ SU(2) $ chiral sigma model including hidden sector vector meson. With the mean field approximation, we find that one can treat the equation of state (EOS) of our model analytically by introducing a variable which depends on the Fermi momentum. The EOS is specified by the two parameters $ C'_{/sigma} $,$ C'_{/omega} $, and we discuss how these parameters affect on the mass-radius r…
We study nucleon structure with positive and negative parities using a parity doublet model endowed with hidden local symmetry (HLS) with the objective to probe dense baryonic matter. The model -- that we shall refer to as "PDHLS model" for short -- allows a chiral-invariant mass of the nucleons unconnected to spontaneously broken chiral symmetry which comes out to be m_0 ~ 200 MeV at tree level from fitting to the decay width of the parity doubler, N(1535), to nucleon-pion and nucleon axial coupling g_A=1.267. The presence of a substantial m_0 that remains non-vanishing at chiral restoration …
We study the energy dispersions of holographic light mesons and their decay constants on dense nuclear medium. As the spatial momenta of mesons along the boundary direction increase, both observables of the mesons not only increase but also split according to the isospin charges. The decay constant of the negative meson is more large than that of the positive meson of the same type due to the chemical potentials of the background nucleons.
In a simple holographic model for QCD in which the Chern-Simons term is incorporated to take into account the QCD chiral anomaly, we show that baryons arise as stable solitons which are the 5D analogs of 4D skyrmions. Contrary to 4D skyrmions and previously considered holographic scenarios, these solitons have sizes larger than the inverse cut-off of the model, and therefore they are predictable within our effective field theory approach. We perform a numerical determination of several static properties of the nucleons and find a satisfactory agreement with data. We also calculate the amplitud…
