We study baryons as Skyrmions in holographic QCD with D4/D8/D8-bar multi-D brane system in type IIA superstring theory, and also in the non-linear sigma model with hidden local symmetry (HLS). Comparing these two models, we find that the extra-dimension and its nontrivial curvature can largely change the role of (axial) vector mesons for baryons in four-dimensional space-time. In the HLS approach, the rho-meson field as a massive Yang-Mills field has a singular configuration in Skyrmion, which gives a strong repulsion for the baryon as a stabilizer. When a_1 meson is added in this approach, the stability of Skyrmion is lost by the cancellation of rho and a_1 contributions. On the contrary, in holographic QCD, the rho-meson field does not appear as a massive Yang-Mills field due to the extra-dimension and its nontrivial curvature. We show that the rho-meson field has a regular configuration in Skyrmion, which gives a weak attraction for the baryon in holographic QCD. We argue that Skyrmion with pi, rho and a_1 mesons become stable due to the curved extra-dimension and also the presence of the Skyrme term in holographic QCD.
From this result, we also discuss the features of our truncated-resonance analysis on baryon properties with pi and rho mesons below the cutoff scale M_KK about 1GeV in holographic QCD, which is compared with other 5D instanton analysis.
We introduce a novel Skyrme-like conserved current in the effective theory of pions and vector mesons based on the idea of hidden local symmetry. The associated charge is equivalent to the skyrmion charge for any smooth configuration. In addition, there exist singular configurations that can be identified as N_f=1 baryons charged under the new symmetry. Under this identification, the vector mesons play the role of the Chern-Simons vector fields living on the quantum Hall droplet that forms the N_f=1 baryon. We propose that this current is the correct effective expression for the baryon current…
7D Randall-Sundrum cosmology, brane-bulk energy exchange and holography
我们讨论了7 D Randall-Sundrum（RS）引力系统的宇宙学意义和全息对偶理论。在7维重力场的一侧加入一般物质，我们研究了由膜-体能量交换参数的非零值所推断的宇宙演化。这种分析是实现详细的内部空间演化的特定假设，包括分析考虑和数值结果。对偶理论，然后构建，利用全息重整化过程。由此产生的重整化6D CFT是异常的，并耦合到6D重力加高阶修正。对膜进行了临界点分析。最后，我们勾勒出两个双重描述之间的比较。此外，我们推广的AdS/CFT对偶理论的非共形和相互作用的情况下，有关的能量交换参数的体积重力描述隐藏和可见部门之间的新的相互作用。
I survey recent developments in hadron physics which follow from the application of superconformal quantum mechanics and light-front holography. This includes new insights into the physics of color confinement, chiral symmetry, the spectroscopy and dynamics of hadrons, as well as surprising supersymmetric relations between the masses of mesons, baryons, and tetraquarks. I also will discuss some novel features of QCD -- such as color transparency, hidden color, and asymmetric intrinsic heavy-quark phenomena. The elimination of renormalization scale ambiguities and the modification of QCD sum ru…
The role of rescaling (expansion or squeezing) of quantized skyrmions is studied for the spectrum of baryons beginning with nucleon and $Δ(1232)$, and with flavors strangeness, charm or beauty. The expansion of skyrmions due to the centrifugal forces has influence on the masses of baryons without flavor ($N$ and especially $Δ$). The rescaling of skyrmions has smaller influence on the spectrum of strange baryons, it is more important for the case of charm, and is crucial for baryons with beauty quantum number, where strong squeezing takes place. Two competing tendencies are clearly observed: ex…
Gerry Brown was a godfather of our hidden local symmetry (HLS) for the vector meson from the birth of the theory throughout his life. The HLS is originated from very nature of the nonlinear realization of the symmetry G based on the manifold G/H, and thus is universal to any physics based on the nonlinear realization. Here I focus on the Higgs Lagrangian of the Standard Model (SM), which is shown to be equivalent to the nonlinear sigma model based on G/H= SU(2)_L x SU(2)_R/SU(2)_V with additional symmetry, the nonlinearly realized scale symmetry. Then the SM does have a dynamical gauge boson o…
In 2013, Balasubramanian presented a 5+1 dimensional holographic toy model that allows for an exact solution to Einstein's equations in the bulk in which the isometries of $AdS_5$ appear to be broken to an isometry group describing a discretely scale invariant and Poincaré invariant setup [arXiv:1301.6653]. In this paper, we investigate this solution in more detail. By analytically solving the Killing equations, we prove that the full $AdS_5$ isometry group is still present, although in a somewhat hidden way. We will also comment on the prospects of finding other holographic bottom up toy mode…
Braneworld theories are often described as low-energy effective field theories (EFTs) featuring an infinitely thin 3-brane and 4D fields exactly localized on it. We investigate whether an exactly localized braneworld can arise as a limit of a theory of 5D fields. Using a holographic formalism we argue that such limit does not exist in the presence of gravity, therefore implying a discontinuity in the space of EFTs. We then present specific models involving exactly localized fields in which inconsistencies appear, which are solved when fields are taken as quasilocalized. Part of our arguments r…
The Standard Model (SM) Higgs Lagrangian is straightforwardly rewritten into the {\it scale-invariant} nonlinear sigma model $G/H=[SU(2)_L \times SU(2)_R]/SU(2)_{V}\simeq O(4)/O(3)$, with the (approximate) scale symmetry realized nonlinearly by the (pseudo) dilaton ($=$ SM Higgs). It is further gauge equivalent to that having the symmetry $O(4)_{\rm global}\times O(3)_{\rm local}$, with $O(3)_{\rm local}$ being the Hidden Local Symmetry (HLS). In the large $N$ limit of the scale-invariant version of the Grassmannian model $G/H=O(N)/[O(N-3)\times O(3)] $ $\simeq O(N)_{\rm global}\times [O(N-3)\…
The nonextremal Kerr black holes have been considered to be holographically dual to two-dimensional (2D) conformal field theories (CFTs). In this paper, we extend the holography to the case of an asymptotically anti--de Sitter (AdS) rotating charged black holes in $f$($T$) gravity, where $f(T) = T + αT^2$, where $α$ is a constant. We find that the scalar wave radial equation at the near-horizon region implies the existence of the 2D conformal symmetries. We note that the $2π$ identification of the azimuthal angle $ϕ$ in the black hole line element, corresponds to a spontaneous breaking of the …
The QCD light-front (LF) Hamiltonian equation H_{LF}|Ψ> = M^2 |Ψ> derived from quantization at fixed LF time τ= t+z/c provides a causal, frame-independent, method for computing hadron spectroscopy as well as dynamical observables such as structure functions, transverse momentum distributions, and distribution amplitudes. The LF formalism also leads to novel nuclear phenomena, such as "hidden color", "color transparency", "nuclear-bound quarkonium" and the shadowing and antishadowing of nuclear structure functions. For example, there are five distinct color-singlet Fock state representations of…
