||Reduction of the K* meson abundance and freeze-out conditions in heavy ion collisions
||We discuss the reduction of the K* meson abundance during the hadronic stage in heavy ion collisions, and further investigate the freeze-out conditions of a particle in order to understand the productions of resonances, hadronic molecules and light nuclei in heavy ion collisions. Applying the kinetic freeze-out condition to the daughter particles of K* mesons, we find that the larger suppression of the yield ratio of K*/K at LHC than at RHIC compared to the expectations from the statistical hadronization model reflects the lower kinetic freeze-out temperature at LHC than at RHIC. Moreover, we argue that for the light nuclei or hadronic molecules that are bound, the yields are affected by the freeze-out condition of the respective particle in the hadronic matter, leading to the observation that the deuteron production yields are independent of the size of deuteron, and depend only on the number of ground state constituents.
||The Lambda-proton interaction can be studied by looking at the correlation in the momentum space for particle pairs produced in hadron-hadron collisions. In this talk we present the correlation measured for Lambda-proton pairs produced in p+Nb at 3.5 GeV by the HADES collaboration. The sensitivity of the method to different scattering length predicted by LO and NLO calculation is tested and will be discussed.
||Partial Wave Analysis of the p+p -> pKLambda reactions
||A global Partial Wave Analysis ( PWA) of seven data set measured for the reaction p+p-> pKLambda at beam kinetic energies varying from 1.9 to 3.5 GeV is presented. This analysis allowed to extract for the first time the excitation function of N*+ resonances coupling to the KLambda channel, test the signature of the Cusp signal at different energies and study the final state interaction in a coherent way. Final results will be discussed during this talk
||Lambda-Lambda correlations from an integrated dynamical model
||We investigate two-particle correlation functions of Lambdas in high-energy nuclear collisions at the RHIC energy from an integrated dynamical model. This model includes Monte-Carlo Glauber model, ideal hydrodynamics and hadronic cascade model for each stage of the collisions. In analyses of two-particle correlation functions, the source function (distribution of the relative distance of emission points between two particles under consideration) is needed to estimate the correlation functions. The integrated dynamical model, which has been successful in reproducing many observables, provides the information about the last interaction points for final observed hadrons. Thus, without any assumption for the source function, we are able to estimate the two-particle correlation functions.
||Quark mass dependence of the Lambda-Lambda interaction
||We study the quark mass dependence of the H-dibaryon in the strangeness S=-2 baryon-baryon scattering. The low-energy effective field theory is used to describe the baryon-baryon scattering, in which the quark mass dependence is incorporatd so as to reproduce the lattice QCD data in the heavy quark mass region. We show that the H-dibaryon is unbound at the physical point and the unitary limit of the Lambda Lambda scattering is achieved by an appropriate tuning of the quark masses.
||Compositeness of near threshold quasi-bound states
||In the framework of the nonrelativistic effective field theory, we study the relation between the compositeness of stable bound states with observables. We generalize this relation for the unstable quasi-bound states with finite decay width. Using the generalized relation, we discuss the internal structure of exotic hadron candidates.
||Exotic hadron spectroscopy at Belle and Belle II
||Belle is an asymmetric energy e+e- collider experiment constructed to study the CP-violation in the B-meson decay to prove the Kobayashi-Maskawa theory. Unexpected bonus of the Belle?is discoveries of a large number of "new hadrons", which include candidates of exotic states such as X(3872). In this talk, I will overview the hadron spectroscopy at Belle mainly focusing on the exotic states and present future prospect with Belle II experiment.
||Light nuclei production in relativistic heavy ion collisions
||Using the coalescence model based on the phase-space distributions of nucleons from both a multiphase transport (AMPT) model and the blast wave model, we study the production of light nuclei in relativistic heavy ion collisions at both RHIC and LHC. The resulting transverse momentum spectra, elliptic flows and coalescence parameters for these nuclei are presented and compared with available experimental data. We also show the constituent number scaled elliptic flows of these nuclei and discuss its implications.
|Su Houng Lee
||Exotics from a constituent quark model and its implication to ExHIC
||We look at the possibility of compact multiquark configuration from a constituent quark model. We discuss the implication of our result to ExHIC.
||Understanding the nature of the heavy pentaquarks and searching for them in pion-induced reactions
||The LHCb collaborations recently reported the observations of two resonance-like structures, which could be the long-searching-for pentaquark states. When studying these heavy pentaquark candidates, usually one will confront two issues, i.e., what their underlying structures are and how to search for them in experiments. We indicated that these resonance-like peaks may be resulted from some kinematic threshold effects, in particular the triangle singularity mechanism. The triangle singularity mechanism is a highly process-dependent mechanism, which is very different from other dynamic mechanisms. This may bring ambiguities on our understanding of the nature of those exotic states. We therefore needs different kinds of processes to check this mechanism. The piN scattering into J/psi-pion-proton could be a promising reaction to search for the heavy pentaquark or the effects induced by the triangle singularity mechanism. The forthcoming J-PARC pion-induced experiment may offer us a good opportunity to check different kinematic or dynamic mechanisms and clarify the ambiguities.
||The charm baryon - nucleon interaction and Lambda_c-NN nuclei
||There are many studies about not only nucleons and nuclei but also hyperons and hypernuclei theoretically and experimentally. We look at the physics with a charm quark as the next level, which is heavier than a strange quark. We construct the potential with One Boson Exchange Potential and Quark Cluster Model repulsion. In this study, we obtain four sets of parameters (a -- d) and calculate the bound and resonance states with the potential. In addition, we construct an effective Lambda_c-N one-channel potential and apply it to the 3-body Lambda_c-NN system.
||Thermal modifications of meson states in lattice QCD and relations to heavy ion collisions
||Thermal fluctuations cause modifications of meson states, which play an important role in the analysis of sequential melting patterns of open-flavor mesons and quarkonium. We present recent results in full-QCD lattice simulations of in-medium modifications of mesonic excitations containing up/down, strange and charmed quarks. The lattice QCD simulations is the 1st principle calculations, in particular, based on the precisely determined fundamental parameters in QCD, all the results at finite temperature becomes pure theoretical predictions. However when measuring the mesonic states at finite temperature, one fases several difficulties in normal approaches.
After berief introductions such difficulties in lattice QCD, we propose the spatial correlation function which provides a direct signal for the thermal modifications of spectral functions carrying all the informations about in-medium properties of mesons and their dissolution. As a consequence of the lattice QCD simulations we find that even below the QCD transition temperature the thermal fluctuations significantly affect all meson states except for the charmonium which remains stable states beyond the transition temperature. We also show modification patterns of those states and discuss relations of the lattice results to phenomena in the heavy ion collisions.
||Xi resonances in the weak decay of Xi_c
||Recently, three-body decay of Xi_c has been measured by Belle and BESIII Collaborations. The decay leads to the analysis of interesting baryon resonances with strangeness such as Xi(1690) through the final state interaction of the meson-baryon pair. In this work, we study the weak decay process theoretically, and calculate the spectra of Xi resonances. From this analysis, we conclude that this process is quite useful to clarify the nature of the baryon resonances.
||Probing Omega-Nucleon interaction in relativistic heavy ion collisions
||We discuss proton-Omega correlation in heavy ion collisions based on nucleon -Omega interaction potential extracted from lattice QCD by HAL QCD collaboration.
||Hadron-Hadron Correlation and Interaction from Heavy-Ion Collisions and Summary
|Neha Shah, Jinhui Chen
||Hyperon interactions from heavy ion collisions
||Resonance production in ALICE at the LHC
||The measurement of resonances in ultra-relativistic heavy-ion collisions provides a glimpse of the properties of the hadronic medium and its evolution at different stages. Due to their relatively short lifetimes, resonances are good candidates to probe the interplay of particle re-scattering and regeneration in the hadronic phase, which could result in a modification of the measured yield of resonances reconstructed in hadronic decay channels. In addition, the measurement of resonances containing one or more strange (anti-)quarks contributes to the study of strangeness production. The produc- tion of hyperons (Lambda, Xi, Omega) and resonances (K*, phi, Sigma*, Xi*) has been measured with the ALICE detector in proton-proton, proton-lead and lead-lead collisions at different energies. We report on the transverse momentum distributions and integrated particle ratios and their dependence on charged-particle multiplicity density, with special em- phasis on comparing excited states and long-lived particles. Finally, we also present comparisons to various model predictions.
||Charmed and exotic hadron measurements with ALICE at the LHC
||Ultra-relativistic heavy-ion collisions provide a unique opportunity to study the properties of rare hadrons. The ALICE detector has ideal features to measure charmed and exotic hadron production in heavy-ion collisions, such as tracking and particle identification capabilities down to low $p_T$. In this presentation, I will report the results and the status of $\Lambda_c$, $D$-mesons, hypernuclei and H-dibaryon measurements in pp, p-Pb and Pb-Pb collisions with ALICE at the LHC.
||Charm nuclei and related topics
||We discuss exotic nuclei with charm flavor. Based on the heavy-quark spin symmetry, we investigate the general properties of charm nuclei and study the mass spectrum for which an anti-D meson has the pion exchange interaction with a nucleon. We discuss the the mass modification of the anti-D meson is related to the gluon dynamics in the nuclear system. We also discuss the Kondo effect in charm nuclei, namely that the isospin exchange between the anti-D meson and a nucleon induces an enhancement of the effective interaction in the low-energy scattering.
||Coalescence model for resonances
||The coalescence model for resonance particle production in high energy heavy ion collisions
is formulated in the way it is observed in experiments. A simple S-wave Lee-type model, in which two
particles, a and b, couple to a particle, c, forming a resonance in the (a,b) scattering states, is used to
clarify the discussion. The probability of finding the two particles with a given asymptotic relative
momentum is decomposed into the contribution of (a, b) pairs and that of the particle c in the collision
complex, and the former is further decomposed into the background, interaction and interference terms.
A sum rule based on the completeness of the (a, b) scattering states is derived for the interaction and
interference terms. Numerical examples with a simplified model of Lambda(1405) in our mind show that the
relative momentum spectra of the two particles (a, b) are sensitive to the widths of the resonances
and also the nature of the collision complex. The way of extracting the resonance particle production
probabitity from the observed invariant mass spectra of the two particles and its implication for ExHIC
||Heavy meson in a magnetic field
||Heavy meson in a homogeneous magnetic field are analyzed by using a potential model with
constituent quarks. To obtain the eigenvalues and anisotropic wave functions from this model, cylindrical Gaussian expansion method (CGEM) are developed, where basis of a spacial wave function is expanded by superposition of two Gaussian basis for transverse and longitudinal directions in the cylindrical coordinate. We obtained mass shifts and deformations of wave functions of S-wave heavy meson caused by the kinetic and magnetic-moment terms coupled with the magnetic field. Magnetic behaviors of excited states show level structures by mixing between the spin partners. Our predictions can indicate possible observables by heavy-ion collision experiments and future lattice QCD.