This conference aims at bringing together people from various areas of physics to learn new methods, get new inspiration and finding new interesting problems to work on. Low energy physics has faced the problems of strong coupling in the QCD sector of the standard model, since the standard model was established as the correct fundamental theory of physics. Almost all nuclear physics models are phenomenological and data-driven and do not "know anything" about QCD, directly. Holographic methods have been developed in many groups in the past couple of decades, but often in parallel with nuclear physicists' work with little communication between the communities. The chiral Lagrangian has a geometric description of nuclei in terms of Skyrmions, which are instantons in holographic models, like the Witten-Sakai-Sugimoto model and this approach, in principle, fixes all low-energy constants (LEC) in nuclear physics. An alternative and possibly equivalent way to fix the LECs is by assuming hidden local symmetry. The extraction of the nucleon-nucleon potential from such a model has been nontrivial and has only been done successfully very recently. Hopefully, this conference will provide an atmosphere for discussion of many topics, and lead to new ideas and methods.
Eric Sere (法国巴黎第九大学)
I will introduce some simply constructed holographic QCD models with good properties which are consistent with low-energy QCD, including a consistent description for the mass spectra of light hadrons, the chiral phase transition and also the equations of state of QCD that indicate the deconfinement properties.Stefano Bolognesi（意大利比萨大学） - Holographic Nuclear Physics with Massive Quarks and near-BPS limits
We discuss nuclear physics in the Witten-Sakai-Sugimoto model, in the limit of large number Nc of colors, with the addition of a finite mass for the quarks. In the large 't Hooft coupling limit the individual baryons are described by classical solitons whose size is much smaller than the typical distance at which they settle in a nuclear bound state. Thus we can use the linear approximation to compute the interaction potential and provide a natural description for bound states. One of the interesting features that we find is that holographic nuclear physics provides a natural description for lightly bound states when λ is large. We find the classical geometry of nuclear bound states and the finite density case. In the, less explored, small 't Hooft coupling limit the model reproduces the so called BPS Skyrme model. Binding energies are still small, but for a reason quite different from the previous limit of large 't Hooft coupling.Eric Sere (法国巴黎第九大学) - Dirac-Coulomb operators: what is the optimal charge distribution?
This talk is based on joint work with M.J. Esteban and M. Lewin. Consider an electron moving in the attractive Coulomb potential generated by a positive finite measure representing an external charge density. If the total charge is fixed, it is well known that the lowest eigenvalue of the corresponding Schrödinger operator is minimized when the measure is a delta. We investigate the conjecture that the same holds for the relativistic Dirac-Coulomb operator. First we give conditions ensuring that this operator has a natural self-adjoint realisation and that its eigenvalues are given by min-max formulas. Then we define a critical charge such that, if the total charge is fixed below it, then there exists a measure minimising the first eigenvalue of the Dirac-Coulomb operator. Thanks to a new unique continuation principle for Dirac operators, we find that this optimal measure concentrates on a compact set of Lebesgue measure zero.张瑞凤（河南大学） - Existence of static BPS bimagnetic monopoles
In this talk, we study bimagnetic monopoles which are topological solitons in three space dimensions. We prove the existence and uniqueness of a static and radially symmetric BPS bimagnetic monopoles formulated and presented in a recent study of Bazeia, Marques and Menezes. Our method is based on a dynamical shooting approach depending on two shooting parameters which provides an effective framework for constructing the BPS equations in magnetic core and magnetic shell. Furthermore, we obtain the relation between the BPS and non-BPS bimagnetic monopoles solutions and properties of static bimagnetic monopoles solutions.田雨（中国科学院大学） - Solitons and non-equilibrium physics in holography
Solitons play an important role in superfluid instability and dynamics, including quantum turbulence. Moreover, a superfluid soliton is itself unstable, which leads to interesting non-equilibrium physics, like dynamic phase transition. I will introduce those aspects of solitons in this talk, in particular from a holographic point of view.Lorenzo Bartolini（河南大学） - Holographic Baryons: θ and quark mass perturbations
Baryons are realized as solitonic configurations in holographic QCD: in the model of Witten-Sakai-Sugimoto (WSS), they can be approximated as Instantons, with corrections to this approximation arising from curved space and deformations to the action. In this talk, we consider an interesting deformation of the WSS model that accounts for the presence of quark mass. From QCD we know that nonvanishing quark masses can lead to the presence of a physically meaningful θ parameter in the theory: we show how the physics of the θ angle is reproduced from the WSS model and its effects on baryons, in particular how it produces nonvanishing electric dipole moments (EDMs) for the nucleons and the deuteron bound state.
Finally, we show how the introduction of a difference in up and down quark masses (which explicitly breaks isospin symmetry) produces a pattern of splittings in the masses of baryons.
To demonstrate the Goldstone nature of neutral pions, we construct the corresponding generalized Nambu-Goldstone pion, which emerges as a linear combination of the conventional chiral condensate vacuum π0 and the tensor condensate vacuum π0. We analytically showed that any finite mixture will reduce the mass of π0.Derek Harland（英国利兹大学） - From skyrmions to the nucleon-nucleon potential
The Skyrme model is a low-energy effective theory for QCD in which nuclei are modelled by topological solitons, known as skyrmions. In this talk I will describe a new approach to calculating the nucleon-nucleon potential using skyrmions. This problem has a long history, and early efforts struggled to reproduce important features of the potential such as the spin-orbit interaction. Our new approach overcomes these difficulties and leads to a more realistic nucleon-nucleon potential. This opens up the possibility of studying larger systems of nuclei and their interactions using skyrmions.赵行波（中国科学院近代物理研究所） - Light-front approach to the pion and nucleon structure
The light front is a three-dimensional hyper-surface tangential to the light cone. Field theories quantized on the light front exhibit unique advantages in studying the structure of relativistic bound states. In this talk I will introduce a nonperturbative approach to relativistic bound states based on the light front quantization and Hamiltonian formalism of quantum field theory. I will illustrate this method through the applications to the pion and the nucleon systems. I will show the resulting observables characterizing the structure of these systems, such as the form factors, parton distribution functions, generalized parton distribution functions and transverse-momentum-dependent parton distribution functions, and make comparison with those from other approaches and the experimental data. Finally I will discuss our preliminary results on the gluon distribution in these systems.李丹凝（暨南大学） - Thermal properties of light mesons and chiral phase transition from holography
The thermal properties of light mesons, including the temperature dependence of their masses (both screening and pole masses) and thermal widths, are studied in a two-flavor (Nf = 2) soft-wall AdS/QCD model. By solving the spatial correlation functions, we extract the screening masses (mscr) from their poles. The screening masses of pseudo-scalar, axial-vector mesons increase (almost) monotonically with the temperature, while the screening masses of scalar and vector mesons decrease at low temperatures and increase at high temperatures. Besides, the pole masses mpole and thermal widths Γ are worked out from the temporal correlation functions and the corresponding spectral functions. The results indicate that the pole masses have local minimums at low temperatures and grow at high temperatures. The thermal widths grow rapidly above the chiral crossover temperature Tcp, indicating the dissociation of mesons at high temperatures. Furthermore, degeneration of chiral partners (pion and σ mesons, ρ and a1) above Tcp are observed both from screening masses and pole masses, revealing the restoration of chiral symmetry at the spectral level. Finally, we verify numerically that the spectral functions in the temporal regime are strongly related to the quasi-normal modes with complex frequencies ω0 = mpole - iΓ/2.张宏宝（北京师范大学） - Thermal Equilibrium of charged fluids in electromagnetic fields and gravitational fields
In this talk, I will revisit the condition for the thermal equilibrium of charged fluids in electromagnetic fields and gravitational fields, where the Tolman law is derived by the maximal entropy principle from scratch. As a warm up, I will first address the case with the electromagnetic fields and gravitational fields fixed as background fields. After this, I will move onto the nontrivial case by taking into account the backreaction of charged fluids onto the electromagnetic fields and gravitational fields through Maxwell equation and Einstein equation. I will conclude my talk with another perspective into the presented derivation.吴超（安徽大学） - Second order transport coefficients of the strongly coupled non-conformal relativistic fluids from Dp-branes
We will mainly talk about the calculations of the dynamical second order transport coefficients of strongly coupled, non-conformal relativistic fluids that are dual to Dp-branes via the fluid/gravity correspondence. It will proceed in the following steps. First, we will introduce the related background knowledge about the second order relativistic fluids and look back on the popular methods and known results of the holographic studies on non-conformal relativistic fluids. Then, we will illustrate the fluid/gravity correspondence in non-conformal regime by the example of D4-brane with one world-volume direction compactified. In the next step, the cases of other (compactified) Dp-branes will be discussed. At last, we will give some remarks and comments on the results and mention some future directions.