November 1999 arXiv papers — page 16

D. A. Demir, A. Masiero, O. Vives

We address the question of the relation between supersymmetry breaking and the origin of flavor in the context of CP violating phenomena. We prove that, in the absence of the Cabibbo-Kobayashi-Maskawa phase, a general Minimal Supersymmetric Standard Model with all possible phases in the soft-breaking terms, but no new flavor structure beyond the usual Yukawa

F. Frontera, L. Amati, E. Costa, J. M. Muller

We investigated the spectral evolution in the 2--700 keV energy band of Gamma-Ray Bursts (GRBs) detected by the Gamma-Ray Burst Monitor (GRBM) and localized with the Wide Field Cameras (WFCs) aboard the BeppoSAX satellite before May 1998. Most of them have been followed-up with the Narrow Field Instruments aboard the same satellite. In the light of these res

Igor R. Klebanov, Nikita A. Nekrasov

We study fractional branes in ${\CN}=2$ orbifold and ${\CN}=1$ conifold theories. Placing a large number $N$ of regular D3-branes at the singularity produces the dual ${\bf AdS}_5\times X^5$ geometry, and we describe the fractional branes as small perturbations to this background. For the orbifolds, $X^5={\bf S}^5/Γ$ and fractional D3-branes excite complex s

Barbara M. Terhal

We analyze and compare the mathematical formulations of the criterion for separability for bipartite density matrices and the Bell inequalities. We show that a violation of a Bell inequality can formally be expressed as a witness for entanglement. We also show how the criterion for separability and a description of the state by a local hidden variable theory

J. Arlt, O. Marago', E. Hodby, S. A. Hopkins

We describe the construction and operation of a time-orbiting potential trap (TOP trap) that has different oscillation frequencies along its three principal axes. These axes can be rotated and we have observed Bose-Einstein condensates of 87^Rb with a rotating ellipsoidal shape. Under these conditions it has been predicted that quantized vortices form and ar

Zurab Berezhiani, Alessandro Drago

The Pseudo-Goldstone Boson (PGB) emission could provide a very efficient mechanism for explaining the cosmic Gamma Ray Bursts (GRBs). The PGBs could be produced during the merging of two compact objects like two neutron stars or neutron star - black hole, and then decay into electron-positron pairs and photons at distances ~ 100-1000 km. In this way, a huge

M. Grigoriev, P. H. Damgaard

Using a superfield formulation of extended phase space, we propose a new form of the Hamiltonian action functional. A remarkable feature of this construction is that it directly leads to the BV master action on phase space. Conversely, superspace can be used to construct nilpotent BRST charges directly from solutions to the classical Lagrangian Master Equati

Nick Dorey, David Tong

We study three dimensional gauge theories with N=2 supersymmetry. We show that the Coulomb branches of such theories may be rendered compact by the dynamical generation of Chern-Simons terms and present a new class of mirror symmetric theories in which both Coulomb and Higgs branches have a natural description in terms of toric geometry.

Pierre-Henri Chavanis

We develop a quasilinear theory of the 2D Euler equation and derive an integro-differential equation for the evolution of the coarse-grained vorticity. This equation respects all the invariance properties of the Euler equation and conserves angular momentum in a circular domain and linear impulse in a channel. We show under which hypothesis we can derive a H

Alexander A. Chernitskii

Born-Infeld nonlinear electrodynamics with point singularities having both electric and magnetic charges are considered. Problem of interaction between the associated soliton dyon solutions is investigated. For the case of long-range interaction at first order by a small field of distant solitons we obtain that the generalized Lorentz force is acted on a dyo

Gregory F. Lawler, Oded Schramm, Wendelin Werner

This paper proves conjectures originating in the physics literature regarding the intersection exponents of Brownian motion in a half-plane. For instance, suppose that B and B' are two independent planar Brownian motions started from distinct points in a half-plane H. Then, as $t \to \infty$, $$ P [ B[0,t] \cap B'[0,t] = \emptyset, B[0,t] \cup B'

Y. Chen, S. H. Guo, Z. B. Li, S. Marculescu

The renormalisation group approach is applied to the study of the short-time critical behaviour of the $d$-dimensional Ginzburg-Landau model with long-range interaction of the form $p^σ s_{p}s_{-p}$ in momentum space. Firstly the system is quenched from a high temperature to the critical temperature and then relaxes to equilibrium within the model A dynamics

Masayuki Matsuzaki, Tomonori Tanigawa

We construct phenomenologically a relativistic particle-particle channel interaction which suits the gap equation for nuclear matter. This is done by introducing a density-independent momentum-cutoff parameter to the relativistic mean field (Hartree and Hartree-Fock) models so as to reproduce the pairing properties obtained by the Bonn-B potential and not to

You-Quan Li, U. Eckern

The Hubbard model for electrons with orbital degeneracy is shown to have an underlying SU_d(4) symmetry of spin-orbital double. A hidden charge SU_c(4) symmetry is exposed and an extended Lieb-Mattis transformation which maps these two symmetries into each other is given. On the basis of elementary degenerate perturbative theory, it is shown that the system

M. D. Sumption, R. M. Scanlan, A. Nijhuis, E. W. Collings

Calorimetric measurements of AC loss and hence interstrand contact resistance (ICR), were measured on three samples of Rutherford cable wound with Cu-stabilized jelly-roll type unplated Nb3Al strand. One of the cable types was furnished with a thin core of AISI 316L stainless steel and the other two were both uncored but insulated in different ways. The cabl

Diego J. Navarro, Jose Navarro-Salas, Pedro Navarro

We show that a realization of the correspondence AdS_2/CFT_1 for near extremal Reissner-Nordstrom black holes in arbitrary dimensional Einstein-Maxwell gravity exactly reproduces, via Cardy's formula, the deviation of the Bekenstein-Hawking entropy from extremality. We also show that this mechanism is valid for Schwarzschild-de Sitter black holes around

Alok Kumar

We write down charged macroscopic string solutions in type II string theories, compactified on torii, and present an explicit solution of the spinor Killing equations to show that they preserve 1/2 of the type II supersymmetries. The S-duality symmetry of the type IIB string theory in ten-dimensions is used to write down the SL(2,Z) multiplets of such string

Jerome Martin, Dominik Schwarz

Inflationary predictions for the anisotropy of the cosmic microwave background radiation (CMBR) are often based on the slow-roll approximation. We study the precision with which the multipole moments of the temperature two-point correlation function can be predicted by means of the slow-roll approximation. We ask whether this precision is good enough for the

Ryuichiro Kitano, Kin-ya Oda

We propose an extension of the supersymmetric standard model with right-handed neutrinos and a singlet Higgs field, and study the neutrino masses in this model. The Majorana masses for the right-handed neutrinos are generated around the supersymmetry breaking scale through the vacuum expectation value of the singlet Higgs field. This model may induce spontan

A. P. Balachandran, T. R. Govindarajan, B. Ydri

We propose a resolution for the fermion doubling problem in discrete field theories based on the fuzzy sphere and its Cartesian products.

Won Tae Kim, John J. Oh

We study Dirac commutators of canonical variables on D-branes with a constant Neveu-Schwarz 2-form field by using the Dirac constraint quantization method, and point out some subtleties appearing in previous works in analyzing constraint structure of the brane system. Overcoming some ad hoc procedures, we obtain desirable noncommutative coordinates exactly c

I. Chiorescu, W. Wernsdorfer, A. Müller, H. Bögge

The V_{15} polyoxovanadate molecule is made of 15 spins 1/2 with antiferromagnetic couplings. It belongs to the class of molecules with very large Hilbert space dimension (2^{15} in V_{15}, 10^8 in Mn_{12}-ac). It is a low-spin/big-molecule with spin S=1/2. Contrary large-spins/big-molecules of the Mn_{12}-ac type, V_{15} has no energy barrier against spin r

Yong-Hoon Kim, In-Ho Lee, Satyadev Nagaraja, Jean-Pierre Leburton

We investigate the behavior of three-dimensional (3D) exchange-correlation energy functional approximations of density functional theory in anisotropic systems with two-dimensional (2D) character. Using two simple models, quasi-2D electron gas and two-electron quantum dot, we show a {\it fundamental limitation} of the local density approximation (LDA), and i

Morten Krogh

We give a simple proof of the known S-duality of Heterotic String theory compactified on a T^6. Using this S-duality we calculate the tensions for a class of BPS 5-branes in Heterotic String theory on a circle. One of these, the Kaluza-Klein monopole, becomes tensionless when the radius of the circle is equal to the string length. We study the question of st

Lincoln D. Carr, Charles W. Clark, William P. Reinhardt

All stationary solutions to the one-dimensional nonlinear Schroedinger equation under box or periodic boundary conditions are presented in analytic form for the case of attractive nonlinearity. A companion paper has treated the repulsive case. Our solutions take the form of bounded, quantized, stationary trains of bright solitons. Among them are two uniquely

Lincoln D. Carr, Charles W. Clark, William P. Reinhardt

All stationary solutions to the one-dimensional nonlinear Schroedinger equation under box and periodic boundary conditions are presented in analytic form. We consider the case of repulsive nonlinearity; in a companion paper we treat the attractive case. Our solutions take the form of stationary trains of dark or grey density-notch solitons. Real stationary s

Mehmet O. Oktel, Thomas C. Killian, Daniel Kleppner, L. S. Levitov

We develop an exact sum rule that relates the spectral shift of a trapped gas undergoing cold collisions to measurable quantities of the system. The method demonstrates the dependence of the cold collision frequency shift on the quantum degeneracy of the gas and facilitates extracting scattering lengths from the data. We apply the method to analyzing spectra

Fuqiang Wang

It is found that the baryon phase-space density obtained from the ratio of deuteron to proton yields is nearly constant over centrality in Au+Au collisions at the AGS. The finding offers an explanation for the puzzling centrality independence of the ratio of charged kaon total yields. The correlation between the charged kaon ratio and the average baryon phas

I. T. Habibullin, A. N. Vil'danov

The initial boundary value problem on a half-line for the KdV equation with the boundary conditions $u|_{x=0}=a\leq0$, $u_{xx}|_{x=0}=3a^2$ is integrated by means of the inverse scattering method. In order to find the time evolution of the scattering matrix it turned out to be sufficient to solve the Riemann problem on a hyperelliptic curve of genus two, whe

Dagmar Bruss, Asher Peres

We present a new family of bound-entangled quantum states in 3x3 dimensions. Their density matrix depends on 7 independent parameters and has 4 different non-vanishing eigenvalues.

S. N. Molotkov, S. S. Nazin

A new relativistic quantum protocol is proposed allowing to implement the bit commitment scheme. The protocol is based on the idea that in the relativistic case the field propagation to the region of space accessible to measurement requires, contrary to the non-relativistic case, a finite non-zero time which depends on the structure of the particular state o

Gilles Brassard, Norbert Lütkenhaus, Tal Mor, Barry C. Sanders

The use of quantum bits (qubits) in cryptography holds the promise of secure cryptographic quantum key distribution schemes. Unfortunately, the implemented schemes can be totally insecure. We provide a thorough investigation of security issues for practical quantum key distribution, taking into account channel losses, a realistic detection process, and modif

Jae-Seung Lee, Yongwook Chung, Jaehyun Kim, Soonchil Lee

We describe a practical method of constructing quantum combinational logic circuits with basic quantum logic gates such as NOT and general $n$-bit Toffoli gates. This method is useful to find the quantum circuits for evaluating logic functions in the form most appropriate for implementation on a given quantum computer. The rules to get the most efficient cir

Kalman Varga

The stability of Coulombic systems containing positrons are investigated by the stochastic variational method. The existence of several new exotic atoms are predicted, including HPse+, LiPs2e+, or (H-,Ps2). Similar systems (replacing the positrons by holes) might be observed in semiconductors.

C M Care, R Ettelaie

We describe an algorithm for the Rosenbluth Monte Carlo enumeration of clusters and lattice animals. The method may also be used to calculate associated properties such as moments or perimeter multiplicities of the clusters. The new scheme is an extension of the Rosenbluth method for growing polymer chains and is a simplification of a scheme reported earlier

Ernst Karl Kunst

An analysis of the Lorentz transformation shows that the unchangeability of the space-time coordinates of the inertial systems under consideration and the possibility of a direct projection of those coordinates onto another are the underlying assumptions as to its unlimited validity. It is demonstrated that from a empiric-physical point of view these assumpt

A. Mary Selvam, A. S. Ramachandra Murty

Extensive aircraft cloud physical observations made in more than 2000 tropical cumulus clouds indicated new observational evidence viz., (1) horizontal structure of the air flow inside the cloud has consistent variations with successive positive and negative values of vertical velocity representative of ascending and descending currents, (2) regions of ascen

Karl Svozil

Special relativity theory is generalized to two or more ``maximal'' signalling speeds. This framework is discussed in three contexts: (i) as a scenario for superluminal signalling and motion, (ii) as the possibility of two or more ``light'' cones due to the a ``birefringent'' vaccum, and (iii) as a further extension of conventionality

H. D. Marta, R. Donangelo, J. O. Fernandez Niello, A. J. Pacheco

We extend a semiclassical model of transfer reactions to the case in which one of the collision partners is a vibrational nucleus. The model is applied to one- and two-proton stripping reactions in the 37Cl + 98Mo system, for which a rapid transition from normal to anomalous slope in the two proton transfer reaction at energies around the Coulomb barrier is

E. Oset, E. Marco, J. C. Nacher, J. A. Oller

By means of a coupled channel non-perturbative unitary approach, it is possible to extend the strong constrains of Chiral Perturbation Theory to higher energies. In particular, it is possible to reproduce the lowest lying resonances in meson-meson scattering up to 1.2 GeV using the parameters of the O(p^2) and O(p^4) Chiral Lagrangian. The meson baryon secto

Y. R. Shimizu, P. Donati, R. A. Broglia

We develop a scheme to exactly evaluate the correlation energy in the random-phase approximation, based on linear response theory. It is demonstrated that our formula is completely equivalent to a contour integral representation recently proposed by Donau et al. being numerically more efficient for realistic calculations. Numerical examples are presented for

A1 Mainz Helium Collaboration, A. Kozlov

A high-resolution study of the (e,e'p) reaction on Helium-4 was carried out at the Institut fuer Kernphysik in Mainz, Germany. The measurements were done in parallel kinematics (momentum transfer q=685 MeV/c, energy transfer omega=334 MeV) at different incident beam energies in order to enable the Rosenbluth separation of the longitudinal and transverse

C. -Y. Liu, A. R. Young, S. K. Lamoreaux

The ultracold neutron (UCN) upscattering rate from para-deuterium contaminated solid deuterium near T=0K is calculated and found to be 4 msec for a room-temperature-equilibrium concentration. The para-deuterium contamination appears to be responsible for the apparent loss of UCN in the Los Alamos spallation-driven UCN source.

Renat Zhdanov, Alexander Zhalij

We classify (1+3)-dimensional Schrödinger equations for a particle interacting with the electromagnetic field that are solvable by the method of separation of variables. As a result, we get eleven classes of the electromagnetic vector potentials of the electromagnetic field $A(t, \vec x)=(A_0(t, \vec x)$, $\vec A(t, \vec x))$ providing separability of the co

Bart de Smit, Bas Edixhoven

We generalize a result of Chen concerning an isogeny between products of jacobians of modular curves associated to subgroups of GL(2,F_p). This generalization concerns objects with an action by GL(2,F) with F an arbitrary finite field, in more general additive categories.

Andrew Granville, K. Soundararajan

Given a multiplicative function f satisfying |f(n)| <= 1 for all n, the authors study the problem of obtaining explicit upper bounds on the mean-value 1/x |sum_{n <= x} f(n)|.

B. Enriquez, V. Rubtsov

We study the parametrization of the moduli space Bun_2(C)_L of rank 2 bundles over a curve C with fixed determinant, provided by Hecke modifications at fixed points of the trivial bundle. This parametrization is closely related to the Tyurin parametrization of vector bundles over curves. We use it to parametrize the Hitchin and KZB systems, as well as lifts

F. Gesztesy, A. G. Ramm

We study quantum scattering theory off $n$ point inhomogeneities ($n\in\bbN$) in three dimensions. The inhomogeneities (or generalized point interactions) positioned at $\{ξ_1,...,ξ_n\}\subset\bbR^3$ are modeled in terms of the $n^2$ (real) parameter family of self-adjoint extensions of $-Δ\big|_{C^\infty_0(\bbR^3\backslash\{ξ_1,...,ξ_n\})}$ in $L^2(\bbR^3)$

David J. Green, Pham Anh Minh

Let P be an extraspecial p-group which is neither dihedral of order 8, nor of odd order p^3 and exponent p. Let G be a finite group having P as a Sylow p-subgroup. Then the mod-p cohomology ring of G coincides with that of the normalizer N_G(P).

Martin A. Stanev

We consider weighted banach spaces of holomorphic functions on the upper half plane that are determined by $ \|f\|=\sup_{y>0,-\infty<x<\infty}p(y)|f(x+iy)|<\infty $ for a very large class of weight functions p. We completely solve the problem whether such banach spaces are trivial or not by giving necessary and sufficient conditions stated in terms of some s

Michel Brion

Let F be the flag variety of a complex semi-simple group G, let H be an algebraic subgroup of G acting on F with finitely many orbits, and let V be an H-orbit closure in F. Expanding the cohomology class of V in the basis of Schubert classes defines a union V_0 of Schubert varieties in F with positive multiplicities. If G is simply-laced, we show that these

Kenichi Konishi, Kazunori Takenaga

We identify two distinct, complementary gauge field configurations for QCD with SU(2) gauge group, one (instanton-like configurations) having to do with chiral symmetry breaking but not with confinement, the other (regularized Wu-Yang monopoles) very likely responsible for confinement but unrelated to chiral symmetry breaking. Our argument is based on a semi

A. Smailagic, E. Spallucci

We show that dualization of Stueckelberg-like massive gauge theories and $B\wedge F$ models, follows form a general p-dualization of interacting theories in d spacetime dimensions. This is achieved by a particular choice of the external current.

J. K. Erickson, G. W. Semenoff, R. J. Szabo, K. Zarembo

We compute the leading order perturbative correction to the static potential in ${\cal N}=4$ supersymmetric Yang-Mills theory. We show that the perturbative expansion contains infrared logarithms which, when resummed, become logarithms of the coupling constant. The resulting correction goes in the right direction to match the strong coupling behavior obtaine

Andrew P. Billyard, Alan A. Coley, James E. Lidsey

A complete qualitative study of the dynamics of string cosmologies is presented for the class of isotopic curvature universes. These models are of Bianchi types I, V and IX and reduce to the general class of Friedmann-Robertson-Walker universes in the limit of vanishing shear isotropy. A non-trivial two-form potential and cosmological constant terms are incl

Cheng-Wei Chiang, Lincoln Wolfenstein

In general there are nine observables in the decay of a B meson to two vector mesons defined in terms of polarization correlations of these mesons. Only six of these can be detected via the subsequent decay angular distributions because of parity conservation in those decays. The remaining three require the measurement of the spin polarization of one of the

Gennaro Corcella, Michael H. Seymour

We review the present status of simulations of top production and decay in the HERWIG event generator. We show the phenomenological impact of the recently-implemented matrix-element corrections to top decays for e+e- collisions at 360 GeV and discuss possible further improvements for studies of future experiments at the Linear Collider.

Basarab Nicolescu

We present in this talk the phenomenological and theoretical advances in Odderon physics which occured since the last EDS Blois Workshop (Seoul, 1997).

J. L. Domenech, M. A. Sanchis-Lozano

Inclusive bottomonium hadroproduction at the Tevatron is firstly examined in a Monte Carlo framework with the colour-octet mechanism implemented in the event generation. We extract some NRQCD colour-octet matrix elements relevant for $Υ(1S)$ hadroproduction. Remarkably we find a quite small contribution (compatible with zero) from feeddown of $χ_{bJ}$ states

C. Merino, A. B. Kaidalov, D. Pertermann

The CKMT model for the nucleon structure function F_2 is in good agreement with the HERA data at low and moderate Q^2. The fit to the same data obtained with a modified version of the model in which a logarithmic dependence on Q^2 has been included is also discussed. Finally, we show how the parametrization of the CKMT model for the nucleon structure functio

S. Polityko, N. Takahashi, M. Kato, Y. Yamada

Differential and integral cross sections of the muon are calculated in the materials: water, standard rock, iron and lead with and without the LPM effect. The corresponding cross sections are also calculated with dielectric supression effect (Ter-Mikaelian effect), in addition to the LPM effect. To demonstrate the importance of the LPM effect in the bremsstr

Nir Polonsky

The Higgsino mass, or equivalently the $μ$-parameter, plays an essential role in determining the phenomenology of any supersymmetric model. Particularly, the size of the supersymmetry conserving mu-parameter must be correlated with the size of the soft supersymmetry breaking parameters. The source of this correlation in the underlying ultra-violet theory is

V. V. Andreev

In the work we have considered the reduction techniques matrix element of the reaction interaction of elementary particles for massive fermions to spinor products . The our procedure is not more complex than CALCUL spinor techniques for massless fermions. It is relatively simple and leads to basic spinor products with any polarizationod fermions. Also obtain

Xiaoping Zheng, Jisheng Chen, Jiarong Li, Lianggang Liu

Non-Abelian kinetic effects are taken into account for the study of the relaxation of collective motion in a quark-gluon plasma(QGP). An explicit Compton scattering is considered to calculate the relaxation time. It is shown that the new non-Abelian relaxation has a physical mechanism from the non-linear dynamics and the meaning of the relaxation is discusse

Yasunori Nomura, T. Watari, T. Yanagida

If a global chiral symmetry is explicitly broken by anomalies in nonabelian gauge theories, a pseudo Nambu-Goldstone boson (axion) associated with a spontaneous breakdown of such a global symmetry acquires a mass through nonperturbative instanton effects. We calculate the axion mass assuming a supersymmetric SU(2) gauge theory and show that the axion obtains

Yu. L. Dokshitzer

A short review is given of the present status of the studies of genuine confinement effects in multiple hadron production in hard processes

A. Belyaev, M. Drees, O. J. P Eboli, J. K. Mizukoshi

We study the potential of hadron colliders in the search for the pair production of neutral Higgs bosons in the framework of the Minimal Supersymmetric Standard Model. Using analytical expressions for the relevant amplitudes, we perform a detailed signal and background analysis, working out efficient kinematical cuts for the extraction of the signal. The imp

C. T. Sachrajda

I review some of the contributions which lattice simulations are likely to make during the next five years or so to the development of our understanding of particle physics. Particular emphasis is given to the evaluation of non-perturbative QCD effects in experimentally measurable amplitudes, and the corresponding extraction of fundamental parameters.

Walter Wilcox

A discussion of methods for reducing the noise variance of flavor singlet quantities (&#34;disconnected diagrams&#34;) in lattice QCD is given. After an introduction, the possible advantage of partitioning the Wilson fermion matrix into disjoint spaces is discussed and a numerical comparison of the variance for three possible partitioning schemes is carried

L3 Collaboration

We have measured the probability, n(g->cc~), of a gluon splitting into a charm-quark pair using 1.7 million hadronic Z decays collected by the L3 detector. Two independent methods have been applied to events with a three-jet topology. One method relies on tagging charmed hadrons by identifying a lepton in the lowest energy jet. The other method uses a neural

G. Bagliesi

This article describes the status of the ALPHA^{++} project of the ALEPH collaboration. The ALEPH data have been converted from Fortran data structures (BOS banks) into C^{++} objects and stored in a object oriented database (Objectivity/DB), using tools provided by the RD45 collaboration and the LHC^{++} software project at CERN. A description of the databa

E. J. Thomson

New results on interface effects and correlations are reviewed, including Fermi-Dirac and Bose-Einstein correlations in hadronic Z0 decays at LEP1.

Jaime F. Villas da Rocha, Anzhong Wang

The Riemann, Ricci and Einstein tensors for N-dimensional spherically symmetric spacetimes in various systems of coordinates are studied, and the general metric for conformally flat spacetimes is given. As an application, all the Friedmann-Robertson-Walker-like solutions for a perfect fluid with an equation of state $p = k ρ$ are found. Then, these solutions

S. Banerjee, M. Widom

Theoretical calculations, computer simulations and experiments indicate the possible existence of a ferromagnetic liquid state, although definitive experimental evidence is lacking. Should such a state exist, demagnetization effects would force a nontrivial magnetization texture. Since liquid droplets are deformable, the droplet shape is coupled with the mag

Giuliano Benenti, Giulio Casati, Giulio Maspero, Dima L. Shepelyansky

We study the time dependence of the ionization probability of Rydberg atoms driven by a microwave field, both in classical and in quantum mechanics. The quantum survival probability follows the classical one up to the Heisenberg time and then decays algebraically as P(t) ~ 1/t. This decay law derives from the exponentially long times required to escape from

Yuan Chen, Shuohong Guo, Zhibing Li, Aijun Ye

The kinetic spherical model with long-ranged interactions and an arbitrary initial order m_{0} quenched from a very high temperature to T < T_{c} is solved. In the short-time regime, the bulk order increases with a power law in both the critical and phase-ordering dynamics. To the latter dynamics, a power law for the relative order m_{r} ~ -t^{-k} is found i

J. Christian Schoen, P. Sibani

We investigate the multi-valley energy landscape of a 3-D on-lattice network model for covalent glasses, numerically determining the shape of the valleys, the local density of states, the density of minima and the local connectivity. We present some of these quantities in a graphical birds-eye view of the landscape, and discuss their implications for the rel

M. D. Sumption, E. W. Collings, A. Nijhuis, R. M. Scanlan

AC loss measurements were made on a series of Rutherford cables wound from stabrite-coated NbTi/Cu multifilamentary strand, from the results of which interstrand contact resistances were calculated. The 28-strand, 15 mm wide, LHC-inner type cables contained stainless steel cores of various widths. Calorimetric loss measurements were made on all samples using

O. M. Marago&#39;, S. A. Hopkins, J. Arlt, E. Hodby

We report the observation of the scissors mode of a Bose-Einstein condensed gas of 87^Rb atoms in a magnetic trap, which gives direct evidence of superfluidity in this system. The scissors mode of oscillation is excited by a sudden rotation of the anisotropic trapping potential. For a gas above T_c (normal fluid) we detect the occurrence of oscillations at t

M. -H. Julien, T. Feher, M. Horvatic, C. Berthier

Doping the high-Tc superconductor YBa2Cu3O6.7 with 1.5 % of non-magnetic Zn impurities in CuO2 planes is shown to produce a considerable broadening of 63Cu NMR spectra, as well as an increase of low-energy magnetic fluctuations detected in 63Cu spin-lattice relaxation measurements. A model-independent analysis demonstrates that these effects are due to the d

You-Quan Li

The validity of Bethe ansatz wave function without the backward scattering for the problem of impurity in correlated hosts with periodic boundary condition is illustrated by a simple example of quantum mechanics. An long being overlooked point in solving Hubbard model by means of Bethe ansatz is indicated. A possible repairing on the Hamiltonian is suggested

T. Saitoh, D. S. Dessau, Y. Moritomo, T. Kimura

Direct electronic structure measurements of a variety of the colossal magnetoresistive oxides show the presence of a pseudogap at the Fermi energy E_F which drastically suppresses the electron spectral function at E_F. The pseudogap is a strong function of the layer number of the samples (sample dimensionality) and is strongly temperature dependent, with the

Markus Buttiker

It is shown that the dephasing rate in Coulomb coupled mesoscopic structures is determined by charge relaxation resistances. The charge relaxation resistance together with the capacitance determines the RC-time of the mesoscopic structure and at small frequencies determines the voltage fluctuation spectrum. Self-consistent expressions are presented which giv

Zhen Yao, Charles L. Kane, Cees Dekker

Using low-resistance electrical contacts, we have measured the intrinsic high-field transport properties of metallic single-wall carbon nanotubes. Individual nanotubes appear to be able to carry currents with a density exceeding 10^9 A/cm^2. As the bias voltage is increased, the conductance drops dramatically due to scattering of electrons. We show that the

Masatoshi Imada, Masanori Kohno

Routes to enhance superconducting instability are explored for doped Mott insulators. With the help of insights for criticalities of metal-insulator transitions, geometrical design of lattice structure is proposed to control the instability. A guideline is to explicitly make flat band dispersions near the Fermi level without suppressing two-particle channels

A. Buhot, A. Halperin

The helix-coil transition is modified by grafting to a surface. This modification is studied for short peptides capable of forming $α$-helices. Three factors are involved: (i) the grafting can induced change of the boundary free energy of the helical domain (ii) the van der Waals attraction between the helices and (iii) the crowding induced stretching of the

Eric Akkermans, Alain Comtet, Jean Desbois, Gilles Montambaux

We study the spectral determinant of the Laplacian on finite graphs characterized by their number of vertices V and of bonds B. We present a path integral derivation which leads to two equivalent expressions of the spectral determinant of the Laplacian either in terms of a V x V vertex matrix or a 2B x 2B link matrix that couples the arcs (oriented bonds) to

P. Carretta, A. Lascialfari, A. Rigamonti, A. Rosso

Magnetization and 63Cu NMR-NQR relaxation measurements are used to study the superconducting fluctuations in YBa2Cu3O6+x (YBCO) oriented powders. In optimally doped YBCO the fluctuating negative magnetization M_{fl}(H,T) is rather well described by an anisotropic Ginzburg-Landau (GL) functional and the curves M_{fl}/sqrt{H} cross at Tc. In underdoped YBCO, i

Shin-ichi Sasa, Teruhisa S. Komatsu

This paper discusses the thermodynamic irreversibility realized in high-dimensional Hamiltonian systems with a time-dependent parameter. A new quantity, the irreversible information loss, is defined from the Lyapunov analysis so as to characterize the thermodynamic irreversibility. It is proved that this new quantity satisfies an inequality associated with t

Pavel Exner, Alain Joye, Hynek Kovarik

We investigate a charged two-dimensional particle in a homogeneous magnetic field interacting with a periodic array of point obstacles. We show that while Landau levels remain to be infinitely degenerate eigenvalues, between them the system has bands of absolutely continuous spectrum and exhibits thus a transport along the array. We also compute the band fun

F. Borgonovi, F. M. Izrailev

We study the emergence of Boltzmann&#39;s law for the &#34;single particle energy distribution&#34; in a closed system of interacting classical spins. It is shown that for a large number of particles Boltzmann&#39;s law may occur, even if the interaction is very strong. Specific attention is paid to classical analogs of the average shape of quantum eigenstat

Arjendu K. Pattanayak

We establish that the entropy production rate of a classically chaotic Hamiltonian system coupled to the environment settles, after a transient, to a meta-stable value given by the sum of positive generalized Lyapunov exponents. A meta-stable steady state is generated in this process. This behavior also occurs in quantum systems close to the classical limit

Niels Sondergaard, Gabor Vattay, Gergely Palla, Andre Voros

We consider an evolution operator for a discrete Langevin equation with a strongly hyperbolic classical dynamics and noise with finite moments. Using a perturbative expansion of the evolution operator we calculate high order corrections to its trace in the case of a quartic map and Gaussian noise. The leading contributions come from the period one orbits of

G. Cicogna, M. Santoprete

Using a completely analytic procedure - based on a suitable extension of a classical method - we discuss an approach to the Poincaré-Mel&#39;nikov theory, which can be conveniently applied also to the case of non-hyperbolic critical points, and even if the critical point is located at the infinity. In this paper, we concentrate our attention on the latter ca

F. Camilo, D. R. Lorimer, P. Freire, A. G. Lyne

We have used a new observing system on the Parkes radio telescope to carry out a series of pulsar observations of the globular cluster 47 Tucanae at 20-cm wavelength. We detected all 11 previously known pulsars, and have discovered nine others, all of which are millisecond pulsars in binary systems. We have searched the data for relatively short orbital peri

Jennifer M. Lotz, Henry C. Ferguson, Ralph C. Bohlin

We investigate the effects of abundance and age on the mid-UV spectra and Mg_{2} strengths of stellar populations using simple population synthesis models. These models are used to constrain the star formation history of four nearby elliptical galaxies and spiral bulges. The mid-UV (1800 - 3200 Å) light of evolved stellar populations (> 1 Gyr) is dominated b

F. Crawford, V. M. Kaspi, R. N. Manchester

We present radio polarimetry results for nine Southern pulsars. Six of the nine are young, with characteristic ages less than 100 kyr and high spin-down luminosities. All six show significant linear polarization, and we confirm a previously noticed trend in which the degree of linear polarization increases with spin-down luminosity. We have used the rotating

Liliya L. R. Williams, Prasenjit Saha

Observed time delays between images of a lensed QSO lead to the determination of the Hubble constant by Refsdal&#39;s method, provided the mass distribution in the lensing galaxy is reasonably well known. Since the two or four QSO images usually observed are woefully inadequate by themselves to provide a unique reconstruction of the galaxy mass, most previou

F. Crawford, V. M. Kaspi, J. F. Bell

We have searched 92 unidentified sources from the FIRST and NVSS radio catalogs for pulsations at 610 MHz. The selected sources are bright, have no identifications, are unresolved and have significant linear polarization. Our search was sensitive to sub-millisecond pulsations from pulsars with a large range of dispersion measures. We have detected no radio p

Qing Zhang, S. Michael Fall

We determine the mass function of young star clusters in the merging galaxies the ``Antennae&#39;&#39; (NGC 4038/39) from deep images taken with the WFPC2 on the refurbished Hubble Space Telescope (HST). This is accomplished by means of reddening-free parameters and a comparison with stellar population synthesis tracks to estimate the intrinsic luminosity an