January 2000 arXiv papers — page 23

CLEO Collaboration

We search for CP-violating asymmetries (Acp) in the B meson decays to K+- pi-+, K+- pi0, Ks pi+-, K+- eta', and omega pi+-. Using 9.66 million Upsilon(4S) decays collected with the CLEO detector, the statistical precision on Acp is in the range of \pm 0.12 to \pm 0.25 depending on decay mode. While CP-violating asymmetries of up to \pm 0.5 are possible w

A. Alavi-Harati

We report on a search for the decay \klpimumu carried out as a part of the KTeV experiment at Fermilab. This decay is expected to have a significant $CP$ violating contribution and a direct measurement will either support the CKM mechanism for CP violation or point to new physics. Two events were observed in the 1997 data with an expected background of $0.87

A. Alavi-Harati

We have observed the decay $K_L\to μ^+μ^- γγ$ at the KTeV experiment at Fermilab. This decay presents a formidable background to the search for new physics in $K_L\toπ^0μ^+μ^-$. The 1997 data yielded a sample of 4 signal events, with an expected background of 0.155 $\pm$ 0.081 events. The branching ratio is ${\mathcal B}(K_L\to μ^+μ^- γγ$) $ = (10.4^{+7.5}_{

Koji Ichidayama

It made that the new symmetric property, the binary law, existed newly in our time and space at the thing except the symmetric property of the principle of general relativity which is already known in this paper clear. The introduction of this symmetric property will have made dealing with the position tensor of us handy as much as the surprise.

Wlodek Zadrozny

We present a non-vacuous definition of compositionality. It is based on the idea of combining the minimum description length principle with the original definition of compositionality (that is, that the meaning of the whole is a function of the meaning of the parts). The new definition is intuitive and allows us to distinguish between compositional and non-c

Y. Zhang, N. P. Ong, Z. A. Xu, R. Gagnon

The Wiedemann-Franz (WF) ratio compares the thermal and electrical conductivities in a metal. We describe a new way to determine its value, based on the thermal Hall conductivity. The technique is applied to copper and to untwinned YBaCuO. In the latter, we uncover a T-linear dependence and suppression of the Hall-channel WF ratio. We discuss the implication

K. Park, J. K. Jain

We consider the effect of interactions on electrons confined to two dimensions at Landau level filling $ν=2$, with the specific aim to determine the range of parameters where the fully polarized state is stable. We calculate the charge and the spin density collective modes in random phase approximation (RPA) including vertex corrections (also known as time d

D. Yu. Vodolazov, I. L. Maksimov

A one-dimensional equation describing the distribution of the effective vector potential $\bar A(y)$ across a film width, which holds for thin ($d<λ$) and thick ($d>λ$) films alike, is derived based on the analysis of a 2D Maxwell-Londons equation for superconducting films in a perpendicular magnetic field. The validity of this equation for a finite-thicknes

Panayotis Benetatos, M. Cristina Marchetti

Nonlinear hydrodynamics is used to evaluate disorder-induced corrections to the vortex liquid tilt modulus for finite screening length and arbitrary disorder geometry. Explicit results for aligned columnar defects yield a criterion for locating the Bose glass transition line at all fields.

T. M. Mishonov, A. A. Donkov, R. K. Koleva, E. S. Penev

The oxygen O2p_sigma and copper Cu4s and Cu3d_x^2-y^2 orbitals are involved in a simple LCAO model for determination of the conduction band and the oxygen-oxygen hopping is considered as a small parameter with respect to the transition amplitude between nearest neighbours. The traditional Cooper pairing is obtained by taking into account the double-electron

V. Yu. Irkhin, A. A. Katanin

The thermodynamics of layered antiferro- and ferromagnets with a weak interlayer coupling and/or easy-axis anisotropy is investigated. A crossover from an isotropic 2D-like to 3D Heisenberg (or 2D Ising) regime is discussed within the renormalization group (RG) analysis. Analytical results for the the (sublattice) magnetization and the ordering temperature a

Todor M. Mishonov, Mihail T. Mishonov

The thermal fluctuations of the electric field between the CuO_2 planes of layered cuprates are considered as an origin of the electrical resistivity. The model evaluation employs a set of separate plane capacitors each having area equal to the squared in-plane lattice constant a_0^2. It is shown that the scattering of charge carriers by the fluctuation of e

G. Ruocco, F. Sette, R. Di Leonardo, G. Monaco

A relaxation process, with the associated phenomenology of sound attenuation and sound velocity dispersion, is found in a simulated harmonic Lennard-Jones glass. We propose to identify this process with the so called microscopic (or instantaneous) relaxation process observed in real glasses and supercooled liquids. A model based on the memory function approa

E. Schachinger, J. P. Carbotte

The vortex state thermal and transport properties of the high T_c copper oxides can be understood in a d-wave gap model and are dominated by the extended quasiparticle states that exist along the nodal directions in momentum space. The Doppler shift on these states due to the circulating supercurrents around the vortex core, introduces new van Hove ridges in

S. K. Kwon, S. J. Youn, B. I. Min

We have investigated electronic and magnetic properties of the pyrite-type CoS_2 using the linearized muffin-tin orbital (LMTO) band method. We have obtained the ferromagnetic ground state with nearly half-metallic nature. The half-metallic stability is studied by using the fixed spin moment method. The non-negligible orbital magnetic moment of Co 3d electro

Y. Takagi, M. Fujita, K. Wakabayashi, M. Igami

We propose a class of networks which can be regarded as an extension of the graphitic network. These networks are constructed so that surface states with non-bonding character (edge states) are formed in a tight-binding model with one orbital for each atomic site. Besides, for several networks, the tight-binding electronic structures become a zero-gap semico

Satoru Muto, Hideo Aoki

Vibrational density of states of a classical two-dimensional electron system obtained with a molecular-dynamics simulation is shown to have a peak in both solid and liquid phases. From an exact diagonalisation of the dynamical matrix, the peak is identified to be vibrational modes having wavelengths of the order of the electron spacing, and the result is int

A. J. Scott, C. A. Holmes, G. J. Milburn

In this paper we investigate the quantum and classical dynamics of a single trapped ion subject to nonlinear kicks derived from a periodic sequence of Guassian laser pulses. We show that the classical system exhibits diffusive growth in the energy, or &#39;heating&#39;, while quantum mechanics suppresses this heating. This system may be realized in current s

V. E. Margoniner, R. R. de Carvalho

We present gri CCD photometry of 44 Abell clusters and 4 cluster candidates. Twenty one clusters in our sample have spectroscopic redshifts. Fitting a relation between mean g, r and i magnitudes, and redshift for this subsample, we have calculated photometric redshifts for the remainder with an estimated accuracy of 0.03. The resulting redshift range for the

M. A. Jalali, A. R. Rafiee

We introduce a class of eccentric discs with &#34;strong&#34; density cusps whose potentials are of Stäckel form in elliptic coordinates. Our models exhibit some striking features: sufficiently close to the location of the cusp, the potential and surface density distribution diverge as $Φ\propto r^{-1}$ and $Σ\propto r^{-2}$, respectively. As we move outward

Sidney van den Bergh

The present note updates the information published in my recent monograph on \underline{The Galaxies of the Local Group}. Highlights include (1) the addition of the newly discovered Cetus dwarf spheroidal as a certain member of the Local Group, (2) an improved distance for SagDIG, which now places this object very close to the edge of the Local Group zero-ve

R. Valdarnini, S. Ghizzardi, S. Bonometto

A large set of TREESPH simulations is used to test the global morphology of galaxy clusters and its evolution against X-ray data. A powerful method to investigate substructures in galaxy clusters are the power ratios introduced by Buote & Tsai. We consider three flat cosmological models: CDM, LCDM($Ω_Λ= 0.7$) and CHDM($Ω_h = 0.2$, 1 massive $ν$), all normali

F. Herpin, J. Cernicharo

We present ISO LWS observations of the proto-planetary nebula CRL 618, a star evolving very fast to the planetary nebula stage. In addition to the lines of 12CO, 13CO, HCN and HNC, we report on the detection of H2O and OH emission together with the fine structure lines of [OI] at 63 and 145 um. The abundance of the latter three species relative to 12CO are 4

A. C. Brinkman, C. J. T. Gunsing, J. S. Kaastra, R. L. J. van der Meer

We present the first X-ray spectrum obtained by the Low Energy Transmission Grating Spectrometer (LETGS) aboard the Chandra X-ray Observatory. The spectrum is of Capella and covers a wavelength range of 5-175 A (2.5-0.07 keV). The measured wavelength resolution, which is in good agreement with ground calibration, is $Δλ\simeq$ 0.06 A (FWHM). Although in-flig

S. A. Trushkin

Variable non-thermal radio emission from Galactic X-ray binaries is a trace of relativistic jets, created near accretion disks. The spectral characteristics of a lot of radio flares in the X-ray binaries with jets (RJXB) is discussed in this report. We carried out several long daily monitoring programs with the RATAN-600 radio telescope of the sources: SS433

Richard N. Hook, Ethan J. Schreier, George Miley

The optical structure of several AGN has been studied using the Fine Guidance Sensors (FGS) on the Hubble Space Telescope (HST). The FGSs are interferometric devices which can resolve structure on scales of 20 milliarcsecs or less and hence have the potential to improve on the resolution attainable by HST&#39;s cameras. The FGSs produce interferometric fring

Robert Lucas, Pierre Cox, Patrick J. Huggins

We present high resolution (1.1x0.9&#39;&#39;) imaging of the proto-planetary nebula AFGL 2688 in the CO (J=2-1) line using the IRAM interferometer. The observations reveal with unprecedented detail the structure and the kinematics of the gas ejected by the star over the past few hundred years and exemplify the mechanism by which point symmetries are imprint

R. Della Ceca, T. Maccacaro, P. Rosati, V. Braito

In this paper we report the discovery of an hard X-ray selected Type 2 Seyfert galaxy and we present and discuss its X-ray and optical spectrum together with the radio to X-ray energy distribution. The X-ray source - AXJ2254+1146 - is part of the ASCA Hard Serendipitous Survey (HSS). What makes this discovery particularly noteworthy is the fact that the Type

J. H. Fan

In this paper, the compiled long-term optical and infrared measurements of some blazars are used to analyze the variation properties and the optical data are used to search for periodicity evidence in the lightcurve by means of the Jurkevich technique and the discrete correlation function (DCF) method. Following periods are found: 4.52-year for 3C 66A; 1.56

J. H. Fan, R. G. Lin

In this paper, the post-1977 photometric observations of PKS 2155-304 are compiled and used to discuss the variation periodicity. Largest amplitude variations ($ΔU = 1^{m}.5$; $ΔB = 1^{m}.65$; $ΔV = 1^{m}.85 $; $ΔR = 1^{m}.25$; $ΔI = 1^{m}.14 $) and color indices ($(B-V) = 0.30\pm 0.06$; $(U-B) = -0.72\pm 0.08$; $(B-R) = 0.62\pm 0.07$; $(V-R) = 0.32\pm 0.04$

Enrique Vázquez-Semadeni, Adriana Gazol, John Scalo

We investigate numerically the role of thermal instability (TI) as a generator of density structures in the interstellar medium (ISM), both by itself and in the context of a globally turbulent medium. Simulations of the instability alone show that the condenstion process which forms a dense phase (``clouds&#39;&#39;) is highly dynamical, and that the boundar

Scott Tremaine, Qingjuan Yu

We suggest that polar rings and/or counter-rotating disks in flattened galaxies can be formed from stars captured at the Binney resonance, where the rate of precession of the angular momentum vector of a disk star equals the pattern speed of a triaxial halo. If the halo pattern speed is initially retrograde and slowly decays to zero, stars can be trapped as

Jian-Xin Zhu, C. S. Ting, C. W. Chu

The phase diagram of temperature versus exchange field is obtained within a BCS model for d-wave superconductivity in CuO_2 layers which is coupled to ferromagnetic RuO_2 layers in RuSr_2GdCu_2O_8. It is found that the Fulde-Ferrell-Larkin-Ovchinnikov state is very sensitive to the band filling factor. For strong exchange field, we point out that superconduc

Daniel G. Barci, L. E. Oxman

Using bosonization techniques for (2+1)D systems, we show that the transverse conductance for a system with general current interactions, when measured between perfect Hall regions is not renormalized at low temperatures. Our method extends and combines two results we have recently obtained on low dimensional fermionic systems: on the one hand, the relations

L. Mersini

We examine the cosmology of the Randall-Sundrum model in a dynamic setting where scalar fields are present in the bulk as well as the branes. This generates a mechanism similar to that of Goldberger-Wise for radion stabilization and the recovery of late-cosmology features in the branes. Due to the induced radion dynamics, the inflating branes roll towards th

John A. Smolin

I present a four-party unlockable bound-entangled state, that is, a four-party quantum state which cannot be written in a separable form and from which no pure entanglement can be distilled by local quantum operations and classical communication among the parties, and yet when any two of the parties come together in the same laboratory they can perform a mea

X. S. Rao, C. K. Ong, B. B. Jin, Y. P. Feng

The anomalous decrease in microwave surface resistance, R_{s}, of superconducting YBa_{2}Cu_{3}O_{7-d} (YBCO) thin films in the presence of a low dc magnetic field is studied using a microstrip resonator technique. We have done a dc field hysteresis measurement of R_{s} to study the effects of vortex penetration on the anomalous effect. It is shown that the

M. C. Gonzalez-Garcia, C. Peña-Garay

In this talk we present the results of an updated global analysis of two-flavor MSW solutions to the solar neutrino problem in terms of conversions of $ν_e$ into active or sterile neutrinos including the the full data set corresponding to the 825-day Super-Kamiokande data sample as well as to Chlorine, GALLEX and SAGE experiments.

Dongsheng Du, Zhengtao Wei

T violation should be tested independently of CP violation. Besides K system, B meson decays provide another good place to study T violation. In the Standard Model, T violation in $B^0 \rightleftharpoons \bar{B^0}$ oscillation is expected to be small. The angular distribution of $B\to VV$ decay permits one to extract the T-odd correlation. In the absence of

Mahn-Soo Choi, C. Bruder, Daniel Loss

We study a double quantum dot each dot of which is tunnel-coupled to superconducting leads. In the Coulomb blockade regime, a spin-dependent Josephson coupling between two superconductors is induced, as well as an antiferromagnetic Heisenberg exchange coupling between the spins on the double dot which can be tuned by the superconducting phase difference. We

Sylvio Klose

In 1997 the first optical afterglow of a cosmic Gamma-Ray Burst was discovered, and substantial progress has been achieved since then. Here we present a short review of some recent developments in this field, with emphasis on observational aspects of the GRB phenomenon.

Hyun-Tak Kim

In order to explain the metal-Mott-insulator transition, the Brinkman-Rice (BR) picture is extended. In the case of less than one as well as one electron per atom, the on-site Coulomb repulsion is given by U={kappa}{rho}^2U_c by averaging the electron charge per atom over all atomic sites, where {kappa} is the correlation strength of U, {rho} is the band fil

Dmitri S. Kilin

The work is devoted to the investigation of the influence of a heat bath on the physical processes in a quantum system. We use the density matrix theory as one of the most powerfool tool for investigation of quantum relaxation. In the beginning of the work (chapter 2) we mention and recall the most important steps of derivation of the equation of motion for

Joel M. Williams

The MCAS Way extends the MCAS concept of atomic orbitals to molecular bonding. There are many examples given for each bonding type. Part I: The MCAS atomic orbital concept. There are no spherical orbitals and spin pairing does not occur through spin reversal. Quantum numbers do not validate coexistence in identical space. Part II: Single bonds. There are no

Ariel Caticha

The emission of electromagnetic waves from a source within or near a non-trivial medium (with or without boundaries, crystalline or amorphous, with inhomogeneities, absorption and so on) is sometimes studied using the reciprocity principle. This is a variation of the method of Green&#39;s functions. If one is only interested in the asymptotic radiation field

A. P. Potylitsyn

The new method for producing of the polarized relativistic positrons is suggested. A beam of unpolarized positrons accelerated up to a few GeV can be polarized during a head-on collision with an intense circularly polarized lazer wave. After a multiple Compton backscattering process the initial positrons may lose a substantial part of its energy and, as cons

Gao Shan

We show that we can know more than the orthodox view does, as one example, we make a new analysis about double-slit experiment, and demonstrate that we can measure the objective state of the particles passing through the two slits while not destroying the interference pattern, the measurement method is to use protective measurement.

R. Rodriguez-Guzman, J. L. Egido, L. M. Robledo

A microscopic angular momentum projection after variation is used to describe quadrupole collectivity in (^{30,32,34}Mg) and (^{32,34,36,38}Si). The Hartree-Fock-Bogoliubov states obtained in the quadrupole constrained mean field approach are taken as intrinsic states for the projection. Excitation energies of the first (2^{+}) states and the (B(E2,0^{+}\to

Mark S. Alber, Charles A. Miller

A new parameterization of the Jacobi inversion problem is used along with the dynamics of the peaks to describe finite time interaction of peakon weak solutions of the Shallow Water equation.

Mark S. Alber, Gregory G. Luther, Charles A. Miller

The algebraic geometric approach to $N$-component systems of nonlinear integrable PDE&#39;s is used to obtain and analyze explicit solutions of the coupled KdV and Dym equations. Detailed analysis of soliton fission, kink to anti-kink transitions and multi-peaked soliton solutions is carried out. Transformations are used to connect these solutions to several

L. G. S. Duarte, L. A. da Mota, J. E. F. Skea

An extension of the ideas of the Prelle-Singer procedure to second order differential equations is proposed. As in the original PS procedure, this version of our method deals with differential equations of the form y&#39;&#39;={M(x,y,y&#39;)}/{N(x,y,y&#39;)}, where M and N are polynomials with coefficients in the field of complex numbers C. The key to our ap

Aleksandar Mikovic

We study the matrix factorization problem associated with an SO(2) spinning top by using the algebro-geometric approach. We derive the explicit expressions in terms of Riemann theta functions and discus some related problems including a non-compact extension and the case when the Lax matrix contains higher-order powers of the spectral parameter.

Markus Kunze, Herbert Spohn

We study the Abraham model for $N$ charges interacting with the Maxwell field. On the scale of the charge diameter, $R_ϕ$, the charges are a distance $\eps^{-1}R_ϕ$ apart and have a velocity $\sqrt{\eps} c$ with $\eps$ a small dimensionless parameter. We follow the motion of the charges over times of the order $\eps^{-3/2}R_ϕ/c$ and prove that on this time s

B. Enriquez, G. Felder

We introduce a flat version of the KZB connection. This connection is defined on the complement of the locus of Weierstrass points on the moduli space of genus $g$ complex curves with marked points. We then give integral formulas for flat sections of this connection, using the parametrization of conformal blocks and of the KZB connection of our earlier paper

Gautam Chinta, Paul E. Gunnells, Robert Sczech

We discuss computation of the special values of partial zeta functions associated to totally real number fields. The main tool is the \emph{Eisenstein cocycle} $Ψ$, a group cocycle for $GL_{n} (\Z )$; the special values are computed as periods of $Ψ$, and are expressed in terms of generalized Dedekind sums. We conclude with some numerical examples for cubic

Randall Dougherty

A famous result of Hausdorff states that a sphere with countably many points removed can be partitioned into three pieces A,B,C such that A is congruent to B (i.e., there is an isometry of the sphere which sends A to B), B is congruent to C, and A is congruent to (B union C); this result was the precursor of the Banach-Tarski paradox. Later, R. Robinson char

Randall Dougherty

Hausdorff&#39;s paradoxical decomposition of a sphere with countably many points removed (the main precursor of the Banach-Tarski paradox) actually produced a partition of this set into three pieces A,B,C such that A is congruent to B (i.e., there is an isometry of the set which sends A to B), B is congruent to C, and A is congruent to (B union C). While ref

Maciej Dunajski, Lionel J. Mason

A twistor construction of the hierarchy associated with the hyper-Kähler equations on a metric (the anti-self-dual Einstein vacuum equations, ASDVE, in four dimensions) is given. The recursion operator R is constructed and used to build an infinite-dimensional symmetry algebra and in particular higher flows for the hyper-Kähler equations. It is shown that R

S. O. Warnaar

Using matrix inversion and determinant evaluation techniques we prove several summation and transformation formulas for terminating, balanced, very-well-poised, elliptic hypergeometric series.

Takeshi Usa

This is a survey of our research on geometric structures of projective embeddings and includes some topics of our talks in several symposia during 1990-99. We clarify our main problem, which is to construct a kind of geometric composition series of projective embeddings. The concept of &#34;geometric composition series&#34; is an analogy in Algebraic Geometr

Donald Spector

We study some of the algebraic properties of the non-relativistic monopole. We find that we can construct theories that possess an exotic conserved fermionic charge that squares to the Casimir of the rotation group, yet do not possess an ordinary supersymmetry. This is in contrast to previous known examples with such exotic fermionic charges. We proceed to s

Sheng Li, Yong Zhang, Zhongyuan Zhu

By making use of the complete decomposition of SO(3) spin connection, the topological defect in 3-dimensional Euclidean gravity is studied in detail. The topological structure of disclination is given as the combination of a monopole structure and a vortex structure. Furthermore, the Kac-Moody algebra generated by the monopole and vortex is discussed in thre

Rudolf Haag

An assessment of the present status of the theory, some immediate tasks which are suggested thereby and some questions whose answers may require a longer breath since they relate to significant changes in the conceptual and mathematical structure of the theory.

M. Cvetic, H. Lu, C. N. Pope

We point out that massive gauged supergravity potentials, for example those arising due to the massive breathing mode of sphere reductions in M-theory or string theory, allow for supersymmetric (static) domain wall solutions which are a hybrid of a Randall-Sundrum domain wall on one side, and a dilatonic domain wall with a run-away dilaton on the other side.

L. C. Liu, Wei-hsing Ma

We examine the possibility that the xi(2230) meson is a member of the Pomeron trajectory. A method of connecting the xi --> p pbar decay width and the pp cross sections through the Pomeron residue function is presented. We have used a relativistic, singularity-free form factor to make the analytic continuation of the residue function between crossed channels

E. Accomando, R. Arnowitt, B. Dutta, Y. Santoso

The neutralino-proton cross section is examined for supergravity models with R-parity invariance with universal and non-universal soft breaking. The region of parameter space that dark matter detectors are currently (or will be shortly) sensitive i.e. $(0.1-10)\times 10^{-6}$ pb, is examined. For universal soft breaking (mSUGRA), detectors with sensitivity $

M. S. Berger

Muon colliders might greatly extend the energy frontier of collider physics. One can contemplate circular colliders with center-of-mass energies in excess of 10 TeV. Some physics issues that might be relevant at such a machine are discussed.

R. Enberg, G. Ingelman, N. Timneanu

Models based on soft colour exchanges to rearrange colour strings in the final state provide a general framework for both diffractive and non-diffractive events in ep and hadron-hadron collisions. We study two such models and find that they can reproduce rapidity gap data from both HERA and the Tevatron. We also discuss the influence of parton cascades and m

J. Nieves, E. Ruiz Arriola

Based on the recent phenomenological analysis done by M. Mojzis, Eur. Phys. Jour. {\bf C2} (1998) 182, of $πN $ scattering within the framework of Heavy Baryon Chiral Perturbation Theory we predict, after a suitable unitarization of the amplitude, the $Δ$ resonance at $\sqrt{s} = M_Δ= 1238 \er{22}{18}{\rm MeV} $ and with a width of $ Γ_Δ= 150 \er{43}{31} {\r

M. T. Hussein, R. Elmualed, N. M. Hassan

The problem of electron-proton scattering is handed over both the elastic and inelastic scattering. Two models are presented in this sense. The first, depends on the multi photon exchange ladder diagram, where the transition matrix is expanded in multi steps form. The second model uses the multi peripheral mechanism developed for the electromagnetic field. I

De-Min Li, Hong Yu, Qi-Xing Shen

Based on a $2\times 2$ mass matrix, the mixing angle of the axial vector states $f_1(1420)$ and $f_1(1285)$ is determined to be $51.5^{\circ}$, and the theoretical results about the decay and production of the two states are presented. The theoretical results are in good agreement with the present experimental results, which suggests that $f_1(1420)$ can be

John Ellis, Andrew Ferstl, Keith A. Olive

We examine the cross sections for the elastic scattering of neutralinos $χ$ on nucleons $p,n$, as functions of $m_χ$ in the constrained minimal supersymmetric standard model. We find narrow bands of possible values of the cross section, that are considerably lower than some previous estimates. The constrained model is based on the minimal supergravity-inspir

Shailesh Chandrasekharan

The recent solution to the fermion sign problem allows, for the first time, the use of cluster algorithm techniques to compute certain fermionic path integrals. To illustrate the underlying ideas behind the progress, a cluster algorithm is constructed to study the chiral phase transition in a strongly interacting staggered fermion model with an arbitrary mas

Poul H. Damgaard

A large-N_f expansion is used to compute the partially quenched chiral condensate of QCD in the microscopic finite-volume scaling region.

İ Yavuz, U. Camcı

Ricci and contracted Ricci collineations of the Bianchi type II, VIII, and IX space-times, associated with the vector fields of the form (i) one component of $ξ^a(x^b)$ is different from zero and (ii) two components of $ξ^a(x^b)$ are different from zero, for $a,b=1,2,3,4$, are presented. In subcase (i.b), which is $ξ^a= (0,ξ^2(x^a),0,0)$, some known solution

Alexander Yu. Vlasov

The name of John von Neumann is common both in quantum mechanics and computer science. Are they really two absolutely unconnected areas? Many works devoted to quantum computations and communications are serious argument to suggest about existence of such a relation, but it is impossible to touch the new and active theme in a short review. In the paper are de

T. Wu, S. B. Ogale, J. E. Garrison, B. Nagaraj

The sensitivity of transport in CMR manganite to external fields is examined using a PZT-based field effect configuration with a La0.7Ca0.3MnO3 channel subjected to electric and magnetic fields, separately and in conjugation. We not only find a colossal electroresistance (CER) of ~76% at 4X10^5 V/cm, but also a remarkable complimentarity of this CER with the

T. Neicu, A. Pradhan, D. A. Larochelle, A. Kudrolli

We report the spatio-temporal response of {\it Bacillus subtilis} growing on a nutrient-rich layer of agar to ultra-violet (UV) radiation. Below a crossover temperature, the bacteria are confined to regions that are shielded from UV radiation. A forced convection of the population is effected by rotating a UV radiation shield relative to the petri dish. The

A. H. MacDonald, Matthew P. A. Fisher

Recent transport experiments have established that two-dimensional electron systems with high-index partial Landau level filling, $ν^{*} =ν- \lbrack ν\rbrack$, have ground states with broken orientational symmetry. In a mean-field theory, the broken symmetry state consists of electron stripes with local filling factor $\lbrack ν\rbrack + 1 $, separated by ho

Amit Kr. Chattopadhyay

The static and dynamic roughenings of a growing crystalline facet is studied where the growth mechanism is controlled by a restricted-curvature (RC) geometry. A continuum equation, in analogy with the Kardar-Parisi-Zhang (KPZ) equation is considered for the purpose. It is shown here that although the growth process begins with a RC geometry, a structural pha

Roberto Franzosi, Raoul Gatto, Giulio Pettini, Marco Pettini

It is shown that the nonlinear wave equation $\partial_t^2ϕ- \partial^2_x ϕ-μ_0\partial_x(\partial_xϕ)^3 =0$, which is the continuum limit of the Fermi-Pasta-Ulam (FPU) beta model, has a positive Lyapunov exponent lambda_1, whose analytic energy dependence is given. The result (a first example for field equations) is achieved by evaluating the lattice-spacin

K. Malarz

In this paper we would like give a short review of our recent works and current investigation in modeling of solid film surfaces growth based on computer Monte Carlo simulations. We also discuss effect of some simplification in growth rules on speed-up of computations, and the time evolution of surface morphology (for example its roughness or anisotropy). We

Oleg A. Starykh, Philippe R. J. Jacquod, Evgenii E. Narimanov, A. Douglas Stone

We consider the effect of dynamical localization on the lifetimes of the resonances in open wave-chaotic dielectric cavities. We show that dynamical localization leads to a log-normal distribution of the resonance lifetimes which scales with the localization length in excellent agreement with the results of numerical calculations for open rough microcavities

W. Z. Shangguan, T. C. Au-Yeung

A universal mechanism of superconductivity applicable to ``low temperature&#39;&#39; and ``high temperature&#39;&#39; superconductors is proposed in this paper. With this model of mechanism experimental facts of superconductors can be qualitatively explained. A function is introduced to describe the average separation distance between vibrating lattice atoms

O. Derzhko, J. Richter, O. Zaburannyi

We calculate exactly the density of magnon states of the regularly alternating spin-1/2 XX chain with Dzyaloshinskii-Moriya interaction. The obtained results permit us to examine the stability of the chain with respect to spin-Peierls dimerization. We found that depending on the dependences of Dzyaloshinskii-Moriya interaction on distortion amplitude it may

Oleg Derzhko, Taras Krokhmalskii

We examine numerically the dynamics of zz correlations in the spin-1/2 isotropic XY chain with random intersite coupling and on-site transverse field that depends linearly on the neighbouring couplings (correlated off-diagonal and diagonal disorder). We discuss the changes in the frequency profiles of zz dynamic structure factor caused by disorder.

A. V. Shytov

The Landau-Zener transition in a two level system can be suppressed or enhanced by coupling to an environment, depending on the temperature and the environment spectral function. We consider the marginal spectral function, when the dissipation effects are important for arbitrarily slow motion. Landau-Zener transition rate demonstrates a non-trivial dependenc

V. Latora, A. Rapisarda, S. Ruffo

We study chaos in the Hamiltonian Mean Field model (HMF), a system with many degrees of freedom in which $N$ classical rotators are fully coupled. We review the most important results on the dynamics and the thermodynamics of the HMF, and in particular we focus on the chaotic properties.We study the Lyapunov exponents and the Kolmogorov--Sinai entropy, namel

Sujeet Chaudhary, A. K. Rajarajan, Kanwal Jeet Singh, S. B. Roy

We present results of transport measurements showing distinct path dependence of the electrical resistance in the superconducting vortex state of single crystal samples of CeRu$_2$ and V$_3$Si. Resistance measured in the vortex state of both the systems prepared by field cooling (FC), indicates a relatively higher degree of disorder than when it is prepared

G. Baskaran

The field of condensed matter physics had its genesis this century and it has had a remarkable evolution. A closer look at its growth reveals a hidden aim in the collective consciousness of the field - a part of the development this century is a kind of warm up exercise to understand the nature of living condensed matter, namely the field of biology, by a gr

Carl Heiles, L. M. Haffner, R. J. Reynolds, S. L. Tufte

We derive the radio spectral index of the Barnard Loop (BL) from large-scale radio surveys at four frequencies and find it to be a thermal source. We use the radio data together with H-alpha data to determine the electron temperature in BL, the lambda-Ori HII region, and a high-latitude filament; all of these regions are somewhat cooler than typical HII regi

Neal J. Evans

ALMA will revolutionize the study of star formation by providing a combination of angular resolution and sensitivity that far exceeds that of present instruments. I will focus on studies of relatively isolated cores that are forming low-mass stars. There is a general paradigm for the formation of such stars, and there are detailed theoretical predictions for

Catherine S. Trotter, Joshua N. Winn, Jacqueline N. Hewitt

We employ a multipole-Taylor expansion to investigate how tightly the gravitational potential of the quadruple-image lens MG J0414+0534 is constrained by recent VLBI observations. These observations revealed that each of the four images of the background radio source contains four distinct components, thereby providing more numerous and more precise constrai

Michiel R. Hogerheijde, Goeran Sandell

This paper examines the density and velocity structure of envelopes around young stellar objects through submillimeter continuum imaging of four objects in Taurus and previously obtained molecular-line data. Observations carried out with the SCUBA on the JCMT at 850 and 450 micron of L1489 IRS, L1535 IRS, L1527 IRS, and TMC 1 reveal ~2000 AU elongated struct

J. A. Lopez, J. Meaburn, L. F. Rodriguez, R. Vazquez

Narrow-band images of the core of the extraordinary poly-polar planetary nebula KjPn 8 have been obtained with the WFPC2 camera on board the Hubble Space Telescope. Spasmodic bipolar ejections, in changing directions have occurred over thousands of years to create KjPn 8. The central star is finally revealed in these observations and its compact nebular core

K. Hurley, N. Lund, S. Brandt, C. Barat

We present 3rd interplanetary network (IPN) localization data for 56 gamma-ray bursts in the GRANAT/ WATCH catalog which occurred between 1990 November and 1994 September. These localizations are obtained by triangulation using various combinations of spacecraft in the IPN, which consisted of Ulysses, BATSE, Pioneer Venus Orbiter (PVO), Mars Observer (MO), W

Christopher Sneden, Inese I. Ivans, Robert P. Kraft

Recent improvements in globular cluster colour-magnitude diagrams, coupled with an increase in large-sample spectroscopic abundance studies of cluster giants, finally allow some attempts at a statistically meaningful comparison of the chemical compositions of red giant branch (RGB) and asymptotic branch (AGB) cluster stars. We review some of the extant data

F. Herpin, J. Cernicharo, A. Heras

We present a complete study of the H2 infrared emission, including the pure rotational lines, of the proto Planetary Nebulae CRL 618 with the ISO SWS. A large number of lines are detected. The analysis of our observations shows: (i) an OTP ratio very different from the classical value of 3, probably around 1.76-1.87; (ii) a stratification of the emitting reg

M. A. Zwaan, F. H. Briggs

The Arecibo HI Strip Survey probed the halos of ~300 cataloged galaxies and the environments of ~14 groups with sensitivity to neutral hydrogen masses > 10^7 M_sun. The survey detected no objects with properties resembling the High Velocity Clouds (HVCs) associated with the Milky Way or Local Group. If the HVCs were typically M_HI=10^{7.5} M_sun objects dist

T. M. Tauris, E. P. J. van den Heuvel

We present an updated list of direct strong evidence in favour of kicks being imparted to newborn neutron stars. In particular we discuss the new cases of evidence resulting from recent observations of the X-ray binary Circinus X-1 and the newly discovered binary radio pulsar PSR J1141-6545. We conclude that the assumption that neutron stars receive a kick v