November 1999 arXiv papers — page 2

Patrick E. McSharry, Leonard A. Smith

A new approach to nonlinear modelling is presented which, by incorporating the global behaviour of the model, lifts shortcomings of both least squares and total least squares parameter estimates. Although ubiquitous in practice, a least squares approach is fundamentally flawed in that it assumes independent, normally distributed (IND) forecast errors: nonlin

Vassiliki Kalogera

This paper is a brief review of the topic of binary systems as sources of gravitational-wave emission for both LIGO and LISA. In particular I review the current estimates of the associated Galactic event rates and their implications for expected detection rates. I discuss the estimates for (i) the coalescence of close binaries containing neutron stars or bla

D. Lin, I. A. Smith, E. P. Liang, T. Bridgman

We report the results of our multi-wavelength observations of GRS 1758-258 made in August 1997. The energy bands include radio, millimeter, X-ray, and gamma-ray. The observations enable us to obtain a complete spectrum of the source over an energy range of 2 - 500 keV. The spectrum shows that GRS 1758-258 was in its hard state. It is well fitted by the Sunya

Carlo Baccigalupi, Francesca Perrotta

We predict the imprint of linear bubbly perturbations on the polarization and temperature anisotropies of the cosmic microwave background (CMB). We analytically model a bubbly density perturbation at the beginning of the radiation dominated era and we apply the linear theory of cosmological perturbations to compute its time evolution. At decoupling, it uniqu

Kunegunda E. Belle, Steve B. Howell, Amy Mills

We present simultaneous X-ray (lambda_peak ~ 44A) and EUV (lambda_peak = 89A) light curves for the magnetic cataclysmic variable QQ Vulpeculae, obtained with the EUVE satellite. We find that the unique shape of the X-ray light curve is different from previously obtained X-ray light curves of QQ Vul and provides evidence for two-pole accretion. Detailed exami

Shoko Sakai, Dennis Zaritsky, Robert Kennicutt

We present the I-band luminosity function of the red giant branch stars in the Large Magellanic Cloud (LMC) using the data from the Magellanic Clouds Photometric Survey (Zaritsky, Harris & Thompson, 1997). Selecting stars in uncrowded, low-extinction regions, a discontinuity in the luminosity function is observed at I_0 = 14.54 mag. Identifying this feature

Patrick Cote, Ronald O. Marzke, Michael J. West, Dante Minitti

The possibility that the Galactic spheroid was assembled from numerous chemically-distinct, proto-Galactic fragments is investigated using a Monte-Carlo technique designed to simulate the chemical evolution of the Galaxy in hierarchical formation scenarios which involve no gas dissipation. By comparing the observed and simulated metallicity distributions of

G. J. Wasserburg, Y. -Z. Qian

We present a model to explain the wide range of abundances for heavy r-process elements (mass number A > 130) at low [Fe/H]. This model requires rapid star formation and/or an initial population of supermassive stars in the earliest condensed clots of matter to provide a prompt or initial Fe inventory. Subsequent Fe and r-process enrichment was provided by t

Marco Sirianni, Antonella Nota, Claus Leitherer, Guido De Marchi

We report the result of a study in which we have used very deep broadband V and I WFPC2 images of the R136 cluster in the Large Magellanic Cloud from the HST archive, to sample the luminosity function below the detection limit of 2.8 Mo previously reached. In these new deeper images, we detect stars down to a limiting magnitude of m_F555W = 24.7 (~ 1 magnitu

M. H. Pinsonneault, D. M. Terndrup, Y. Yuan

The difference between the Hipparcos open cluster distance scale and that obtained from main sequence fitting is examined. The two color main sequence fitting technique of Pinsonneault et al. (1998) is extended to NGC 2516, NGC 6475, and NGC 6633. The error sources for main sequence fitting are examined, and possible evidence for systematic errors in the Hip

K. Iwasawa, S. Ettori, A. C. Fabian, A. C. Edge

We report the discovery of highly distorted X-ray emission associated with the nearby cluster Zw1718.1-0108, one of whose dominant members is the powerful radio galaxy 3C353. This cluster has been missed by previous X-ray cluster surveys because of its low Galactic latitude (b = 19.5deg), despite its brightness in the hard X-ray band (2-10 keV flux of 1.2E-1

S. Masi, P. A. R. Ade, R. Artusa, J. J. Bock

The BOOMERanG experiment is a stratospheric balloon telescope intended to measure the Cosmic Microwave Background anisotropy at angular scales between a few degrees and ten arcminutes. The experiment features a wide focal plane with 16 detectors in the frequency bands centered at 90, 150, 220, 400 GHz, with FWHM ranging between 18 and 10 arcmin. It will be f

D. R. Lorimer

A crucial test any proposed evolutionary scenario must pass is can the birth rate of the sources we see be sustained by the proposed progenitor population? In this review, I investigate the methods used to determine the birth rates of normal and millisecond radio pulsars and summarise recent results for these two distinct neutron star populations.

P. A. Milne, M. D. Leising, L. -S. The

The energy deposition into the ejecta of type Ia supernovae is dominated at late times by the slowing of positrons produced in the $β^{+}$ decays of $^{56}$Co. Fits of model-generated light curves to observations of type Ia supernovae suggest that a significant number of positrons escape the ejecta and annihilate as a delayed emission. In this work, the isot

K. S. Cheng, Z. G. Dai

Quiescence and burst emission and relativistic particle winds of soft gamma-ray repeaters (SGRs) have been widely interpreted to result from ultrastrongly magnetized neutron stars. In this magnetar model, the magnetic energy and gravitational energy of the neutron stars are suggested as the energy sources of all the emission and winds. However, Harding, Cont

Martin G. Haehnelt, Guinevere Kauffmann

We discuss constraints on the assembly history of supermassive black holes from the observed remnant black holes in nearby galaxies and from the emission caused by accretion onto these black holes. We also summarize the results of a specific model for the evolution of galaxies and their central black holes which traces their hierachical build-up in CDM-like

G. P. Rowell, T. Naito, S. A. Dazeley, P. G. Edwards

The southern supernova remnant (SNR)W28 was observed in 1994 and 1995 by the CANGAROO 3.8m telescope in a search formulti-TeV gamma ray emission, using the Cerenkov imaging technique. We obtained upper limits for a variety of point-like and extended features within a +-1 degree-region and briefly discuss these results, together with that of EGRET within the

Hidetoshi Kubo, S. A. Dazeley, P. G. Edwards, S. Gunji

CANGAROO group constructed an imaging air Cherenkov telescope (CANGAROO-II) in March 1999 atWoomera, South Australia to observe celestial gamma-rays in hundreds GeV region. It has a 7m parabolic mirror consisting of 60 small plastic spherical mirrors, and the prime focus is equipped with a multi-pixel camera of 512 PMTs covering the field of view of 3 degree

Akiko Kawachi

We have developed light and durable mirrors made of CFRP (Carbon Fiber Reinforced Plastics) laminates for the reflector of the new CANGAROO-II 7 m telescope. The reflector has a parabolic shape (F/1.1) with a 30 m^2 effective area which consists of 60 small spherical mirrors. The attitude of each mirror can be remotely adjusted by stepping motors. After the

N. M. Stout-Batalha, C. C. Batalha, G. S. Basri

It is widely accepted that much of the stochastic variability of T Tauri stars is due to accretion by a circumstellar disk. The emission line spectrum as well as the excess continuum emission are common probes of this process. In this communication, we present additional probes of the circumstellar environment in the form of resonance lines of low ionization

Donald M. Terndrup, John R. Stauffer, Marc H. Pinsonneault, Alison Sills

We have obtained high-resolution spectra of 89 M dwarf members of the Pleiades and Hyades and have derived radial velocities, H-alpha equivalent widths, and spectroscopic rotational velocities for these stars. Typical masses of the newly-observed Pleiades and Hyades stars are ~ 0.4 M_{\sun} and ~ 0.2 M_{\sun}, respectively. We combine our new observations wi

Steven S. Vogt, Geoffrey W. Marcy, R. Paul Butler, Kevin Apps

We report results of a search for planets around 500 main sequence stars using the Keck high resolution spectrometer which has provided Doppler precision of 3 m/s during the past 3 yr. We report 6 new strong planet candidates having complete Keplerian orbits, with periods ranging from 24 d to 3 yr. We also provide updated orbital parameters for 4 previously

Gary A. Mamon

Analytical estimates of the mass and radial dependence of the rates of galaxy mergers and of tidal interactions are derived for clusters and groups of galaxies, taking into account the tides from the system potential that limit the sizes of galaxies. Only high mass galaxies undergo significant major merging before being themselves cannibalized by more massiv

Horatiu Nastase, Diana Vaman, Peter van Niewenhuizen

We discuss the full nonlinear Kaluza-Klein (KK) reduction of the original formulation of d=11 supergravity on $AdS_7\times S_4$ to gauged maximal ({\cal N}=4) supergravity in 7 dimensions. We derive the full nonlinear embedding of the d=7 fields in the d=11 fields (``the ansatz'') and check the consistency of the ansatz by deriving the d=7 supersymme

C. Klimcik

A two dimensional gauge theory is canonically associated to every Drinfeld double. For particular doubles, the theory turns out to be e.g. the ordinary Yang-Mills theory, the G/G gauged WZNW model or the Poisson $σ$-model that underlies the Kontsevich quantization formula. We calculate the arbitrary genus partition function of the latter. The result is the $

V. Barger, S. Geer, R. Raja, K. Whisnant

Within the framework of three-flavor neutrino oscillations, we consider the physics potential of ν_e --> ν_μappearance and ν_μ--> ν_μsurvival measurements at a neutrino factory for a leading oscillation scale δm^2 ~ 3.5 \times 10^{-3} eV^2. Event rates are evaluated versus baseline and stored muon energy, and optimal values discussed. Over a sizeable region

J. M. Roman, J. Soto

We present the effective lagrangian for low energy and momentum spin waves in canted phases at next to leading order in the derivative expansion. The symmetry breaking pattern SU(2) --> 1 of the internal spin group and that of the crystallographic space group imply that there is one ferromagnetic and one antiferromagnetic spin wave. The interaction of the sp

Soonkeon Nam

We consider the Newton's force law for brane world consisting of periodic configuration of branes. We show that it supports a massless graviton. Furthermore, this massless mode is well separated from the Kaluza-Klein spectrum by a mass gap. Thus most of the problems in phenomenology coming from continuum of Kaluza-Klein modes without mass gap are potentially

F. V. Tkachov

The evolution of the distribution-theoretic methods in perturbative quantum field theory is reviewed starting from Bogolyubov's pioneering 1952 work with emphasis on the theory and calculations of perturbation theory integrals.

Tianjun Li

We construct the general model with only parallel positive tension 3-branes on $M^4 \times R^1$ and $M^4 \times R^1/Z_2$. The cosmology constant is sectional constant along the fifth dimension. In this general scenario, the 5-dimensional GUT scale on each brane can be indentified as the 5-dimensional Planck scale, but, the 4-dimensional Planck scale is gener

Herbert H. H. Homeier, Johann Strasser, Hartmut Yersin

The dynamics of spin-lattice relaxation (slr) of metal-organic Pt(II) compounds is studied. Often, such systems are characterized by pronounced zero-field splittings (zfs) of the lowest-lying triplets. Previous expressions for the Orbach slr process do not allow to treat such splitting patterns properly. We discuss the behavior of a modified Orbach expressio

V. Barger, Chung Kao, Ren-Jie Zhang

Supersymmetric (SUSY) models with heavy sfermions ($m_{\tilde{f}} \sim 10$ TeV) in the first two generations and the third generation sfermion masses below 1 TeV can solve the SUSY flavor and the CP problems as well as satisfy naturalness constraints. We study the phenomenology of a string-inspired scenario and compare it with the minimal supergravity unifie

S. Virmani, M. B. Plenio

We demonstrate that all good asymptotic entanglement measures are either identical or place a different ordering on the set of all quantum states.

Barbara M. Terhal, Pawel Horodecki

We introduce the notion of a Schmidt number of a bipartite density matrix, characterizing the minimum Schmidt rank of the pure states that are needed to construct the density matrix. We prove that Schmidt number is nonincreasing under local quantum operations and classical communication. We show that $k$-positive maps witness Schmidt number, in the same way

Rafael I. Nepomechie

Corresponding to the Izergin-Korepin (A_2^(2)) R matrix, there are three diagonal solutions (``K matrices'') of the boundary Yang-Baxter equation. Using these R and K matrices, one can construct transfer matrices for open integrable quantum spin chains. The transfer matrix corresponding to the identity matrix K=1 is known to have U_q(o(3)) symmetry.

Reinoud J. Slagter

We investigated the SU(2) Einstein-Yang-Mills system on a time-dependent non-diagonal cylindrical symmetric space-time. From the numerical investigation, wave-like solutions are found, consistent with the familiar string-like features. They possess an angle-deficit which depends on the initial form of the magnetic component of the YM field, i.e., the number

M. Znojil

Suitable complexification of the well known solvable oscillators in one dimension is shown to give the four exactly solvable models which combine the shape- and PT-invariance. In version v2 the result is extended of the s-wave shape-invariant forces.

W. F. Kao, Ue-Li Pen, Pengjie Zhang

Stability analysis on the De Sitter universe in pure gravity theory is known to be useful in many aspects. We first show how to complete the proof of an earlier argument based on a redundant field equation. It is shown further that the stability condition applies to $k \ne 0$ Friedmann-Robertson-Walker spaces based on the non-redundant Friedmann equation der

A. A. Abramov, A. Aslanyan, E. B. Davies

We obtain bounds on the complex eigenvalues of non-self-adjoint Schr\"odinger operators with complex potentials, and also on the complex resonances of self-adjoint Schr\"odinger operators. Our bounds are compared with numerical results, and are seen to provide useful information.

F. M. L. Almeida, M. Barbi, M. A. B. do Vale

We obtain an approximate Gaussian distribution from a Poisson distribution after doing a change of variable. A new chi-square function is obtained which can be used for parameter estimations and goodness-of-fit testing when adjusting curves to histograms. Since the new distribution is approximately Gaussian we can use it even when the bin contents are small.

F. Corberi, G. Gonnella, D. Suppa

We extend the analysis of the mean field schematic model recently introduced for the description of glass forming liquids to the case of a supercooled fluid subjected to a shear flow of rate $γ$. After quenching the system to a low temperature $T$, a slow glassy regime is observed before stationarity is achieved at the characteristic time $τ_g$. $τ_g$ is of

L. Giusti, M. L. Paciello, S. Petrarca, B. Taglienti

We propose a non-perturbative procedure to fix generic covariant gauges on the lattice. Varying the gauge parameter, this gauge fixing provides a concrete method to check numerically the gauge dependence of correlators measured on the lattice. The new algorithm turns out to converge with a good efficiency. As a preliminary physical result, we find a sensitiv

M. Ishibashi, Y. Kikukawa, T. Noguchi, A. Yamada

We discuss the weak coupling expansion of lattice QCD with the overlap Dirac operator. The Feynman rules for lattice QCD with the overlap Dirac operator are derived and the quark self-energy and vacuum polarization are studied at the one-loop level. We confirm that their divergent parts agree with those in the continuum theory.

John Cardy

Non-local twist operators are introduced for the O(n) and Q-state Potts models in two dimensions which, in the limits n -> 0 (resp. Q -> 1) count the numbers of self-avoiding loops (resp. percolation clusters) surrounding a given point. This yields many results, for example the distribution of the number of percolation clusters which must be crossed to conne

Kiyoshi Higashijima, Muneto Nitta

Quantum corrections to Legendre transformations are shown to cancel to all orders in supersymmetric theories in path integral formalism. Using this result, lagrangians for auxiliary fields are generalized to non-quadratic forms. In supersymmetric effective nonlinear lagrangians, the arbitrariness due to the existence of quasi Nambu-Goldstone bosons is shown

N. Haba, M. Matsuda, M. Tanimoto

It is well known that Zee type neutrino mass matrix can provide bi-maximal neutrino mixing for three neutrinos. We study the reconciliation of this model with the gauge mediated supersymmetry breaking scenario, which naturally suppresses the large flavor changing neutral current and CP violation in the supersymmetric standard model. When the messenger fields

Xiao-Guang Wang

We show that various kinds of one-photon quantum states studied in the field of quantum optics admit ladder operator formalisms and have the generally deformed oscillator algebraic structure. The two-photon case is also considered. We obtain the ladder operator formalisms of two general states defined in the even/odd Fock space. The two-photon states may als

Richard L. Hall, Nasser Saad

A variational analysis is presented for the generalized spiked harmonic oscillator Hamiltonian operator H, where H = -(d/dx)^2 + Bx^2+ A/x^2 + lambda/x^alpha, and alpha and lambda are real positive parameters. The formalism makes use of a basis provided by exact solutions of Schroedinger's equation for the Gol'dman and Krivchenkov Hamiltonian (alpha

L. Lanz, B. Vacchini

Inside quantum mechanics the problem of decoherence for an isolated, finite system is linked to a coarse-grained description of its dynamics.

Zhang Yang, Zhou Haijun, Ouyang Zhongcan

Metropolis Monte Carlo simulation is used to investigate the elasticity of torsionally stressed double-stranded DNA, in which twist and supercoiling are incorporated as a natural result of base-stacking interaction and backbone bending constrained by hydrogen bonds formed between DNA complementary nucleotide bases. Three evident regimes are found in extensio

O. Krehl, C. Hanhart, S. Krewald, J. Speth

We investigate the structure of the nucleon resonance N^*(1440) (Roper) within a coupled-channel meson exchange model for pion-nucleon scattering. The coupling to pipiN states is realized effectively by the coupling to the sigmaN, piDelta and rhoN channels. The interaction within and between these channels is derived from an effective Lagrangian based on a c

Yuri F. Smirnov, Nadya A. Smirnova, Piet Van Isacker

It is shown that the spectrum of the asymmetric rotor can be realized quantum mechanically in terms of a system of interacting bosons. This is achieved in the SU(3) limit of the interacting boson model by considering higher-order interactions between the bosons. The spectrum corresponds to that of a rigid asymmetric rotor in the limit of infinite boson numbe

Pablo A. Ferrari, L. Renato G. Fontes, M. Eulalia Vares

We consider the one dimensional totally asymmetric simple exclusion process with initial product distribution with densities $0 \leq ρ_0 < ρ_1 <...< ρ_n \leq 1$ in $(-\infty,c_1\ve^{-1})$, $[c_1\ve^{-1},c_2ε^{-1}),...,[c_n \ve^{-1}, + \infty)$, respectively. The initial distribution has shocks (discontinuities) at $ε^{-1}c_k$, k=1,...,n and we assume that in

Klaus Hulek

In this paper we prove two results concerning the classification of Siegel modular threefolds. Let A_{1,d}(n) be the moduli space of abelian surfaces with a (1,d)-polarization and a full level-n structure and let A_{1,d}^{lev}(n) be the space where one has fixed an additional canonical level structure. We prove that A_{1,d}(n) is of general type if (d,n)=1 a

Emmanuel Giroux

In this paper, we study the global behaviour of contact structures on oriented manifolds V which are circle bundles over a closed orientable surface S of genus g>0. We establish in particular contact analogs of a number of classical results about foliations due to Milnor, Wood, Thurston, Matsumoto, and Ghys. In Section~1, we prove that V carries a (positive)

K. A. Brown, I. Gordon

Let H be a Hopf algebra which is a finite module over a central sub-Hopf algebra R. The ramification behaviour of the maximal ideals of Z(H) with respect to the subalgebra R is studied. In the case when H is U(g), the enveloping algebra of a semisimple Lie algebra g, a conjecture of Humphreys is confirmed. In the case when H is the quantised enveloping algeb

Mikhail Krichman, Eduardo D. Sontag, Yuan Wang

This work explores Lyapunov characterizations of the input-output-to-state stability (IOSS) property for nonlinear systems. The notion of IOSS is a natural generalization of the standard zero-detectability property used in the linear case. The main contribution of this work is to establish a complete equivalence between the input-output-to-state stability pr

Saharon Shelah, Pauli Väisänen

For a cardinal kappa and a model M of cardinality kappa let No(M) denote the number of non-isomorphic models of cardinality kappa which are L_{infty,kappa}--equivalent to M. In [Sh:133] Shelah established that when kappa is a weakly compact cardinal and mu<=kappa is a nonzero cardinal, there exists a model M of cardinality kappa with No(M)=mu. We prove here

Saharon Shelah, Pauli Väisänen

Let kappa be an uncountable regular cardinal. Call an equivalence relation on functions from kappa into 2 Sigma_1^1-definable over H(kappa) if there is a first order sentence F and a parameter R subseteq H(kappa) such that functions f,g:kappa --> 2 are equivalent iff for some h:kappa --> 2, the structure (H(kappa),in,R,f,g,h) satisfies F, where in, R, f, g,

Deepak Parashar, Roger J. McDermott

The two parameter quantum group G_r,s is generated by five elements, four of which form a Hopf subalgebra isomorphic to GL_q(2), while the fifth generator relates G_r,s to GL_p,q(2). We construct explicitly the dual algebra of G_r,s and show that it is isomorphic to the single parameter deformation of gl(2) + gl(1), with the second parameter appearing in the

Jean-Pierre Demailly, Jawher El Goul

The main goal of this work is to prove that a very generic surface of degree at least 21 in complex projective 3-dimensional space is hyperbolic in the sense of Kobayashi. This means that every entire holomorphic map $f:{\Bbb C} \to X$ to the surface is constant. In 1970, Kobayashi conjectured more generally that a (very) generic hypersurface of sufficiently

N. P. Warner

The use of gauged ${\cal N} = 8$ supergravity as a tool in studying the AdS/CFT correspondence for ${\cal N} = 4$ Yang-Mills theory is reviewed. The supergravity potential implies a non-trivial, supersymmetric IR fixed point, and the flow to this fixed point is described in terms of a supergravity kink. The results agree perfectly with earlier, independent f

R. Jackiw

Various fluid mechanical systems, governed by nonlinear differential equations, enjoy a hidden, higher-dimensional dynamical Poincar\'e symmetry, which arises owing to their descent from a Nambu-Goto action. Also, for the same reason, there are equivalence transformations between different models. These interconnections are discussed in this lecture, and are

Manoelito M de Souza

The use of proper time as a tool for causality implementation in field theory is clarified and extended to allow a manifestly covariant definition of discrete fields proper to be applied in field theory and quantum mechanics. It implies on a constraint between a radiation field and its sources, valid in principle for all fundamental interactions and with a s

Dmitri Antonov

By making use of the path-integral duality transformation, string representation of the Abelian-projected SU(3)-QCD with the $Θ$-term is derived. Besides the short-range (self-)interactions of quarks (which due to the $Θ$-term acquire a nonvanishing magnetic charge, i.e. become dyons) and electric Abrikosov-Nielsen-Olesen strings, the resulting effective act

Abhay Ashtekar, Saurya Das

Asymptotically anti-de Sitter space-times are considered in a general dimension $d\ge 4$. As one might expect, the boundary conditions at infinity ensure that the asymptotic symmetry group is the anti-de Sitter group (although there is an interesting subtlety if d=4). Asymptotic field equations imply that, associated with each generator $ξ$ of this group, th

L. R. Huiszoon, A. N. Schellekens, N. Sousa

The open descendants of simple current automorphism invariants are constructed. We consider the case where the order of the current is two or odd. We prove that our solutions satisfy the completeness conditions, positivity and integrality of the open and closed sectors and the Klein bottle constraint (apart from an interesting exception). In order to do this

Noboru Kawamoto, Noriaki Sato, Yukiya Uchida

We propose the lattice version of $BF$ gravity action whose partition function leads to the product of a particular form of 15-$j$ symbol which corresponds to a 4-simplex. The action is explicitly constructed by lattice $B$ field defined on triangles and link variables defined on dual links and is shown to be invariant under lattice local Lorentz transformat

H. Zerrouki

Different models of field theories in two dimensions can be described by the action $Tr\int \vf F$. In the presence of a curved background, we construct a local supersymmetry-like transformations under which the action is invariant. Furthermore, by analysing the cohomology of the theory we show the absence of anomalies. Also the ultraviolet as well as the in

Ramesh Anishetty, R. Parthasarathy

We show that quantized matter fields in the presence of background metrics with Horizon exhibit spontaneous time asymmetry. All quantized matter fields have to vanish at the horizon. Some phenemenological applications of this in the context of black holes and early universe are considered.

A. Niegawa, K. Okano, H. Ozaki

A complete derivation, from first principles, of the reaction-rate formula for a generic reaction taking place in an out of equilibrium quantum-field system is given. It is shown that the formula involves no finite-volume correction. Each term of the reaction-rate formula represents a set of physical processes that contribute to the reaction under considerat

Dmitri Antonov, Dietmar Ebert

By making use of the Abelian projection method, a dual version of the SU(2)-gluodynamics with manifest monopole-like excitations, arising from the integration over singular gauge transformations, is formulated in the continuum limit. The resulting effective theory emerges due to the summation over the grand canonical ensemble of these excitations in the dilu

Antti J. Niemi, Kaupo Palo, Sami Virtanen

In gauge theories with an extended Higgs sector the classical equations of motion can have solutions that describe stable, closed finite energy vortices. Such vortices separate two disjoint Higgs vacua, with one of the vacua embedded in the other in a manner that forms a topologically nontrivial knot. The knottedness stabilizes the vortex against shrinkage i

Yuri V. Kovchegov, Eugene Levin

We derive an evolution equation describing the high energy behavior of the cross section for the single diffractive dissociation in deep inelastic scattering on a hadron or a nucleus. The evolution equation resums multiple BFKL pomeron exchanges contributing to the cross section of the events with large rapidity gaps. Analyzing the properties of an approxima

G. D&#39;Ambrosio, G. Isidori, G. Martinelli

An analysis of the CP violating asymmetry in $K^\pm \to (3π)^\pm$ decays in the Standard Model and, by means of the mass insertion approximation, in a wide class of possible supersymmetric extensions, is presented. We find that the natural order of magnitude for this asymmetry is $\cO(10^{-5})$ in both cases. Within supersymmetric models effects as large as

D. Boyanovsky, H. J. de Vega

The dynamics of a symmetry breaking phase transition is studied in a radiation and matter dominated spatially flat FRW cosmology in the large N limit of a scalar field theory.The quantum density matrix is evolved from an initial state of quasiparticles in thermal equilibrium at a temperature higher than the critical. The cosmological expansion decreases the

H. Sazdjian

The relationship between the pionium lifetime and the $ππ$ scattering lengths is established, including the sizable electromagnetic corrections. The bound state formalism that is used is that of constraint theory which provides a covariant three-dimensional reduction of the Bethe--Salpeter equation. The framework of generalized chiral perturbation theory all

E. R. Berger

In this report diffractive high energy reactions are discussed in a functional integral approach where hadronic amplitudes are calculated from vacuum expectation values of lightlike Wegner-Wilson loops. In the first part we calculate elastic differential cross sections for high energy and small momentum transfer elastic proton-proton (pp) scattering which ar

D. Melikhov, S. Simula

We present a new approach to the analysis of quark-binding effects in inclusive decays of heavy mesons within the relativistic dispersion quark model. Various differential distributions, such as electron energy spectrum, $q^2$- and $M_X$-distributions, are calculated in terms of the $B$ meson soft wave function which also determines long-distance effects in

Karim Benakli

In IIB orientifold models, the singlet twisted moduli appear in the tree-level gauge kinetic function. They might be responsible for generating gaugino masses if they acquire non-vanishing F-terms. We discuss some aspects of this new possibility, such as the size of gaugino masses and their non-universalities. A possible brane setting is presented to illustr

A. Ringwald, F. Schrempp

We describe a Monte Carlo event generator for the simulation of QCD-instanton induced processes in deep-inelastic scattering (HERA). The QCDINS package is designed as an ``add-on&#39;&#39; hard process generator interfaced to the general hadronic event simulation package HERWIG. It incorporates the theoretically predicted production rate for instanton-induce

C. Heinemann, E. Iancu, C. Martin, D. Vautherin

For a SU(N) Yang-Mills theory, we present variational calculations using gaussian wave functionals combined with an approximate projection on gauge invariant states. The projection amounts to correcting the energy of the gaussian states by substracting the spurious energy associated with gauge rotations. Based on this improved energy functional, we perform v

Kh. M. Beshtoev

Two particle vacuum transitions (oscillations) are studied in the general case. We found that: 1) a nondiagonal mass term characterising oscillations is the width of two particle transitions into each other (this width can be computed by the standard method); 2) two types of oscillations take place: real and virtual. Solution of the problem of origin of mixi

V. V. Anisovich, V. A. Nikonov

In the framework of the dispersion relation N/D-method we restore the low-energy pi-pi (IJ^{PC}=00^{++})-wave amplitude sewing it with the previously obtained K-matrix solution for the region 450--1900 MeV [V.V. Anisovich, Yu.D. Prokoshkin and A.V. Sarantsev, Phys. Lett. B389, 388 (1996)]. The restored N/D-amplitude has a pole on the second sheet of the comp

Y. Sumino

I review the theoretical progress made in these 4 years concerning the process e+e- -> ttbar in the threshold region. I summarize the progress towards each of the three major physics goals that should be achieved at ttbar threshold region.

Yutaka Sakamura

We show that in the context of large extra dimensions enough CP violation can be obtained from the spontaneous breaking in a simple non-SUSY model, which is usually considered not to cause the spontaneous CP violation. We estimate ε_{K} in our scenario to be of order 10^{-3} consistent with the experimental value. We also propose a modification to the see-sa

Xiao-Jun Wang, Mu-Lin Yan

We study SU(3)$_L\timesSU(3)_R$ chiral quark model of mesons up to the next to leading order of $1/N_c$ expansion. Composite vector and axial-vector mesons resonances are introduced via non-linear realization of chiral SU(3) and vector meson dominant. Effects of one-loop graphs of pseudoscalar, vector and axial-vector mesons is calculated systematically and

PACS Collaboration, A. Ali Khan, S. Aoki, R. Burkhalter

We report on a study of B mesons on N_f = 2 full QCD configurations using an RG-improved gauge action, NRQCD heavy quark action and tadpole-improved clover light quark action. Results on the heavy-light spectrum and the decay constants from 16^3x32 lattices at a^{-1} ~ 1.5 GeV are presented, and compared with quenched results obtained with the same action co

JLQCD Collaboration, S. Aoki, M. Fukugita, S. Hashimoto

We report results on semileptonic $B\toπl\barν$ decay form factors near $q^2_{\rm max}$ using NRQCD heavy quark and clover light quark actions and currents improved through $O(αa)$. An inconsistency with the soft pion relation $f^0(q^2_{\rm max})= f_B/f_π$ found in a previous work is confirmed, and a possible solution with nonperturbative renormalization is

Vitaliano Ciulli

Recent results on the spectroscopy of excited b and c states are presented. In particular, these include the first observation of the D_1 (light quark spin j=1/2) resonance, searches for radially excited D*&#39; and observations of orbitally excited B*_J states. The current experimental status on excited charmed baryons is also briefly reviewed.

P. F. Loverre, R. Santacesaria, F. R. Spada

We study the feasibility of a long baseline neutrino experiment from CERN to Gran Sasso LNGS Laboratories using the CERN PS accelerator. Baseline and neutrino energy spectrum are suitable to explore a region of the (Dm2, Sin2(theta)) parameters space which is not reached by K2K, the first experiment that will test at accelerator the atmospheric neutrino anom

The WA102 Collaboration, D. Barberis

The reactions pp -> pf (X0) ps, where X0 is observed decaying to eta etaprime and etaprime etaprime, have been studied at 450 GeV/c. This is the first time that these channels have been observed in central production and only the second time that the etaprime etaprime channel has been observed in any production mechanism. In the eta etaprime channel there is

Brett E. Taylor, William A. Hiscock, Paul R. Anderson

Semiclassical perturbations to the Reissner-Nordstrom metric caused by the presence of a quantized massive scalar field with arbitrary curvature coupling are found to first order in ε= \hbar/M^2. The DeWitt-Schwinger approximation is used to determine the vacuum stress-energy tensor of the massive scalar field. When the semiclassical perturbation are taken i

Othmar Brodbeck, Marco Zagermann

Dimensional reductions of various higher dimensional (super)gravity theories lead to effectively two-dimensional field theories described by gravity coupled G/H nonlinear sigma-models. We show that a new set of complexified variables can be introduced when G/H is a Hermitian symmetric space. This generalizes an earlier construction that grew out of the Ashte

Hans Ringstrom

The maximal globally hyperbolic development of non-Taub-NUT Bianchi IX vacuum initial data and of non-NUT Bianchi VIII vacuum initial data is C2 inextendible. Furthermore, a curvature invariant is unbounded in the incomplete directions of inextendible causal geodesics.

Ivangoe B. Pestov

The concept of wave field is introduced to represent oriented media. The wave field is a tensor field of second rank, and directors are its eigenvectors. This exhibition of directors defines a natural gauge group inherit in continua and allows one to derive from variational principle general relativistic and gauge invariant equations for the wave field in qu

Hideo Hasegawa

Numerical calculations have been made on the spike-train response of a pair of Hodgkin-Huxley (HH) neurons coupled by synapses and axons with time delay. The recurrent excitatory-excitatory, inhibitory-inhibitory, excitatory-inhibitory, and inhibitory-excitatory couplings are adopted. The coupled, excitable HH neurons are assumed to receive the two kinds of

D. Abraimov, P. Caputo, G. Filatrella, M. V. Fistul

We present an experimental and theoretical study of row switching in two-dimensional Josephson junction arrays. We have observed novel dynamic states with peculiar percolative patterns of the voltage drop inside the arrays. These states were directly visualized using laser scanning microscopy and manifested by fine branching in the current-voltage characteri

Debasis Dan, Mangal C. Mahato, A. M. Jayannavar

Efficiency of generation of net unidirectional current in an adiabatically driven symmetric periodic potential system is studied. The efficiency shows a maximum, in the case of an inhomogeneous system with spatially varying periodic friction coefficient, as a function of temperature. The ratchet is not most efficient when it gives maximum current. The direct

R. Burghaus

For an ordered array of critical volatile wetting droplets the formation of a super lattice by an Ostwald-ripening like competition process is considered. The underlying diffusion problem is treated within a quasistatic approximation and to first order in the inverse droplets distance. The approach is rather general but a square lattice and a triangular latt