June 1998 arXiv papers — page 3

S. J. Peale

The dependence of microlensing time scale frequency distributions and optical depth toward the galactic center on galactic model parameters is explored in detail for a distribution of stars consisting of the Zhao (1996) bar and nucleus and the Bahcall and Soneira (1980) double exponential disk. The high sensitivity of these two microlensing measures to the c

Guillermo Tenorio-Tagle, Gustavo Medina Tanco

Several structures have been discovered embedded in regions of recent or ongoing star formation, which point to the importance of the interaction between fast moving wind-blowing stars and their environment. Using hydrodynamic simulations, we investigate the passage through the interstellar medium of a supersonic stellar wind source, and show how it can natu

Satoshi Sawai, Yoji Aizawa

A simple coupled oscillator system with chemotaxis is introduced to study morphogenesis of cellular slime molds. The model successfuly explains the migration of pseudoplasmodium which has been experimentally predicted to be lead by cells with higher intrinsic frequencies. Results obtained predict that its velocity attains its maximum value in the interface r

S. Deser, Orit Levin

We present a unified description of temperature and entropy in spaces with either "true" or "accelerated observer" horizons: In their (higher dimensional) global embedding Minkowski geometries, the relevant detectors have constant accelerations a_{G}; associated with their Rindler horizons are temperature a_{G}/2πand entropy equal to 1/4 the

J. Steinbach, C. C. Gerry

We propose a method for generating maximally entangled states of N two-level trapped ions. The method is deterministic and independent of the number of ions in the trap. It involves a controlled-NOT acting simultaneously on all the ions through a dispersive interaction. We explore the potential application of our scheme for high precision frequency standards

K. Itakura, S. Maedan, M. Tachibana

We investigate canonical structure of the Abelian Higgs model within the framework of DLCQ. Careful boundary analysis of differential equations, such as the Euler-Lagrange equations, leads us to a novel situation where the canonical structure changes in a drastic manner depending on whether the (light-front) spatial Wilson line is periodic or not. In the for

R. M. Kippen, M. S. Briggs, J. M. Kommers, C. Kouveliotou

The recent discovery of a supernova (SN 1998bw) seemingly associated with GRB~980425 adds a new twist to the decades-old debate over the origin of gamma-ray bursts. To investigate the possibility that some (or all) bursts are associated with supernovae, we performed a systematic search for temporal/angular correlations using catalogs of BATSE and BATSE/{\it

M. D. Todorov

The classical Helmholtz problem is applied for modelling and numerical investigation of inviscid cusp-ended separated flow around circular cylinder. Two coordinate systems are used: polar for initial calculations and parabolic as topologically most suited for infinite stagnation zone. Scaling by the shape of the unknown free line renders the problem to compu

Vladimir Pavlov, Andrei Starinets

We study geometry of the phase space for finite-dimensional dynamical systems with degenerate Lagrangians. The Lagrangian and Hamiltonian constraint formalisms are treated as different local-coordinate pictures of the same invariant procedure. The invariant description is given in terms of geometrical objects associated with the structure of foliation on the

Jan Cnops, Vladimir Kisil

We describe several different representations of nilpotent step two Lie groups in spaces of monogenic Clifford valued functions. We are inspired by the classic representation of the Heisenberg group in the Segal-Bargmann space of holomorphic functions. Connections with quantum mechanics are described. Keywords: Segal-Bargmann space, Heisenberg group, coheren

J. N. Prata

We consider the SU(2) Principal Chiral Model (at level $k=1$) on the half-line with scale invariant boundary conditions. By looking at the IR limiting conformal field theory and comparing with the Kondo problem, we propose the set of permissible boundary conditions and the corresponding reflection factors.

A. A. Andrianov, R. Soldati, L. Sorbo

We study the renormalizable abelian vector-field models in the presence of the Wess-Zumino interaction with the pseudoscalar matter. The renormalizability is achieved by supplementing the standard kinetic term of vector fields with higher derivatives. The appearance of fourth power of momentum in the vector-field propagator leads to the super-renormalizable

Hugo Christiansen

We analyze the formation of fermionic condensates in two dimensional quantum chromodynamics for matter in the fundamental representation of the gauge group. We show that a topological regular instanton background is crucial in order to obtain nontrivial correlators. We discuss both massless and massive cases.

M. A. Stephanov

We show that current experimental knowledge of QCD together with general model independent arguments such as continuity, universality and thermodynamic relations, as well as the information gained from various models can be used to constrain the phase diagram of QCD as a function of temperature and baryon chemical potential.

J. P. B. C de Melo, A. E. A. Amorim, Lauro Tomio, T. Frederico

The Relativistic formulation of the three-boson model interacting via a zero-range two-body force in the null-plane is given in 2+1 and 1+1 space-time dimension. The bound state energy is calculed as function of the two-body boson binding energy.

W. R. B. de Araujo, J. P. B. C de Melo, T. Frederico

The proton is formulated as a relativistic system of three constituent quarks interacting via a zero-range two-body force in the null-plane. The covariance of the null-plane Faddeev-like equation under kinematical front-form boosts is discussed. A simplified three-boson model of the nucleon wave-function is obtained numerically. The proton electric form-fact

G. Raffelt

The status of several current and proposed experiments to search for galactic dark-matter and solar axions is reviewed in the light of astrophysical and cosmological limits on the Peccei-Quinn scale.

Ting-Wai Chiu, Chih-Wei Wang, Sergei V. Zenkin

We analyse the structure of solutions of the Ginsparg-Wilson relation for lattice Dirac operator in topologically trivial gauge sector. We show that the properties of such solutions relating to the perturbative stability of the pole of the fermion propagator as well as to the structure of the Yukawa models based on these solutions are solely determined by th

The OPAL Collaboration, K. Ackerstaff et al

An upper limit for the tau-neutrino mass has been determined from the decay tau -> 5pi+- ν_tau using data collected with the OPAL detector from 1991 to 1995 in e+e- collisions at \sqrt{s} ~ M_Z. A limit of 43.2 MeV at 95% CL is obtained using a two-dimensional method in the 5pi invariant mass and energy distribution from 22 selected events. Combining this re

Reza Mansouri, Kourosh Nozari

Colombeau's generalized functions are used to adapt the distributional approach to singular hypersurfaces in general relativity with signature change. Equations governing the dynamics of singular hypersurface is obtained and it is shown that matching leads to de Sitter space for the Lorentzian region. The matching is possible for different sections of th

Hideki Asada, Toshifumi Futamase

We discuss various aspects of the post-Newtonian approximation in general relativity. After presenting the foundation based on the Newtonian limit, we use the (3+1) formalism to formulate the post-Newtonian approximation for the perfect fluid. As an application we show the method for constructing the equilibrium configuration of nonaxisymmetric uniformly rot

J. M. Kosterlitz, N. Akino

The two dimensional XY spin glass is studied numerically by a finite size scaling method at T=0 in the vortex representation which allows us to compute the exact (in principle) spin and chiral domain wall energies. We confirm earlier predictions that there is no glass phase at any finite T. Our results strongly support the conjecture that both spin and chira

Mincheol Shin, Seongjae Lee, Kyoung Wan Park, El-Hang Lee

We have theoretically investigated the transport properties of a ring-shaped array of small tunnel junctions, which is weakly coupled to the drain electrode. We have found that the long range interaction together with the semi-isolation of the array bring about the formation of stable standing configurations of electrons. The stable configurations break up d

Patrick S. Osmer, Julia D. Kennefick, Patrick B. Hall, Richard F. Green

We make available in electronic form the stellar catalog of 19,494 objects from the Deep Multicolor Survey (DMS). The DMS is based on CCD imaging with the Mayall 4-m telescope in U,B,V,R',I75,I86 and covers 0.83 sq. deg. in six fields at high galactic latitude. The survey reached 5 sigma limiting magnitudes of 22.1 in I86 to 23.8 in B. The catalog gives

R. P. van der Marel

The surface brightness profiles of early-type galaxies have central cusps. Two characteristic profile types are observed with HST: `core&#39; profiles have a break at a resolved radius and logarithmic cusp slope gamma < 0.3 inside that radius; `power-law&#39; profiles have no clear break and gamma > 0.3. With few exceptions, galaxies with M_V < -22 have core

Maxim Lyutikov, Roger D. Blandford, George Machabeli

A theory of pulsar radio emission generation, in which the observed waves are produced directly by maser-type plasma instabilities operating at the anomalous cyclotron-Cherenkov resonance $ω- k_{\parallel} v_{\parallel} + ω_B/ γ_{res}=0$ and the Cherenkov-drift resonance $ω- k_{\parallel} v_{\parallel} - k_{\perp} u_d =0$, is capable of explaining the main o

Wayne Hu, Daniel J. Eisenstein, Max Tegmark, Martin White

Determining the properties of the dark components of the universe remains one of the outstanding challenges in cosmology. We explore how upcoming CMB anisotropy measurements, galaxy power spectrum data, and supernova (SN) distance measurements can observationally constrain their gravitational properties with minimal assumptions on the theoretical side. SN ob

J. Williams, R. Walser, J. Cooper, E. Cornell

We propose an experiment that would demonstrate nonlinear Josephson-type oscillations in the relative population of a driven, two-component Bose-Einstein condensate. An initial state is prepared in which two condensates exist in a magnetic trap, each in a different hyperfine state, where the initial populations and relative phase between condensates can be c

Stanislaw Mrowczynski

The so-called $Φ$ parameter, which measures the transverse momentum or energy correlations (fluctuations) in high-energy collisions independently of the particle multiplicity, is computed for the equilibrium ideal gas. As expected $Φ$ vanishes for the particles obeying Boltzmann statistics but is finite for the quantum particles, positive for bosons and nega

Angel Ballesteros, Francisco J. Herranz, Preeti Parashar

Multiparametric quantum deformations of $gl(2)$ are studied through a complete classification of $gl(2)$ Lie bialgebra structures. From them, the non-relativistic limit leading to harmonic oscillator Lie bialgebras is implemented by means of a contraction procedure. New quantum deformations of $gl(2)$ together with their associated quantum $R$-matrices are o

Daniel Kabat, Gilad Lifschytz

Any probe which crosses the horizon of a black hole should be absorbed. In M(atrix) theory, for 0-brane probes of Schwarzschild black holes, we argue that the relevant absorption mechanism is a tachyon instability which sets in at the horizon. We give qualitative arguments, and some quantitative large-N calculations, in support of this claim. The tachyon ins

Valeria Ferrari, Sabino Matarrese, Raffaella Schneider

We estimate the spectral properties of the stochastic background of gravitational radiation emitted by a cosmological population of hot, young, rapidly rotating neutron stars. Their formation rate as a function of redshift is deduced from an observation-based determination of the star formation history in the Universe, and the gravitational energy is assumed

J. Eisert, M. Wilkens, M. Lewenstein

We investigate the quantization of non-zero sum games. For the particular case of the Prisoners&#39; Dilemma we show that this game ceases to pose a dilemma if quantum strategies are allowed for. We also construct a particular quantum strategy which always gives reward if played against any classical strategy.

WA98 Collaboration, M. M. Aggarwal et al

The production of neutral pions in 158AGeV Pb+Pb collisions has been studied in the WA98 experiment at the CERN SPS. Transverse momentum spectra are studied for the range 0.3 GeV/c < mT-m0 < 4.0 GeV/c. The results for central collisions are compared to various models. The centrality dependence of the neutral pion spectral shape and yield is investigated. An

Michael Lassig

This article reviews recent developments in statistical field theory far from equilibrium. It focuses on the Kardar-Parisi-Zhang equation of stochastic surface growth and its mathematical relatives, namely the stochastic Burgers equation in fluid mechanics and directed polymers in a medium with quenched disorder. At strong stochastic driving -- or at strong

Alexei Kolesnikov

We apply the diagram-technique formalism beyond the Hartree-Fock approximation to a two-dimensional nearly ideal electron gas in a weak perpendicular magnetic field. The case of an almost completely filled upper Landau level (filling factor $ν_0 \lesssim 1$) with a quantum number $N_0 \gg 1$ is considered. We uncover two regimes of renormalization by electro

M. Lubo, M. Rooman, Ph. Spindel

We investigate, in the framework of (2+1) dimensional gravity, stationary, rotationally symmetric gravitational sources of the perfect fluid type, embedded in a space of arbitrary cosmological constant. We show that the matching conditions between the interior and exterior geometries imply restrictions on the physical parameters of the solutions. In particul

D. Falcone, F. Tramontano

Simple transformation formulas between fermion matrices and observables, and numerical values of quark matrices, are obtained on a particular weak basis with one quark matrix diagonal and the other with vanishing elements 1-1, 1-3 and 3-1, and with only the element 2-2 complex. When we choose $M_u$ diagonal, then $M_d$ shows intriguing numerical properties w

E. T. Akhmedov

The correspondence between the four-dimensional SU(N), $\cN = 4$ SYM taken at large $N$ and the type II B SUGRA on the $AdS_5\times S_5$ background is considered. We argue that the classical equations of motion in the SUGRA picture can be interpreted as that of the renormalization group on the SYM side. In fact, when the D3-brane is slightly excited higher d

Marc Chemtob, Grégory Moreau

We examine the effects of the R parity odd renormalizable interactions on flavor changing rates and CP violation asymmetries in the production of fermion-antifermion pairs at $e^-- e^+$ leptonic colliders. The produced fermions may be leptons, down-quarks or up-quarks, and the center of mass energies may range from the Z-boson pole up to $ 1000$ GeV. Off the

Mulugeta Bekele, S. Rajesh, G. Ananthakrishna, N. Kumar

Kinetic aspect of Landauer&#39;s blowtorch effect is investigated for a model double-well potential with localized heating. Using the supersymmetric approach, we derive an approximate analytical expression for the equilibration rate as function of the strength, width and the position of the hot zone, and the barrier height. We find that the presence of the h

Sergio Lupia

The QCD evolution equations in Modified Leading Log Approximation for the factorial moments of the multiplicity distribution in quark and gluon jets are numerically solved with initial conditions at threshold by fully taking into account the energy conservation law. After applying Local Parton Hadron Duality as hadronization prescription, a consistent quanti

Monique Arnaud, August E. Evrard

We re-examine the X-ray luminosity-temperature relation using a nearly homogeneous data set of 24 clusters selected for statistically accurate temperature measurements and absence of strong cooling flows. The data exhibit a remarkably tight power-law relation between bolometric luminosity and temperature with a slope 2.88 \pm 0.15. With reasonable assumption

G. E. Arutyunov, S. A. Frolov

The standard formulation of the AdS/CFT correspondence is incomplete since it requires adding to a supergravity action some a priori unknown boundary terms. We suggest a modification of the correspondence principle based on the Hamiltonian formulation of the supergravity action, which does not require any boundary terms. Then all the boundary terms of the st

P. D. Drummond, J. F. Corney

We report on dynamical simulations of Bose-Einstein condensation via evaporative cooling in an atomic trap. The results show evidence for spontaneous vortex formation and quantum dynamics in small traps.

A. Refregier, D. N. Spergel, T. Herbig

(Abridged) While the major contribution to the Cosmic Microwave Background (CMB) anisotropies are the sought-after primordial fluctuations produced at the surface of last scattering, other effects produce secondary fluctuations at lower redshifts. Here, we study the extragalactic foregrounds of the CMB in the context of the upcoming MAP mission. We first sur

Jiunn-Wei Chen, Harald W. Griesshammer, Martin J. Savage, Roxanne P. Springer

The scalar and tensor polarizabilities of the deuteron are calculated using the recently developed effective field theory that describes nucleon-nucleon interactions. Leading and next-to-leading order contributions in the perturbative expansion predict a scalar electric polarizability of 0.595 fm^3. The tensor electric polarizability receives contributions s

Ruvin Ferber

The paper presents an attempt to suggest an alternative way of considering the fundamentals of Einstein&#39;s special relativity theory. Its formulation based on introducing an inertial reference system by rigid linking of clocks to a free entity to define proper time is self-contradictory since the operation of rigid linking involves interaction which is ex

Craig D. Roberts

These lecture notes illustrate the application of Dyson-Schwinger equations in QCD. The extensive body of work at zero temperature and chemical potential is represented by a selection of contemporary studies that focus on solving the Bethe-Salpeter equation, deriving an exact mass formula in QCD that describes light and heavy pseudoscalar mesons simultaneous

P. Papazoglou, D. Zschiesche, S. Schramm, J. Schaffner-Bielich

Nuclei can be described satisfactorily in a nonlinear chiral SU(3)-framework, even with standard potentials of the linear $σ$-model. The condensate value of the strange scalar meson is found to be important for the properties of nuclei even without adding hyperons. By neglecting terms which couple the strange to the nonstrange condensate one can reduce the m

Guy Chanfray, Dany Davesne

This paper is devoted to the interplay between p-wave, s-wave pion-nucleon/ nucleus interaction and in-medium pion-pion interaction with special emphasis on the role of the nuclear pionic scalar density driving a large amount of chiral symmetry restoration. In particular we show that the $πNN$ coupling constant and the Goldberger-Treiman relation are preserv

Takashi Nakatsukasa, Yoshifumi R Shimizu

We investigate the effect of the Coriolis coupling and the residual interactions upon the inter-band transition rates for the vibrational bands and the decay of two-quasiparticle high-K isomers.

Takashi Nakatsukasa, Niels R Walet

We discuss the application of a theory of large-amplitude collective motion to a simple model mimicking the pairing-plus-quadrupole model of nuclear physics.

J. Uhlig, J. C. Lemm, A. Weiguny

Three variants of mean field methods for atomic and nuclear reactions are compared with respect to both conception and applicability: The time--dependent Hartree--Fock method solves the equation of motion for a Hermitian density operator as initial value problem, with the colliding fragments in a continuum state of relative motion. With no specification of t

K. Kar, S. Chakravarti, A. Ray, S. Sarkar

A detailed model for the calculation of beta decay rates of the $fp$ shell nuclei for situations prevailing in pre-supernova and collapse phases of evolution of the core of massive stars leading to supernova explosion has been extended for electron-capture rates. It can also be used to determine the half-lives of neutron-rich nuclei in the $fp/fpg$ shell. Th

W. C. Haxton, R. G. H. Robertson

The ratio of 18O nuclei to electrons in SuperKamiokande is quite small, about 1:5000. However this nucleus provides two unpaired neutrons and a low threshold for solar neutrino absorption, resulting in an unusually large cross section. The 18O nuclei, together with 17O and deuterium, will produce in excess of 460 scattered electrons per year with energies ab

Marjorie Batchelor

Measuring comodules are defined and shown to provide a useful generalization of the set of maps between modules with a broad range of applications. Three applications are described. Connections on bundles are described in terms of measuring comodules, enabling curvature to be defined under general algebraic circumstances. Loop algebras are realized via a sho

Gunnar Floystad

This is a little investigation into the classification of complexes of direct sums of line bundles on projective spaces. We consider complexes on projective k-space Pk : O_Pk(-1)^a --> O_Pk^b --> O_Pk(1)^c, with the first map injective and the second map surjective. This is called a monad. We classify completely when such monads exist. Furthermore, whenever

Dominic Joyce

Let X/G be a 3-dimensional Calabi-Yau orbifold with codimension 2 singularities. The topology of crepant resolutions of X/G is described by the McKay correspondence (Reid, Ito). We study Calabi-Yau 3-folds Y that arise by deforming the complex structure of X/G. The McKay correspondence does not hold for such Y. We describe the topology of Y using the `Weyl g

C. Badea

Various notions of stable ranks are studied for topological algebras. Some partial answers to R.G. Swan&#39;s problem (Have two Banach or good Fréchet algebras as in the density theorem in K-theory the same stable rank ?) are obtained. For example, a Fréchet dense $\ast$-subalgebra $A$ of a $C^\ast$-algebra $B$, closed under $C^\infty$-functional calculus of

S. Di Rocco, A. J. Sommese

We characterize the triples (X,L,H), consisting of holomorphic line bundles L and H on a complex projective manifold X, such that for some positive integer k, the k-th holomorphic jet bundle of L, J_k(L), is isomorphic to a direct sum H+...+H. Given the geometrical constrains imposed by a projectivized line bundle being a product of the base and a projective

G. Akemann

Universality of multicritical unitary matrix models is shown and a new scaling behavior is found in the microscopic region of the spectrum, which may be relevant for the low energy spectrum of the Dirac operator at the chiral phase transition.

Kunihiko Uehara

The theory on M_4 x Z_2 geometry is applied to the Einstein gravity to yield the Brans-Dicke theory on M_4 geometry. The geometrical meaning and the relation between the curvatures and the torsions are clarified. The cosmological constant is also introduced into the pure Einstein action on M_4 x Z_2 in order to determine the explicit form of the cosmological

H. W. Lee, Y. S. Myung

We analyze the potentials which arise from the D1--D5 brane (5D black hole). In the sufficiently low energy ($ω\ll 1$), we can derive the Schrodinger-type equation with potential $V_N$ from the linearized equations. In this case one can understand the difference between absorption cross section for a free and two fixed scalars intuitively in terms of their p

A. N. Sissakian, O. Yu. Shevchenko, S. B. Solganik

Two closely related topological phenomena are studied at finite density and temperature. These are chiral anomaly and Chern--Simons term. It occurs that the chiral anomaly doesn&#39;t depend on density and temperature. Chern-Simons term appearance in even dimensions is studied under two types of constraints: chiral and usual charges conservation. In odd dime

S. I. Bityukov, N. V. Krasnikov

We study a possibility to detect charged sleptons and flavour lepton number violation at LHC (CMS). We investigate the production and decays of right- and left-handed sleptons separately. We have found that for luminosity L = 10**5 1/pb it would be possible to detect right-handed sleptons with a mass up to 325 GeV and left-handed ones with a mass up to 350 G

Gabor Papp

We summarize some recent results on the application of macroscopic spectral properties of random matrix models (RMM) to the QCD spectra. A comparison to existing lattice simulation is presented both for staggered and Wilson fermions for high but finite temperature. We consider two type of mixing between the four lowest Matsubara modes, corresponding to third

O. Teryaev, B. Pire, J. Soffer

The spin structure of nucleon at twist 2 and 3 levels is analyzed. The contribution of quark and gluon spins to nucleon spin are Lorentz invariant, while it is not sure for orbital angular momentum. The conserved fractional moments of transversity distribution are considered. The scenario of decoupled total angular momentum, determined predominantly by the u

Gerhard Buchalla, Gino Isidori

The rare decay $K_L\toπ^0ν\barν$ is dominated by direct CP violation and can be computed with extraordinarily high precision. In principle also a CP conserving contribution to this process can arise within the Standard Model. We clarify the structure of the CP conserving mechanism, analyzing both its short-distance and long-distance components. It is pointed

J. Sa Borges, J. Soares Barbosa, M. D. Tonasse, J. Haidenbauer

We want to test the predictive power of Chiral Perturbation Theory (ChPT). In this work, we use the ChPT pion-pion scattering amplitude, including two loop contributions, and we obtain S- and P-wave low-energy phase shifts. We show that, by varying just one free parameter, the resulting S- and P-wave phase shifts are in reasonable agreement with the experime

Duane A. Dicus, Chung Kao, Wayne W. Repko

The cross sections for the processes $γν\to γγν$, $γγ\toγν\barν$ and $ν\barν\toγγγ$ are calculated for a range of center of mass energies from below $m_e$ to considerably above $m_e$, but much less than $m_W$. This enables us to treat the neutrino--electron coupling as a four--Fermi interaction and results in amplitudes which are electron box diagrams with t

B. Ziaja

Recent discussion of the possibility to study intermittency in individual events of high multiplicity by A. Bialas and myself is reported. In the framework of $α-$model it is found that, for a cascade long enough, the dispersion of intermittency exponents obtained from individual events is fairly small. This fact opens the possibility to study the distributi

I. Bertram, T. Carli, G. Gustafson, J. Hartmann

Recent measurements and theoretical developments on the hadronic final state in deep-inelastic scattering, pp and ee collisions are presented.

I. V. Kolokolov, P. V. Vorob&#39;ev

The Cherenkov radiation of magnons at passage of the heavy slow magnetic monopole through an ordered magnetic matter is considered. Also the Cherenkov radiation of phonons at monopole movement in medium is discussed.

Sandhya Choubey, Srubabati Goswami

In this paper we note that for neutrino mass squared differences in the range $10^{-4} - 10^{-1} eV^2$, vacuum neutrino oscillations can take place between the neutrino-sphere and the weak freeze-out radius in a type II supernova. Requiring that such oscillations are consistent with the r-process nucleosynthesis from supernovae one can constrain the mixing o

K. F. Liu, S. J. Dong, T. Draper, D. Leinweber

A valence QCD theory is developed to study the valence quark properties of hadrons. To keep only the valence degrees of freedom, the pair creation through the Z graphs is deleted in the connected insertions; whereas, the sea quarks are eliminated in the disconnected insertions. This is achieved with a new ``valence QCD&#39;&#39; lagrangian where the action i

Thomas J. Weiler, DJ Wagner

The model-independent &#34;box&#34; parameterization of neutrino oscillations is examined. The invariant boxes are the classical amplitudes of the individual oscillating terms. Being observables, the boxes are independent of the choice of parameterization of the mixing matrix. Emphasis is placed on the relations among the box parameters due to mixing--matrix

Dennis Silverman

We extend the range of predictions of the isosinglet (or vector) down quark model to the fully allowed physical ranges, and also update this with the effect of new physics constraints. We constrain the present allowed ranges of sin(2*beta) and sin(2*alpha), gamma, x_s, and A_{B_s}. In models allowing mixing to a new isosinglet down quark (as in E_6) flavor c

P. J. Mulders, T. Sloan

The problem of our understanding of the spin structure of the nucleon has been with us since the publication of the EMC measurements of the polarised structure function of the proton in 1987. In this talk a brief history of the subject is given followed by a review of the results presented in this workshop and the progress made to date.

CDF Collaboration, F. Abe et al

We present a detailed description of a search for anomalous production of missing E_T ($\mett$), jets, leptons ($e, μ, τ$), b-quarks, or additional photons in events containing two isolated, central ($|η|<1.0$) photons with $\Et > 12$ GeV}. The results are consistent with standard model expectations, with the possible exception of one event that has in addit

C. Chicone, B. Mashhoon, D. G. Retzloff

The long-term dynamical evolution of a Keplerian binary orbit due to the emission and absorption of gravitational radiation is investigated. This work extends our previous results on transient chaos in the planar case to the three dimensional Kepler system. Specifically, we consider the nonlinear evolution of the relative orbit due to gravitational radiation

J. Cruz, J. Navarro-Salas, M. Navarro

We give an explicit canonical transformation which transforms a generic chiral 2D dilaton gravity model into a free field theory.

Guillermo A. Mena Marugan, Manuel Montejo

Pure gravitational plane waves are considered as a special case of spacetimes with two commuting spacelike Killing vector fields. Starting with a midisuperspace that describes this kind of spacetimes, we introduce gauge-fixing and symmetry conditions that remove all non-physical degrees of freedom and ensure that the classical solutions are plane waves. In t

Jörg Frauendiener

We present a numerical scheme for determining hyperboloidal initial data sets for the conformal field equations by using pseudo-spectral methods. This problem is split into two parts. The first step is the determination of a suitable conformal factor which transforms from an initial data set in physical space-time to a hyperboloidal hypersurface in the ambie

K. A. Bronnikov

Multidimensional gravity interacting with intersecting electric and magnetic $p$-branes is considered for fields depending on a single variable. Some general features of the system behaviour are revealed without solving the field equations. Thus, essential asymptotic properties of isotropic cosmologies are indicated for different signs of spatial curvature;

Nancy P. Sandler, Claudio de C. Chamon, Eduardo Fradkin

We present a calculation of noise in the tunneling current through junctions between two two-dimensional electron gases (2DEG) in inequivalent Laughlin fractional quantum Hall (FQH) states, as a function of voltage and temperature. We discuss the interpretation of measurements of suppressed shot noise levels of tunneling currents through a quantum point cont

R. Konik, F. Lesage, A. W. W. Ludwig, H. Saleur

Recently Lin, Balents, and Fisher have demonstrated that two-leg Hubbard ladders and armchair carbon nanotubes renormalize onto the integrable SO(8) Gross-Neveu model. We exploit this integrability to examine these systems in their doped phase. Using thermodynamic Bethe ansatz, we compute exactly both the spin and single particle gaps and the Luttinger param

Marcelo R. Ubriaco

We study the properties of a thermodynamic system having the symmetry of a quantum group and interacting with a harmonic potential. We calculate the dependence of the chemical potential, heat capacity and spatial distribution of the gas on the quantum group parameter $q$ and the number of spatial dimensions $D$. In addition, we consider a fourth-order intera

E. A. Jagla

Geometrical arrangements of minimum energy of a system of identical repelling particles in two dimensions are studied for different forms of the interaction potential. Stability conditions for the triangular structure are derived, and some potentials not satisfying them are discussed. It is shown that in addition to the triangular lattice, other structures m

N. V. Brilliantov, Yu. A. Andrienko, P. L. Krapivsky, J. Kurths

We investigate the process of random sequential adsorption of polydisperse particles whose size distribution exhibits a power-law dependence in the small size limit, $P(R)\sim R^{α-1}$. We reveal a relation between pattern formation kinetics and structural properties of arising patterns. We propose a mean-field theory which provides a fair description for su

Jeferson J. Arenzon

An infinite range spin glass like model for granular systems is introduced and studied through the replica mean field formalism. Equilibrium, density dependent properties under vibration and gravity are obtained.

C. P. Moca, I. Tifrea, M. Crisan

Using the flow-equations method we showed analytically the occurence of dispersion for the local bosons in a model of hybridized of local bosons and fermions.

C. P. Moca, M. Crisan, I. Tifrea

The flow equation method has been used to calculate the energy of single impurity in a superconductor for the Anderson model with $U \neq 0$. We showed that the energy of the impurity depends only of the $Δ^{2}_{R}$ (renormalized order parameter) which depends on the renormalized Hubbard repulsion$U^R$. For a strong Hubbard repulsion $U^R = U$ and $Δ^R = Δ^I

V. N. Glazkov, A. I. Smirnov, O. A. Petrenko, D. Mck. Paul

ESR-study of the Ni-doped spin-Peierls compound CuGeO3 has been performed in the frequency range 9-75 GHz. At low temperatures the g-factor is smaller than the value expected for Cu- and Ni-ions. This anomaly is explained by the formation of magnetic clusters around the Ni-ions within a nonmagnetic spin-Peierls matrix. The transition into the AFM-state detec

R. F. Bishop, D. J. J. Farnell, Chen Zeng

The spin-half Heisenberg antiferromagnet (HAF) on the square and triangular lattices is studied using the coupled cluster method (CCM) technique of quantum many-body theory. The phase relations between different expansion coefficients of the ground-state wave function in an Ising basis for the square lattice HAF is exactly known via the Marshall-Peierls sign

H. Frauenkron, U. Bastolla, E. Gerstner, P. Grassberger

We demonstrate that the recently proposed pruned-enriched Rosenbluth method PERM (P.~Grassberger, Phys.~Rev.~{\bf E 56} (1997) 3682) leads to very efficient algorithms for the folding of simple model proteins. We test it on several models for lattice heteropolymers, and compare to published Monte Carlo studies of the properties of particular sequences. In al

P. Grassberger, und H. Frauenkron

We describe a general strategy, PERM (Pruned-Enriched Rosenbluth Method), for sampling configurations from a given Gibbs-Boltzmann distribution. The method is not based on the Metropolis concept of establishing a Markov process whose stationary state is the wanted distribution. Instead, it starts off building instances according to a biased distribution, but

N. I. Lebovka, N. V. Vygornitskii

We study numerically a two-component A-B spreading model (SMK model) for concave and convex radial growth of 2d-geometries. The seed is chosen to be an occupied circle line, and growth spreads inside the circle (concave geometry) or outside the circle (convex geometry). On the basis of generalised diffusion-annihilation equation for domain evolution, we deri

Mario Liu

Two questions connected to the macroscopic Maxwell equations are addressed: First, which form do they assume in the hydrodynamic regime, for low frequencies, strong dissipation and arbitrary field strengths. Second, what does this tell us about irreversibility and coarse-grained description.

Mario Liu

Starting from the entropy production being invariant under time reversal, one can (i) easily proof, and understand, many aspects of the linear Onsager relations and (ii) deduce the result that all quadratic Onsager coefficients for hydrodynamic fluxes vanish.