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47
2007-02-27
Couplings of N=1 chiral spinor multiplets
We derive the action for chiral spinor multiplets coupled to vector and scalar multiplets. We give the component form of the action, which contains gauge invariant mass terms for the antisymmetric tensors in the spinor superfield and additional Green-Schwarz couplings to vector fields. We observe that supersymmetry pro...
0702211v2
2004-08-31
Topological complexity of the relative closure of a semi-Pfaffian couple
Gabrielov introduced the notion of relative closure of a Pfaffian couple as an alternative construction of the o-minimal structure generated by Khovanskii's Pfaffian functions. In this paper, use the notion of format (or complexity) of a Pfaffian couple to derive explicit upper-bounds for the homology of its relative c...
0409002v3
2005-05-11
Coupled Painlevé II Systems in Dimension 4 and the systems of type ${A_4}^{(1)}$
We find and study coupled Painlev\'e II systems in dimension 4, which can be obtained by a degeneration from the systems of type ${A_4}^{(1)}$. We compare these systems with other types of coupled Painlev\'e II systems from the viewpoint of the local index. We also give the phase spaces for these systems.
0505203v2
2005-07-07
Mirror symmetry, Kobayashi's duality, and Saito's duality
M. Kobayashi introduced a notion of duality of weight systems. We tone this notion slightly down to a notion called coupling. We show that coupling induces a relation between the reduced zeta functions of the monodromy operators of the corresponding singularities generalizing an observation of K. Saito concerning Arnol...
0507134v1
2005-09-30
Counting carefree couples
A pair of natural numbers (a,b) such that a is both squarefree and coprime to b is called a carefree couple. A result conjectured by Manfred Schroeder (in his book `Number theory in science and communication') on carefree couples and a variant of it are established using standard arguments from elementary analytic nu...
0510003v2
2006-05-10
Regularity of coupled two-dimensional nonlinear Fokker-Planck and Navier-Stokes systems
We consider systems of particles coupled with fluids. The particles are described by the evolution of their density, and the fluid is described by the Navier-Stokes equations. The particles add stress to the fluid and the fluid carries and deforms the particles. Because the particles perform rapid random motion, we ass...
0605245v1
2006-05-18
Phase transitions in a piecewise expanding coupled map lattice with linear nearest neighbour coupling
We construct a mixing continuous piecewise linear map on [-1,1] with the property that a two-dimensional lattice made of these maps with a linear north and east nearest neighbour coupling admits a phase transition. We also provide a modification of this construction where the local map is an expanding analytic circle m...
0605501v1
1999-06-29
Difference in the number of operators between coupled and uncoupled basis for the general SU(n) Lie algebra
For the cases of irreducible representation, the complete set of operators necessary to specify uniquely the states. There are two ways of representing the state, using uncoupled and coupled basis. Here we discuss, how the number of operators for the cases of coupled and uncoupled basis changes as well as their differe...
9906025v1
2001-12-06
Enhanced Binding in non-relativistic QED
We consider a spinless particle coupled to a photon field and prove that even if the Schr\"odinger operator $p^2 + V$ does not have eigenvalues the system can have a ground state. We describe the coupling by means of the Pauli-Fierz Hamiltonian and our result holds in the case where the coupling constant $\alpha$ is sm...
0112010v2
2002-04-27
Increase of the binding energy of an electron by coupling to a photon field
We look at an electron in the field of an arbitrary external potential $V$, such that the Schr\"odinger operator $p^2 + V$ has at least one eigenvalue, and show that by coupling to a quantized radiation field the binding energy increases, at least for small enough values of the coupling constant $\alpha$. Moreover, we ...
0204052v1
2003-03-03
Spectra of soft ring graphs
We discuss of a ring-shaped soft quantum wire modeled by $\delta$ interaction supported by the ring of a generally nonconstant coupling strength. We derive condition which determines the discrete spectrum of such systems, and analyze the dependence of eigenvalues and eigenfunctions on the coupling and ring geometry. In...
0303006v1
2003-09-05
Janossy Densities of Coupled Random Matrices
We explicitly calculate Janossy densities for a special class of finite determinantal point processes with several types of particles introduced by Pr\"ahofer and Spohn and, in the full generality, by Johansson in connection with the analysis of polynuclear growth models. The results of our paper generalize the theorem...
0309019v4
2003-12-10
Analyticity of the SRB measure of a lattice of coupled Anosov diffeomorphisms of the torus
We consider the "thermodynamic limit"of a d-dimensional lattice of hyperbolic dynamical systems on the 2-torus, interacting via weak and nearest neighbor coupling. We prove that the SRB measure is analytic in the strength of the coupling. The proof is based on symbolic dynamics techniques that allow us to map the SRB m...
0312032v1
2004-04-07
Precise coupling terms in adiabatic quantum evolution
It is known that for multi-level time-dependent quantum systems one can construct superadiabatic representations in which the coupling between separated levels is exponentially small in the adiabatic limit. For a family of two-state systems with real-symmetric Hamiltonian we construct such a superadiabatic representati...
0404021v1
2004-11-05
Coupling of eigenvalues of complex matrices at diabolic and exceptional points
The paper presents a general theory of coupling of eigenvalues of complex matrices of arbitrary dimension depending on real parameters. The cases of weak and strong coupling are distinguished and their geometric interpretation in two and three-dimensional spaces is given. General asymptotic formulae for eigenvalue surf...
0411024v4
2005-08-23
Approximations of permutation-symmetric vertex couplings in quantum graphs
We consider boundary conditions at the vertex of a star graph which make Schroedinger operators on the graph self-adjoint, in particular, the two-parameter family of such conditions invariant with respect to permutations of graph edges. It is proved that the corresponding operators can be approximated in the norm-resol...
0508046v1
1996-09-23
Substrate-adsorbate coupling in CO-adsorbed copper
The vibrational properties of carbon monoxide adsorbed to the copper (100) surface are explored within density functional theory. Atoms of the substrate and adsorbate are treated on an equal footing in order to examine the effect of substrate--adsorbate coupling. This coupling is found to have a significant effect on t...
9609004v1
2000-02-14
Phase synchronization in coupled nonidentical excitable systems and array enhanced coherence resonance
We study the dynamics of a lattice of coupled nonidentical Fitz Hugh-Nagumo system subject to independent external noise. It is shown that these stochastic oscillators can lead to global synchronization behavior {\sl without an external signal}. With the increase of the noise intensity, the system exhibits coherence re...
0002019v1
2000-02-22
Stability of Oscillating Hexagons in Rotating Convection
Breaking the chiral symmetry, rotation induces a secondary Hopf bifurcation in weakly nonlinear hexagon patterns which gives rise to oscillating hexagons. We study the stability of the oscillating hexagons using three coupled Ginzburg-Landau equations. Close to the bifurcation point we derive reduced equations for the ...
0002038v1
2000-02-29
Localized structures in coupled Ginzburg-Landau equations
Coupled Complex Ginzburg-Landau equations describe generic features of the dynamics of coupled fields when they are close to a Hopf bifurcation leading to nonlinear oscillations. We study numerically this set of equations and find, within a particular range of parameters, the presence of uniformly propagating localized...
0002053v1
2000-05-26
From synchronization to multistability in two coupled quadratic maps
The phenomenology of a system of two coupled quadratic maps is studied both analytically and numerically. Conditions for synchronization are given and the bifurcations of periodic orbits from this regime are identified. In addition, we show that an arbitrarily large number of distinct stable periodic orbits may be obta...
0005053v1
2000-06-23
Periodicity Manifestations in the Turbulent Regime of Globally Coupled Map Lattice
We revisit the globally coupled map lattice (GCML). We show that in the so called turbulent regime various periodic cluster attractor states are formed even though the coupling between the maps are very small relative to the non-linearity in the element maps. Most outstanding is a maximally symmetric three cluster at...
0006038v1
2000-07-20
Directional coupling of optical signals by odd dark beams with mixed phase dislocations
Numerical simulations on the evolution of step-screw and edge-screw optical phase dislocations in bulk saturable self-defocusing nonlinear media are presented, with emphasis on their ability to induce steering waveguides for signal beams (pulses). Two schemes for directional coupling of such signals, both ensuring reas...
0007026v1
2002-01-05
Modeling of Spiking-Bursting Neural Behavior Using Two-Dimensional Map
A simple model that replicates the dynamics of spiking and spiking-bursting activity of real biological neurons is proposed. The model is a two-dimensional map which contains one fast and one slow variable. The mechanisms behind generation of spikes, bursts of spikes, and restructuring of the map behavior are explained...
0201006v1
2002-01-07
Coupling the Sine-Gordon Field Theory to a Mechanical System at the Boundary
We describe an integrable system consisting of the sine-Gordon field, restricted to the half line, and coupled to a non-linear oscillator at the boundary. By extension of the coupling constant to imaginary values we also outline the equivalent system for the sinh-Gordon field. We show how Sklyanin's formalism can be ap...
0201007v1
2002-01-22
Coupled Map Networks as Communication Schemes
Networks of chaotic coupled maps are considered as string and language generators. It is shown that such networks can be used as encrypting systems where the ciphertext contains information about the evolution of the network and also about the way to select the plaintext symbols from the string associated to the networ...
0201042v1
2002-04-10
Magic Number 7 +- 2 in Globally Coupled Dynamical Systems?
The prevalence of Milnor attractors has recently been reported in a class of high-dimensional dynamical systems. We study how this prevalence depends on the number of degrees of freedom by using a globally coupled map and show that the basin fraction of Milnor attractors increases drastically around 5-10 degrees of fre...
0204013v1
2002-04-11
New Darboux Transformation for Hirota-Satsuma coupled KdV System
A new Darboux transformation is presented for the Hirota-Satsuma coupled KdV system. It is shown that this Darboux transformation can be constructed by means of two methods: Painlev\'{e} analysis and reduction of a binary Darboux transformation. By iteration of the Darboux transformation, the Grammian type solutions ar...
0204018v1
2002-05-09
The Onset of Synchronization in Systems of Globally Coupled Chaotic and Periodic Oscillators
A general stability analysis is presented for the determination of the transition from incoherent to coherent behavior in an ensemble of globally coupled, heterogeneous, continuous-time dynamical systems. The formalism allows for the simultaneous presence of ensemble members exhibiting chaotic and periodic behavior, an...
0205018v1
2002-08-21
Scaling at the onset of chaos in a network of logistic maps with two types of global coupling
We study a network of logistic maps with two types of global coupling, inertial and dissipative. Features of the clusterization process are revealed and compared, which are associated with presence of each type of couplings. For the parameter region near the onset of chaos we outline scaling properties in dynamical beh...
0208026v1
2003-03-16
Generalized Turing Patterns and Their Selective Realization in Spatiotemporal Systems
We consider the pattern formation problem in coupled identical systems after the global synchronized state becomes unstable. Based on analytical results relating the coupling strengths and the instability of each spatial mode (pattern) we show that these spatial patterns can be selectively realized by varying the coupl...
0303030v1
2003-04-11
On nonlocally coupled complex Ginzburg-Landau equation
A Ginzburg-Landau type equation with nonlocal coupling is derived systematically as a reduced form of a universal class of reaction-diffusion systems near the Hopf bifurcation point and in the presence of another small parameter. The reaction-diffusion systems to be reduced are such that the chemical components constit...
0304017v1
2003-06-11
Irreversible quantum graphs
Irreversibility is introduced to quantum graphs by coupling the graphs to a bath of harmonic oscillators. The interaction which is linear in the harmonic oscillator amplitudes is localized at the vertices. It is shown that for sufficiently strong coupling, the spectrum of the system admits a new continuum mode which ex...
0306017v1
2003-07-02
Energy Trapping in Loaded String Models with Long- and Short-Range Couplings
This note illustrates the possibility in simple loaded string models of trapping most of the system energy in a single degree of freedom for very long times, demonstrating in particular that the robustness of the trapping is enhanced by increasing the `connectance' of the system, i.e., the extent to which many degrees ...
0307004v1
2003-10-28
Measurement of synchronization properties in systems with different excitation levels
We devised a measure based on the distributions of relative event timings of two coupled units. The measure dynamically evaluates temporal interdependencies between the two coupled units. Using this we show that even in the event of symmetrical coupling, non-identical units (having different control parameters) have sm...
0310042v1
2004-05-21
How Crucial is Small World Connectivity for Dynamics?
We study the dynamical behaviour of the collective field of chaotic systems on small world lattices. Coupled neuronal systems as well as coupled logistic maps are investigated. We observe that significant changes in dynamical properties occur only at a reasonably high strength of nonlocal coupling. Further, spectral fe...
0405049v1
2004-06-14
Nonlinear absorption in discrete systems
In the context of nonlinear scattering, a continuous wave incident onto a nonlinear discrete molecular chain of coupled oscillators can be partially absorbed as a result of a 3-wave resonant interaction that couples two HF-waves of frequencies close to the edge of the Brillouin zone. Hence both nonlinearity and discret...
0406024v1
2004-07-06
Effect of the Introduction of Impurities on the Stability Properties of Multibreathers at Low Coupling
sing a theorem dubbed the {\em Multibreather Stabiliy Theorem} [Physica D 180 (2003) 235-255] we have obtained the stability properties of multibreathers in systems of coupled oscillators with on-site potentials, with an inhomogeneity. Analytical results are obtained for 2-site, 3-site breathers, multibreathers, phonob...
0407009v1
2004-07-07
Stability analysis of coupled map lattices at locally unstable fixed points
Numerical simulations of coupled map lattices (CMLs) and other complex model systems show an enormous phenomenological variety that is difficult to classify and understand. It is therefore desirable to establish analytical tools for exploring fundamental features of CMLs, such as their stability properties. Since CMLs ...
0407014v2
2004-10-19
Emergence of chaotic attractor and anti-synchronization for two coupled monostable neurons
The dynamics of two coupled piece-wise linear one-dimensional monostable maps is investigated. The single map is associated with Poincare section of the FitzHugh-Nagumo neuron model. It is found that a diffusive coupling leads to the appearance of chaotic attractor. The attractor exists in an invariant region of phase ...
0410032v1
2004-11-09
Coupled-mode theory for spatial gap solitons in optically-induced lattices
We develop a coupled-mode theory for spatial gap solitons in the one-dimensional photonic lattices induced by interfering optical beams in a nonlinear photorefractive crystal. We derive a novel system of coupled-mode equations for two counter-propagating probe waves, and find its analytical solutions for stationary gap...
0411021v1
2005-02-09
Birhythmicity, Synchronization, and Turbulence in an Oscillatory System with Nonlocal Inertial Coupling
We consider a model where a population of diffusively coupled limit-cycle oscillators, described by the complex Ginzburg-Landau equation, interacts nonlocally via an inertial field. For sufficiently high intensity of nonlocal inertial coupling, the system exhibits birhythmicity with two oscillation modes at largely dif...
0502015v1
2005-04-23
An approach to chaotic synchronization
This paper deals with the chaotic oscillator synchronization. A new approach to the synchronization of chaotic oscillators has been proposed. This approach is based on the analysis of different time scales in the time series generated by the coupled chaotic oscillators. It has been shown that complete synchronization, ...
0504045v1
2005-04-24
Intermittent generalized synchronization in unidirectionally coupled chaotic oscillators
A new behavior type of unidirectionally coupled chaotic oscillators near the generalized synchronization transition has been detected. It has been shown that the generalized synchronization appearance is preceded by the intermitted behavior: close to threshold parameter value the coupled chaotic systems demonstrate the...
0504048v1
2005-05-13
Independent Component Analysis of Spatiotemporal Chaos
Two types of spatiotemporal chaos exhibited by ensembles of coupled nonlinear oscillators are analyzed using independent component analysis (ICA). For diffusively coupled complex Ginzburg-Landau oscillators that exhibit smooth amplitude patterns, ICA extracts localized one-humped basis vectors that reflect the characte...
0505036v1
2005-06-17
Instabilities of multi-hump vector solitons in coupled nonlinear Schroedinger equations
Spectral stability of multi-hump vector solitons in the Hamiltonian system of coupled nonlinear Schr\"{o}dinger (NLS) equations is investigated both analytically and numerically. Using the closure theorem for the negative index of the linearized Hamiltonian, we classify all possible bifurcations of unstable eigenvalues...
0506034v1
2005-07-16
Generalized synchronization in coupled Ginzburg-Landau equations and mechanisms of its arising
Generalized chaotic synchronization regime is observed in the unidirectionally coupled one-dimensional Ginzburg-Landau equations. The mechanism resulting in the generalized synchronization regime arising in the coupled spatially extended chaotic systems demonstrating spatiotemporal chaotic oscillations has been describ...
0507035v2
2005-08-22
Coupled KdV equations derived from atmospherical dynamics
Some types of coupled Korteweg de-Vries (KdV) equations are derived from an atmospheric dynamical system. In the derivation procedure, an unreasonable $y$-average trick (which is usually adopted in literature) is removed. The derived models are classified via Painlev\'e test. Three types of $\tau$-function solutions an...
0508029v1
2005-09-06
On possibility of realization of the phenomena of complex analytic dynamics in physical systems. Novel mechanism of the synchronization loss in coupled period-doubling systems
The possibility of realization of the phenomena of complex analytic dynamics for the realistic physical models are investigated. Observation of the Mandelbrot and Julia sets in the parameter and phase spaces both for the discrete maps and non-autonomous continuous systems is carried out. For these purposes, the method,...
0509012v1
2005-09-07
Nonsingular positon and complexiton solutions for the coupled KdV system
Taking the coupled KdV system as a simple example, analytical and nonsingular complexiton solutions are firstly discovered in this letter for integrable systems. Additionally, the analytical and nonsingular positon-negaton interaction solutions are also firstly found for S-integrable model. The new analytical positon, ...
0509018v1
2005-11-16
Low-dimensional chaos in populations of strongly-coupled noisy maps
We characterize the macroscopic attractor of infinite populations of noisy maps subjected to global and strong coupling by using an expansion in order parameters. We show that for any noise amplitude there exists a large region of strong coupling where the macroscopic dynamics exhibits low-dimensional chaos embedded in...
0511031v1
2006-01-31
Duration of the Process of Complete Synchronizationof Two Coupled Identical Chaotic Systems
We consider the time required for complete synchronization of two identical one-way coupled vander Pol-Duffing oscillators occurring in the regime of dynamic chaos. The influence of the initial phase differ-ence between oscillators on the duration of the process of complete synchronization has been studied. At a fixedp...
0601073v1
2006-03-08
A geometric framework for phase synchronization in coupled noisy nonlinear systems
A geometric approach is introduced for understanding the phenomenon of phase synchronization in coupled nonlinear systems in the presence of additive noise. We show that the emergence of cooperative behaviour through a change of stability via a Hopf bifurcation entails the spontaneous appearance of a gauge structure in...
0603015v1
2006-05-10
Synchronisation schemes for two dimensional discrete systems
In this work we consider two models of two dimensional discrete systems subjected to three different types of coupling and analyse systematically the performance of each in realising synchronised states.We find that linear coupling effectively introduce control of chaos along with synchronisation,while synchronised cha...
0605022v1
2006-06-14
Strength distributions and symmetry breaking in coupled microwave billiards
Flat microwave cavities can be used to experimentally simulate quantum mechanical systems. By coupling two such cavities, we study the equivalent to the symmetry breaking in quantum mechanics. As the coupling is tunable, we can measure resonance strength distributions as a function of the symmetry breaking. We analyze ...
0606037v1
2006-07-22
Simultaneous and Sequential Synchronisation in Arrays
We discuss the possibility of simultaneous and sequential synchronisation in vertical and horizontal arrays of unidirectionally coupled discrete systems. This is realized for the specific case of two dimensional Gumowski-Mira maps. The synchronised state can be periodic,thereby bringing in control of chaos, or chaotic ...
0607049v1
2007-03-07
Sublattice synchronization of chaotic networks with delayed couplings
Synchronization of chaotic units coupled by their time delayed variables are investigated analytically. A new type of cooperative behavior is found: sublattice synchronization. Although the units of one sublattice are not directly coupled to each other, they completely synchronize without time delay. The chaotic trajec...
0703009v1
2007-03-09
Chimera Ising Walls in Forced Nonlocally Coupled Oscillators
Nonlocally coupled oscillator systems can exhibit an exotic spatiotemporal structure called chimera, where the system splits into two groups of oscillators with sharp boundaries, one of which is phase-locked and the other is phase-randomized. Two examples of the chimera states are known: the first one appears in a ring...
0703015v1
1995-11-03
Bounds on new Majoron models from the Heidelberg-Moscow-Experiment
In recent years several new Majoron models were invented to avoid shortcomings of the classical models while leading to observable decay rates in double beta experiments. We give the first experimental half life bounds on double beta decays with new Majoron emission and derive bounds on the effective neutrino--Majoron ...
9511001v1
1992-11-11
On the pion-nucleon coupling constant
In view of persisting misunderstanding about the determination of the pion-nucleon coupling constants in the Nijmegen multienergy partial-wave analyses of pp, np, and pbar-p scattering data, we present additional information which may clarify several points of discussion. We comment on several recent papers addressing ...
9211007v1
1993-12-22
Theory of Coupled Pion--Trinucleon Systems
We derive the dynamical equations which consistently couple the four--body ($\pi$NNN) system to the underlying three--nucleon system. Our treatment can be considered the proper generalization of the Afnan--Blankleider equations for the coupled NN--$\pi$NN system. The resulting connected--kernel equation resembles in st...
9312016v1
1994-08-16
Limits on the Domain of Coupling Constants for Binding N-Body Systems with No Bound Subsystems
We study the domain of coupling constants for which a 3-body or 4-body system is bound while none of its subsystems is bound. Limits on the size of the domain are derived from a variant of the Hall--Post inequalities which relate $N$-body to $(N-1)$-body energies at given coupling. Possible applications to halo nuclei ...
9408017v1
1995-06-08
Extraction of the $πNN$ coupling constant from NN scattering data
We reexamine Chew's method for extracting the $\pi NN$ coupling constant from np differential cross section measurements. Values for this coupling are extracted below 350 MeV, in the potential model region, and up to 1 GeV. The analyses to 1~GeV have utilized 55 data sets. We compare these results to those obtained via...
9506005v1
1995-12-06
QCD Scales in Finite Nuclei
The role of QCD scales and chiral symmetry in finite nuclei is examined. The Dirac-Hartree mean-field coupling constants of Nikolaus, Hoch, and Madland (NHM) are scaled in accordance with the QCD-based prescription of Manohar and Georgi. Whereas the nine empirically-based coupling constants of NHM span thirteen orders ...
9512011v1
1996-02-02
Derivative-Coupling Models and the Nuclear-Matter Equation of State
The equation of state of saturated nuclear matter is derived using two different derivative-coupling Lagrangians. We show that both descriptions are equivalent and can be obtained from the sigma-omega model through an appropriate rescaling of the coupling constants. We introduce generalized forms of this rescaling to s...
9602004v1
1996-02-09
Collective Coordinates and the Absence of Yukawa Coupling in the Classical Skyrme Model
In systems with constraints, physical states must be annihilated by the constraints. We make use of this rule to construct physical asymptotic states in the Skyrme model. The standard derivation of the Born terms with asymptotic physical states shows that there is no Yukawa coupling for the Skyrmion. We propose a remed...
9602014v1
1997-03-12
f [N pi N]: from quarks to the pion derivative coupling
We study the N pi N coupling, in the framework of a QCD-inspired confining Nambu-Jona-Lasinio model. A simple relativistic confining and instantaneous quark model is reviewed. The Salpeter equation for the nucleon and the boosted pion is solved. The f [n pi n] and f[n pi Delta] couplings are calculated and they turn ou...
9703027v1
1997-12-10
Translationally-invariant coupled-cluster method for finite systems
The translational invariant formulation of the coupled-cluster method is presented here at the complete SUB(2) level for a system of nucleons treated as bosons. The correlation amplitudes are solution of a non-linear coupled system of equations. These equations have been solved for light and medium systems, considering...
9712038v1
1998-04-01
$νd \to μ^- Δ^{++} n$ Reaction and Axial Vector $N-Δ$ Coupling
The reaction $\nu d \to \mu^- \Delta^{++} n$ is studied in the region of low $q^2$ to investigate the effect of deuteron structure and width of the $\Delta$ resonance on the differential cross section. The results are used to extract the axial vector $N-\Delta$ coupling $C^{A}_5$ from the experimental data on this reac...
9804007v1
1998-05-04
Axial Vector Coupling Constant in Chiral Colour Dielectric Model
The axial vector coupling constants of the $\beta$ decay processes of neutron and hyperon are calculated in SU(3) chiral colour dielectric model (CCDM). Using these axial coupling constants of neutron and hyperon, in CCDM we calculate the integrals of the spin dependent structure functions for proton and neutron. Our r...
9805005v1
1998-05-07
Quark-meson coupling model with constituent quarks: Exchange and pionic effects
The binding energy of nuclear matter including exchange and pionic effects is calculated in a quark-meson coupling model with massive constituent quarks. As in the case with elementary nucleons in QHD, exchange effects are repulsive. However, the coupling of the mesons directly to the quarks in the nucleons introduces ...
9805019v1
1998-08-11
Inside Mesons: Coupling Constants and Form Factors
We illustrate the progress of covariant QCD phenomenology for the description of meson coupling constants and form factors. As examples, we discuss the $\rho\pi\pi$ and $\gamma \pi\rho$ interactions, the $\rho$ contribution to the pion charge radius, and the $\rho NN$ and $\omega NN$ vector and tensor coupling constant...
9808029v1
1998-11-24
The $K^\ast Kπ$ and $ρππ$ couplings in QCD
The light cone QCD sum rules are derived for the $K^\ast K\pi$ coupling $g_{K^\ast K\pi} $ and the $\rho\pi\pi$ coupling $g_{\rho\pi\pi}$. The contribution from the excited states and the continuum is subtracted cleanly through the double Borel transform with respect to the two external momenta, $p_1^2$, $p_2^2=(p-q)^2...
9811086v1
1999-05-06
The $ΛΛ-ΞN$ Coupling and the Binding Energy of $_{ΛΛ}^{6}}$He
To understand the difference between the value of the nn and Lambda-Lambda two-body matrix elements, we examine the role of the coupling between the Lambda-Lambda and Xi-N channels, first within the framework of SU(3), and second in the numerical results for the binding energy of Lambda-Lambda 6He. We find that it is e...
9905014v1
1999-08-18
Sensitivity to the pion-nucleon coupling constant in partial-wave analyses of elastic pi-N and NN scattering and pion photoproduction
We summarize results obtained in our studies of the pion-nucleon coupling constant. Several different techniques have been applied to pi-N and NN elastic scattering data, and the existing database for single-pion photoproduction. The most reliable determination comes from pi-N elastic scattering. The sensitivity in thi...
9908057v1
1999-10-19
Nuclear Matter with Quark-Meson Coupling II: Modeling a Soliton Liquid
We study in further detail a nontopological soliton model with coupling between quarks and mesons selected as promising in the previous work. Here we go beyond the Wigner-Seitz approximation by introducing the disorder necessary to reproduce the liquid state. We study nuclear matter, with particular interest in the tra...
9910051v1
1999-10-20
Color superconductivity in weak coupling
We derive perturbatively the gap equations for a color-superconducting condensate with total spin J=0 in dense QCD. At zero temperature, we confirm the results of Son for the dependence of the condensate on the coupling constant, and compute the prefactor to leading logarithmic accuracy. At nonzero temperature, we find...
9910056v1
1999-12-22
Statistical aspects of nuclear coupling to continuum
Various global characteristics of the coupling between the bound and scattering states are explicitly studied based on realistic Shell Model Embedded in the Continuum. In particular, such characteristics are related to those of the scattering ensemble. It is found that in the region of higher density of states the coup...
9912055v1
2000-08-28
Supersymmetric Transformations in Coupled-Channel Systems
A transformation of supersymmetric quantum mechanics for N coupled channels is presented, which allows the introduction of up to N degenerate bound states without altering the remaining spectrum of the Hamiltonian. Phase equivalence of the Hamiltonian can be restored by two successive supersymmetric transformations at ...
0008054v1
2000-11-30
Parity-Violating Pion-Nucleon Coupling h_{πNN}^{(1)} from π^+ Electroproton Production Near the Threshold
We study the possibility of measuring parity-violating pion-nucleon coupling h_{\pi NN}^{(1)} from \pi^+ electroproton production in the threshold region. We calculate the electron-helicity asymmetry in terms of h_{\pi NN}^{(1)} and the Z-boson exchange between the electron and proton in leading-order heavy-baryon chir...
0011100v1
2001-02-13
Propagation of mesons in asymmetric nuclear matter in a density dependent coupling model
We study the propagation of the light mesons sigma, omega, rho, and a0(980) in dense hadronic matter in an extended derivative scalar coupling model. Within the scheme proposed it is possible to unambiguously define effective density-dependent couplings at the Lagrangian level. We first apply the model to study asymmet...
0102029v1
2001-03-04
Quark mean field model with density dependent couplings for finite nuclei
The quark mean field model, which describes the nucleon using the constituent quark model, is applied to investigate the properties of finite nuclei. The couplings of the scalar and vector mesons with quarks are made density dependent through direct coupling to the scalar field so as to reproduce the relativistic Bruec...
0103008v1
2001-03-13
The coupling constants g_{ρπγ} and g_{ωπγ} as derived from QCD sum rules}
We employ QCD sum rules to calculate the coupling constants g$_{\rho\pi\gamma}$ and g$_{\omega\pi\gamma}$ by studying the three point ${\rho\pi\gamma}$- and ${\omega\pi\gamma}$-correlation functions. Our results for the decay widths $\Gamma(\rho^0\to \pi^0\gamma)$ and $\Gamma(\omega\to \pi^0\gamma)$ calculated using th...
0103033v1
2001-05-07
Effective hadron masses and couplings in nuclear matter and incompressibility
The role of effective hadron masses and effective couplings in nuclear matter is studied using a generalized effective Lagrangian for sigma-omega model. A simple relation among the effective masses, the effective couplings and the incompressibility K is derived. Using the relation, it is found that the effective repuls...
0105020v2
2001-09-19
Effect of particle-phonon coupling on pairing correlations in nuclei
The influence of particle-phonon coupling on pairing correlations in nuclei is studied by solving the Dyson equation including the anomalous (pairing) Green function. We develop the formalism for solving the equation with the minimum of approximations. The solution of the Dyson equation is compared with the diagonaliza...
0109056v1
2001-11-29
Self-consistent quantum effects in the quark meson coupling model
We derive the equation of state of nuclear matter including vacuum polarization effects arising from the nucleons and the sigma mesons in the quark-meson coupling model which incorporates explicitly quark degrees of freedom with quark coupled to the scalar and vector mesons. This leads to a softer equation of state for...
0111085v1
2002-05-08
Calculation of strongly-coupled rotational bands in terms of the tilted axis cranking model
Recently observed strongly-coupled rotational bands associated with the $\nu [505]{11/2}^-$ quasiparticle state are studied by means of a microscopic tilted axis cranking (TAC) model. The results of calculation for the routhians and the $B(M1)/B(E2)$ ratios are investigated in the light of other existing models, i.e. t...
0205023v1
2002-08-19
Microscopic $NN\to NN^{\ast}(1440)$ transition potential: Determination of $πNN^{\ast}(1440)$ and $σNN^{\ast}(1440) $ coupling constants
A $NN\to NN^{\ast}(1440)$ transition potential, based on an effective quark-quark interaction and a constituent quark cluster model for baryons, is derived in the Born-Oppenheimer approach. The potential shows significant differences with respect to those obtained by a direct scaling of the nucleon-nucleon interaction....
0208033v1
2002-08-26
Coupling of giant resonances to soft E1 and E2 modes in B-8
The dynamic coupling between giant resonance states and "soft", low-energy excitation, modes in weakly-bound nuclei is investigated. A coupled-channels calculation is reported for the reaction 8B + Pb --> p + 7Be + Pb at 83 MeV/nucleon. It is shown that the low-energy response is only marginally modified by transitions...
0208054v1
2002-10-16
Nuclear and Neutron Star Radii
We investigate the correlation between nuclear neutron radii and the radius of neutron stars. We use a well-established hadronic SU(3) model based on chiral symmetry that naturally includes non-linear vector meson and scalar meson - vector meson couplings. The relative strengths of the couplings modify the nuclear isos...
0210053v1
2002-11-12
Effect of tensor couplings in a relativistic Hartree approach for finite nuclei
The relativistic Hartree approach describing the bound states of both nucleons and anti-nucleons in finite nuclei has been extended to include tensor couplings for the $\omega$- and $\rho$-meson. After readjusting the parameters of the model to the properties of spherical nuclei, the effect of tensor-coupling terms ris...
0211034v1
2003-04-14
Fusion and Breakup of Halo Nuclei
We discuss the effect of the coupling to the break-up channel on the total fusion involving a halo nucleus with a heavy target. We show that there is a competition between the hindrance arising from this coupling, mostly at above barrier energies, and the enhancement which ensues at sub-barrier energies owing to the st...
0304043v1
2003-06-13
Warm asymmetric matter in the Quark Meson Coupling Model
In this work we study the warm equation of state of asymmetric nuclear matter in the quark meson coupling model which incorporates explicitly quark degrees of freedom, with quarks coupled to scalar, vector and isovector mesons. Mechanical and chemical instabilities are discussed as a function of density and isospin asy...
0306045v1
2003-12-25
Stellar matter in the Quark-Meson-Coupling Model with neutrino trapping
The properties of hybrid stars formed by hadronic and quark matter in $\beta$-equilibrium are described by appropriate equations of state (EoS) in the framework of the quark meson coupling (QMC) model. In the present work we include the possibility of trapped neutrinos in the equation of state and obtain the properties...
0312112v2
2004-02-26
Effects of phonon-phonon coupling on low-lying states in neutron-rich Sn isotopes
Starting from an effective Skyrme interaction we present a method to take into account the coupling between one- and two-phonon terms in the wave functions of excited states. The approach is a development of a finite rank separable approximation for the quasiparticle RPA calculations proposed in our previous work. The ...
0402096v1
2004-03-23
A Semiclassical Approach to Fusion Reactions
The semiclassical method of Alder and Winther is generalized to study fusion reactions. As an illustration, we evaluate the fusion cross section in a schematic two-channel calculation. The results are shown to be in good agreement with those obtained with a quantal Coupled-Channels calculation. We suggest that in the c...
0403070v1
2004-04-26
Role of the Landau-Migdal Parameters with the Pseudovector and the Tensor Coupling in Relativistic Nuclear Models -- The Quenching of the Gamow-Teller Strength --
Role of the Landau-Migdal parameters with the pseudovector ($g_a$) and the tensor coupling ($g_t$) is examined for the giant Gamow-Teller (GT) states in the relativistic random phase approximation (RPA). The excitation energy is dominated by both $g_a$ and $g_t$ in a similar way, while the GT strength is independent of...
0404074v1
2005-01-27
Full-coupled channel approach to S=-2 s-shell hypernuclear systems
We describe full-coupled-channel ab initio calculations among the octet baryons for S=-2 s-shell hypernuclei,_{LambdaLambda}^4H,_{LambdaLambda}^5H and_{LambdaLambda}^6He. The wave function includes Lambda Lambda, Lambda Sigma, N Xi, and Sigma Sigma channels. Minnesota NN, D2^\prime YN and Nijmegen model D simulated YY ...
0501071v1
2005-02-02
J/Psi strong couplings to the vector mesons
We present a study of the cross sections J/Psi X --> D^(*) \bar D^(*) (X = rho, Phi) based on the calculation of the effective tri- and four-linear couplings J/Psi (X) D^(*) \bar D^(*) within a constituent quark model. In particular, the details of the calculation of the four-linear couplings J/Psi X D^(*)\bar D^(*) ...
0502009v1
2005-03-04
K-Lambda and K-Sigma photoproduction in a coupled channels framework
A coupled channels analysis, based on the K-matrix approach, is presented for photo-induced kaon production. It is shown that channel coupling effects are large and should not be ignored. The importance of contact terms in the analysis, associated with short range correlations, is pointed out. The extracted parameters ...
0503013v3