December 1996 arXiv papers — page 6

V. Spevak, N. Auerbach, V. V. Flambaum

Collective P- and T- odd moments produced by parity and time invariance violating forces in reflection asymmetric nuclei are considered. The enhanced collective Schiff, electric dipole and octupole moments appear due to the mixing of rotational levels of opposite parity. These moments can exceed single-particle moments by more than two orders of magnitude. T

Wolfgang M. Ruppert

This is a revised version of ANT-0045. If K is a number field of degree n with discriminant D, if K=Q(a) then H(a)>c(n)|D|^(1/(2n-2)) where H(a) is the height of the minimal polynomial of a. We ask if one can always find a generator a of K such that d(n)|D|^(1/(2n-2))>H(a) holds. The answer is yes for real quadratic fields.

Marco Abate

The classical Julia-Wolff-Caratheodory theorem gives a condition ensuring the existence of the non-tangential limit of both a bounded holomorphic function and its derivative at a given boundary point of the unit disk in the complex plane. This theorem has been generalized by Rudin to holomorphic maps between unit balls in C^n, and by the author to holomorphi

Brian R. Greene, Yakov Kanter

We discuss some of the classical and quantum geometry associated to the degeneration of cycles within a Calabi-Yau compactification. In particular, we focus on the definition and properties of quantum volume, especially as it applies to identifying the physics associated to loci in moduli space where nonperturbative effects become manifest. We discuss some u

S. A. Gogilidze, Yu. S. Surovtsev

Dynamical systems, described by Lagrangians with first- and second-class constraints, are investigated. In the Dirac approach to the generalized Hamiltonian formalism, the classification and separation of the first- and second-class constraints are presented with the help of passing to an equivalent canonical set of constraints. The general structure of seco

R. W. Gebert

This contribution reviews recent progress in constructing affine Lie algebras at arbitrary level in terms of vertex operators. The string model describes a completely compactified subcritical chiral bosonic string whose momentum lattice is taken to be the (Lorentzian) affine weight lattice. The main feature of the new realization is the replacement of the or

Andreas Recknagel

We construct global observable algebras and global DHR morphisms for the Virasoro minimal models with central charge c(2,q), q odd. To this end, we pass {}from the irreducible highest weight modules to path representations, which involve fusion graphs of the c(2,q) models. The paths have an interpretation in terms of quasi-particles which capture some struct

Edwin Langmann, Jouko Mickelsson

As an application of the renormalization method introduced by the second author we give a causal definition of the phase of the quantum scattering matrix for fermions in external Yang-Mills potentials. The phase is defined using parallel transport along the path of renormalized time evolution operators. The time evolution operators are elements of the restri

C. Devchand, J. Nuyts

We extend the notion of self-duality to spaces built from a set of representations of the Lorentz group with bosonic or fermionic behaviour, not having the traditional spin-one upper-bound of super Minkowski space. The generalized derivative vector fields on such superspaces are assumed to form a superalgebra. Introducing corresponding gauge potentials and h

Ingemar Bengtsson

Born-Infeld theory is formulated using an infinite set of gauge fields, along the lines of McClain, Wu and Yu. In this formulation electromagnetic duality is generated by a fully local functional. The resulting consistency problems are analyzed and the formulation is shown to be consistent.

A. Denner, S. Dittmaier, T. Hahn

The cross-section for ZZ->ZZ with arbitrarily polarized Z bosons is calculated within the electroweak Standard Model including the complete O(alpha) corrections. We show the numerical importance of the radiative corrections and elaborate its characteristic features. The treatment of the Higgs-boson resonance is discussed in different schemes including the S-

Michael Dine

These lectures provide an introduction to supersymmetry phenomenology. They include an overview of the Minimal Supersymmetric Standard Model. The notion of soft breaking is explained, constraints on the standard soft breaking parameters are reviewed, and the standard ansatz of universal soft masses is discussed. The rest of the lectures are devoted to unders

David Atwood, Laura Reina, Amarjit Soni

We present a general phenomenological analysis of a class of Two Higgs Doublet Models with Flavor Changing Neutral Currents arising at the tree level. The existing constraints mainly affect the couplings of the first two generations of quarks, leaving the possibility for non negligible Flavor Changing couplings of the top quark open. The next generation of l

Laura Reina, Giulia Ricciardi, Amarjit Soni

The rare decay B -> X_s gamma gamma is studied in the Standard Model (SM) and in two different versions (Model I and Model II) of the Two Higgs Doublet Model (2HDM). In the SM the branching ratio into ``hard photons'' is about 10^(-7) and can be appreciably different in the 2HDM. We also introduce a forward-backward asymmetry which gives an additiona

Michael A. Doncheski, Stephen Godfrey

We study single leptoquark production in $e^+e^-$, $eγ$, and $μ^+μ^-$ collisions due to the quark content of the photon. Leptoquarks can be produced in substantial numbers for masses very close to the centre of mass energy of the collider which results in equivalently high discovery limits. Using polarization asymmetries in an $eγ$ collider the ten different

Stephen Godfrey

We study and compare the discovery potential for heavy neutral gauge bosons (Z') at the various $e^+e^-$ and $μ^+μ^-$ colliders that have been proposed. Typical search limits for the e^+e^- colliders are 2-10 times sqrt{s} with the large variation reflecting the model dependence of the limits. The search limits for the mu^+ mu^- colliders are slightly lo

P. Ciafaloni, D. Espriu

We consider the two Higgs doublet model extension of the Standard Model in the limit where all physical scalar particles are very heavy; too heavy, in fact, to be experimentally produced in forthcoming experiments. The symmetry breaking sector can thus be described by an effective chiral Lagrangian. We obtain the values of the coefficients of the O(p^4) oper

M. Genovese, J. -M. Richard, S. Pepin, Fl. Stancu

We discuss the stability of multiquark systems within the recent model of Glozman et al. where the chromomagnetic hyperfine interaction is replaced by pseudoscalar-meson exchange contributions. In this model the (u,d) diquark S=0 I=0 is strongly bound (more than for the chromomagnetic interaction) and this leads to a bound heavy tetraquark QQ\bar q\bar q whe

S. Hegyi

A few remarks on hep-ph/9612213 are given.

G. Jikia

Full O(alpha) electroweak corrections for gamma-gamma-> W+W- are calculated including virtual corrections, soft and hard real photon and Z-boson emission. The corrections are quite large ranging from -2.5% at 500 GeV to -18% at 2 TeV, |cosθ^\pm| < cos(10^\circ). Contributions from real photon and Z-boson emission are important at high energies where they par

K. Zuber

The significance of light massive neutrinos as hot dark matter is outlined. The power of neutrino oscillation experiments with respect to detect such neutrinos in the eV-region is discussed. Present hints for neutrino oscillations in solar, atmospheric and LSND data are reviewed as well as future experiments and their potential.

Diego F. Torres

A study of an algorithm method capable to reveal anisotropic solutions of general scalar-tensor gravitation -including non-minimally couplings- is presented. It is found that it is possible to classify the behavior of the field of different scalar-tensor theories in equivalence classes, with the same classifier function that was obtained in Friedmann-Roberts

Luca Salasnich

We study the dynamics of a scalar inflaton field with a symmetric double--well potential and prove rigorously the existence of a limit cycle in its phase space. By using analytical and numerical arguments we show that the limit cycle is stable and give an analytical formula for its period.

Yasufumi Kojima

We investigate the quantum mechanical oscillations of neutrinos propagating in weak gravitational field. The correction to the result in the flat space-time is derived.

Ola Bratteli, Palle E. T. Jorgensen

In this paper we show how wavelets originating from multiresolution analysis of scale N give rise to certain representations of the Cuntz algebras O_N, and conversely how the wavelets can be recovered from these representations. The representations are given on the Hilbert space L^2(T) by (S_iξ)(z)=m_i(z)ξ(z^N). We characterize the Wold decomposition of such

Ola Bratteli, Palle E. T. Jorgensen

We study a class of representations of the Cuntz algebras O_N, N=2,3,..., acting on L^2(T) where T=R/2πZ. The representations arise in wavelet theory, but are of independent interest. We find and describe the decomposition into irreducibles, and show how the O_N-irreducibles decompose when restricted to the subalgebra UHF_N\subset O_N of gauge-invariant elem

E. Miranda, V. Dobrosavljevic, G. Kotliar

We present a general model of disorder in Kondo alloys that, under certain conditions, leads to non-Fermi liquid behavior. The central underlying idea is the presence of a distribution of local Kondo temperature scales. If this distribution is broad enough, such that there are sites with arbitrarily low Kondo temperatures, a non-Fermi liquid phase is formed.

J. Schiøtz, A. E. Carlsson

In this Brief Report, we present an algorithm for calculating the elastic Lattice Greens Function of a regular lattice, in which defects are created by removing lattice points. The method is computationally efficient, since the required matrix operations are on matrices that scale with the size of the defect subspace, and not with the size of the full lattic

Alessandro Vespignani, Stefano Zapperi

We present a unified dynamical mean-field theory for stochastic self-organized critical models. We use a single site approximation and we include the details of different models by using effective parameters and constraints. We identify the order parameter and the relevant scaling fields in order to describe the critical behavior in terms of usual concepts o

D. V. Khveshchenko

Experiments show that at even denominator fractions (EDFs) ($ν=1/2, 3/4, 3/2$,...) the two-dimensional electron gas in a strong magnetic field becomes compressible, has no energy gap, and demonstrates the presence of an ostensible Fermi surface. Since this phenomenon results from a minimization of the interaction, rather than the kinetic energy, the EDF stat

Pedro Patricio da Silva, Werner Krauth

In this paper, we present an algorithm for the solution of the von Karman equations of elasticity theory and related problems. Our method of successive reconditioning is able to avoid convergence problems at any ratio of the nonlinear streching and the pure bending energies. We illustrate the power of the method by numerical calculations of pinched or compre

Francesco Benvenuto, Giulio Casati, Dima L. Shepelyansky

We show that dynamical localization for excited hydrogen atoms in magnetic and microwave fields takes place at quite low microwave frequency much lower than the Kepler frequency. The estimates of localization length are given for different parameter regimes, showing that the quantum delocalization border drops significantly as compared to the case of zero ma

Jean-Louis Barrat, James Badro, Philippe Gillet

The transport properties of an ionic model for liquid silica at high temperatures and pressure are investigated using molecular dynamics simulations. With increasing pressure, a clear change from &#34;strong&#34; to &#34;fragile&#34; behaviour (according to Angell&#39;s classification of glass-forming liquids) is observed, albeit only on the small viscosity

Giorgio Mantica

Hamiltonian tridiagonal matrices characterized by multi-fractal spectral measures in the family of Iterated Function Systems can be constructed by a recursive technique here described. We prove that these Hamiltonians are almost-periodic. They are suited to describe quantum lattice systems with nearest neighbours coupling, as well as chains of linear classic

H. -G. Döbereiner, E. Evans, M. Kraus, U. Seifert

Phase-contrast microscopy is used to monitor the shapes of micron-scale fluid-phase phospholipid-bilayer vesicles in aqueous solution. At fixed temperature, each vesicle undergoes thermal shape fluctuations. We are able experimentally to characterize the thermal shape ensemble by digitizing the vesicle outline in real time and storing the time-sequence of im

Elliott Lieb

The proof of the stability of matter is three decades old, but the question of stability when arbitrarily large magnetic fields are taken into account was settled only recently. Even more recent is the solution to the question of the stability of relativistic matter when the electron motion is governed by the Dirac operator (together with Dirac&#39;s prescri

Morena Danieli, Elisabetta Gerbino

In this paper, we describe a set of metrics for the evaluation of different dialogue management strategies in an implemented real-time spoken language system. The set of metrics we propose offers useful insights in evaluating how particular choices in the dialogue management can affect the overall quality of the man-machine dialogue. The evaluation makes use

Eric Agol, Omer Blaes, Cristian Ionescu-Zanetti

Equipartition magnetic fields can dramatically affect the polarization of radiation emerging from accretion disk atmospheres in active galactic nuclei. We extend our previous work on this subject by exploring the interaction between Faraday rotation and absorption opacity in local, plane-parallel atmospheres with parameters appropriate for accretion discs. F

David Schade

Surface brightness evolution has been detected in elliptical galaxies (consistent with passive evolution models of old stellar populations) and in disk galaxies (presumably due to enhanced star-formation rates). The rates of evolution in clusters and the field are not measurably different. In addition to this similarity, the high-redshift populations in both

Robert S. Hill, Michael N. Fanelli, Denise A. Smith, Theodore P. Stecher

The bright Magellanic irregular galaxy NGC 4449 was observed by the Ultraviolet Imaging Telescope (UIT) during the Astro-2 Spacelab mission in March, 1995. Far ultraviolet (FUV) images at a spatial resolution of ~3 arcsec show bright star-forming knots that are consistent with the general optical morphology of the galaxy and are often coincident with bright

J. A. S. Lima, V. Zanchin, R. Brandenberger

The basic equations describing a Newtonian universe with uniform pressure are reexamined. We argue that in the semi-classical formulation adopted in the literature the continuity equation has a misleading pressure gradient term. When this term is removed, the resulting equations give the same homogeneous background solutions with pressure and the same evolut

William H. Waller, Ralph C. Bohlin, Robert H. Cornett, Michael N. Fanelli

We present new evidence for tidal interactions having occurred in the disk of M101 in the last 10^8 - 10^9 years. Recent imaging of the far-ultraviolet emission from M101 by the Shuttle-borne Ultraviolet Imaging Telescope (UIT) reveals with unprecedented clarity a disk-wide pattern of multiple linear arm segments (``crooked arms&#39;&#39;). The deep FUV imag

Zeljko Ivezic, Moshe Elitzur

Dust infrared emission possesses scaling properties. Overall luminosity is never an input parameter of the radiative transfer problem, spectral shape is the only relevant property of the heating radiation when the inner boundary of the dusty region is controlled by dust sublimation. Similarly, the absolute scales of densities and distances are irrelevant; th

Pushpa Khare, R. Srianand, D. G. York, R. Green

We present observations of the Lyman alpha forest towards B2 1225+317 taken at a resolution of 18 km/s. A clean sample of Lyman alpha forest lines is extracted after a careful profile fitting analysis and removal of absorption lines of heavy elements. The sample is analyzed for statistical properties. Eighty percent of the column densities are < 10^{14} cm^{

A. Cavaliere, N. Menci

We probe to what extent not only the counts of the faint blue galaxies and their redshift distribution but also their z-resolved luminosity functions can be explained in terms of binary merging (aggregations). We present a dynamical theory of such interactions. On this basis we find that ``minimal aggregations&#39;&#39; taking place within large scale struct

Laerte Sodre, Hector Cuevas

We have investigated some statistical properties of integrated spectra of galaxies from Kennicutt (1992a) spectrophotometric atlas. The input for the analysis are galaxy spectra sampled in 1300 bins between 3750 Å~ and 6500 Å. We make use of Principal Component Analysis (PCA) to analyse the 1300-dimensional space spanned by the spectra. Their projection onto

R. P. Fender, S. J. Bell Burnell, E. B. Waltman

We review the observational properties, from radio to X-rays, of the eight systems for which there is strong evidence for the formation of a radio jet in a X-ray binary system.

Dan Maoz, Hans-Walter Rix, Avishay Gal-Yam, Andrew Gould

The statistics of gravitationally lensed quasars with multiple images in the 0.1&#39;&#39;-7&#39;&#39; range have been measured in various surveys. Little is known, however, about lensed-quasar statistics at larger image separations, which probe masses on the scale of galaxy clusters. We extend the results of the HST Snapshot Survey for Lensed Quasars to the

Luca Pasquini, Paolo Molaro

We present high resolution observations (FWHM=15 km/sec) of the Li region in 5 stars belonging to the old (14 Gyrs), metal rich ([Fe/H]=-0.7) globular cluster 47Tuc. At the ESO NTT telescope we obtained EMMI spectra for three V about 17.4 magnitude stars located at the turnoff with Teff on the Spite plateau. In two of the turnoff stars the lithium line is cl

Piero Madau

I review some recent progress made in our understanding of galaxy evolution and the cosmic history of star formation. Like bookends, the results obtained from deep ground-based spectroscopy and from the Hubble Deep Field imaging survey put brackets around the intermediate redshift interval, $1<z<2$, where starbirth probably peaked at a rate 10 times higher t

Sutapa Mukherji, Thomas Nattermann

We show that in anisotropic or layered superconductors impurities induce a van der Waals attraction between flux lines. This attraction together with the disorder induced repulsion may change the low B - low T phase diagram significantly from that of the pure thermal case considered recently by Blatter and Geshkenbein [Phys. Rev. Lett. 77, 4958 (1996)].

Barbara Coluzzi, Enzo Marinari, Juan J. Ruiz-Lorenzo

We study the behavior of the Binder cumulant related to long distance correlation functions of the discrete Gaussian model of disordered substrate crystalline surfaces. We exhibit numerical evidence that the non-Gaussian behavior in the low-$T$ region persists on large length scales, in agreement with the broken phase being super-rough.

Hiroshi Suzuki, Hirofumi Yasuta

We apply Borel resummation method to the conventional perturbation series of ground state energy in a metastable potential, $V(x)=x^2/2-gx^4/4$. We observe numerically that the discontinuity of Borel transform reproduces the imaginary part of energy eigenvalue, i.e., total decay width due to the quantum tunneling. The agreement with the exact numerical value

Hideo Hasegawa

A slave-boson functional-integral method has been developed for the Hubbard model with arbitrary, orbital degeneracy $D$. Its saddle-point mean-field theory is equivalent to the Gutzwiller approximation, as in the case of single-band Hubbard model. Our theory is applied to the doubly degenerate ($D = 2$) model, and numerical calculations have been performed

Joa Weber

We use closed geodesics to construct and compute Bott-type Morse homology groups for the energy functional on the loop space of flat $n$-dimensional tori, $n\ge 1$, and Bott-type Floer cohomology groups for their cotangent bundles equipped with the natural symplectic structure. Both objects are isomorpic to the singular homology of the loop space. In an appe

Lorenza Viola, Roberto Onofrio

Free fall in a uniform gravitational field is revisited in the case of quantum states with and without classical analogue. The interplay between kinematics and dynamics in the evolution of a falling quantum test particle is discussed allowing for a better understanding of the equivalence principle at the operational level.

G. W. Carter, P. J. Ellis, S. Rudaz

We investigate the finite temperature behavior of the meson sector of an effective Lagrangian which describes nuclear matter. A method is developed for evaluating the logarithmic terms in the effective potential which involves expansion and resummation; the result is written in terms of the exponential integral. In the absence of explicit chiral symmetry bre

D. Vretenar, G. A. Lalazissis, R. Behnsch, W. Pöschl

Isoscalar and isovector monopole oscillations that correspond to giant resonances in spherical nuclei are described in the framework of time-dependent relativistic mean-field (RMF) theory. Excitation energies and the structure of eigenmodes are determined from a Fourier analysis of dynamical monopole moments and densities. The generator coordinate method, wi

J. A. Niskanen, M. Vestama

We calculate the isospin symmetry violating effects to the reactions $pp\rightarrow dπ^+$ and $np\rightarrow dπ^0$ arising from the different hadron masses and from the Coulomb interaction between the positive pion and the deuteron. These effects are large enough in the cross section and analyzing power $A_y$ that they should be taken into account in compari

A. Sibirtsev, W. Cassing, C. M. Ko

The antikaon production cross section from nucleon-nucleon reactions near threshold is studied in a meson exchange model. We include both pion and kaon exchange, but neglect the interference between the amplitudes. In case of pion exchange the antikaon production cross section can be expressed in terms of the antikaon production cross section from a pion-nuc

Dipali Pal, Pradip Kumar Roy, Sourav Sarkar, Dinesh Kumar Srivastava

The production of low mass dileptons and soft photons from thermalized Quark Gluon Plasma (QGP) and hadronic matter in relativistic heavy ion collisions is evaluated. A boost invariant longitudinal and cylindrically symmetric transverse expansion of the systems created in central collision of lead nuclei at CERN SPS, BNL RHIC, and CERN LHC, and undergoing a

Sathya Guruswamy, Andreas W. W. Ludwig

A `canonical mapping&#39; is established between the c=-1 system of bosonic ghosts and the c=2 complex scalar theory and, a similar mapping between the c=-2 system of fermionic ghosts and the c=1 Dirac theory. The existence of this mapping is suggested by the identity of the characters of the respective theories. The respective c<0 and c>0 theories share the

Sergei V. Ketov

The (2,2) world-sheet supersymmetric string theory is discussed from the viewpoint of string/membrane unification. The effective field theory in the closed string target space is known to be the 2+2 dimensional (integrable) theory of self-dual gravity (SDG). A world-volume supersymmetrization of the Pleba&#39;nski action for SDG naturally implies the maximal

Sergei V. Ketov

The exact effective field equations of motion, corresponding to the perturbative mixed theory of open and closed (2,2) world-sheet supersymmetric strings, are investigated. It is shown that they are only integrable in the case of an abelian gauge group. The gravitational equations are then stationary with respect to the Born-Infeld-type effective action.

Y. I. Shil&#39;nov, V. V. Chitov, A. T. Kotwicki

The dymamical chiral symmetry breaking in higher- derivative quantum gravity has been investigated on the flat background. The Schwinger- Dyson equations numerical solutions have been found in the ladder approximation. Both two- and four- dimensional cases have been considered. The dymamical fermion mass generation accompanied by the second- order phase tran

Gennaro Miele, Patrizia Vitale

The large N limit of the 3-d Gross-Neveu model is here studied on manifolds with positive and negative constant curvature. Using the $ζ$-function regularization we analyze the critical properties of this model on the spaces $S^2 \times S^1$ and $H^2\times S^1$. We evaluate the free energy density, the spontaneous magnetization and the correlation length at t

Anders Westerberg

We discuss a previously discovered [hep-th/9401027] extension of the infinite-dimensional Lie algebras Map(M,g) which generalizes the Kac-Moody algebras in 1+1 dimensions and the Mickelsson-Faddeev algebras in 3+1 dimensions to manifolds M of general dimensions. Furthermore, we review the method of regularizing current algebras in higher dimensions using pse

E. Abdalla

The exact operator solutions of two-dimensional anomaly-free chiral abelian gauge theories are obtained. We show that anomaly-cancellation conditions arise as consistency requirements of these solutions. For a certain class of flavour symmetries, fermion condensates are constructed. These are shown to violate the fermion-number conservation rule. The models

J. Ellis, J. Lopez, D. Nanopoulos

A previous study of supersymmetric models has indicated that they are unlikely to make a large contribution to R_b. We revisit this analysis, taking into account the improved lower limits on sparticle masses provided recently by LEP 2 and the Tevatron, finding that a generic supersymmetric model cannot contribute more than about one-and-a-half current experi

Sarira Sahu

In a relativistic plasma neutrino can emit plasmons by the Cerenkov process which is kinematically allowed for a range of frequencies for which refractive index is greater than one. We have calculated the rate of energy emission by this process. We compute the energy deposited in a stalled supernova shock wave by the Cerenkov process and find that it is much

Thomas R. Hemmert, Barry R. Holstein, Joachim Kambor

Previous calculations of the polarizabilities of the nucleon within the framework of heavy baryon chiral perturbation theory have included the contribution of the $Δ$(1232) only its effect on various contact terms or have been performed in chiral SU(3) where systematic errors are difficult to control. Herein we perfrom a corresponding calculation in chiral S

L. B. Okun

A simple way of deriving and analyzing electroweak radiative corrections to the Z boson decays is presented in the framework of the Standard Model. The talk is based on a review article by the authors &#34;Electroweak radiative corrections in Z decays&#34; published in Uspekhi Fizicheskikh Nauk, 166 (1996) 539-574, in the May issue dedicated to 75th birthday

J. H. Kuehn

Recent theoretical results on heavy flavor production and decay in the framework of perturbative QCD are reviewed. This includes calculations for top production at hadron colliders, inclusive charmonium production and the comparison between the singlet and octet mechanisms. Predictions for heavy flavor production in $e^+e^-$ annihilation will be discussed in

Stephan Güsken

We illustrate the current status of heavy quark physics on the lattice. Special emphasis is paid to the question of systematic uncertainties and to the connection of lattice computations to continuum physics. Latest results are presented and discussed with respect to the progress in methods, statistical accuracy and reliability.

G. Holzwarth

Conservation of baryon number as topological charge in effective chiral field theories imposes a local constraint on the time evolution of field configurations in the commonly used O(4) model. Possible consequences for the formation of chiral condensates after a quench from random initial configurations are discussed. It is argued that efficient dissipative

Debrupa Chakraverty, Triptesh De, Binayak Dutta-Roy, K. S. Gupta

We calculate the decay width for $Λ_b \to Λ_c e {\bar ν}$ in the frame work of a nonrelativistic quark (NRQ) model of heavy baryons where the light quarks play the role of spectators. Our calculation does not make an explicit use of the heavy quark symmetry. The branching ratio for the above process as calculated here agrees reasonably well with the experime

C. B. Yang, X. Cai

The polarization dependence of the electromagnetic vertex for polarized proton is discussed. Such a dependence is shown to be a result of gluon polarization and gluon interactions with the constituents within proton. One more form factor is introduced to give such a dependence in the electromagnetic vertex for proton. Due the polarization dependence of the v

I. Dasgupta, A. R. Levi, V. Lubicz, C. Rebbi

We have used Fortran 90 to implement lattice QCD. We have designed a set of machine independent modules that define fields (gauge, fermions, scalars, etc...) and overloaded operators for all possible operations between fields, matrices and numbers. With these modules it is very simple to write high-level efficient programs for QCD simulations. To increase pe

Jan Czyzewski

We have measured the second-order normalized differential factorial moments as a function of the difference of transverse momentum ($Δp_T$) in $\p^+ p$ and $K^+ p$ collisions at 250 GeV/$c$. The second-order differential factorial moments for like-charged pairs reveal a strong increase with decreasing $Δp_T$. In a small central rapidity window this increase

WA59 Collaboration, W. Burkot, T. Coghen, J. Czyzewski

The production of hadrons in charged-current (anti)neutrino interactions is studied with the bubble chamber BEBC exposed ot the CERN (anti)neutrino wide-band beam. Fast-hadron production in a neon target is found to be attennuated as compared to that in a hydrogen target. This feature is discussed within the theoretical models based on the idea of a hadron f

V. D. Dzhunushaliev

The geometrical model of an electrical charge is proposed. This model has the &#39;&#39;nake&#39;&#39; charge shunted with ``fur - coat&#39;&#39; consisting of virtual wormholes. The 5D wormhole solution in the Kaluza - Klein&#39;s theory is the &#39;&#39;nake&#39;&#39; charge. The splitting off the supplementary coordinates happens on the two spheres (null

W. R. Wood, G. Papini

Following de Broglie and Vigier, a fully relativistic causal interpretation of quantum mechanics is given within the context of a geometric theory of gravitation and electromagnetism. While the geometric model shares the essential principles of the causal interpretation initiated by de Broglie and advanced by Vigier, the particle and wave components of the t

Mariano Cadoni

We investigate the classical and semiclassical features of generic 2D, matter-coupled, dilaton gravity theories. In particular, we show that the mass, the temperature and the flux of Hawking radiation associated with 2D black holes are invariant under dilaton-dependent Weyl rescalings of the metric. The relationship between quantum anomalies and Hawking radi

Carmen Chicone, Bahram Mashhoon, David Retzloff

The method of averaging is used to investigate the phenomenon of capture into resonance for a model that describes a Keplerian binary system influenced by radiation damping and external normally incident periodic gravitational radiation. The dynamical evolution of the binary orbit while trapped in resonance is elucidated using the second order partially aver

Gilles Esposito-Farese

This talk is based on my work in collaboration with Thibault Damour since 1991. Unified theories, like superstrings, predict the existence of scalar partners to the graviton. Such theories of gravity can be very close to general relativity in weak-field conditions (solar-system experiments), but can deviate significantly from it in the strong-field regime (n

W. C. Wu, J. P. Carbotte

We investigate the Raman spectra in the geometry where both incident and scattered photon polarizations are parallel to the $\hat{z}$-direction, for a plane-chain bilayer coupled via a single-particle tunneling $t_\perp$. The Raman vertex is derived in the tight-binding limit and in the absence of Coulomb screening, the Raman intensity can be separated into

M. Milovanovic, N. Read

We describe the invariant structure common to abelian fractional quantum Hall systems with spin. It appears in a generalization of the lattice description of the polarized hierarchy that encompasses both partially polarized and unpolarized ground state systems. We formulate, using the spin-charge decomposition, conditions that should be satisfied so that the

T. Pohjola, J. König, M. M. Salomaa, J. Schmid

We study resonant tunneling through quantum-dot systems in the presence of strong Coulomb repulsion and coupling to the metallic leads. Motivated by recent experiments we concentrate on (i) a single dot with two energy levels and (ii) a double dot with one level in each dot. Each level is twofold spin-degenerate. Depending on the level spacing these systems

X. Leyronas, R. Combescot

We have studied the penetration depth for a model of $YBa_{2}Cu_{3}O_{7}$ involving pairing both in the $CuO_{2}$ planes and in the CuO chains. In this model pairing in the planes is due to an attractive interaction, while Coulomb repulsion induces in the chains an order parameter with opposite sign. Due to the anticrossing produced by hybridization between

Choon-Lin Ho, V. R. Kahlilov, Chi Yang

We obtain the equations that define the equilibrium of a homogeneous relativistic gas of neutrons, protons and electrons in a constant magnetic field as applied to the conditions that probably occur near the center of neutron stars. We compute the relative densities of the particles at equilibrium and the Fermi momentum of electrons in the strong magnetic fi

Glen D. Granzow, Hermann Riecke

We present results of numerical simulations of coupled Ginzburg-Landau equations that describe parametrically excited waves. In one dimension we focus on a new regime in which the Eckhaus sideband instability does not lead to an overall change in the wavelength via the occurrence of a single phase slip but instead leads to ``double phase slips&#39;&#39;. The

Holger R. Dullin

A general formula for the linearized Poincaré map of a billiard with a potential is derived. The stability of periodic orbits is given by the trace of a product of matrices describing the piecewise free motion between reflections and the contributions from the reflections alone. For the case without potential this gives well known formulas. Four billiards wi

Rachel S. Somerville, Joel R. Primack

We discuss variants of Cold Dark Matter (CDM) dominated cosmological models that give good agreement with a range of observations. We consider models with hot dark matter, tilt, $Ω< 1$, or a cosmological constant. We also discuss the sensitivity of the results to other parameters, such as the Hubble parameter and the baryon fraction. We obtain constraints by

Lars Bildsten, Edward F. Brown, Christopher D. Matzner, Greg Ushomirsky

We present an analytic calculation of the thermonuclear depletion of lithium in contracting, fully convective, pre-main sequence stars of mass M < 0.5 M_sun. Previous numerical work relies on still-uncertain physics (atmospheric opacities and convection, in particular) to calculate the effective temperature as a unique function of stellar mass. We assume tha

A. R. King, U. Kolb

We consider constraints on the formation of low-mass X-ray binaries containing neutron stars (NLMXBs) arising from the presence of soft X-ray transients among these systems. We show that in short-period systems driven by angular momentum loss these constraints require the secondary at the beginning of mass transfer to have a mass > 1.2 M_sun, and to be signi

Yu Gao, Robert A. Gruendl, K. Y. Lo, C. Y. Hwang

We present first results of our on-going BIMA Key Project: imaging the CO(1-0) emission from a sample of 10 luminous IR galaxies (LIRGs) that are at various merging stages, with special emphasis on systems apparently in the early/intermediate stages of merging. We present here CO images with $\sim 5&#39;&#39;$ resolution. An important result is the recogniti

Robert H. Cornett, Michael R. Greason, Jesse K. Hill, Joel Wm. Parker

A mosaic of four UIT far-UV (FUV; 1620A) images, which covers most of the SMC bar, is presented, with derived stellar and HII region photometry. The UV morphology of the Bar shows that recent star formation there has left striking features including: a) four concentrations of UV-bright stars spread from northeast to southwest at nearly equal (~30 arcmin=0.5

Richard G. Bower, Ian Smail

In this paper we present weak lensing observations of the fields around 8 z~1 luminous radio sources. These data are searched for the lensing signatures of clusters that are either physically associated with the radio objects, or are foreground systems projected along the line of sight. The radio sources were all imaged with WFPC-2/HST providing high quality

N. Schartel, H. Andernach, J. Greiner

We study positional coincidences between gamma-ray bursts in the BATSE 3B catalogue and quasars/AGN taken from the Veron-Cetty & Veron compilation. For most classes of AGN, for BL Lac objects and for radio-loud quasars, we find no excess coincidences above random expectation, and we give upper limits for their burst emission rate. However, surprising evidenc

Dan Maoz, Eran Ofek, Amotz Shemi

Most of the sources detected in the extreme ultraviolet (EUV; 100 Ang to 600 Ang) by the Rosat WFC and EUVE all-sky surveys have been identified with active late-type stars and hot white dwarfs that are near enough to escape absorption by interstellar gas. However, about 15% of EUV sources are as of yet unidentified with any optical counterparts. We examine