November 1998 arXiv papers — page 15

L. Baudis, G. Heusser, B. Majorovits, Y. Ramachers

The potential of GENIUS as a dark matter detector is discussed. A study was performed to demonstrate the good behaviour of the proposed detector design of naked HPGe-crystals in liquid nitrogen. The expected background components were simulated and are discussed in some detail.With the obtained background GENIUS could cover a large part of the favoured MSSM

ALEPH collaboration

Using a sample of four million hadronic Z events collected in ALEPH from 1991 to 1995, the decays D*+ -> D0pi^+_s, with D0 decaying to K-pi+ or to K+pi-, are studied. The relative branching ratio B(D0 -> K+pi-)/B(D0 -> K-pi+) is measured to be (1.84+-0.59(stat.)+-0.34(syst.))%. The two possible contributions to the D0 -> K+pi- decay, doubly cabibbo-suppresse

Yu. V. Kozlov, S. V. Khalturtsev, I. N. Machulin, A. V. Martemyanov

The investigation of antineutrino-deuteron interaction at Krasnoyarsk reactor are discussed. The characteristics of the installation ''Deuteron'', present results and perspectives of Krasnoyarsk neutrino laboratory are presented.

M. Anikina, L. Chkhaidze, T. Djobava, V. Garsevanishvili

The light front analysis of pi^{-} mesons in A_{P} (He, C, Mg, O) + A_{T} (Li,C, Ne, Mg,Cu,Pb) collisions is carried out. The phase space of secondary pions is naturally divided into two parts in one of which the thermal equilibration assumption seems to be in a good agreement with data. Corresponding temperatures are extracted and compared to the results of

ALEPH collaboration

A search for B0s oscillations is performed using a sample of semileptonic b-hadron decays collected by the ALEPH experiment during 1991-1995. Compared to previous inclusive lepton analyses, the proper time resolution and b-flavour mistag rate are significantly improved. Additional sensitivity to B0s mixing is obtained by identifying subsamples of events havi

Clifford M. Will

The status of experimental tests of general relativity and of theoretical frameworks for analysing them are reviewed. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eötvös experiment, tests of special relativity, and the gravitational redshift experiment. Future tests of EEP will search for new interactions arising fr

Filipe C. Mena, Reza Tavakol

With the help of families of density contrast indicators, we study the tendency of gravitational systems to become increasingly lumpy with time. Depending upon their domain of definition, these indicators could be local or global. We make a comparative study of these indicators in the context of inhomogeneous cosmological models of Lemaitre--Tolman and Szeke

Juan Antonio Valiente Kroon

The connection between the Bondi-Sachs (BS) and the Newman-Penrose (NP) framework for the study of the asymptotics of the gravitational field is done. In particular the coordinate transformation relationg the BS luminosity parameter and the NP affine parameter is obtained. Using this coordinate transformation it is possible to express BS quantities in terms

Elizabeth Anderson, Robert Atkinson, Cynthia Crego, Jean Slisz

This paper addresses the issue of making legacy information (that material held in paper format only) electronically searchable and retrievable. We used proprietary software and commercial hardware to create a process for scanning, cataloging, archiving and electronically disseminating full-text documents. This process is relatively easy to implement and rea

T. Biedl, E. Demaine, M. Demaine, S. Lazard

In this paper, we study movements of simple polygonal chains in 3D. We say that an open, simple polygonal chain can be straightened if it can be continuously reconfigured to a straight sequence of segments in such a manner that both the length of each link and the simplicity of the chain are maintained throughout the movement. The analogous concept for close

Krzysztof R. Apt, Marc Bezem

We provide here a computational interpretation of first-order logic based on a constructive interpretation of satisfiability w.r.t. a fixed but arbitrary interpretation. In this approach the formulas themselves are programs. This contrasts with the so-called formulas as types approach in which the proofs of the formulas are typed terms that can be taken as p

Martin Volk, Gerold Schneider

In this paper we present the results of comparing a statistical tagger for German based on decision trees and a rule-based Brill-Tagger for German. We used the same training corpus (and therefore the same tag-set) to train both taggers. We then applied the taggers to the same test corpus and compared their respective behavior and in particular their error ra

Lunjin Lu, John G. Cleary

An algorithm to decide the emptiness of a regular type expression with set operators given a set of parameterised type definitions is presented. The algorithm can also be used to decide the equivalence of two regular type expressions and the inclusion of one regular type expression in another. The algorithm strictly generalises previous work in that tuple di

J. P. Rodriguez, Emilio Artacho

A magnetic origin for the honeycomb reconstruction of metallic surfaces with three-fold symmetry like Pb/Ge (111) is proposed. Assuming that the groundstate is an antiferromagnetic insulator over the triangular lattice of adatom sites (Pb), we demonstrate that the former is simultaneously unstable to canting and to a structural distortion if the surface is s

H. -J. Miesner, D. M. Stamper-Kurn, J. Stenger, S. Inouye

Bose-Einstein condensates have been prepared in long-lived metastable excited states. Two complementary types of metastable states were observed. The first is due to the immiscibility of multiple components in the condensate, and the second to local suppression of spin-relaxation collisions. Relaxation via re-condensation of non-condensed atoms, spin relaxat

F. Bagnoli, R. Rechtman, S. Ruffo

Using the concept of the Boolean derivative we study damage spreading for one dimensional elementary cellular automata and define their maximal Lyapunov exponent. A random matrix approximation describes quite well the behavior of ``chaotic'' rules and predicts a directed percolation-type phase transition. After the introduction of a small noise eleme

Steven M. Anlage, D. E. Steinhauer, C. P. Vlahacos, B. J. Feenstra

We have developed scanning near-field microwave microscopes which can image electrodynamic properties of superconducting materials on length scales down to about 2 $μ$m. The microscopes are capable of quantitative imaging of sheet resistance of thin films, and surface topography. We demonstrate the utility of the microscopes through images of the sheet resis

Ch. Binek

In order to provide an experimental access to the statistical theory of Lee and Yang (1952) the density function g(theta) of zeros on the Lee-Yang circle has been determined for the first time by analyzing isothermal magnetization data, m(H), of the Ising ferromagnet FeCl2 in axial magnetic fields, H, at temperatures 34 < T < 99K. The validity of our approac

C. Oligschleger, J. C. Sch&#34;on

Using molecular dynamics (MD) with classical interaction potentials we present calculations of thermal conductivity and heat transport in crystals and glasses. Inducing shock waves and heat pulses into the systems we study the spreading of energy and temperature over the configurations. Phonon decay is investigated by exciting single modes in the structures

Yuli V. Nazarov

We review here a novel circuit theory of superconductivity. The existed circuit theory of Andreev reflection has been revised to account for decoherence between electrons and holes and twofold nature of the distribution function. The description of arbitrary connectors has been elaborated. In this way one can cope with the most of the factors that limited ap

Richard P. Sear

Polydisperse mixtures are those in which components with a whole range of sizes are present. It is shown that the fluid phase of polydisperse hard spheres is thermodynamically unstable unless the density of large spheres decreases at least exponentially as their size increases. The instability is with respect to the large spheres crystallising out into multi

A. V. Nikulov, I. N. Zhilyaev

An inhomogeneous superconducting ring placed in a magnetic field is considered. It is shown that the superconducting transition of the section with lowest critical temperature may be a first order phase transition if the magnetic flux contained within the ring is not divisible by the flux quantum. In the visinity of this transition, thermal fluctuations can

Th. Busch, J. R. Anglin

We present analytic and numerical results for a class of monopole solutions to the two-component Gross-Pitaevski equation for a two-species Bose condensate in an effectively two-dimensional trap. We exhibit dynamical instabilities involving vortex production as one species pours through another, from which we conclude that the sub-optical sharpness of potent

Ching-Long Wu, Chung-Yu Mou, Xiao-Gang Wen, Darwin Chang

A preformed-pair model was considered. The quantum disordered phase of the d-wave superconducting state was obtained by turning on an on-site repulsion. The low energy effective theory of the quantum disordered phase was derived, which was found to be qualitatively equivalent to the low energy effective theory of the SU(2) slave-boson theory in the staggered

Claudio Donati, Sharon C. Glotzer, Peter H. Poole

We define a correlation function that quantifies the spatial correlation of single-particle displacements in liquids and amorphous materials. We show for an equilibrium liquid that this function is related to fluctuations in a bulk dynamical variable. We evaluate this function using computer simulations of an equilibrium glass-forming liquid, and show that l

Kent L. McCormick, Michael T. Woodside, Mike Huang, Mingshaw Wu

Using an atomic force microscope as a local voltmeter, we measure the Hall voltage profile in a 2D electron gas in the quantum Hall (QH) regime. We observe a linear profile in the bulk of the sample in the transition regions between QH plateaus and a distinctly nonlinear profile on the plateaus. In addition, localized voltage drops are observed at the sample

Robert Antonucci

It is becoming possible to detect high redshift quasars in various molecular lines, and to show by mapping lensed objects that the strong dust and molecular emission arises in warm dense ~100 pc-scale &#34;tori.&#34; The properties of ULIRGs, at least those with AGN-like narrow line regions, are very similar, as expected in the hidden quasar hypothesis. Seve

A. Aparicio

Dwarf galaxies may play a key role in the formation and evolution of bigger systems. This make a topic of major interest knowing how they form and evolve and, in particular, how their star formation histories (SFHs) have proceed since their birth. For nearby galaxies, the color-magnitude diagram (CMD) contains stars formed over all their lifetime. It is henc

Will Sutherland

There is abundant evidence that the mass of the Universe is dominated by dark matter of unknown form. The MACHO project is one of several teams searching for the dark matter around our Galaxy in the form of Massive Compact Halo Objects (MACHOs). If a compact object passes very close to the line of sight to a background star, the gravitational deflection of l

Brian D. Fields, Keith A. Olive

We review the Galactic chemical evolution of Li6 and compare these results with recent observational determinations of the lithium isotopic ratio. In particular, we concentrate on so-called standard Galactic cosmic-ray nucleosynthesis in which Li, Be, and B are produced (predominantly) by the inelastic scattering of accelerated protons and α&#39;s off of CNO

D. Engels, F. Tesch, C. Ledoux, J. Wei

We are searching for large-scale structures in the distribution of AGN discovered by the ROSAT All-Sky Survey. The RASS detected > 60000 X-ray objects, of which approximately 35% are AGN at z < 0.5. The surface density in the extragalactic sky is approximately 0.5 AGN/deg^2, which has not been reached until now by any other survey for this redshift range. We

Nicolas Cretton, Frank C. van den Bosch

We have constructed axisymmetric dynamical models of the edge-on S0 galaxy NGC 4342: simple two-integral Jeans models as well as fully general, three-integral models using a modified version of Schwarzschild&#39;s orbit superposition technique. The two-integral models suggest a black hole (BH) of 3 or $6\times 10^8 M_\odot$, depending on the data set. The th

R. Silvotti, S. Dreizler, G. Handler, X. J. Jiang

We present the results from 135 hours of nearly continuous time series photometry on the ``hybrid&#39;&#39; (H-rich) PG1159 variable star HS2324+3944, obtained in August-September 1997. The power spectrum of the data shows several frequencies (about 20 or more), concentrated in three narrow and very crowded regions near 475, 390 and 950 microHz in decreasing

E. Oliva, A. Marconi, A. F. M. Moorwood

Spectra of extranuclear clouds within the ionization cone of Circinus galaxy are presented and modelled assuming photoionization by the Seyfert 2 nucleus but no preconceived assumption concerning the spectral shape of the ionizing AGN radiation or the gas density distribution. The most important result is that, regardless of the assumed AGN spectral shape or

G. Bono, S. Cassisi

We discuss theoretical predictions for ZAHB models constructed either by including or neglecting the He extra-mixing effect recently suggested by Sweigart (1997). The comparison in the $log T_e -log g$ plane suggests that within current observational uncertainties canonical hot HB models based on new input physics agree with empirical data in Galactic globul

Ruth Durrer, Martin Kunz, Alessandro Melchiorri

We investigate the global texture model of structure formation in cosmogonies with non-zero cosmological constant for different values of the Hubble parameter. We find that the absence of significant acoustic peaks and little power on large scales are robust predictions of these models. However, from a careful comparison with data we conclude that at present

Guido De Marchi, Bruno Leibundgut, Francesco Paresce, Luigi Pulone

The VLT on Cerro Paranal was used to observe four fields located at 2.3&#39; from the center of the Galactic globular cluster NGC 6712 in the V and R bands. The resulting color-magnitude diagram shows a well defined main sequence reaching down to the 5 sigma detection limit at V~25, R~23.5 or approximately 4 mag below the main sequence turn-off, the deepest

D. W. Sciama

Recent Super-Kamiokande data have greatly strengthened the hypothesis that the atmospheric neutrino anomaly is mainly due to nearly maximal oscillations between $ν_μ$ and either $ν_τ$ or a sterile neutrino $ν^s_μ$.In this letter we point out that the decaying neutrino theory for the ionisation of hydrogen in the interstellar medium, in conjunction with the a

X. -Y. Xia, Shude Mao, H. Wu, Z. Zheng

We study optical and X-ray properties of the ultraluminous IRAS galaxy 10026+4347. This galaxy is a narrow-line QSO with very strong FeII emission. Three optical spectra were taken over two years. The full widths at half maximum (FWHMs) of the emission lines are constant whereas the third spectrum seems to show a continuum change. Intermediate-band photometr

H. Hirashita

Using a one-zone model for the evolution of dust in spiral galaxies and applying the instantaneous recycling approximation to the model equations, we investigate dust-to-gas ratio of spiral galaxies. Four processes are considered; dust formation from heavy elements ejected by stellar mass loss, dust destruction in supernova remnants, dust destruction in star

K. C. Chambers

The continuum morphologies of high redshift radio galaxies and quasars can be modeled as enormous bipolar reflection nebulae from shells of dust swept up by bipolar outflows. If the observed shape of a particular object is fit with an analytic function, then the velocity of the shell is specified by the equations of motion. The predicted kinematics can be co

Wayne Hu, Max Tegmark

Weak lensing of galaxies by large scale structure can potentially measure cosmological quantities as accurately as the cosmic microwave background (CMB). However, the relation between observables and fundamental parameters is more complex and degenerate, especially in the full space of adiabatic cold dark matter models considered here. We introduce a Fisher

Philip R. Maloney, J. Bland-Hawthorn

We investigate how much warm (T \sim 10^6 K) gas may exist in a Local Group corona, and, in particular, whether such a corona could be detected indirectly through its ionizing radiation. We calculate the non-LTE cooling of warm, low-density gas and the resulting ionizing photon emissivities for a range of metallicities. In principle a corona can produce a ph

Lawrence J. Hall, Neal Weiner

A U(2) flavor symmetry can successfully describe the charged fermion masses and mixings, and supress SUSY FCNC processes, making it a viable candidate for a theory of flavor. We show that a direct application of this U(2) flavor symmetry automatically predicts a mixing of 45 degrees for nu_mu to nu_s, where nu_s is a light, right-handed state. The introducti

Christof Gattringer

We study a generalized 8-vertex model where the vertices are coupled to a locally varying field. We rewrite the partition function as an integral over Grassmann variables. In this form it is possible to explicitly evaluate all terms of the hopping expansion. Applications of the resulting formula, in particular its relation to 2-D lattice field theories with

H. M. Antia, Sarbani Basu

We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 <ν<10 mHz) using the ring diagram technique applied to power spectra obtained from MDI (Michelson Doppler Imager) data. The f-mode ridge extends up to degree of approximately 3000, where the line width becomes very large, implying a damping ti

Shoichi Ichinose

We give an interpretation to the issue of the chiral determinant in the heat-kernel approach. The extra dimension (5-th dimension) is interpreted as (inverse) temperature. The 1+4 dim Dirac equation is naturally derived by the Wick rotation for the temperature. In order to define a ``good&#39;&#39; temperature, we choose those solutions of the Dirac equation

A. DeBenedictis

The gravitational back-reaction is calculated for the conformally invariant scalar field within a black cosmic string interior with cosmological constant. Using the perturbed metric, the gravitational effects of the quantum field are calculated. It is found that the perturbations initially strengthen the singularity. This effect is similar to the case of sph

Arjun Berera, Thomas W. Kephart

A string motivated, N=1 global supersymmetric, general Lagrangian is obtained that represents an inflaton interacting with the modes of a string. Focus is placed on the Lagrangian&#39;s relevance to warm inflation, which is a cosmology based on dissipative dynamics. Several interaction schemes are identified from the general Lagrangian that may have interest

W. Kummer, D. V. Vassilevich

The effective one-loop action for general dilaton theories with arbitrary dilaton-dependent measure and nonminimal coupling to scalar matter is computed. As an application we determine the Hawking flux to infinity from black holes in d-dimensions. We resolve the recently resurrected problem of an apparent negative flux for nonminimally coupled scalars: For a

Gian F. Giudice, Riccardo Rattazzi, James D. Wells

Recently it has been pointed out that the characteristic quantum-gravity scale could be as low as the weak scale in theories with gravity propagating in higher dimensions. The observed smallness of Newton&#39;s constant is a consequence of the large compactified volume of the extra dimensions. We investigate the consequences of this supposition for high-ener

A. Tounsi, J. Letessier, J. Rafelski

We obtain the hadronic mass spectrum in the `bag of bags' statistical bootstrap model (BBSBM), implementing the colorless state condition, aside of baryon and strangeness conservation, using group projection method. We study the partition function, investigate the properties of dense hadronic matter, and determine the conditions under which the system underg

Francesca Perrotta, Carlo Baccigalupi

We consider the problem of the initial conditions and behaviour of the perturbations in scalar field cosmology with general potential. We use the general definition of adiabatic and isocurvature conditions to set the appropriate initial values for the perturbation in the scalar field and in the ordinary matter and radiation components. In both the cases of i

L. O&#39;Raifeartaigh, J. M. Pawlowski, V. V. Sreedhar

The quantisation of the two-dimensional Liouville field theory is investigated using the path integral, on the sphere, in the large radius limit. The general form of the $N$-point functions of vertex operators is found and the three-point function is derived explicitly. In previous work it was inferred that the three-point function should possess a two-dimen

Je-Young Choi, Seok-In Hong

We consider supersymmetric quantum mechanical models with both local and nonlocal potentials. We present a nonlocal deformation of exactly solvable local models. Its energy eigenfunctions and eigenvalues are determined exactly. We observe that both our model Hamiltonian and its supersymmetric partner may have normalizable zero-energy ground states, in contra

Michele Maggiore, Antonio Riotto

D-branes, topological defects in string theory on which string endpoints can live, may give new insight into the understanding of the cosmological evolution of the Universe at early epochs. We analyze the dynamics of D-branes in curved backgrounds and discuss the parameter space of M-theory as a function of the coupling constant and of the curvature of the U

N. Sandulescu, Nguyen Van Giai, R. J. Liotta

A method for incorporating the effect of the resonant continuum into Hartree-Fock+BCS equations is proposed. The method is applied for the case of a neutron-rich nucleus calculated with a Skyrme-type force plus a zero-range pairing interaction and the results are compared with Hartree-Fock-Bogoliubov calculations. It is shown that the widths of resonant stat

Antonio L. Maroto, Anupam Mazumdar

We consider the resonant production of fermions from an oscillating axial background. The classical evolution of the axial field is given by that of a massive pseudovector field, as suggested by the renormalizability of the theory. We look upon both the massive and the massless fermion production from a perturbative point of view. We obtain the corresponding

Feng Yuan, Kuang-Ta Chao

The large transverse momentum muon pair and W boson productions in the quark initiated coherent diffractive processes at hadron colliders are discussed under the framework of the two-gluon exchange parametrization of the Pomeron model. In this approach, the production cross sections are related to the small-x off-diagonal gluon distribution and the large-x q

E. H. Hwang, S. Das Sarma

Collective modes of bilayered superconducting superlattices (e.g., YBCO) are investigated within the conserving gauge-invariant ladder diagram approximation including both the nearest interlayer single electron tunneling and the Josephson-type Cooper pair tunneling. By calculating the density-density response function including Coulomb and pairing interactio

K. Saito, K. Tsushima, A. W. Thomas

The spectra of the scalar ($σ$) and vector ($ω$) mesons in nuclear matter are studied in detail using the quark-meson coupling (QMC) model. It is shown that above normal nuclear matter density the effects of $σ$-$ω$ mixing and the decay of the $σ$ into $2π$ change the spectra of $σ$ and $ω$ mesons considerably. As in Quantum Hadrodynamics we find a remarkabl

G. Tondo, C. Morosi

We discuss from a bi-Hamiltonian point of view the Hamilton-Jacobi separability of a few dynamical systems. They are shown to admit, in their natural phase space, a quasi-bi-Hamiltonian formulation of Pfaffian type. This property allows us to straightforwardly recover a set of separation variables for the corresponding Hamilton-Jacobi equation.

C. Morosi, G. Tondo

It is shown that a class of dynamical systems (encompassing the one recently considered by F. Calogero [J. Math. Phys. 37 (1996) 1735]) is both quasi-bi-Hamiltonian and bi-Hamiltonian. The first formulation entails the separability of these systems; the second one is obtained trough a non canonical map whose form is directly suggested by the associated Nijen

Akira Inomata, Georg Junker

A history of Feynman&#39;s sum over histories is presented in brief. A focus is placed on the progress of path-integration techniques for exactly path-integrable problems in quantum mechanics.

M. Olshanii, N. Dekker, C. Herzog, M. Prentiss

We propose a simple method for the deterministic generation of an arbitrary continuous quantum state of the center-of-mass of an atom. The method&#39;s spatial resolution gradually increases with the interaction time with no apparent fundamental limitations. Such de-Broglie Wave-Front Engineering of the atomic density can find applications in Atom Lithograph

C. A. Mosbacher, F. Osterfeld

The pi+ d scattering and the d(p,n) charge exchange reaction are used to study the Delta-Nucleon interaction in the Delta resonance energy region. Various observables, such as inclusive and exclusive cross sections, angular distributions, and analyzing powers, are calculated in a coupled channel approach and shown to be influenced by the Delta-Nucleon potent

D. Drechsel

Form factors, polarizabilities and excitation spectra are different aspects of many-body structures. These aspects are constrained by sum rules based on general principles like relativity, gauge invariance, causality and unitarity. Several such structure effects of baryons and mesons will be reviewed, with particular emphasis on the neutron charge form facto

C. A. Mosbacher, F. Osterfeld

The deuteron spectrum in n+p -> d+pi+pi at k_n = 1.88 GeV/c and theta_d = 0 deg is explained by considering a Delta-Delta excitation as the reaction mechanism for the 2pi production. We study the influence of intermediate Delta-Delta and Delta-Nucleon interactions on the spectrum. The angular distribution of the pions is predicted.

M. Oka, Y. Tani, T. Inoue, K. Sasaki

The short range parts of the strong and weak hyperon-nucleon interactions are studied with quark substructure of the baryons taken into account. A summary of the quark cluster model calculations of the baryon-baryon interactions is presented. It is pointed out that the spin-flavor symmetry structure determines the qualitative behaviors of the short-range YN

F. Kleefeld

High energy strong interaction physics is successfully described by the local renormalizable gauge theory called Quantum-Chromo-Dynamics (QCD) with quarks and gluons as ``elementary&#39;&#39; degrees of freedom, while intermediate energy strong interaction physics shows up to be determined by a non-local, non--renormalizable effective field theory (EFT) of `

A. K. Pogrebkov

The discrete Schrödinger equation with potential belonging to $\F_{2}$ is solved explicitly. On this base the associated (1+1)-dimensional cellular automaton is examined and corresponding set of integrals of motions is constructed.

Johannes Huebschmann

Twilled L(ie)-R(inehart) algebas generalize, in the Lie-Rinehart context, complex structures on smooth manifolds. An almost complex manifold determines an almost twilled pre-LR algebra, which is a true twilled LR-algebra iff the almost complex structure is integrable. We characterize twilled LR-structures in terms of certain associated differential (bi)grade

Alain Connes

We give a spectral interpretation of the critical zeros of the Riemann zeta function as an absorption spectrum, while eventual noncritical zeros appear as resonances. We give a geometric interpretation of the explicit formulas of number theory as a trace formula on the noncommutative space of Adele classes. This reduces the Riemann hypothesis to the validity

Miklos Bona

We examine the poset $P$ of 132-avoiding $n$-permutations ordered by descents. We show that this poset is the &#34;coarsening&#34; of the well-studied poset $Q$ of noncrossing partitions . In other words, if $x<y$ in $Q$, then $f(y)<f(x)$ in $P$, where $f$ is the canonical bijection from the set of noncrossing partitions onto that of 132-avoiding permutation

Peter Donnelly, Steven N. Evans, Klaus Fleischmann, Thomas G. Kurtz

Analogues of stepping--stone models are considered where the site--space is continuous, the migration process is a general Markov process, and the type--space is infinite. Such processes were defined in previous work of the second author by specifying a Feller transition semigroup in terms of expectations of suitable functionals for systems of coalescing Mar

Philippe Eyssidieux

Let $X$ be a smooth compact projective variety over $\mathbb C$. Let $H^2(π_1(X),\mathbb R)^{1,1}$ be the intersection of $H^{1,1}(X,{\mathbb R})$ with the image of the map $H^2(π_1(X),{\mathbb R})\to H^2(X)$ induced by the classifying map $X\to Bπ_1(X)$. Let $NS(X)$ be the Néron-Severi group of $X$. Let $[ω]\in H^2(π_1(X),\mathbb R)^{1,1}+ NS(X)\otimes {\ma

R. Chakrabarti, C. Quesne

The $R_h^{j_1;j_2}$ matrices of the Jordanian U$_h$(sl(2)) algebra at arbitrary dimensions may be obtained from the corresponding $R_q^{j_1;j_2}$ matrices of the standard $q$-deformed U$_q$(sl(2)) algebra through a contraction technique. By extending this method, the coloured two-parametric ($h, α$) Jordanian $R_{h,α}^{j_1,z_1;j_2,z_2}$ matrices of the U$_{h

M. V. Cougo-Pinto, C. Farina, M. R. Negrao

We compute the combined effect of confinement, an external magnetic field and temperature on the vacuum of the charged scalar field using Schwinger&#39;s formula for the effective action in the imaginary time formalism. The final result reproduces an effective Lagrangian similar to the Heisenberg-Euler one in the limit of no confinement, in the case of confi

Kwan-Leung Chan

Massless BPS-saturated states in toroidally compactified heterotic string were discussed first. Then, I constructed a large class of BPS-saturated states of toroidally compactified type II string theories. They were parametrized by four independent parameters. Both orthogonal and non-orthogonal intersections of non-perturbative states in the corresponding te

Jeremy S. Heyl, Lars Hernquist

We examine wave propagation and the formation of shocks in strongly magnetized plasmas by applying a variational technique and the method of characteristics to the coupled magnetohydrodynamic (MHD) and quantum-electrodynamic (QED) equations of motion. In sufficiently strong magnetic fields such as those found near neutron stars, not only is the plasma extrem

David Kastor, Jennie Traschen

We study two systems of BPS solitons in which spin-spin interactions are important in establishing the force balances which allow static, multi-soliton solutions to exist. Solitons in the Israel-Wilson-Perjes (IWP) spacetimes each carry arbitrary, classical angular momenta. Solitons in the Aichelburg-Embacher &#34;superpartner&#34; spacetimes carry quantum m

N. Sasakura, S. Sugimoto

We discuss BPS states preserving 1/4 supersymmetries of N=4 supersymmetric Yang-Mills theory as M2-branes holomorphically embedded and ending on M5-branes. We use techniques in electrodynamics to find the M2-brane configurations, and give some explicit examples. In case the M2-brane worldsheet has handles, the worldsheet moduli of the M2-brane is constrained

Sheng Li, Yishi Duan

By making use of the decomposition theory of gauge potential, the inner structure of SU(2) and SO(4) gauge theory is discussed in detail. We find the SO(4) monopole can be given via projecting the SO(4) gauge field onto an antisymmetric tensor. This projection fix the coset $% SU(2)/U(1)\bigotimes SU(2)/U(1)$ of SO(4) gauge group. The generalized Hopf map is

Gia Dvali, Lawrence M. Krauss

Supersymmetric flat directions allow a generic counterexample to the phenomenon of symmetry restoration at high temperatures. We show that (exponentially) large VEVs can be developed along these directions through temperature-induced `dimensional transmutation&#39;. A minimum with broken gauge charges (e.g. electric charge) can exist at arbitrarily high temp

A. Yu. Smirnov

We consider main ingredients which determine neutrino transformations in media. Strong transformations relevant for the astrophysics can be due to large depth oscillations, resonance conversion, parametric resonance effect, interplay of oscillations and inelastic collisions. Properties of transitions are discussed using the graphic representation. The applic

V. I. Zakharov

We review status of the power corrections in QCD. The topics include shape variables, unconventional 1/Q^2 corrections, tachyonic gluon mass as a fit parameter to the 1/Q^2 corrections. The selection of the material is determined mostly by results presented at the Conference QCD&#39;98 (Montpellier, July 1998). Some background comments are also included.

Jan Fischer, Ivo Vrkoc

The role of the operator-product expansion in QCD calculations is discussed. Approximating the two-point correlation function by several terms and assuming an upper bound on the truncation error along the euclidean ray, we consider two model situations to examine how the bound develops with increasing deflection from the euclidean ray towards the cut. We obt

Han-Wen Huang

In terms of multiple scattering picture, we calculate the double scattering effect in the transverse momentum distribution of $J/ψ$ photoproduction. Applying the generalized factorization theorem, we find that the contributions from double scattering can be expressed in terms of twist-4 nuclear parton correlation functions, which is the same as that used to

Jackie Grant, Mark Hindmarsh

We investigate the effect on the sphaleron in the two Higgs doublet electroweak theory of including CP violation in the Higgs potential. To have better control over the relation between the sphaleron energy and the physical quantities in the theory, we show how to parametrize the Higgs potential in terms of physical masses and mixing angles, one of which cau

Vladimir G. Baryshevsky

T-odd P-odd phenomenon of the photon polarization plane rotation (circular dichroism) is considered for an atomic (molecules) gas placed to an electric field. The expression for the T non-invariant polarizability of an atom (molecule) placed to an electric field is obtained. It is shown that the T-odd plane rotation angle increases when the interaction energ

A. V. Gulov, V. V. Skalozub

In the Yukawa model with two different mass scales the renormalization group equation is used to obtain relations between scattering amplitudes at low energies. Considering fermion-fermion scattering as an example, a basic one-loop renormalization group relation is derived which gives possibility to reduce the problem to the scattering of light particles on

Christof Gattringer

We show that the fermion determinant for 2-D Wilson lattice fermions coupled to an external scalar field is equivalent to self avoiding loops interacting with the external field. In an application of the resulting formula we integrate the scalar field with a Gaussian action to generate the N-component Gross-Neveu model. The loop representation for this model

Ping Chen, Norman H. Christ, George R. Fleming, Adrian L. Kaehler

We examine the chiral limit of domain wall fermions in quenched QCD. One expects that in a quenched simulation, exact fermion zero modes will give a divergent, 1/m behavior in the chiral condensate for sufficiently small valence quark masses. Unlike other fermion formulations, domain wall fermions clearly demonstrate this behavior.

Saverio Braccini

The K0sK0s final state in two-photon collisions is studied with the L3 detector at LEP using data at centre of mass energies from 91 GeV to 183 GeV. The K0sK0s mass spectrum is dominated by the formation of the f_2&#39;(1525) tensor meson whose two-photon partial width is measured. Clear evidence for destructive f_2-a_2 interference is observed. No signal is

Fermilab E791 Collaboration, E. M. Aitala

We report the results of a precise measurement of the Ds meson lifetime based on 1662 +/- 56 fully reconstructed Ds -> phi pi decays, from the charm hadroproduction experiment E791 at Fermilab. Using an unbinned maximum likelihood fit, we measure the Ds lifetime to be 0.518 +/- 0.014 +/- 0.007 ps. The ratio of the measured Ds lifetime to the world average D0

ALEPH collaboration

The data set collected with the ALEPH detector from 1991 to 1995 at LEP has been analysed to measure the charm forward-backward asymmetry at the Z. Out of a total of 4.1 million hadronic Z decays, about 36000 high momentum D*+, D+ and D0 decays were reconstructed, of which 80% originate from Z -> ccbar events...

Leor Barack

We apply a new analytic scheme, developed in a preceding paper, in order to calculate the late time behavior of scalar test fields evolving outside a Schwarzschild black hole. The pattern of the late time decay at future null infinity is found to be the same as in the shell toy-model studied in the preceding paper. A simple late time expansion of the scalar

Leor Barack

We present a new analytic approach for the study of late time evolution of linear test-fields, propagating on the exterior of black holes. This method provides a calculation scheme applicable to Kerr black holes (for which case no analytic calculation of the late time tails has been presented so far). In this paper we develop the new technique and apply it t

P. J. Forrester, T. Nagao, G. Honner

For the orthogonal-unitary and symplectic-unitary transitions in random matrix theory, the general parameter dependent distribution between two sets of eigenvalues with two different parameter values can be expressed as a quaternion determinant. For the parameter dependent Gaussian and Laguerre ensembles the matrix elements of the determinant are expressed i

Ashfaq S. Thanawalla, B. J. Feenstra, Wensheng Hu, D. E. Steinhauer

We have developed a scanning near-field microwave microscope that operates at cryogenic temperatures. Our system uses an open-ended coaxial probe with a 200 mm inner conductor diameter and operates from 77 to 300 K in the 0.01-20 GHz frequency range. In this paper, we present microwave images of the electric field distribution above a Tl2Ba2CaCu2O8 microstri