Meson-Meson and Meson-Baryon Interactions in Lattice QCD

We study the meson-meson and meson-baryon interactions in lattice QCD. The simulation is performed on 20^3 * 24 lattice at \beta=5.7 using Wilson gauge action and Wilson fermion at the quenched level. By adopting one static quark for each hadron as "heavy-light meson" and "heavy-light-light baryon", we define the distance $r$ of two hadrons and extract the inter-hadron potential from the energy difference of the two-particle state and its asymptotic state. We find that both of the meson-meson and meson-baryon potentials are nontrivially weak for the whole range of 0.2 fm <= r <= 0.8 fm. The effect of including/excluding the quark-exchange diagrams is found to be marginal.Comment: Talk given at Particles and Nuclei International Conference (PANIC05), Santa Fe, NM, USA, 24-28 Oct. 2005. 3 pages, 2 figure

Multi-Quarks and Two-Baryon Interaction in Lattice QCD

We study multi-quark (3Q,4Q,5Q) systems in lattice QCD. We perform the detailed studies of multi-quark potentials in lattice QCD to clarify the inter-quark interaction in multi-quark systems. We find that all the multi-quark potentials are well described by the OGE Coulomb plus multi-Y-type linear potential, i.e., the multi-Y Ansatz. For multi-quark systems, we observe lattice QCD evidences of ``flip-flop'', i.e., flux-tube recombination. These lattice QCD studies give an important bridge between elementary particle physics and nuclear physics.Comment: A talk given at Particles and Nuclei International Conference(PANIC05), Santa Fe, NM, Oct. 24-28, 2005. 3 pages, 6 figure

Multi-antikaonic nuclei in the relativistic mean-field theory

Properties of multi-antikaonic nuclei (MKN), where several numbers of $K^-$ mesons are bound, are studied in the relativistic mean-field model, combined with chiral dynamics for kaonic part of the thermodynamic potential. The density profiles for nucleons and $K^-$ mesons, the single particle energy of the $K^-$ mesons, and binding energy of the MKN are obtained. The effects of the $\bar K-\bar K$ interactions on these quantities are discussed in comparison with other meson ($\sigma$, $\omega$, and $\rho$)-exchange models. It is shown that the $\bar K-\bar K$ interactions originate from two contributions: One is the contact interaction between antikaons inherent in chiral symmetry, and the other is the one generated through coupling between the $K^-$ and meson mean fields. Both effects of the $\bar K-\bar K$ repulsive interactions become large on the ground state properties of the MKN as the number of the embedded $K^-$ mesons increases. A relation between the multi-antikaonic nuclei and kaon condensation in infinite and uniform matter is mentioned.Comment: 27 pages, 13 figure

Off-diagonal Gluon Mass Generation and Infrared Abelian Dominance in Maximally Abelian Gauge in SU(3) Lattice QCD

In SU(3) lattice QCD formalism, we propose a method to extract gauge fields from link-variables analytically. With this method, we perform the first study on effective mass generation of off-diagonal gluons and infrared Abelian dominance in the maximally Abelian (MA) gauge in the SU(3) case. Using SU(3) lattice QCD, we investigate the propagator and the effective mass of the gluon fields in the MA gauge with U(1)_3 \timesU(1)_8 Landau gauge fixing. The Monte Carlo simulation is performed on $16^4$ at $\beta$=5.7, 5.8 and 6.0 at the quenched level. The off-diagonal gluons behave as massive vector bosons with the approximate effective mass $M_{\mathrm{off}} \simeq 1.1-1.2\mathrm{GeV}$ in the region of $r =0.3-0.8$fm, and the propagation is limited within a short range, while the propagation of diagonal gluons remains even in a large range. In this way, infrared Abelian dominance is shown in terms of short-range propagation of off-diagonal gluons. Furthermore, we investigate the functional form of the off-diagonal gluon propagator. The functional form is well described by the four-dimensional Euclidean Yukawa-type function $e^{-m_{\rm off}r}/r$ with $m_{\rm off} \simeq 1.3-1.4\mathrm{GeV}$ for $r = 0.1- 0.8$ fm. This also indicates that the spectral function of off-diagonal gluons has the negative-value region

A unified origin for the 3D magnetism and superconductivity in Nax_xCoO2_2

We analyze the origin of the three dimensional (3D) magnetism observed in nonhydrated Na-rich Na$_x$CoO$_2$ within an itinerant spin picture using a 3D Hubbard model. The origin is identified as the 3D nesting between the inner and outer portions of the Fermi surface, which arise due to the local minimum structure of the $a_{1g}$ band at the $\Gamma$-A line. The calculated spin wave dispersion strikingly resembles the neutron scattering result. We argue that this 3D magnetism and the spin fluctuations responsible for superconductivity in the hydrated systems share essentially the same origin.Comment: 5pages, 6figure

Instantaneous Interquark Potential in Generalized Landau Gauge in SU(3) Lattice QCD: A Linkage between the Landau and the Coulomb Gauges

We investigate in detail "instantaneous interquark potentials", interesting gauge-dependent quantities defined from the spatial correlators of the temporal link-variable $U_4$, in generalized Landau gauge using SU(3) quenched lattice QCD. The instantaneous Q$\bar{\rm Q}$ potential has no linear part in the Landau gauge, and it is expressed by the Coulomb plus linear potential in the Coulomb gauge, where the slope is 2-3 times larger than the physical string tension. Using the generalized Landau gauge, we find that the instantaneous potential can be continuously described between the Landau and the Coulomb gauges, and its linear part rapidly grows in the neighborhood of the Coulomb gauge. We also investigate the instantaneous 3Q potential in the generalized Landau gauge, and obtain similar results to the Q$\bar{\rm Q}$ case. $T$-length terminated Polyakov-line correlators and their corresponding "finite-time potentials" are also investigated in generalized Landau gauge

Creation of an isolated turbulent blob fed by vortex rings

Turbulence is hard to control. A plethora of experimental methods have been developed to generate this ephemeral state of matter, leading to fundamental insights into its statistical and structural features as well as its onset at ever higher Reynolds numbers. In all cases however, the central role played by the material boundaries of the apparatus poses a challenge on understanding what the turbulence has been fed, and how it would freely evolve. Here, we build and control a confined state of turbulence using only elemental building blocks: vortex rings. We create a stationary and isolated blob of turbulence ($Re_\lambda$=50-300) in a quiescent environment, initiated and sustained solely by vortex rings. We assemble a full picture of its three-dimensional structure, onset, energy budget and tunability. Crucially, the incoming vortex rings can be endowed with conserved quantities, such as helicity, which can then be controllably transferred to the turbulent state. Our `one eddy at a time' approach paves the way for sculpting turbulent flows much as a state of matter, `printing' it at a targeted position, localizing it, and ultimately harnessing it. Our work paves the way to gaining a complete picture of this ephemeral state of flow.Comment: 68 pages, 43 figures, manuscript and supplementary informatio

構造集団と改革: ハンガリー経済改革の社会学

T.Kolosi[著] 堀林,巧[訳] Horibayashi, Takum

Eye lens β-crystallins are predicted by native ion mobility-mass spectrometry and computations to form compact higher-ordered heterooligomers

Eye lens crystallin proteins maintain the refractive properties of the lens but are not replaced after denucleation. Rolland et al. use native ion mobility-mass spectrometry, kinetics experiments, and computations to reveal that b-crystallins form heterodimers. These likely assemble into compact heterooligomers that enable the very high protein concentrations found in lens tissue