July 2001 arXiv papers — page 13

S. Basak, Asit K. De

Gauge fixed domain wall fermions are investigated in the reduced model at small Yukawa couplings. We present chiral propagators at the waveguide boundaries using quenched numerical simulations and analytic methods. There is no evidence of mirror chiral modes at the waveguide boundaries.

T. Asaga, L. Benet, T. Rupp, H. A. Weidenmueller

We consider $m$ spinless Bosons distributed over $l$ degenerate single-particle states and interacting through a $k$-body random interaction with Gaussian probability distribution (the Bosonic embedded $k$-body ensembles). We address the cases of orthogonal and unitary symmetry in the limit of infinite matrix dimension, attained either as $l \to \infty$ or a

N. Haba, Y. Shimizu, Tomoharu Suzuki, Kazumasa Ukai

We suggest a simple grand unified theory where the fifth dimensional coordinate is compactified on an $S_1/(Z_2 \times Z_2')$ orbifold. This model is based on the supersymmetric flipped $SU(5) \times U(1)$ grand unified theory, which can realize not only the triplet-doublet splitting but also the natural fermion mass hierarchies. The triplet-doublet spli

M. De Naurois, J. Holder, R. Bazer-Bachi, H. Bergeret

We have converted the former solar electrical plant THEMIS (French Pyrenees) into an atmospheric Cherenkov detector called CELESTE, which records gamma rays above 30 GeV (7E24 Hz). Here we present the first sub-100 GeV detection by a ground based telescope of a gamma ray source, the Crab nebula, in the energy region between satellite measurements and imaging

Hiroshi Kontani

We present a microscopic theory for the thermoelectric power (TEP) in high-Tc cuprates. Based on the general expression for the TEP, we perform the calculation of the TEP for a square lattice Hubbard model including all the vertex corrections necessary to satisfy the conservation laws. In the present study, characteristic anomalous temperature and doping dep

Chuan-Hung Chen

We study $B_{s}\to KK$ decays in the framework of the PQCD. We show that the branching ratios of $B_{s}\to (K^+ K^-, K^0 \bar{K}^0)$ are about $(22.43, 25.78) \times 10^{-6}$ for $ϕ_{3}(γ)\simeq72^0$, which are consistent with the model-independent estimations. We find that the typical scale of the decays is near 1.7 GeV. We also point out that the induced s

André de Gouvêa, C. Peña-Garay

We study what will be learnt about the solar neutrino puzzle and solar neutrino oscillations once the data from the KamLAND reactor neutrino experiment (soon to become available) are combined with those from the current solar neutrino experiments. We find that, in agreement with previous estimates, if the solution to the solar neutrino puzzle falls on the LM

J. D. Denlinger, G. -H. Gweon, J. W. Allen, J. L. Sarrao

A dramatic temperature dependent enhancement of U 5f spectral weight at $E_F$ is observed in angle-resolved photoemission measurements of $URu_2Si_2$ at the center of an X-point hole-pocket. Comparison of this temperature dependent behavior for excitation both at and below the U $5d \to 5f$ resonant threshold is presented.

António Silva, Hyun-Chul Kim, Klaus Goeke

The strange properties of the nucleon are investigated within the framework of the SU(3) chiral quark-soliton model assuming isospin symmetry and applying the symmetry conserving SU(3) quantization. We present the form factors $G^0_{E,M}(Q^2)$, $G^Z_M(Q^2)$ and the electric and magnetic strange form factors $G^s_{E,M}(Q^2)$ incorporating pion and kaon asympt

S. Michael Fall, Qing Zhang

We present a series of simple, largely analytical models to compute the effects of disruption on the mass function of star clusters. Our calculations include evaporation by two-body relaxation and gravitational shocks and mass loss by stellar evolution. We find that, for a wide variety of initial conditions, the mass function develops a turnover or peak and

E. Friedman

Extensive data on strong interaction effects in pionic atoms are analyzed with a density-dependent isovector scattering amplitude suggested recently by Weise to result from a density dependence of the pion decay constant. Most of the so-called `missing s-wave repulsion' is removed when adopting this approach, thus indicating a partial chiral symmetry res

M. Fujita, H. Goka, K. Yamada, M. Matsuda

We have performed a series of elastic neutron scattering measurements on 1/8-hole doped La$_{1.875}$Ba$_{0.125-x}$Sr$_{x}$CuO$_{4}$ single crystals with {\it x} = 0.05, 0.06, 0.075 and 0.085. % Both charge-density-wave (CDW) and spin-density-wave (SDW) orders are found to develop simultaneously below the structural transition temperature between the low-temp

S. Y. Li, W. Q. Mo, M. Yu, W. H. Zheng

The thermopower and thermal conductivity of superconducting perovskite $MgCNi_3$ ($T_c \approx$ 8 K) have been studied. The thermopower is negative from room temperature to 10 K. Combining with the negative Hall coefficient reported previously, the negative thermopower definetly indicates that the carrier in $MgCNi_3$ is electron-type. The nonlinear temperat

H. M. Cataldo, D. M. Jezek

The longitudinal friction acting on a vortex line in superfluid $^4$He is investigated within a simple model based on the analogy between such vortex dynamics and that of the quantal Brownian motion of a charged point particle in a uniform magnetic field. The scattering of superfluid quasiparticle excitations by the vortex stems from a translationally invari

Harumichi Nishimura, Masanao Ozawa

This paper positively solves the quantum subroutine problem for fully quantum oracles. The quantum subroutine problem asks whether a quantum computer with an efficiently computable oracle can be efficiently simulated by a non-oracle quantum computer. We extends the earlier results obtained by Bennett, Bernstein, Brassard, and Vazirani, and by Aharonov, Kitae

S. J. van Enk, H. J. Kimble

Control fields in quantum information processing are virtually always, almost by definition, assumed to be classical. In reality, however, when such a field is used to manipulate the quantum state of qubits, the qubits never remain completely unentangled with the field. For quantum information processing this is an undesirable property, as it precludes perfe

F. Schmidt-Kaler, J. Eschner, G. Morigi, C. F. Roos

A novel method of ground state laser cooling of trapped atoms utilizes the absorption profile of a three (or multi-) level system which is tailored by a quantum interference. With cooling rates comparable to conventional sideband cooling, lower final temperatures may be achieved. The method was experimentally implemented to cool a single Ca$^+$ ion to its vi

Jan Perina, Ondrej Haderka, Jan Soubusta

A photon source based on postselection from entangled photon pairs produced by parametric frequency down-conversion is suggested. Its ability to provide good approximations of single-photon states is examined. Application of this source in quantum cryptography for quantum key distribution is discussed. Advantages of the source compared to other currently use

A. John Arul

Is there any point of principle that prohibits us from doing one or more forms of quantum information processing? It is now well known that an unknown quantum state can neither be copied nor deleted perfectly. Given a set of states which are not necessarily orthogonal, is it possible to compare any two states from the set, given some reasonable ordering of s

Chi Yu Hu, David Caballero, Zoltán Papp

We assume all interaction to be Coulombic and solve the modified Faddeev equation for energies between the $Ps(n=2)$ and $\bar{H}(n=3)$, which involve six and eight open channels. We find that 99% of the antihydrogen are formed in $\bar{H}(n=2)$. Just above the $Ps(n=2)$ threshold the S, P, and D partial waves contribute more than 4000 square Bohr radii near

Uwe Boerner, Andreas Deutsch, Hans Reichenbach, Markus Baer

Experiments with myxobacterial aggregates reveal standing waves called rippling patterns. Here, these structures are modelled with a simple discrete model based on the interplay between migration and collisions of cells. Head-to-head collisions of cells result in cell reversals. To correctly reproduce the rippling patterns, a refractory phase after each cell

H. Rohde, J. Eschner, F. Schmidt-Kaler, R. Blatt

The dynamical response of an optical Fabry-Perot cavity is investigated experimentally. We observe oscillations in the transmitted and reflected light intensity if the frequency of the incoupled light field is rapidly changed. In addition, the decay of a cavity-stored light field is accelerated if the phase and intensity of the incoupled light are switched i

Harald R. Telle, Burghard Lipphardt, Jörn Stenger

We introduce a novel concept for optical frequency measurement and division which employs a Kerr-lens mode-locked laser as a transfer oscillator whose noise properties do not enter the measurement process. We experimentally demonstrate, that this method opens up the route to phase-link signals with arbitrary frequencies in the optical or microwave range whil

V. A. Yerokhin, V. M. Shabaev

A part of the two-loop self-energy correction, the so-called P term, is evaluated numerically for the 1s state to all orders in Zα. Our calculation, combined with the previous investigation [S. Mallampalli and J. Sapirstein, Phys. Rev. A 57, 1548 (1998)], yields the total answer for the two-loop self-energy correction in H-like uranium and bismuth. As a resu

A. V. Kochin

The paper presents a model of electric charge generation in precipitating clouds due to breaking of large particles in low melting layer. The Earth's electric field polarises the droplets and they break into small negatively charged and large positively charged fragments. A negatively charged cloud region is formed below melting layer. The charged region

Jan Gruenert, Andreas Hemmerich

We investigate the production of long lived metastable (3P2, n=4) calcium atoms in a magneto-optical trap operating on the 1S0 to 1P1 transition at 423 nm. For excited 1P1-atoms a weak decay channel into the triplet states 3P2 and 3P1 exists via the singlet 1D2 (n=3) state. The undesired 3P1-atoms decay back to the ground state within 0.4 ms and can be fully

V. Grassi, R. A. Leo, G. Soliani, P. Tempesta

The Navier-Stokes-Fourier model for a 3D thermoconducting viscous fluid, where the evolution equation for the temperature T contains a term proportional to the rate of energy dissipation, is investigated analitically at the light of the rotational invariance property. Two cases are considered: the Couette flow and a flow with a radial velocity between two ro

Y. Yamamoto, T. Tamagawa, T. Fukuda, T. Motoba

$Ξ^-$ escaping and scattering probabilities in the $(K^-,K^+)$ reaction with nuclear targets is investigated on the basis of the eikonal approximation. Calculations are performed using the $S=-2$ sector of the Nijmegen model-D interaction, whose hard core radii are treated phenomenologically. %The $Ξ^- N$, $Ξ^- p$ and $Ξ^- n$ elastic cross sections are The $

H. Xu, R. Alfaro, B. Davin, L. Beaulieu

Isotope ratios of fragments produced at mid-rapidity in peripheral and central collisions of 114Cd ions with 92Mo and 98Mo target nuclei at E/A = 50 MeV are compared. Neutron-rich isotopes are preferentially produced in central collisions as compared to peripheral collisions. The influence of the size (A), density, N/Z, E*/A, and Eflow/A of the emitting sour

Sanjay Jain, Sandeep Krishna

The causes of major and rapid transitions observed in biological macroevolution as well as in the evolution of social systems are a subject of much debate. Here we identify the proximate causes of crashes and recoveries that arise dynamically in a model system in which populations of (molecular) species co-evolve with their network of chemical interactions.

Sanjay Jain, Sandeep Krishna

A model of an evolving network of interacting molecular species is shown to exhibit repeated rounds of crashes in which several species get rapidly depopulated, followed by recoveries. The network inevitably self-organizes into an autocatalytic structure, which consists of an irreducible `core' surrounded by a parasitic `periphery'. Crashes typically

Yuri V. Andreyev, Alexander S. Dmitriev, Elena V. Efremova

The problem of separation of an observed sum of chaotic signals into the individual components in the presence of noise on the path to the observer is considered. A noise threshold is found above which high-quality separation is impossible. Below the threshold, each signal is recovered with any prescribed accuracy. This effect is shown to be associated with

Tae-Wook Ko, Seong-Ok Jeong, Hie-Tae Moon

We propose a spatially continuous and temporally discrete model for pattern formation in vertically vibrated granular layers. The grain transfer and the grain mobility transitions are introduced qualitatively, but explicitly. This model reproduces experimentally observed f/2 patterns, including squares in high-mobility conditions and stripes in low-mobility

Y. Latushkin, Y. Li, M. Stanislavova

We study the spectral properties of the linearized Euler operator obtained by linearizing the equations of incompressible two dimensional fluid at a steady state with the vorticity that contains only two nonzero complex conjugate Fourier modes. We prove that the essential spectrum coincides with the imaginary axis, and give an estimate from above for the num

Jennifer Henry

We develop a method to find a set of diminimal polyhedral maps on the torus from which all other polyhedral maps on the torus may be generated by face splitting and vertex splitting. We employ this method, though not to its completion, to find 53 diminimal polyhedral maps on the Torus.

E. V. Ferapontov

The class of surfaces in 3-space possessing nontrivial deformations which preserve principal directions and principal curvatures (or, equivalently, the shape operator) was investigated by Finikov and Gambier as far back as in 1933. We review some of the known examples and results, demonstrate the integrability of the corresponding Gauss-Codazzi equations and

Boris Tsirelson

Filtered probability spaces (called "filtrations" for short) are shown to satisfy such a topological zero-one law: for every property of filtrations, either the property holds for almost all filtrations, or its negation does. In particular, almost all filtrations are conditionally nonatomic. An accurate formulation is given in terms of orbit equivale

Ralf Alfons Engeldinger

The gauge field term in the Standard Model Lagrangian is slightly rewritten, suggesting that the three gauge couplings have absorbed factors which depend on the dimensions of the corresponding gauge groups. The ratios of the physical couplings may turn out to be dominated by these factors, with deviations due to quantum corrections.

J. M. Camino, A. V. Ramallo

We study the motion of a D(8-p)-brane probe in the background created by a stack of non-threshold (D(p-2), Dp) bound states for $2\le p\le 6$. The brane probe and the branes of the background have two common directions. We show that for a particular value of the worldvolume gauge field there exist configurations of the probe brane which behave as massless pa

Renat Kh. Gainutdinov

We discuss the dynamical situation which arises in a local quantum field theory after renormalization. By using the example of the three-dimensional theory of a neutral scalar field interacting through the quartic coupling, we show that after renormalization the dynamics of a theory is governed by a generalized dynamical equation with a nonlocal interaction

Ralph Blumenhagen, Boris Kors, Dieter Lust, Tassilo Ott

We analyze the perturbative stability of non-supersymmetric intersecting brane world models on tori. Besides the dilaton tadpole, a dynamical instability in the complex structure moduli space occurs at string disc level, which drives the background geometry to a degenerate limit. We show that in certain orbifold models this latter instability is absent as th

Kamran Diba, David A. Lowe

We study the decay of a near-extremal black hole in AdS$_2$, related to the near-horizon region of 3+1-dimensional Reissner-Nordström spacetime, following Fabbri, Navarro, and Navarro-Salas. Back-reaction is included in a semiclassical approximation. Calculations of the stress-energy tensor of matter coupled to the physical spacetime for an affine null obser

W. L. van Neerven, A. Vogt

We summarize recent results on the evolution of unpolarized parton densities and deep-inelastic structure functions in massless perturbative QCD. Due to last year's extension of the integer-moment calculations of the three-loop splitting functions, the NNLO evolution of the parton distributions can now be performed reliably at momentum fractions x >= 10^

W. L. van Neerven

We will give a review of the computation of exact next-to-leading order corrections to heavy quark production in deep inelastic lepton-hadron scattering and discuss the progress made in this field over the past ten years. In this approach, hereafter called EXACT, where the heavy quark mass is taken to be of the same order of magnitude as the other large scal

J. Seixas, J. T. Mendonca

We analyze the known moving boundary effects in plasma and briefly review a mechanism for particle acceleration through a plasma front. We then show how this mechanism may affect particles crossing the boundary of an expanding quark gluon plasma.

Zhiguang Xiao, Hanqing Zheng

Studies on the IJ=00 $ππ$ and $K\bar K$ coupled--channel system are made using newly derived dispersion relations between the phase shifts and poles and cuts. It is found that the $σ$ resonance must be introduced to explain the experimental phase shifts, after evaluating the cut contribution. The effects of nearby branch point singularities to the determinat

Kim Maltman, Joachim Kambor

A number of recent determinations of $m_s$ using hadronic $τ$ decay data involve inclusive analyses based on the so-called $(k,0)$ spectral weights. We show here that the OPE representations of the longitudinal contributions appearing in these analyses, which are already known to be poorly converging, have in addition an unphysical $k$ dependence which produ

Massimo Blasone, Antonio Capolupo, Giuseppe Vitiello

We comment on the paper ``Remarks on flavor-neutrino propagators and oscillation formulae'' [Phys. Rev. D64, 013011 (2001)]. We show that the conclusions presented in that paper do not apply to the exact field theoretical oscillation formulae obtained in the BV formalism (for three flavors) which are free from the dependence on arbitrary mass paramet

Jonathan L. Feng, Konstantin T. Matchev, Yael Shadmi

We examine the muon's electric dipole moment $\dmu$ from a variety of theoretical perspectives. We point out that the reported deviation in the muon's g-2 can be due partially or even entirely to a new physics contribution to the muon's {\em electric} dipole moment. In fact, the recent g-2 measurement provides the most stringent bound on $\dmu$ t

E852 Collaboration, G. S. Adams

A new measurement of the reaction pi- p -> K+ K- pi0 n has been made at a beam energy of 18 GeV. A partial wave analysis of the K+ K- pi0 system shows evidence for three pseudoscalar resonances, eta(1295), eta(1416), and eta(1485), as well as two axial vectors, f1(1285), and f1(1420). Their observed masses, widths and decay properties are reported. No signal

K2K MRD Group, T. Ishii, T. Inagaki, J. Breault

A muon range detector (MRD) has been constructed as a near detector for the KEK-to-Kamioka long-baseline neutrino experiment (K2K). It monitors the neutrino beam properties at the near site by measuring the energy, angle and production point of muons produced by charged-current neutrino interaction. The detector has been working stably since the start of the

Luciano Rezzolla, Frederick L. Lamb, Dragoljub Markovic, Stuart L. Shapiro

The evolution of the r-mode instability is likely to be accompanied by secular kinematic effects which will produce differential rotation with large scale drifts of fluid elements, mostly in the azimuthal direction. As first discussed by Rezzolla, Lamb and Shapiro 2000, the interaction of these secular velocity fields with a pre-existing neutron star magneti

Luciano Rezzolla, Frederick L. Lamb, Dragoljub Markovic, Stuart L. Shapiro

The instability of r-mode oscillations in rapidly rotating neutron stars has attracted attention as a potential mechanism for producing high frequency, almost periodic gravitational waves. The analyses carried so far have shown the existence of these modes and have considered damping by shear and bulk viscosity. However, the magnetohydrodynamic coupling of t

B. V. Ivanov

It is shown that different approaches towards the solution of the Einstein equations for a static spherically symmetric perfect fluid with a gamma-law equation of state lead to an Abel differential equation of the second kind. Its only integrable cases at present are flat spacetime, de Sitter solution and its Buchdahl transform, Einstein static universe and

Roberto Bruni, Ugo Montanari, Francesca Rossi

We apply to logic programming some recently emerging ideas from the field of reduction-based communicating systems, with the aim of giving evidence of the hidden interactions and the coordination mechanisms that rule the operational machinery of such a programming paradigm. The semantic framework we have chosen for presenting our results is tile logic, which

Radu Florian, Grace Ngai

This paper presents a novel method that allows a machine learning algorithm following the transformation-based learning paradigm \cite{brill95:tagging} to be applied to multiple classification tasks by training jointly and simultaneously on all fields. The motivation for constructing such a system stems from the observation that many tasks in natural languag

Grace Ngai, Radu Florian

Transformation-based learning has been successfully employed to solve many natural language processing problems. It achieves state-of-the-art performance on many natural language processing tasks and does not overtrain easily. However, it does have a serious drawback: the training time is often intorelably long, especially on the large corpora which are ofte

J. E. Hirsch

The paper by Pan et al, cond-mat/0107347, reports the discovery of 'electronic inhomogeneity' and 'spatial variations in the local density of states' in high $T_c$ cuprates. In my paper ``Effect of local potential variations in the model of hole superconductivity'', Physica C {\bf 194}, 119 (1992), many of the findings of Pan et al we

J. Ricardo G. de Mendonca

We provide finite-size scaling estimates for the dynamical critical exponent of the even parity-conserving universality class of critical behavior through exact numerical diagonalizations of the time evolution operator of an even-parity-conserving contact process. Our data seem to indicate that upon the introduction of a small diffusion rate in the process i

M. H. S. Amin, M. Coury, G. Rose

A new DC-SQUID is proposed that exploits the properties of the grain boundary junctions in high T_c superconductors. The orientations of the grain boundaries are chosen in such a way to establish a pi/2 (rather than 0 or pi) phase difference between the equilibrium phases of the two Josephson junctions in the SQUID loop. This property is exploited to increas

V. Senz, T. Ihn, T. Heinzel, K. Ensslin

The temperature dependence of a system exhibiting a `metal-insulator transition in two dimensions at zero magnetic field' (MIT) is studied up to 90K. Using a classical scattering model we are able to simulate the non-monotonic temperature dependence of the resistivity in the metallic high density regime. We show that the temperature dependence arises fro

Phillip L. Geissler, Eugene I. Shakhnovich

We have analyzed the equilibrium response of chain molecules to stretching. For a homogeneous sequence of monomers, the induced transition from compact globule to extended coil below the $θ$-temperature is predicted to be sharp. For random sequences, however, the transition may be smoothed by a prevalence of necklace-like structures, in which globular region

T. Asaga, L. Benet, T. Rupp, H. A. Weidenmueller

We investigate the shape of the spectrum and the spectral fluctuations of the $k$-body Embedded Gaussian Ensemble for Bosons in the dense limit, where the number of Bosons $m \to \infty$ while both $k$, the rank of the interaction, and $l$, the number of single-particle states, are kept fixed. We show that the relative fluctuations of the low spectral moment

József Cserti, Gyula Dávid, Attila Piróth

The resistance between arbitrary nodes of infinite networks of resistors is studied when the network is perturbed by removing one bond from the perfect lattice. A connection is made between the resistance and the lattice Green's function of the perturbed network. Solving Dyson's equation the Green's function and the resistance of the perturbed la

A. Mourachkine

We present direct measurements of the density of states by tunneling spectroscopy on slightly overdoped Bi2212 single crystals at low temperature using break-junction and point-contact techniques. We find that (i) the variation of the gap magnitude, Delta, between 20 and 36 meV is likely to be intrinsic to the Bi2212, and (ii) there is a correlation between

Robert S. Whitney, Yuval Gefen

Berry phase was originally defined for systems whose states are separated by finite energy gaps. One might naively expect that a system without a gap cannot have a Berry phase. Despite this we ask whether a Berry phase can be observed in a system which has a continuous spectrum because its coupling to the environment has broadened its energy levels. We find

R. L. C. Vink, G. T. Barkema, M. A. Stijnman, R. H. Bisseling

The atomic structure of amorphous materials is believed to be well described by the continuous random network model. We present an algorithm for the generation of large, high-quality continuous random networks. The algorithm is a variation of the "sillium" approach introduced by Wooten, Winer, and Weaire. By employing local relaxation techniques, loc

Yasufumi Yamashita, Kazuo Ueda, Manfred Sigrist

The ground-state properties of the spin-1 pyrochlore antiferromagnet are studied by applying the VBS-like tetrahedron-unit decomposition to the original spin system. The symmetrization required on every vertex is taken into account by introducing a ferromagnetic coupling. The pairwise effective Hamiltonian between the adjacent tetrahedrons is obtained by con

Hyun-Sik Chang, Hu-Jong Lee, Migaku Oda

We observed an enhancement of the $c$-axis differential conductance around the zero-bias in Au$/$Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (Bi2212) junctions near the superconducting transition temperature $T_c$. We attribute the conductance enhancement to the Andreev reflection between the surface Cu-O bilayer with suppressed superconductivity and the neighboring super

Y. Itoh, T. Machi, N. Koshizuka, T. Masuda

We report on a zero-field 63Cu nuclear quadrupole resonance (NQR) study of nonmagnetic Mg impurity substituted Cu1-xMgxGeO3 (single crystals; the spin-Peierls transition temperature Tsp~14, 13.5, and 11 K for x=0, 0.0043, and 0.020) in a temperature range from 4.2 K to 250 K. We found that below T*~77 K, Cu NQR spectra are broadened and nonexponential Cu nuc

N. Kiriushcheva, Peter H. Poole

We conduct molecular dynamics computer simulations of a system of Lennard-Jones particles, polydisperse in both size and mass, at a fixed density and temperature. We test for and quantify systematic changes in dynamical properties that result from polydispersity, by measuring the pair distribution function, diffusion coefficient, velocity autocorrelation fun

P. G. Pagliuso, R. Movshovich, A. D. Bianchi, M. Nicklas

Magnetic susceptibility, electrical resistivity and heat capacity data for single crystals of Ce(Rh,Ir)1-x(Co,Ir)xIn5 (0 < x < 1) have allowed us to construct a detailed phase diagram for this new family of heavy-fermion superconductors(HFS). CeRh1-xIrxIn5 displays superconductivity(SC) (Tc < 1 K) over a wide range of composition, which develops out of and c

A. E. Shapley, C. C. Steidel, K. L. Adelberger, M. Dickinson

We present the results of a near-infrared imaging survey of z~3 Lyman Break Galaxies (LBGs). The survey covers a total of 30 arcmin^2 and includes 118 photometrically selected LBGs with K_s band measurements, 63 of which also have J band measurements, and 81 of which have spectroscopic redshifts. Using the distribution of optical {\cal R} magnitudes from pre

Gabriela Canalizo, Alan Stockton

Low-ionization broad absorption line (BAL) QSOs present properties that cannot generally be explained by simple orientation effects. We have conducted a deep spectroscopic and imaging study of the host galaxies of the only four BAL QSOs that are currently known at z < 0.4, and found that all four objects reside in dusty, starburst or post-starburst, merging

Shih-Ping Lai, Richard M. Crutcher, Jose M. Girart, Ramprasad Rao

We present the first interferometric polarization map of the W51 e1/e2 molecular cores obtained with the BIMA array at 1.3 mm wavelength with approximately 3 arcsecond resolution. The polarization angle varies smoothly across the double cores with an average position angle of 23+-5 degrees for W51 e1 and 15+-7 degrees for W51 e2. The inferred magnetic field

S. C. C. Ng, N. J. Nunes, F. Rosati

We develop a framework to study the phase space of a system consisting of a scalar field rolling down an arbitrary potential with varying slope and a background fluid, in a cosmological setting. We give analytical approximate solutions of the field evolution and discuss applications of its features to the issues of quintessence, moduli stabilisation and quin

Toshiya Ueta, David Fong, Margaret Meixner

We present high-sensitivity near-IR images of a carbon-rich proto-planetary nebula, AFGL 618, obtained with the Subaru Telescope. These images have revealed ``bullets&#39;&#39; and ``horns&#39;&#39; extending farther out from the edges of the previously known bipolar lobes. The spatial coincidence between these near-IR micro-structures and the optical collim

Weidong Li, Alexei V. Filippenko, Elinor Gates, Ryan Chornock

We present extensive photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2000cx in the S0 galaxy NGC 524, which reveal it to be peculiar. Photometrically, SN 2000cx is different from all known SNe Ia, and its light curves cannot be fit well by the fitting techniques currently available. There is an apparent asymmetry in the $B$-band p

Adrian M. Silva, Sergio A. Cellone

We present two-colour CCD imaging of 2060 Chiron obtained between 1996 and 1998 with the 2.15 m telescope at CASLEO (San Juan, Argentina). These post-perihelion observations show that Chiron was then near its historical brightness minima, however a coma was clearly detected. The dynamical state of the coma is studied by means of azimuthally averaged surface

Ruben Krasnopolsky, Zhi-Yun Li, Roger D. Blandford

Protostellar jets and winds are probably driven magnetocentrifugally from the surface of accretion disks close to the central stellar objects. The exact launching conditions on the disk, such as the distributions of magnetic flux and mass ejection rate, are poorly unknown. They could be constrained from observations at large distances, provided that a robust

L. Sertorio, G. Tinetti

The quest for life in the Universe is often affected by the free use of extrapolations of our phenomenological geocentric knowledge. We point out that the existence of a living organism, and a population of organisms, requires the existence of available energy or, more precisely, available power per unit volume (Sect. 1). This is not a geocentric concept, bu

D. Sinachopoulos, Th. Nakos, P. Boumis, E. van Dessel

We present the results of a photometric CCD monitoring of the gravitational lens system UM 673, that took place from 1995 to 2000. In total, the doubly-imaged quasar was observed in the R-band during 29 photometric nights, using optical telescopes with dimensions in the range 0.6 m to 1.3 m. We detected a significant variability in the total light of the UM

R. W. Schmidt, S. W. Allen, A. C. Fabian

We present the analysis of 30 ksec of Chandra observations of the galaxy cluster Abell 1835. Overall, the X-ray image shows a relaxed morphology, although we detect substructure in in the inner 30 kpc radius. Spectral analysis shows a steep drop in the X-ray gas temperature from ~12 keV in the outer regions of the cluster to ~4 keV in the core. The Chandra d

D. Varshalovich, A. Ivanchik, P. Petitjean, R. Srianand

We have analyzed the spectrum of the quasar PKS 1232+082 obtained by Petitjean et al. (2000). HD molecular lines are identified in an absorption system at the redshift z=2.3377. The column density of HD molecules in the system is estimated, N(HD)=(1-4)x10^{14} cm^{-2}. The temperature of excitation of the first rotational level J=1 relative to the ground sta

A. P. Schoenmakers, A. G. de Bruyn, H. J. A. Rottgering, H. van der Laan

We have used the Westerbork Northern Sky Survey (WENSS) to define a sample of 47 low redshift (z < 0.4) giant radio galaxies. This is the largest sample yet of such radio sources originating from a single survey. We present radio maps of the newly discovered giants and optical images and spectra of their host galaxies. We present some of their properties and

Patrick M Motl, Joel E Tohline, Juhan Frank

We describe computational tools that have been developed to simulate dynamical mass transfer in semi-detached, polytropic binaries that are initially executing synchronous rotation upon circular orbits. Initial equilibrium models are generated with a self-consistent field algorithm; models are then evolved in time with a parallel, explicit, Eulerian hydrodyn

V. Berezinsky

About 400 years have passed since the great discoveries by Galilei, Kepler and Newton, but astronomy still remains an important source of discoveries in physics. They start with puzzles, with phenomena difficult to explain, and which in fact need for explanation the new physics. Are such puzzles existing now? There are at least three candidates: absence of a

D F Roscoe

The 900 ORCs of Mathewson, Ford & Buchhorn which were folded by Persic & Salucci (astro-ph/9502091) are analysed. A technique for removing that part of an ORC most dominated by the central region it introduced (see astro-ph/0107300 for a far more comprehensive discussion of this). The analysis then shows that a power-law model of the form V = A R^b, where th

John E. Norris, Sean G. Ryan, Timothy C. Beers

High-resolution, high-signal-to-noise (<S/N> = 85) spectra have been obtained for five stars -- CD-24:17504, CD-38:245, CS 22172-002, CS 22885-096, and CS 22949-037 -- having [Fe/H] < -3.5 according to previous lower S/N material. LTE model-atmosphere techniques are used to determine [Fe/H] and relative abundances, or their limits, for some 18 elements, and

Milan M. Cirkovic

A recent criticism of cosmological methodology and achievements by Disney (2000) is assessed. Some historical and epistemological fallacies in the said article have been highlighted. It is shown that---both empirically and epistemologically---modern cosmology lies on sounder foundations than it is portrayed. A brief historical account demonstrates that this

P. Jablonka

This review presents the current status of our knowledge of M31 star clusters. Given the broadness of the subject, I chose to focus on some of its aspects which are not covered by the other participants in this conference.

Eric Emsellem

Density waves in the central kpc of galaxies, taking the form of spirals, bars and/or lopsided density distributions are potential actors of the redistribution of angular momentum. They thus play an important role in the overall evolution of the central structures, not mentioning the possible link with the active/non-active nucleus. I present here kinematica

Stephen E. Zepf

This review focuses on how galaxies and their globular cluster systems form. I first discuss the now fairly convincing evidence that some globular clusters form in galaxy starbursts/mergers. One way these observations are valuable is they place important constraints on the physics of the formation of globular clusters. Moreover, it is natural to associate th

S. S. Eikenberry, P. B. Cameron, B. W. Fierce, D. M. Kull

We present observations of the optical ``moving lines&#39;&#39; in spectra of the Galactic relativistic jet source SS433 spread over a twenty year baseline from 1979 to 1999. The red/blue-shifts of the lines reveal the apparent precession of the jet axis in SS433, and we present a new determination of the precession parameters based on these data. We investi

N. Kauer, D. Zeppenfeld

Production cross sections for t\bar{t} and t\bar{t}j events at hadron colliders are calculated, including finite width effects and off resonance contributions for the entire decay chain, t --> bW --> b\ellν, for both top quarks. Resulting background rates to Higgs search at the CERN LHC are updated for inclusive H --> WW studies and for H --> ττand H --> WW

Jonathan Bagger, Ferruccio Feruglio, Fabio Zwirner

We reconsider the phenomenon of mass generation via coordinate-dependent compatifications of higher-dimensional theories on orbifolds. For definiteness, we study a generic five-dimensional (5D) theory compactified on S^1/Z_2. We show that the presence of fixed points, where the fields or their derivatives may be discontinuous, permits new realizations of the

G. S. Atwal, N. W. Ashcroft

The dynamic response of an interacting electron system is determined by an extension of the relaxation-time approximation forced to obey local conservation laws for number, momentum and energy. A consequence of these imposed constraints is that the local electron equilibrium distribution must have a space- and time-dependent chemical potential, drift velocit

M. Benayoun, H. B. O&#39;Connell

We study the way isospin symmetry violation can be generated within the Hidden Local Symmetry (HLS) Model. We show that isospin symmetry breaking effects on pseudoscalar mesons naturally induces correspondingly effects within the physics of vector mesons, through kaon loops. In this way, one recovers all features traditionally expected from $ρ-\omg$ mixing a

Pinaki Chatterjee, Lars Hernquist, Abraham Loeb

We develop a simple physical model to describe the dynamics of a massive point-like object, such as a black hole, near the center of a dense stellar system. It is shown that the total force on this body can be separated into two independent parts, one of which is the slowly varying influence of the aggregate stellar system, and the other being the rapidly fl

S. Atag, O. Cakir, B. Dilec

The potential of ep collision to prospect for anomalous Wtb vertex is discussed from the single top quark production process $ep\to t\barν+X$ for TESLA+HERAp and CLIC+LHC energies. Sensitivities to anomalous couplings $F_{2L}$ and $F_{2R}$, in the case of CLIC+LHC, are shown to be comparable with LHC.