| Speaker | Title | Abstract |
| Takashi Ezoe | Kaon-Nucleon interaction in the Skyrme model | We study the (anti)kaon nucleon interaction in the Skyrme model. The kaon field is introduced as a fluctuation around the rotating Skyrmion for the nucleon. As an extension of our previous work, we study scattering states and examine phase shifts in various kaon-nucleon channels. Then we study the interaction, where we find that it consists of central and spin-orbit components for isospin channels, I = 0, 1, with energy dependence and nonlocality. The interaction is then fitted to a Shr ?odinger equivalent local potential for s- and p-waves. (This talk is based on the following paper, arXiv:1703.01004.) |
| Gergely Fejos | Mesonic and nucleon fluctuation effects at finite baryon density | Mesonic and nucleon fluctuation effects are investigated in medium. We couple the nucleon field to the 2+1 flavor meson model and investigate the finite temperature and density behavior of the system. Somewhat contrary to earlier expectations we find that the axial anomaly tends to strengthen at finite density. At lower temperatures nucleon density fluctuations can cause a relative difference in the U_A(1) axial anomaly of about 20%. Based on details of chiral symmetry restoration it is argued that there has to be a competition between underlying QCD effects of the anomaly and fluctuations of the low energy hadronic degrees of freedom, and the fate of the U_A(1) coefficient should be decided by taking into account both effects simultaneously. |
| Philipp Gubler | Vector and axial-vector mesons in nuclear matter - recent results | In this presentation, I will summarize and discuss recent theoretical work related to vector and axial-vector mesons in nuclear matter, particularly focusing on the phi meson and the f_1(1280), their potential modifications at finite density and possible interpretations of these modifications in terms of QCD. |
| Tetsuo Hatsuda | YN and YY interactions from Lattice QCD | I review the recent progresses for baryon-baryon interactions in lattice QCD on be half of HAL QCD Collaboration |
| Koichi Hattori | QCD Kondo effect in dense quark matter | I will discuss the QCD Kondo effect which occurs in the presence of a large Fermi sphere. The QCD Kondo effect gives rise to a strong correlation between light quarks in a bulk and impurities. I will show renormalization-group analyses. |
| Wataru Horiuchi | Few-body calculations for kaonic nuclear and atomic systems | We will present our recent studies on kaonic nuclear and atomic systems with a precise few-body method, correlated Gaussian method. |
| Atsushi Hosaka | Charm hadron spectroscopy | TBA |
| Tetsuo Hyodo | Kbar N interaction and Kaonic nuclei | We show the construction of the realistic Kbar N interaction and its application to the few-body Kaonic nuclei. |
| Yoichi Ikeda | Zc(3900) from lattice QCD | I will discuss the structure of the tetraquark candidate Zc(3900) from the meson-meson coupled-channel scattering on the lattice. The Zc(3900) is experimentally reported as a peak in the pi J/psi invariant mass in the Y(4260)-->pi pi J/psi decay. To understand the nature of the Zc(3900), it is most important to extract the coupled pi J/psi - rho eta_c - anti-D D* interactions. We apply the coupled-channel HAL QCD method to the Zc(3900). The s-wave coupled-channel meson-meson potential relevant to the Zc(3900) is extracted, and scattering observables such as invariant mass spectra and the pole position of the S-matrix on the complex energy plane are calculated. Also, we calculate the decay rate of the Y(4260)-->pi pi J/psi reaction and compare with the experiments. All of our results show that the Zc(3900) is not a conventional resonance but a threshold cusp associated with the opening of the anti-D D* threshold. |
| Masahiko Iwasaki | E15 experiment | TBA |
| Yuki Kamiya | Determination of compositeness with generalized weak-binding relation | Understanding of the structure of exotic hadrons is an important topic of the current hadron physics. For a stable shallow bound state, Weinberg has derived the model-independent relation between the compositeness and the observables. To study the structure of the exotic hadrons, we focus on this model-independent determination of the compositeness. Within the framework of the nonrelativistic effective field theory, we extend the weak-binding relation to be applicable for the unstable quasibound state with including the CDD pole contribution. Finally we apply the generalized relation to Lambda(1405), f0(980) and a0(980) and discuss their internal structures from the experimental observables. |
| Kouji Kashiwa | Determination of deconfinement transition by Roberge-Weiss periodicity | In this talk, I will report recent progresses of the deconfinement transition in QCD from topological view point. We have proposed a new determination of the confinement-deconfinement transition by using the imaginary chemical potential. The imaginary chemical potential can be interpreted as the Aharonov-Bohm phase and then an analogy of the topological order suggests that the Roberge-Weiss endpoint would define the deconfinement temperature. Based on the topological property, we can construct a new quantity which describes the confinement-deconfinement transition. This quantity is defined as the integral of the quark number susceptibility along the closed loop of the dimensionless imaginary chemical potential. |
| Daisuke Kawai | rho resonance from the I=1 pipi potential in lattice QCD | The first principle calculation of hadron-hadron interaction is an important step toward the understanding of nuclear physics from QCD. The HAL QCD method is largely contributing to this purpose by making it possible to calculate nuclear potentials in lattice QCD. In this talk, we present results of pipi potentials extracted in 2+1 flavor lattice QCD at m_pi =410 MeV, using all-to-all propagators with LapH smearing. We first investigate the sink operator dependence of the I=2 pipi potential. While the potential from the smeared sink operators drastically changes it shape from the conventional one with the local sink operator, physical observables such as the scattering phase shift are unchanged as long as the next-to-leading order term is included in the smeared potential. We then extract the I=1 pipi potential with the smeared sink operator, whose scattering phase shift reproduces rho resonance. We also identify the rho pole of the S-matrix in the complex energy plane. |
| Michio Kohno | Hyperons in nuclear matter with YN and YNN interactions of ChEFT | Properties of the lambda, sigma and cascade hyperons in nuclear matter are discussed on the basis hyperon-nucleon interaction of chiral effective field theory. Effects of the three-body $Lambda$NN forces and $Lambda$NN-$Sigma$NN coupling interactions are taken into account by reducing them to effective density-dependent two-body interactions. |
| Teiji Kunihiro | Microscopic derivation of (non-)relativistic second-order hydrodynamics from Boltzmann equation | We apply the renormalization group method to derive the second-order hydrodynamic equations from the Boltzmann equation together with the microscopic expressions of all the transport coefficeints and reaxation times/lengths, the former of which coincide with those by Chapman-Enskog method, while the latter is given for the first time. We discuss the physical properties of these results in relation to the relativistic heavy-ion collisions and cold fermionic atomic gass. |
| Kenta Miyahara | Theoretical study of Lambda(1405) in Xi_c decays | In this talk, I will study a Xi_c decay reaction to obtain a new information about the Lambda(1405). The Lambda(1405) is a resonance state in the KbarN and piSigma coupled-channel amplitude. This state has been considered to be an exotic hadron, which is difficult to be described with usual quark models.The Lambda(1405) can be seen in the piSigma scattering amplitudes, T_{KbarN -> piSigma} and T_{piSigma -> piSigma}. Most of existing experiments are considered to be dominated by T_{KbarN -> piSigma}. On the other hand, there is no direct data of T_{piSigma -> piSigma}, which is necessary to clarify the Lambda(1405) nature. In this work, considering the Cabibbo-Kobayashi-Maskawa coefficients, the kinematical condition, and the diquark correlation, we show that in the final state interaction of the Xi_c^0 -> K^0bar(piSigma)^0 reaction, T_{KbarN -> piSigma} is suppressed. Thus, this decay reaction is useful for the analysis of T_{piSigma -> piSigma}. We then calculate the piSigma invariant mass distribution in this decay reaction with the meson-baryon final state interaction by the coupled channel approach based on the chiral effective field theory. We find that the peak in the decay spectrum does not always correspond to the resonance, Lambda(1405), when T_{KbarN -> piSigma} is suppressed. |
| Takaya Miyamoto | Lambda_c N interaction from lattice QCD and Lambda_c nuclei | A study of interactions between charmed baryons and a nucleon(N) is important to investigate the role of a charm quark in hadronic matters. The interaction of Lambda_c N system were first investigated for the charmed baryon interactions at more than 40 years ago. Although the Lambda_c N interaction has been studied for a long time, its detailed properties are inconclusive due to lack of experimental data. A new approach that investigates baryon-baryon interactions from lattice QCD has been proposed and developed extensively by the HAL QCD Collaboration. On the basis of the HAL QCD method, we investigate the Lambda_c N interaction from lattice QCD. We calculate the central potential in 1S0 channel as well as the central and the tensor potentials in 3S1-3D1 channel. In order to investigate the nature of Lambda_c N interaction, we calculate the phase shifts and the scattering lengths from obtained potentials. Furthermore, we also calculate the folding-! potentials to investigate the possibility of Lambda_c nuclei. In this talk, we present the current status of our research project on Lambda_c N interactions as well as Lambda_c nuclei. |
| Kenji Morita | YN and YY interactions from heavy-ion collisions | I will talk about recent development in two-particle momentum correlation technique for relativistic heavy-ion collisions. Particular emphasis will be put on hyperon-nucleon and hyperon-hyperon correlation from which their pair wise interaction can be constrained by experimental measurements. I will also discuss the importance of comparing the correlation data between difference system size to extract the strong interaction property in the presence of Coulomb interaction. |
| Takumi Muto | Interplay of kaon condensation and hyperons in nuclei and in neutron stars | We consider interplay between K^- mesons and hyperons in both nuclei and neutron stars, and clarify a possible coexistence of them in multi-strangeness system. We base our framework on the relativistic mean-field theory for baryon (B)-B interaction, coupled with the effective chiral Lagrangian incorporating K-B and nonlinear K-K interactions. We discuss similarity and difference between kaon dynamics in nuclei and that in neutron stars. |
| Chiho Nonaka | Scalar mesons in lattice QCD | Since f_0(600) or sigma reappeared in the 2002 edition of PDG, there has been an increasing interest in scalar mesons. However the nature of scalar mesons is still under discussion, though they are key particles in hadron physics in terms of chiral symmetry in QCD. For example, there are long standing controversies on their structure. The candidates of it are a usual q-qbar meson, four quark states, pi-pi or K-Kbar molecules, glue balls and a mixed state among them. In addition, the kappa meson with I=1/2 is reported to exist with a mass about 800 MeV. The kappa meson is supposed to constitute the nonet scalar states together with the sigma meson. Our study on scalar mesons in lattice QCD started from investigation of f_0(600) or sigma. We explored existence of the sigma meson as a pole in QCD, using a full lattice QCD. Then we studied the kappa meson using lattice QCD simulation in the quenched approximation. We also investigated the possible significance of four-quark state in the isosinglet scalar mesons. In this presentation, I will mainly show recent progress of our study on scalar mesons in lattice QCD; screening masses of scalar, pseudoscalar, vector and axial vector mesons at finite temperature and new results of scalar mesons using the configurations produced with domain wall fermions. |
| Akira Ohnishi | Dense matter equation of state from heavy-ion collisions and neutron stars | I discuss the implications for the equation of state of dense matter from heavy-ion collision data and neutron star observations. We have recently examined that recent observation of the negative directed flow slope at RHIC is found to suggest the EOS is soften at high densities [1]. While standard hadronic cascade models predict a positive slope of the directed flow at $sqrt{s_{NN}} < 20$ GeV, negative slopes appear when the softening effects are included by introducing the attractive orbit collisions. Baryon densities probed in this energy range are 5-10 $ho_0$, then the data may suggest the existence of the QCD phase transition. By comparison, the discovery of massive neutron stars around two solar mass implies the EOS needs to be stiff enough, and the neutron radius observation tells us that the nuclear symmetry energy is not very large at high densities. We are now trying to obtain satisfying the requirements from neutron stars and explaining the finite nuclear prop erties. In the presentation, I report our recent activities shown above, and discuss how can we understand heavy-ion data and neutron stars consistently. |
| Makoto Oka | Hidden-charm Pentaquarks in a Constitutent Quark Picture | TBA |
| Sho Ozaki | QCD Kondo effect - from perturbative to non-perturbative - | In this presentation, I will talk about QCD Kondo effect from perturbative and non-perturbative approaches. Recently, we proposed a new type of Kondo effect realized in high density quark matter with a heavy quark impurity. We call it QCD Kondo effect. We have firstly analyzed QCD Kondo effect from perturbative RG approach. By using the same method, we also found QCD Kondo effect induced by strong magnetic fields. Owing to asymptotic freedom of the Kondo system, the effective coupling between a light quark near the Fermi surface and the heavy quark impurity grows as the energy scale decreases, and diverges at a certain IR scale, so-called the Kondo scale. This indicates that the system becomes non-perturbative one below the Kondo scale. In order to study IR behavior of QCD Kondo effect below the Kondo scale, we apply CFT approach as a non-perturbative method known in condensed matter physics, and successfully obtain several observables, including impurity entropy, specific heat, susceptibility and the Wilson ratio, in the vicinity of the IR fixed point. |
| Kenji Sasaki | Lattice QCD studies on baryon interactions in the strangeness -2 sector | We investigate baryon-baryon (BB) interactions via the time-dependent HAL QCD method which enables us to derive potentials from Nambu-Bethe-Salpeter (NBS) wave function simulated on the lattice. The simulations are performed with (almost) physical quark masses (Mpi=146MeV) and a huge lattice volume of La = 8.1fm. We report the latest results of BB potentials and their scattering observables in the strangeness S=-2 sector. We also discuss the fate of H-dibaryon state through the Lambda-Lambda and N-Xi coupled-channel scatterings. |
| Daisuke Satow | Transport coefficients of quark-gluon plasma in strong magnetic fields | We compute the effect of the strong magnetic field (B), which is expected to be generated in heavy ion collision, on the transport coefficients at finite temperature in magnetohydrodynamics. We use the lowest Landau level approximation, in which the 1-to-2 scattering process is kinematically allowed in contrast to the B=0 case. We find that this effect is significant in the electrical conductivity and the bulk viscosity: The contribution from the light quarks to the conductivity is much larger than that from the strange quark, in terms of the chirality conservation. By contrast, the strange quark contribution to the bulk viscosity is found to be much larger than the light quarks contribution, which can be understood from the conformal invariance. This presentation is partially based on Phys. Rev. D 94, 114032 (2016) and arXiv:1610.06839 [hep-ph]. |
| Takayasu Sekihara | Compositeness for the N* and Delta* resonances from the pi N scattering amplitude | The meson-baryon components for the N* and Delta* resonances can be investigated in terms of the compositeness, which is defined as the norm of the two-body wave function from the meson-baryon scattering amplitudes. For this purpose I first show that one can calculate the two-body wave function from the scattering amplitudes (not by the Schrodinger equation) by considering several schematic models. Then I explain my plan to evaluate N*/Delta* compositeness from the pi N scattering amplitudes, which are determined precisely in the partial wave analyses. |
| Takayasu Sekihara | On the structure observed in the in-flight 3He ( K^-, Lambda p ) n reaction at J-PARC | We theoretically investigate the origin of the peak structure around the K-pp threshold observed in the in-flight 3He(K-, Lambda p)n reaction in the recent E15 experiment at J-PARC. For this purpose, we consider two scenarios to produce the peak. One is that the Lambda(1405) is generated but it does not correlate with p, and the uncorrelated Lambda(1405)p system subsequently decays into Lambda p. The other one is that the KbarNN bound state is indeed generated and decays into Lambda p. As a result, the experimental signal is qualitatively well reproduced in the KbarNN bound scenario, definitely discarding the uncorrelated Lambda(1405)p one. |
| Daiki Suenaga | Spectral function for excited anti-D meson in nuclear matter with partial restoration of chiral symmetry | We investigate a spectral function for $¥bar{D}_0^*$ $0^+$ meson channel in nuclear matter. $¥bar{D}$ mesons are introduced as chiral partner in the chiral symmetry broken vacuum, hence they are useful to explore the partial restoration of the broken chiral symmetry in nuclear matter. We consider the linear sigma model to describe the chiral symmetry breaking. We find three peaks in the spectral function for $¥bar{D}_0^*$ meson. The first peak which corresponds to the resonance of $¥bar{D}_0^*$ meson is broadened by collisions with nucleons in medium, and the peak position shifts to lower mass due to the partial restoration of chiral symmetry as the density increases. The second peak is identified as a threshold enhancement which shows a remarkable enhancement as the density increase. The third peak is Landau damping. The obtained properties of $¥bar{D}_0^*$ meson in nuclear matter will provide useful information for experiments. |
| Hiroshi Toki | Tensor optimized antisymmetrized molecular dynamics for nuclei using bare NN interaction | TBA |
| Hidekazu Tsukiji | Early time production of the Husimi-Wehrl entropy in the Yang-Mills field from the McLerran-Venugopalan model initial conditionr | Understanding the probable early thermalization suggested for the relativistic heavy-ion collisions is still a theoretical challenge. We explore whether the entropy is created in the quantum Yang-Mills field (YM) with the realistic McLerran-Venugopalan initial condition in the semi-classical approximation, and show that the entropy is surely created within the early dynamics. We perform a numerical calculation of the Husimi-Wehrl (HW) entropy defined through the non-negative quantum distribution function called Husimi functional, a coarse-grained Wigner functional. We employ a product ansatz for the Husimi functional, which turns to lead to a 10-20 per cent over estimate. We also find comparable time scales between the entropy production and the isotropization of the pressure. |
| Wolfram Weise | Lambda-nuclear interaction and hyperon puzzle in neutron stars | Hyperon-nucleon interactions derived from chiral SU(3) effective field theory are reviewed and estimates for Lambda-NN three-body forces are presented. Brueckner theory ist then used to study in-medium properties of the Lambda hyperon in nuclear and neutron matter. It is demonstrated that the Lambda single particle potential, while consistent with the binding of hypernuclei, becomes strongly repulsive with increasing baryon densities. Possible consequences for neutron stars are discussed. It is argued that the onset for hyperon formation in the core of neutron stars is shifted to extremely high baryon densities, thus potentially resolving the so-called "hyperon puzzle". |
| Toshimitsu Yamazaki | Toward High-Density Kaonic Proton Matter (KPM) | Discussion of a hypothetical Kaonic Proton Matter (KPM), predicted by Akaishi and Yamazaki arXiv: 1610.01249, will be discussed from theoretical and experimental viewpoints. Experimental studies of precursors, such as K-K-pp, are proposed. |
| Di-Lun Yang | Side-Jumps and Collisions in Chiral Kinetic Theory from Quantum Field Theories | In recent years, chiral magnetic/vortical effects related to quantum anomalies have been intensively studied. These anomalous effects could affect the transport properties of quark gluon plasmas in heavy ion collisions. The chiral kinetic theory is particularly useful for the study of such effects in non-equilibrium conditions. However, there exist potential problems associated with Lorentz symmetry and collisions in the existing formalism. We will address these issues in the talk. We will present the derivation of the chiral kinetic theory for Weyl fermions with collisions in the presence of weak electric and magnetic fields from quantum field theories. It is found that the side-jump terms in the perturbative solution of Wigner functions play a significant role for the derivation. Moreover, such terms manifest the breaking of Lorentz symmetry for distribution functions. The Lorentz covariance of Wigner functions thus leads to modified Lorentz transformation associated with side-jump phenomena further influenced by background fields and collisions. |
| Shigehiro Yasui | QCD Kondo effect of heavy quarks in dense matter | We discuss QCD Kondo effect charm quarks in dense matter with low temperature. Assuming the relativistic gas for light quark matter, we consider that heavy quarks exist in the matter as impurity particles. We investigate the heavy-light condensate and focus on the topological properties by heavy quark spin in momentum space. |
| Nobutoshi Yasutake | Inhomogeneous Coulomb crystalline and chiral crystalline in neutron stars | We study the possibility of two types of inhomogeneous phase transition in neutron stars: one is the Coulomb crystalline, which is known as pasta structures, and another one is chiral crystalline. Optimal structures are given by numerical simulations based on the valuational principle. The structures may change not only the neutron star structures, e.g. mass-radius relations, but also the Maxwell equation itself. |
| Takeru Yokota | Character change and tachyonic instability of the soft mode at QCD critical point based on Functional renormalization-group method | We investigate spectral properties of the collective excitations around the QCD critical point(CP) by applying the functional renormalization-group(FRG) method to the two-flavor quark-meson model with current quark mass m_q being varied. It is known that the nature of the CP is affected by the value of m_q: The FRG method is applied to derive the O(4) critical line for the chiral limit and also the Z2 critical one for the finite m_q in the three-dimensional (T, mu, m_q) space. Then we examine the spectral properties of excitation modes in the scalar and pseudoscalar channel around these critical lines. We find that the dispersion relation of the sigma mesonic mode shows a non-monotonic behavior as the system approaches the CP; i.e., it first moves up to higher-energy region and then moves down to lower-energy region for relatively small m_q. As the current quark mass is increased so as to approach the physical value at which the pion mass has the empirical value, the sigma mesonic mode can become superluminal, which might possibly indicate that the assumed equilibrium state is unstable and the system has already undergone a phase transition to an unconventional phases such as the chiral inhomogeneous phase. No such an anomalous behavior is found in the pseudoscalar channel. |