Identification of Oceanographic Parameters for Determining Pelagic Tuna Fishing Ground in the North Papua Waters Using Multi-sensor Satellite Data

The North Papua waters as one of the important fishing grounds in the world contribute approximately 75% of world production of pelagic tunas. These fishing grounds are still determined by hunting method. This method is time consuming and costly. However, in many areas determination of fishing ground using satellited data lias been applied by detecting the important oceanographic parameter of the presence of fish schooling such as, sea surface temperature and chlorophyl. Mostly these parameters are used integratedly. The aim of this study is to assess the important oceanographic parameters detected from multi-sensor satellites (NOAA/AVHRR, Seawifs and Topex Poisedon) for determining fishing ground of pelagic tunas in the North Papua waters at east season. The parameters include Sea Surface Temperature (STT), chlorophyl-a and currents. The availability of data from optic sensor (Seawifs: chl-a and AVHRR: Thermal) is limited by the presence of cloud cover. In that case, Topex Poseidon satellite data can be used to provide the currents data. The integration of data from multi-sensors increases the availability of the oceanographic parameters for prediction of the potential fishing zones in the study area

K−K^- - nucleus relativistic mean field potentials consistent with kaonic atoms

$K^-$ atomic data are used to test several models of the $K^-$ nucleus interaction. The t($\rho$)$\rho$ optical potential, due to coupled channel models incorporating the $\Lambda$(1405) dynamics, fails to reproduce these data. A standard relativistic mean field (RMF) potential, disregarding the $\Lambda$(1405) dynamics at low densities, also fails. The only successful model is a hybrid of a theoretically motivated RMF approach in the nuclear interior and a completely phenomenological density dependent potential, which respects the low density theorem in the nuclear surface region. This best-fit $K^-$ optical potential is found to be strongly attractive, with a depth of 180 \pm 20 MeV at the nuclear interior, in agreement with previous phenomenological analyses.Comment: revised, Phys. Rev. C in pres

Incremental expansions for Hubbard-Peierls systems

The ground state energies of infinite half-filled Hubbard-Peierls chains are investigated combining incremental expansion with exact diagonalization of finite chain segments. The ground state energy of equidistant infinite Hubbard (Heisenberg) chains is calculated with a relative error of less than $3 \cdot 10^{-3}$ for all values of $U$ using diagonalizations of 12-site (20-site) chain segm ents. For dimerized chains the dimerization order parameter $d$ as a function of the onsite repulsion interaction $U$ has a maximum at nonzero values of $U$, if the electron-phonon coupling $g$ is lower than a critical value $g_c$. The critical value $g_c$ is found with high accuracy to be $g_c=0.69$. For smaller values of $g$ the position of the maximum of $d(U)$ is approximately $3t$, and rapidly tends to zero as $g$ approaches $g_c$ from below. We show how our method can be applied to calculate breathers for the problem of phonon dynamics in Hubbard-Peierls systems.Comment: 4 Pages, 3 Figures, REVTE

Solitonic approach to the dimerization problem in correlated one-dimensional systems

Using exact diagonalizations we consider self-consistently the lattice distortions in odd Peierls-Hubbard and spin-Peierls periodic rings in the adiabatic harmonic approximation. From the tails of the inherent spin soliton the dimerization d_\infty of regular even rings is found by extrapolations to infinite ring lengths. Considering a wide region of electron-electron onsite interaction values U>0 compared with the band width 4t_0 at intermediately strong electron-phonon interaction g, known relationships obtained by other methods are reproduced and/or refined within one unified approach: such as the maximum of d_\infty at U \simeq 3 t_0 for g \simeq 0.5 and its shift to zero for g \to g_c \approx 0.7. The hyperbolic tangent shape of the spin soliton is retained for any U and g <~ 0.6. In the spin-Peierls limit the d_\infty are found to be in agreement with results of DMRG computations.Comment: 4 pages, 4 figures, Physical Review B, Rapid Communications, v. 56 (1997) accepte

Kaon effective mass and energy from a novel chiral SU(3)-symmetric Lagrangian

A new chiral SU(3) Lagrangian is proposed to describe the properties of kaons and antikaons in the nuclear medium, the ground state of dense matter and the kaon-nuclear interactions consistently. The saturation properties of nuclear matter are reproduced as well as the results of the Dirac-Br\"{u}ckner theory. Our numerical results show that the kaon effective mass might be changed only moderately in the nuclear medium due to the highly non-linear density effects. After taking into account the coupling between the omega meson and the kaon, we obtain similar results for the effective kaon and antikaon energies as calculated in the one-boson-exchange model while in our model the parameters of the kaon-nuclear interactions are constrained by the SU(3) chiral symmetry.Comment: 13 pages, Latex, 3 PostScript figures included; replaced by the revised version, to appear in Phys. Rev.

Constraints on the threshold K- nuclear potential from FINUDA (stopped K-, pi-) hypernuclear spectra

1s(Lambda) hypernuclear formation rates in stopped K- reactions on several p-shell targets are derived from hypernuclear formation spectra measured recently by the FINUDA Collaboration and are compared with calculated 1s(Lambda) formation rates based on a KbarN coupled channels chiral model. The calculated rates are about 15% of the derived rates, depending weakly on the depth of the threshold K- nuclear potential. The A dependence of the calculated rates is in fair agreement with that of the derived rates, showing a slight preference for a deep density dependent K- nuclear potential of depth (150-200) MeV at nuclear matter density over a shallow potential of depth about 50 MeV. These new features originate from a substantial energy and density dependence found for the in-medium subthreshold (K- n --> pi- Lambda) branching ratio that serves as input to the K- capture at rest calculations.Comment: 12 pages, 2 figures, 2 tables; v2 is a substantially revised version, v3 matches journal versio

First Order Kaon Condensate

First order Bose condensation in asymmetric nuclear matter and in neutron stars is studied, with particular reference to kaon condensation. We demonstrate explicitly why the Maxwell construction fails to assure equilibrium in multicomponent substances. Gibbs conditions and conservation laws require that for phase equilibrium, the charge density must have opposite sign in the two phases of isospin asymmetric nuclear matter. The mixed phase will therefore form a Coulomb lattice with the rare phase occupying lattice sites in the dominant phase. Moreover, the kaon condensed phase differs from the normal phase, not by the mere presence of kaons in the first, but also by a difference in the nucleon effective masses. The mixed phase region, which occupies a large radial extent amounting to some kilometers in our model neutron stars, is thus highly heterogeneous. It should be particularly interesting in connection with the pulsar glitch phenomenon as well as transport properties.Comment: 25 pagees, 20 figures, Late

Nonequilibrium Weak Processes in Kaon Condensation II - Kinetics of condensation ---

The kinetics of negatively charged kaon condensation in the early stages of a newly born neutron star is considered. The thermal kaon process, in which kaons are thermally produced by nucleon-nucleon collisions, is found to be dominant throughout the equilibration process. Temporal changes of the order parameter of the condensate and the number densities of the chemical species are obtained from the rate equations, which include the thermal kaon reactions as well as the kaon-induced Urca and the modified Urca reactions. It is shown that the dynamical evolution of the condensate is characterized by three stages: the first, prior to establishment of a condensate, the second, during the growth and subsequent saturation of the condensate, and the third, near chemical equilibrium. The connection between the existence of a soft kaon mode and the instability of the noncondensed state is discussed. Implications of the nonequilibrium process on the possible delayed collapse of a protoneutron star are also mentioned.Comment: 27 pages, incl. 8 eps figures, RevTe

On the correllation effect in Peierls-Hubbard chains

We reexamine the dimerization, the charge and the spin gaps of a half-filled Peierls-Hubbard chain by means of the incremental expansion technique. Our numerical findings are in significant quantitative conflict with recently obtained results by M. Sugiura and Y. Suzumura [J. Phys. Soc. Jpn. v. 71 (2002) 697] based on a bosonization and a renormalization group method, especially with respect to the charge gap. Their approach seems to be valid only in the weakly correlated case.Comment: 7pages,4figures(6eps-files

Chiral dynamics of baryon resonances and hadrons in a nuclear medium

In these lectures I make an introduction to chiral unitary theory applied to the meson baryon interaction and show how several well known resonances are dynamically generated, and others are predicted. Two very recent experiments are analyzed, one of them showing the existence of two $\Lambda(1405)$ states and the other one providing support for the $\Lambda(1520)$ resonance as a quasibound state of $\Sigma(1385) \pi$. The use of chiral Lagrangians to account for the hadronic interaction at the elementary level introduces a new approach to deal with the modification of meson and baryon properties in a nuclear medium. Examples of it for $\bar{K}$, $\eta$ and $\phi$ modification in the nuclear medium are presented.Comment: Lectures given in the Workshop on Hadron Physics, Puri (India), march 200