September 1999 arXiv papers — page 14

M. J. Leitch, W. M. Lee, M. E. Beddo, C. N. Brown

Measurements of the suppression of the yield per nucleon of J/Psi and Psi' production for 800 GeV/c protons incident on heavy relative to light nuclear targets have been made with very broad coverage in xF and pT. The observed suppression is smallest at xF values of 0.25 and below and increases at larger values of xF. It is also strongest at small pT. Su

Jerome P. Gauntlett, Chris M. Hull

A state saturating a BPS bound derived from a supersymmetry algebra preserves some fraction of the supersymmetry. This fraction of supersymmetry depends on the charges carried by the system, and we show that in general there are configurations of charges for which a BPS state would preserve more than half the original supersymmetry. We investigate configurat

Fabio Gavarini

The "quantum duality principle" states that the quantization of a Lie bialgebra - via a quantum universal enveloping algebra (QUEA) - provides also a quantization of the dual Lie bialgebra (through its associated formal Poisson group) - via a quantum formal series Hopf algebra (QFSHA) - and, conversely, a QFSHA associated to a Lie bialgebra (via its

M. Wusthoff, A. D. Martin

We review the application of perturbative QCD to diffractive processes. We introduce the two gluon exchange model to describe diffractive qq(bar) and qq(bar)g production in deep inelastic scattering. We study the triple Regge limit and briefly consider multiple gluon exchange. We discuss diffractive vector meson production at HERA both at t = 0 and large |t|

A. Sibirtsev, W. Cassing, U. Mosel

We study $K^+$-meson production in $γ{A}$ interaction at energies below the reaction threshold in free space. The Thomas-Fermi and spectral function approaches are used for the calculations of the production process. It is found that the measurement of the differential spectra may allow to reconstruct the production mechanism and to investigate the dispersio

Koji Hashimoto

Following our previous paper (hep-th/9909027), we generalize a supersymmetric boundary state so that arbitrary configuration of the gauge field coupled to the boundary of the worldsheet is incorpolated. This generalized boundary state is BRST invariant and satisfy the non-linear boundary conditions with non-constant gauge field strength. This boundary state

Marcos Jardim

We construct finite energy instanton connection on $R^4$ which are periodic in two directions via an analogue of the Nahm transform for certain singular solutions of Hitchin's equations defined over a 2-torus.

Xavier Bekaert, Marc Henneaux, Alexander Sevrin

Motivated by a system consisting of a number of parallel M5-branes, we study possible local deformations of a chiral two-form in six dimensions. Working to first order in the coupling constant, this reduces to the study of the local BRST cohomological group at ghost number zero. We obtain an exhaustive list of all possible deformations. None of them allows f

P. Bozhilov, B. Dimitrov

We consider null bosonic p-branes moving in curved space-times. Some exact solutions of the classical equations of motion and of the constraints for the null string and the null membrane in Demianski-Newman background are found.

Takao Suyama

We consider the entropy of a black hole which has zero area horizon. The microstates appear as monopole solutions of the effective theory on the corresponding brane configurations.The resulting entropy formula coincides with the one expected from stringy calculation and agrees with U-duality invariance of entropy.

J. Houdayer, O. C. Martin

A controversial issue in spin glass theory is whether mean field correctly describes 3-dimensional spin glasses. If it does, how can replica symmetry breaking arise in terms of spin clusters in Euclidean space? Here we argue that there exist system-size low energy excitations that are sponge-like, generating multiple valleys separated by diverging energy bar

V. A. Kulbachinskii, V. G. Kytin, A. V. Golikov, R. A. Lunin

The photoconductivity of GaAs structures delta-doped by Sn has been investigated for wavelengths lambda= 650-1200 nm in the temperature interval T= 4.2-300 K. The electron densities and mobilities, before and after illumination, have been determined by magnetoresistance, Shubnikov-de Haas effect and Hall effect measurements, in high magnetic fields. For the

A. Schenck, R. J. Keizer, A. de Visser, A. Amato

The angular and temperature (10-250 K) variation of the Knight shift of single-crystalline U(Pt0.95Pd0.05)3 has been measured in transverse field (B=0.6 T) mSR experiments. By analysing the temperature variation of the Knight shift with a modified Curie-Weiss expression the muon localization site in this hexagonal material is determined at (0,0,0).

Darwin Chang, Xiao-Gang He, Bruce H. J. McKellar

There have been many declarations of the death of the Weinberg model of spontaneous CP violation. Previous studies, before the recent measurements of $ε'/ε$, indicated that the model could not accommodate the experimental values on $ε$ in $K^0-\bar K^0$ mixing, the neutron electric dipole moment (EDM), the branching ratio of $b\to s γ$ and the upper limi

Sahng-Kyoon Yoo, Soo-Young Lee, Dal-Ho Yoon, Chang-Soo Park

The oscillation of tunnel splitting in the biaxial spin system within magnetic field along the anisotropy axis is analyzed within the particle mapping approach, rather than in the (θ-ϕ) spin coherent-state representation. In our mapping procedure, the spin system is transformed into a particle moving in the restricted $S^1$ geometry whose wave function subje

R. Winkler, S. J. Papadakis, E. P. De Poortere, M. Shayegan

The frequencies of Shubnikov-de Haas oscillations have long been used to measure the unequal population of spin-split two-dimensional subbands in inversion asymmetric systems. We report self-consistent numerical calculations and experimental results which indicate that these oscillations are not simply related to the zero-magnetic-field spin-subband densitie

F. D. R. Bonnet, P. O. Bowman, D. B. Leinweber, D. G. Richards

Lattice discretisation errors in the Landau gauge condition are examined. An improved gauge fixing algorithm in which order a^2 errors are removed is presented. Order a^2 improvement of the gauge fixing condition displays the secondary benefit of reducing the size of higher-order errors. These results emphasise the importance of implementing an improved gaug

Yue Yu, Shi-Jie Yang, Zhao-Bin Su

We formulate the composite fermions in the presence of an in-plane magnetic field. As the in-plane field increases, if we assume the state at $ν=5/2$ turns into the mixed state between the unidirectional charge density wave domains and paired Hall state, we can phenomenologically fit the theoretically defined gap to the experimental measured results. We expl

Yshai Avishai, Daniel Berend, Richard Berkovits

This article is concerned with statistics of addition spectra for systems of identical charged particles. A classical model is suggested in order to study fluctuations of Coulomb blockade peak spacings in large two-dimensional semiconductor quantum dots. It is based on the electrostatics of several electron islands among which there are random inductive and

Yuri B. Suris

The motion of a rigid body in a quadratic potential is an important example of an integrable Hamiltonian system on a dual to a semidirect product Lie algebra so(n) x Symm(n). We give a Lagrangian derivation of the corresponding equations of motion, and introduce a discrete time analog of this system. The construction is based on the discrete time Lagrangian

A. K. Svinin

An integrable hierarchies connected with linear stationary Schrödinger equation with energy dependent potentials (in general case) are considered. Galilei-like and scaling invariance transformations are constructed. A symmetry method is applied to construct invariant solutions.

R. Simon

The Peres-Horodecki criterion of positivity under partial transpose is studied in the context of separability of bipartite continuous variable states. The partial transpose operation admits, in the continuous case, a geometric interpretation as mirror reflection in phase space. This recognition leads to uncertainty principles, stronger than the traditional o

Bernard Yurke, Mark Hillery, David Stoler

We show that it is, in principle, possible to perform local realism violating experiments of the Hardy type in which only position and momentum measurements are made on two particles emanating from a common source. In the optical domain, homodyne detection of the in-phase and out-of-phase amplitude components of an electromagnetic field is analogous to posit

Dagmar Bruß, Norbert Lütkenhaus

We review the main protocols for key distribution based on principles of quantum mechanics, describing the general underlying ideas, discussing implementation requirements and pointing out directions of current experiments. The issue of security is addressed both from a principal and real-life point of view.

Alexei Krouglov

Here to represent the propagation of waves I attempted to describe them separately in space and time domains. The time and space wave equations are obtained and investigated, and formulas for the wave propagation are expressed. I also tried to apply the model to the description of such physical phenomena as the constancy of the speed of light and propagation

J. H. O. Sales, T. Frederico, B. V. Carlson, P. U. Sauer

A three-dimensional reduction of the two-particle Bethe-Salpeter equation is proposed. The proposed reduction is in the framework of light-front dynamics. It yields auxiliary quantities for the transition matrix and the bound state. The arising effective interaction can be perturbatively expanded according to the number of particles exchanged at a given ligh

H. Schmieden

At modern electron accelerators with highly polarized, intense, high duty factor beams double polarization coincidence experiments became feasible with good statistical accuracy. The strong potential towards the precise determination of small nucleon structure quantities is illustrated by two recent examples from MAMI. The measurement of $G_E^n$ in the quasi

Oscar Bolina, Pierluigi Contucci, Bruno Nachtergaele, Shannon Starr

It is shown that, with an appropriate scaling, the energy of low-lying excitations of the (1,1,...,1) interface in the $d$-dimensional quantum Heisenberg model are given by the spectrum of the $d-1$-dimensional Laplacian on an suitable domain.

Fedor Andrianov

In this paper we use automorph class theory formalism to construct a lifting of similitudes of quadratic Z-modules of arbitrary ternary nondegenerate quadratic forms to morphisms between certain subrings of associated Clifford algebras. The construction explains and generalizes Shimura's correspondence in the case of theta-series of positive-definite qua

Marc Reversat

We compare modular forms of characteristic $p>0$ (i.e. Drinfeld's modular forms) and automorphic forms. We prove that spaces of these modular forms (which are of characteristic $p$) can be described by function spaces of characteristic zero, close to those of automorphic forms.

V. Vakulenko

We study vector bundles with some additional structures on an elliptic curve and show how there are related to the elliptic Ruijsenaars-Schneider model.

F. Gesztesy, K. A. Makarov, A. K. Motovilov

Let $H_0$ and $V(s)$ be self-adjoint, $V,V'$ continuously differentiable in trace norm with $V''(s)\geq 0$ for $s\in (s_1,s_2)$, and denote by $\{E_{H(s)}(λ)\}_{λ\in\bbR}$ the family of spectral projections of $H(s)=H_0+V(s)$. Then we prove for given $μ\in\bbR$, that $s\longmapsto \tr\big (V'(s)E_{H(s)}((-\infty, μ))\big) $ is a nonincreasing

Jose L. Flores, Miguel Sanchez

A new technique for the study of geodesic connectedness in a class of Lorentzian manifolds is introduced. It is based on arguments of Brouwer's topological degree for the solution of functional equations. It is shown to be very useful for multiwarped spacetimes, which include different types of relativistic spacetimes.

Brendan Hassett, Yuri Tschinkel

Given a variety over a number field, are its rational points potentially dense, i.e., does there exist a finite extension over which rational points are Zariski dense? We study the question of potential density for symmetric products of surfaces. Contrary to the situation for curves, rational points are not necessarily potentially dense on a sufficiently hig

Miguel A. Barja

We study from a geographical point of view fibrations of threefolds over smooth curves, such that the general fibre is of general type. We prove the non-negativity of certain relative invariants under general hypotheses and give lower bounds for the self-interssection of the relative canonical divisor of the fibration, depending on other relative invariants.

Miguel A. Barja

We study lower bounds for the self-intersection of the canonical divisor of "canonical varieties" (i.e. varieties whose canonical linear system gives a birational map). We give some improvements for the known results in the case of surfaces and new bounds for the case of canonical threefolds.

Jacob Mostovoy, Simon Willerton

Finite type invariants (also known as Vassiliev invariants) of pure braids are considered from a group-theoretic point of view. New results include a construction of a universal invariant with integer coefficients based on the Magnus expansion of a free group and a calculation of numbers of independent invariants of each type for all pure braid groups.

Nguyen Anh Ky

The two-parametric quantum superalgebra $U_{p,q}[gl(2/1)]$ is consistently defined. A construction procedure for induced representations of $U_{p,q}[gl(2/1)]$ is described and allows us to construct explicitly all (typical and nontypical) finite-dimensional representations of this quantum superalgebra. In spite of some specific features, the present approach

Frederic Sarkis

The ``complex Plateau problem'' (or boundary problem) in a complexe manifold X is the problem of characterizing the real submanifolds $Γ$ of X which are boundaries of analytic sub-varieties of $X \backslash Γ$. Our principal result treat the case $X=U\timesω$ where $U$ is a connected complex manifold and $ω$ is a disk-convex Kähler manifold. As a con

D. Shklyarov, S. Sinel'shchikov, L. Vaksman

This work presents proofs of the main results of (math.QA/9808015), except those on q-Berezin transform to appear in a subsequent work. The notation and the results of (math.QA/9808037) and (math.QA/9808047) are used.

E. Cremmer, B. Julia, H. Lu, C. N. Pope

It is well known that the toroidal dimensional reduction of supergravities gives rise in three dimensions to theories whose bosonic sectors are described purely in terms of scalar degrees of freedom, which parameterise sigma-model coset spaces. For example, the reduction of eleven-dimensional supergravity gives rise to an E_8/SO(16) coset Lagrangian. In this

Karin Bautier

The Chern-Simons formulation of $AdS_3$ supergravity is considered. Asymptotic conditions on the Rarita-Schwinger fields are given. Together with the known boundary conditions on the bosonic fields, these ensure that the asymptotic algebra is the superconformal algebra, with the same central charge as the one of pure gravity. It is also indicated that the as

Jan Gutowski

We present a generalization of calibrations in which the calibration form is not closed. We use this to examine a class of supersymmetric p-brane worldvolume solitons.As an example we consider M5-brane worldvolume solitons in an AdS background.

Dario Martelli

We review some aspects of Polyakov's proposal for constructing nonsupersymmetric field theories from non-critical Type 0 string theory.

B. Kleihaus, Jutta Kunz

In [hep-th/9907222] Hannibal claims to exclude the existence of particle-like static axially symmetric non-abelian solutions in SU(2) Einstein-Yang-Mills-dilaton theory. His argument is based on the asymptotic behaviour of such solutions. Here we disprove his claim by giving explicitly the asymptotic form of non-abelian solutions with winding number n=2.

John H. Schwarz

In this set of lectures various properties of D-branes are discussed. After reviewing the basics, we discuss unstable D-brane/anti-D-brane systems, a subject pioneered by Sen. Following him, we discuss the construction of the non-BPS D0-brane in type I theory. This state is stable since it carries a conserved Z_2 charge. The general classification of D-brane

Dilip Kumar Ghosh, P. Poulose, K. Sridhar

Theories with large extra compact dimensions predict exciting phenomenological consequences at the TeV scale. Such theories can, consequently, be tested/verified in experiments at future colliders like the Next Linear Collider (NLC). In this paper, we study the production of the spin-2 Kaluza-Klein excitations in NLC operating in the $e γ$ mode. Results for

Dietrich Bodeker

The dynamics of soft ($|\vec{p}|\sim g^2 T$) non-Abelian gauge fields at finite temperature is non-perturbative. The effective theory for the soft fields can be obtained by first integrating out the momentum scale T, which yields the well known hard thermal loop effective theory. Then the latter is used to integrate out the scale gT. One obtains a Boltzmann

F. A. Chishtie, V. Elias, T. G. Steele

We present an asymptotic Pade-approximant estimate for the four-loop coefficients within the linear combination of correlators entering the recently calculated decay rate of a CP-odd Higgs boson, with an assumed mass $m_A = 100 GeV$, into two gluons. All but one of these coefficients are shown to be determined for arbitrary $m_A$ from the known 3-loop-order

D. Boyanovsky, H. J. de Vega

The dynamics of symmetry breaking during out of equilibrium phase transitions is a topic of great importance in many disciplines, from condensed matter to particle physics and early Universe cosmology with definite experimental impact. In these notes we provide a summary of the relevant aspects of the dynamics of symmetry breaking in many different fields wi

A. D. Polosa

I shortly review the application of a recently introduced constituent quark-meson model to the determination of some strong coupling constants governing the decays of charm heavy mesons with one pion in the final state. I present the model directly through its rules for computing amplitudes. For a detailed explanation of the model, the reader is referred to

H. G. Dosch, F. S. Navarra, M. Nielsen

We calculate the nonperturbative charmonium - nucleon cross sections with the model of the stochastic vacuum, which has been succesfully applied in many high energy reactions. We also give a quantitative discussion of pre-resonance formation and medium effects.

A. A. Andrianov, D. Espriu, R. Tarrach

We discuss the truncation of low energy effective action of QCD below the chiral symmetry breaking (CSB) scale, including all operators of dimensionality less or equal to 6 which can be built with quark and chiral fields. We perform its bosonization in the scalar, pseudoscalar, vector and axial-vector channels in the large-N_c and leading-log approximation.

V. B. Kopeliovich, W. J. Zakrzewski

Static properties of multiskyrmions with baryon numbers up to 8 are calculated, including momenta of inertia and sigma-term. The calculations are based on the recently suggested SU(2) rational map ansaetze. Minimization with the help of SU(3) variational minimization program shows that these configurations become local minima in SU(3) configuration space. Th

A. Denner, S. Dittmaier, M. Roth, D. Wackeroth

The structure of the double-pole approximation for the O(alpha) corrections to e^+e^- -> WW -> 4 fermions is described, and some results are presented. Moreover, results on full tree-level predictions for $e^+e^- -> WW -> 4 fermions + gamma are given.

F. Benatti, R. Floreanini

We study the time evolution and decay of the neutral B-meson system using quantum dynamical semigroups. New, nonstandard terms appear in the expression of relevant observables; they can be parametrized in terms of six phenomenological constants. Although very small, these parameters may be detected in the new generation of dedicated B-meson experiments.

S. Frixione

I study the production of prompt photons in polarized hadronic collisions, considering different isolation prescriptions. In particular, I focus on the problem of the measurability of the polarized gluon density in the proton through isolated-photon data.

R. Peschanski

A gluon forward jet playing the role of a deep probe in high energy scattering, we analyze its infinite momentum QCD wave function in terms of dipole (color-singlet quark-antiquark) configurations using k_T-factorization properties. The comparison is made with virtual photon quark-antiquark configurations. Some implications for hard processes with forward je

T. Gasenzer, O. Nachtmann

In this article we study effects of parity nonconservation in atomic dysprosium, where one has a pair of nearly degenerate levels of opposite parity. We consider the time evolution of this two-level system within oscillatory electric and magnetic fields. These are chosen to have a periodical structure with the same period, such that a Floquet matrix describe

A. H. Hoang

Recent results from studies using half the perturbative mass of heavy quark-antiquark n=1, ${}^3S_1$ quarkonium as a new heavy quark mass definition for problems where the characteristic scale is smaller than or of the same order as the heavy quark mass are reviewed. In this new scheme, called the 1S mass scheme, the heavy quark mass can be determined very a

Loretta M. Johnson, Douglas W. McKay

We formulate direct, neutrino flavor-changing interactions in a framework that fits smoothly with the parameterization of two-and three-state mixing of massive neutrino states. We show that even small direct interaction strengths could have important consequences for the interpretation of currently running and proposed oscillation experiments. The oscillatio

Y. Takeuchi, S. Y. Tsai

The recent results on the CP violating parameters Re(e'/e) and Δϕ= ϕ_{00}-ϕ_{+-} reported by the KTeV Collaboration are analyzed with a view to constrain CP, T and CPT violations in a decay process. Combining with some relevant data compiled by the Particle Data Group, we find Re(e_2-e_0) = (0.85 +- 3.11)*10^{-4} and Im(e_2-e_0) = (3.2 +- 0.7)*10^{-4}, w

Sonali Tamhankar, Steven Gottlieb

We study the static potential using gauge configurations that include the effects of two flavors of dynamical Kogut-Susskind quarks. The configurations, generated by the MILC collaboration, and used to study the spectrum and heavy-light decay constants, cover a range $5.3 \le 6/g^2 \le 5.6$. There are at least four quark masses for each coupling studied. Det

Lingling Wu

We present the QCD hadron spectrum for the cases of both quenched and two-flavor dynamical domain wall fermions. We compare the results obtained using the Wilson gauge action and a renormalization group improved gauge action. Finite volume effects and the dependence on the finite extent of the fifth dimension are discussed.

T. Bhattacharya, R. Gupta, W. Lee, S. Sharpe

We impose the axial and vector Ward identities on local fermion bilinear operators in the Sheikholesalami-Wohlert discretization of fermions. From this we obtain all the coefficients needed to improve the theory at O(a), as well as the scale and scheme independent renormalization constants, Z_A, Z_V and Z_S/Z_P.

Wolfgang Bock, Maarten F. L. Golterman, Ka Chun Leung, Yigal Shamir

We report on recent progress with the gauge-fixing approach to lattice chiral gauge theories. The bosonic sector of the gauge-fixing approach is studied with fully dynamical U(1) gauge fields. We demonstrate that it is important to formulate the Lorentz gauge-fixing action such that the dense set of lattice Gribov copies is removed, and the gauge-fixing acti

E. Gabrielli, A. Gonzalez-Arroyo, C. Pena

We study the N=1 supersymmetric SU(N) Yang-Mills theory on the lattice at strong coupling. We analyse and discuss the recent results obtained at strong coupling and large N for the mesonic and fermionic propagators and spectrum.

M. Garcia Perez, A. Gonzalez-Arroyo, A. Montero, C. Pena

We review the recent progress on our understanding of self-dual SU(N) Yang-Mills configurations on the torus.

G. Arnold, Th. Lippert, K. Schilling

We demonstrate that substantial progress can be achieved in the study of the phase structure of 4-dimensional compact QED by a joint use of hybrid Monte Carlo and multicanonical algorithms, through an efficient parallel implementation. This is borne out by the observation of considerable speedup of tunnelling between the metastable states, close to the phase

Derek B. Leinweber, Anthony W. Thomas, Kazuo Tsushima, Stewart V. Wright

Consideration of the analytical properties of pion-induced baryon self-energies leads to new functional forms for the extrapolation of light baryon masses. These functional forms reproduce the leading non-analytic behavior of chiral perturbation theory, the correct heavy-quark limit and have the advantage of containing information on the extended structure o

Harry N. Nelson

We report on a search for D0-D0bar mixing made by a study of the `wrong-sign' process D0 -> K+pi-. The data come from an integrated luminosity of e+e- collisions at sqrt{s} of about 10 GeV consisting of 9.0 1/fb recorded with the CLEO-II.V detector. We measure the time-integrated rate of the `wrong-sign' process D0 -> K+pi-, relative to that of the C

CDF Collaboration, T. Affolder

We present the results of a search for pair production of a fourth-generation charge -1/3 quark (b') in sqrt(s)=1.8 TeV ppbar collisions using 88 pb^(-1) of data obtained with the Collider Detector at Fermilab. We assume that both quarks decay via the flavor-changing neutral current process b' -> bZ and that the b' mass is greater than m_Z + m_b.

S. V. Chekanov, L. Zawiejski

Correlations in deep-inelastic scattering at HERA are investigated in order to test perturbative QCD and quark fragmentation universality. Two-particle correlations at small angular separations are measured in the Breit frame and compared to e+e- collisions. Also presented are the correlations between the current and target regions of the Breit frame.

Sandro Palestini

The effects of space charge due to slowly drifting ions can be relevant for detectors operated at high intensity, or for relatively low values of the bias voltage. Accurate measurements have been obtained with the liquid krypton calorimeter of the NA48 experiment, from data collected in 1997. The build-up of space charge takes place during the first part of

J. William Gary

I present recent results from LEP which utilize differences between gluon and quark jets to make quantitative tests of QCD. The principal topic is a determination of the ratio of QCD color factors, C$_{\mathrm{A}}$/C$_{\mathrm{F}}$, using either the multiplicity or fragmentation functions of the jets. In addition, I discuss a recent measurement of the rate o

Richard Nisius

This review covers selected results from the LEP experiments on the structure of quasi-real and virtual photons. The topics discussed are the total hadronic cross-section for photon-photon scattering, hadron production, jet cross-sections, heavy quark production for photon-photon scattering, photon structure functions, and cross-sections for the exchange of

H. P. de Oliveira, S. L. Sautu, I. Damião Soares, E. V. Tonini

We describe a new statistical pattern in the chaotic dynamics of closed inflationary cosmologies, associated with the partition of the Hamiltonian rotational motion energy and hyperbolic motion energy pieces, in a linear neighborhood of the saddle-center present in the phase space of the models. The hyperbolic energy of orbits visiting a neighborhood of the

Janna Levin, John D. Barrow

A finite universe naturally supports chaotic classical motion. An ordered fractal emerges from the chaotic dynamics which we characterize in full for a compact 2-dimensional octagon. In the classical to quantum transition, the underlying fractal can persist in the form of scars, ridges of enhanced amplitude in the semiclassical wave function. Although the sc

Sharmanthie Fernando

We report a new class of rotating charged solutions in 2+1 dimensions. These solutions are obtained for Einstein-Maxwell gravity coupled to a dilaton field with selfdual electromagnetic fields. The mass and the angular momentum of these solutions computed at spatial infinity are finite. The class of solutions considered here have naked singularities and are

Sviatoslav S. Sokolov, Nelson Studart

The coupled phonon-ripplon modes of the quasi-one-dimensional electron chain on the liquid helium sutface are studied. It is shown that the electron-ripplon coupling leads to the splitting of the collective modes of the wire with the appearance of low-frequency modes and high-frequency optical modes starting from threshold frequencies. The effective masses o

Chia-Ying Liu, D. E. MacLaughlin, A. H. Castro Neto, H. G. Lukefahr

We report measurements of the bulk magnetic susceptibility and ^{29}Si nuclear magnetic resonance (NMR) linewidth in the heavy-fermion alloy CeRhRuSi_2. The linewidth increases rapidly with decreasing temperature and reaches large values at low temperatures, which strongly suggests the wide distributions of local susceptibilities χ_j obtained in disorder-dri

R. Jin, Y. Liu, Z. Q. Mao, Y. Maeno

We have studied the Josephson coupling between a conventional s-wave superconductor (In) and Sr2RuO4 and found that the coupling is allowed in the in-plane direction, but not along the c axis. This selection rule indicates that the symmetry of superconducting order parameter of Sr2RuO4 is either p- or alternatively, purely d-wave. If Sr2RuO4 is a p-wave supe

J. Lesueur, X. Grison, M. Aprili, T. Kontos

We have made in-situ [103] and [110]YBCO/Pb junctions, which display an hysteretic behaviour with both a well-defined Quasi-Particule branch and a Josephson current. A zero energy conductance peak is observed in the tunneling conductance which is a signature of Andreev Bound States (ABS) at a surface of a d-wave superconductor. The observed splitting of this

Y. Moreno, J. B. Gomez, A. F. Pacheco

The dynamics of a fibre-bundle type model with equal load sharing rule is numerically studied. The system, formed by N elements, is driven by a slow increase of the load upon it which is removed in a novel way through internal transfers to the elements broken during avalanches. When an avalanche ends, failed elements are regenerated with strengths taken from

J. Miller, P. B. Weichman

In Hermitean quantum mechanics, extended current-carrying states are distinguished from localized ones by their non-zero Chern number. We generalize the notion of Chern number to non-Hermitean localization problems such as tiltedflux lines in type-II superconductors with line defects and passive scalar transport in random vorticity fields. We find that the u

D. Levesque, J. -J. Weis, J. L. Lebowitz

We study, via computer simulations, the fluctuations in the net electric charge, in a two dimensional one component plasma (OCP) with uniform background charge density $-e ρ$, in a region $Λ$ inside a much larger overall neutral system. Setting $e=1$ this is the same as the fluctuations in $N_Λ$, the number of mobile particles of charge $e$. As expected the

W. I. Skrypnik

For systems of one-component interacting oscillators on the d-dimensional lattice, d>1, whose potential energy besides a large nearest-neighbour (n-n) ferromagnetic translation-invariant quadratic term contains small non-nearest-neighbour translation invariant term, an existence of a ferromagnetic long-range order for two valued lattice spins, equal to a sig

K. Pinn

I present a calculation of the interfacial width within the capillary wave (Gaussian) approximation. The calculation is done on rectangular lattices of size L_1 times L_2, with periodic boundary conditions.

D. E. Wolf, T. Scheffler, J. Schäfer

The non-Newtonian character of granular flow in a vertical pipe is analyzed. The time evolution of the flow velocity and the velocity fluctuations (or granular temperature) is derived. The steady state velocity has a power law dependence on the pipe width with an exponent between 3/4 and 3/2. The flow becomes faster the more efficient the collisional cooling

Zbigniew Koza

We develop a practical method of computing the stationary drift velocity V and the diffusion coefficient D of a particle (or a few particles) in a periodic system with arbitrary transition rates. We solve this problem both in a physically relevant continuous-time approach as well as for models with discrete-time kinetics, which are often used in computer sim

Suman Kumar Banik, Jyotipratim Ray Chaudhuri, Deb Shankar Ray

We consider the motion of a particle in a force field subjected to adiabatic, fluctuations of external origin. We do not put the restriction on the type of stochastic process that the noise is Gaussian. Based on a method developed earlier by us [ J. Phys. A {\bf 31} (1998) 3937, 7301] we have derived the equation of motion for probability distribution functi

Van Lien Nguyen, Enrique Canessa

We test the universal finite-size scaling of the cluster mass order parameter in two-dimensional (2D) isotropic and directed continuum percolation models below the percolation threshold by computer simulations. We found that the simulation data in the 2D continuum models obey the same scaling expression of mass M to sample size L as generally accepted for is

G. G. Batrouni, R. T. Scalettar

We study quantum phase transitions in the ground state of the two dimensional hard-core boson Hubbard Hamiltonian. Recent work on this and related models has suggested ``supersolid'' phases with simultaneous diagonal and off-diagonal long range order. We show numerically that, contrary to the generally held belief, the most commonly discussed ``check

S. Sergeenkov, M. Ausloos, H. Bougrine, A. Rulmont

An unusual temperature and concentration behavior of resistivity in $La_{0.7}Ca_{0.3}Mn_{1-x}Cu_xO_3$ has been observed at slight $Cu$ doping ($0\leq x \leq 0.05$). Namely, introduction of copper results in a splitting of the resistivity maximum around a metal-insulator transition temperature $T_0(x)$ into two differently evolving peaks. Unlike the original

Chen Zeng, Paul L. Leath, Terence Hwa

The thermodynamics of a disordered planar vortex array is studied numerically using a new polynomial algorithm which circumvents slow glassy dynamics. Close to the glass transition, the anomalous vortex displacement is found to agree well with the prediction of the renormalization-group theory. Interesting behaviors such as the universal statistics of magnet

I. Arad, L. Biferale, I. Procaccia

We address the scaling behavior of the covariance of the magnetic field in the three-dimensional kinematic dynamo problem when the boundary conditions and/or the external forcing are not isotropic. The velocity field is gaussian and $δ$-correlated in time, and its structure function scales with a positive exponent $ξ$. The covariance of the magnetic field is

Prasenjit Saha, Liliya L. R. Williams, Hanadi AbdelSalam

The lensing information provided by multiple images, arclets, and statistical distortions can all be formulated as linear constraints on the arrival-time surface, and hence on the mass distribution. This reduces cluster lens reconstruction from combined strong and weak lensing to a standard type of inversion problem. Moreover, the mass sheet degeneracy is br

Liliya L. R. Williams, Prasenjit Saha

The largest source of uncertainty in the determination of H_0 from a multiply-imaged QSO system is the unknown mass distribution in the lensing galaxy. Parametric models severely restrict the shape of the galaxy thereby underestimating errors and biasing the best estimate of H_0. We present a method that explores the whole of the model space allowed by the i

Sarbani Basu, M. H. Pinsonneault, John N. Bahcall

We investigate systematic uncertainties in determining the profiles of the solar sound speed, density, and adiabatic index by helioseismological techniques. We find that rms uncertainties-averaged over the sun of ~ 0.2%-0.4% are contributed to the sound speed profile by each of three sources: 1)the choice of assumed reference model, 2) the width of the inver

John Scalo

The series of papers by Chandrasekhar and Munch in the 1950s were concerned with the use of statistical models to infer the properties of interstellar clouds based on the observed spatial brightness fluctuations of the Milky Way. The present paper summarizes the subsequent influence of this work, concentrating on the departure from their earlier discrete clo