July 1997 arXiv papers — page 12

Corin Adlard, E. R Pike, Sarben Sarkar

Single photon states with arbitrarily fast asymptotic power-law fall-off of energy density and photodetection rate are explicitly constructed. This goes beyond the recently discovered tenth power-law of the Hellwarth-Nouchi photon which itself superseded the long-standing seventh power-law of the Amrein photon.

Asher Peres

The state of a quantum system, consisting of two distinct subsystems, is called separable if it can be prepared by two distant experimenters who receive instructions from a common source, via classical communication channels. A necessary condition is derived and is shown to be more sensitive than Bell's inequality for detecting quantum inseparability. Mo

A. Kuniba, K. C. Misra, M. Okado, T. Takagi

We study, in the path realization, crystals for Demazure modules of affine Lie algebras of types $A^{(1)}_n,B^{(1)}_n,C^{(1)}_n,D^{(1)}_n, A^{(2)}_{2n-1},A^{(2)}_{2n}, and D^{(2)}_{n+1}$. We find a special sequence of affine Weyl group elements for the selected perfect crystal, and show if the highest weight is $l\La_0$, the Demazure crystal has a remarkably

J. A. Acebron, L. L. Bonilla, S. De Leo, R. Spigler

The mean-field Kuramoto model for synchronization of phase oscillators with an asymmetric bimodal frequency distribution is analyzed. Breaking the reflection symmetry facilitates oscillator synchronization to rotating wave phases. Numerical simulations support the results based of bifurcation theory and high-frequency calculations. In the latter case, the or

J. L. Friar, J. Martorell, D. W. L. Sprung

Darwin-Foldy nuclear-size corrections in electronic atoms and nuclear radii are discussed from the nuclear-physics perspective. Interpretation of precise isotope-shift measurements is formalism dependent, and care must be exercised in interpreting these results and those obtained from relativistic electron scattering from nuclei. We strongly advocate that th

Gerald A. Miller, Anthony W. Thomas

We examine the question of the gauge invariance of electromagnetic form factors calculated within the cloudy bag model. One of the assumptions of the model is that electromagnetic form factors are most accurately evaluated in the Breit frame. This feature is used to show that gauge invariance is respected in this frame.

Hans Schoutens

The class of all Artinian local rings of length at most l is A_2-elementary, axiomatised by a finite set of axioms Art_l. We show that its existentially closed models are Gorenstein, of length exactly l and their residue fields are algebraically closed, and, conversely, every existentially closed model is of this form. The theory Gor_l of all Artinian local

Hélène Barcelo, Arun Ram

We attempt to survey the field of combinatorial representation theory, describe the main results and main questions and give an update of its current status. We give a personal viewpoint on the field, while remaining aware that there is much important and beautiful work that we have not been able to mention.

A. Gorsky, S. Gukov, A. Mironov

We discuss supersymmetric Yang-Mills theories with the multiple scales in the brane language. The issue concerns N=2 SUSY gauge theories with massive fundamental matter including the UV finite case of $n_{f}=2n_c$, theories involving products of SU(n) gauge groups with bifundamental matter, and the systems with several parameters similar to $Λ_{QCD}$. We arg

John H. Schwarz

The fivebrane of M theory -- the M5-brane -- is an especially interesting object. It plays a central role in a geometric understanding of the Seiberg-Witten solution of N=2 D=4 gauge theories as well as in certain new 6d quantum theories. The low energy effective action is an interacting theory of a (2,0) tensor multiplet. The fact that this multiplet contai

Marcos Alvarez

It is shown that physical states of a non-abelian Yang-Mills-Higgs dyon are invariant under large gauge transformations that do not commute with its magnetic field. This result is established within an enlarged Hamiltonian formalism where surface terms are kept as dynamical variables. These additional variables are parameters of large gauge transformations,

Z. Was

We present an arbitrary model based on the trefoil knot to construct objects of the same spectrum as that of elementary particles. It includes `waves' and three identical sets of sources. Due to Lorentz invariance, `waves' group into 3 types of 1, 3 and 8 objects and `sources' consists of 3 identical sets of 30+2 elements, which separate into: 1

W. Kummer, H. Liebl, D. V. Vassilevich

Performing an nonperturbative path integral for the geometric part of a large class of 2d theories without kinetic term for the dilaton field, the quantum effects from scalar matter fields are treated as a perturbation. When integrated out to two-loops they yield a correction to the Polyakov term which is still exact in the geometric part. Interestingly enou

R. A. Bertlmann, Tomas Sykora

We analyze the generalized point-splitting method and Jo's result for the commutator anomaly. We find that certain classes of general regularization kernels satisfying integral conditions provide a unique result, which, however differs from Faddeev's cohomological result.

Nikita Nekrasov

We point out a map between the dynamics of a non-relativistic system of $N$ particles in one dimension interacting via the pair-wise potentials $U_I(q) = (ν^2/4R^2)\sin^2(q/2R)$ and the one of the particles with the pair potential $U_{II}(q) = ν^2/q^2$ and the external potential $U_{ext} = ω^2 q^2/2$. The natural relation between the frequency $ω$ and the ra

Subir Ghosh

Anyon gas with interparticle (retarded) Coulomb interaction has been studied. The resulting system is shown to be a collection of dressed anyons, with a screening factor introduced in their spin. Close structural similarity with the Chern-Simons construction of anyons has helped considerably in computing the screening effect. Finally the present model is com

Yoshihisa Kitazawa, Rie Kuriki, Katsumi Shigura

We discuss the renormalizability of quantum gravity near two dimensions based on the results obtained by a computation of the BRST-antibracket cohomology in the space of local functionals of the fields and antifields. We justify the assumption on the general structure of the counterterms which have been used in the original proof of renormalizability of the

Eugene Cremmer, Jean-Loup Gervais

The duality properties of perturbative string characters associated with the transverse space-time rotations are studied. T duality is achieved by suitably integrating over the total momentum, contrary to earlier discussions. The O(8) triality properties of the characters for critical superstrings, are derived. This shows the existence of a third formulation

M. Kachkachi, A. Lamine, M. Sarih

We develop a geometrical structure of the manifolds $Γ$ and $\hatΓ$ associated respectively to the gauge symmetry and to the BRST symmetry. Then, we show that ($\hatΓ,\hatζ,Γ$), where $\hatζ$ is the group of BRST transformations, is endowed with the structure of a principle fiber bundle over the base manifold $Γ$. Furthermore, in this geometrical set up due

Thomas Schmitt

Using a supergeometric interpretation of field functionals, we show that for a class of classical field models used for realistic quantum field theoretic models, an infinite-dimensional supermanifold (smf) of classical solutions in Minkowski space can be constructed. That is, we show that the smf of smooth Cauchy data with compact support is isomorphic with

Antonio Riotto

The scale at which supersymmetry is broken and the mechanism by which supersymmetry breaking is fed down to the observable sector has rich implications on the way Nature may have chosen to accomplish inflation. We discuss a simple model for slow rollover inflation which is minimal in the sense that the inflaton may be identified with the field responsible fo

W. Beenakker, A. P. Chapovsky, F. A. Berends

In this paper we present two methods to evaluate non-factorizable corrections to pair-production of unstable particles. The methods are illustrated in detail for W-pair-mediated four-fermion production. The results are valid a few widths above threshold, but not at threshold. One method uses the decomposition of $n$-point scalar functions for virtual and rea

Varun Sheel, Hiranmaya Mishra, Jitendra C. Parikh

Equal time, point to point correlation functions for spatially separated meson currents are calculated with respect to a variational construct for the ground state of QCD. Given such an ansatz we make no further approximations in the evaluation of the correlators. Our calculations for the vector, axial vector and scalar channels show qualitative agreement wi

Malcolm Anderson, Filipe Bonjour, Ruth Gregory, John Stewart

We examine the leading order corrections to the Nambu effective action for the motion of a cosmic string, which appear at fourth order in the ratio of the width to radius of curvature of the string. We determine the numerical coefficients of these extrinsic curvature corrections, and derive the equations of motion of the worldsheet. Using these equations, we

S. Hegyi

The recently introduced H-function extension of the Negative Binomial Distribution is investigated. The analytic form of P(n) is rederived by means of the Mellin transform. Applications of the HNBD are provided using experimental data for P(n) in e+e-, e+p, inelastic pp and non-diffractive p-pbar reactions.

J. H. Kuehn

Direct and indirect information on the top quark mass and its decay modes is reviewed. The theory of top production in hadron- and electron-positron-colliders is presented.

V. Barone, M. Genovese

We calculate the x dependence of nuclear shadowing at moderate values of Q^2 by using HERA diffractive data and, for consistency, F2 parameterization of ZEUS. We show that no decrease of shadowing occurs down to very low x (x = 10^-4).

A. G. Grozin, M. Neubert

The leading beta_0^(n-1) alpha_s^n terms in the Wilson coefficient and anomalous dimension of the chromomagnetic operator in the heavy-quark effective Lagrangian are summed to all orders of perturbation theory. The perturbation series for the anomalous dimension is well behaved, while that for the Wilson coefficient exhibits a divergent behaviour already in

S. F. King, J. Sanderson

Inverted hybrid inflation (in which the inflaton field slowly rolls away from the origin, giving a spectral index $n\lsim 1$) is an appealing variant of the more usually studied hybrid model. Analysing the model alongside the ordinary hybrid case, we show that, in order to provide the correct density perturbations consistent with the COBE measurements, the d

Sourendu Gupta

We find that single spin asymmetries in NRQCD are non-vanishing in general. They are proportional to the imaginary parts of some non-perturbative matrix elements. With statistics of about 10^6 identified J/psi's, or 10^5 identified chi_2, it is possible to measure these imaginary parts even if they are an order of magnitude smaller than the real parts. S

Dardo Piriz, Jose Wudka

We consider a low-energy supersymmetric scenario in which the effects of heavy supersymmetric interactions are included in a model-independent manner through a series of supersymmetric SU(3)_C*SU(2)_L*U(1)_Y invariant operators; we explicitly construct all such operators of dimension less or equal than 6. From this set, those operators generated at tree leve

C. Dawson, G. Martinelli, G. C. Rossi, C. T. Sachrajda

Lattice QCD should allow a derivation of the $ΔI=1/2$ rule from first principles, but numerical calculations to date have been plagued by a variety of problems. After a brief review of these problems, we present several new methods for calculating $K\toππ$ amplitudes. These are designed for Wilson fermions, though they can be used also with staggered fermion

Massimo Testa

Some general considerations on the problem of non perturbative definition of Chiral Gauge Theories are presented and exemplified within the particular proposal known as the Rome Approach.

Paul R. Anderson, Courtney D. Mull

Constraints on the geometry of a static spherically symmetric black hole are obtained by requiring the spacetime curvature to be analytic at the event horizon. For a zero temperature black hole further constraints are obtained by also requiring that the semiclassical trace equation be satisfied when conformally invariant fields are present. It is found that

Ola Bratteli, Palle E. T. Jorgensen, Derek W. Robinson

We demonstrate that the structure of complex second-order strongly elliptic operators $H$ on ${\bf R}^d$ with coefficients invariant under translation by ${\bf Z}^d$ can be analyzed through decomposition in terms of versions $H_z$, $z\in{\bf T}^d$, of $H$ with $z$-periodic boundary conditions acting on $L_2({\bf I}^d)$ where ${\bf I}=[0,1>$. If the semigroup

Palle E. T. Jorgensen, Gestur Ólafsson

We consider the following class of unitary representations $π$ of some (real) Lie group $G$ which has a matched pair of symmetries described as follows: (i) Suppose $G$ has a period-2 automorphism $τ$, and that the Hilbert space $\mathbf{H} (π)$ carries a unitary operator $J$ such that $Jπ=(π\circ τ)J$ (i.e., selfsimilarity). (ii) An added symmetry is implie

Ewout ter Haar, Valdir Bindilatti, Nei F. Oliveira, G. H. McCabe

The magnetization of Pb_{1-x}Eu_{x}Te samples with x = 1.9, 2.6 and 6.0% was measured at 20 mK in fields up to 50 kOe, and at 0.6 K in fields up to 180 kOe. The 20 mK data show the magnetization steps (MSTs) arising from pairs and from triplets. The pair MSTs are used to obtain the dominant Eu-Eu antiferromagnetic exchange constant, J/k_{B} = -0.264 \pm 0.01

G. E. Granroth, M. W. Meisel, M. Chaparala, Th. Jolicoeur

The magnetic susceptibility of the $S = 2$ quasi-linear chain Heisenberg antiferromagnet (2,$2'$-bipyridine)trichloromanganese(III), MnCl_{3}(bipy), has been measured from 1.8 to 300 K with the magnetic field, H, parallel and perpendicular to the chains. The analyzed data yield $g\approx 2$ and $J\approx 35$ K. The magnetization, M, has been studied at 3

F. Lesage, H. Saleur, P. Simonetti

In a previous paper, we showed that the problem of tunneling in quantum wires was integrable in the isotropic case $g_σ=2$. In the present work, we continue the exploration of the general phase diagram by looking for other integrable cases. Specifically, we discuss in details the manifold $g_ρ+g_σ=2$, where the associated ``double sine-Gordon'' model

M. E. Simon, A. A. Aligia, E. R. Gagliano

We study the Cu and O spectral density of states and the optical conductivity of CuO_2 planes using an effective generalized one-band Hubbard model derived from the extended three-band Hubbard model. We solve exactly a square cluster of 10 unit cells and average the results over all possible boundary conditions, what leads to smooth functions of frequency. U

A. I. Lichtenstein, M. I. Katsnelson

We discuss a general approach to a realistic theory of the electronic structure in materials containing correlated d- or f- electrons. The main feature of this approach is the taking into account the energy dependence of the electron self-energy with the momentum dependence being neglected (local approximation). In the case of strong interactions (U/W>>1 - r

R. Kouba, C. Ambrosch-Draxl

We report first-principles frozen-phonon calculations for the determination of the force-free geometry and the dynamical matrix of the five Raman-active A1g modes in YBa2Cu3O7. To establish the shape of the phonon potentials atomic forces are calculated within the LAPW method. Two different schemes - the local density approximation (LDA) and a generalized gr

A. W. Sandvik

The ground state parameters of the two-dimensional S=1/2 antiferromagnetic Heisenberg model are calculated using the Stochastic Series Expansion quantum Monte Carlo method for L*L lattices with L up to 16. The finite-size results for the energy E, the sublattice magnetization M, the long-wavelength susceptibility chi_perp(q=2*pi/L), and the spin stiffness rh

Martin Fliesser, András Csordás, Robert Graham, Péter Szépfalusy

The dynamics of quasi-particles in repulsive Bose condensates in a harmonic trap is studied in the classical limit. In isotropic traps the classical motion is integrable and separable in spherical coordinates. In anisotropic traps the classical dynamics is found, in general, to be nonintegrable. For quasi-particle energies E much smaller than thechemical pot

Jean Desbois, Sergei Nechaev

We study numerically and analytically the average length of reduced (primitive) words in so-called locally free and braid groups. We consider the situations when the letters in the initial words are drawn either without or with correlations. In the latter case we show that the average length of the reduced word can be increased or lowered depending on the ty

Alain Comtet, Sergei Nechaev

We investigate analytically the problem of enumeration of nonequivalent primitive words in the braid group B_n for n >> 1 by analysing the random word statistics and the target space on the basis of the locally free group approximation. We develop a "symbolic dynamics" method for exact word enumeration in locally free groups and bring arguments in su

V. V. Cheianov, A. P. Dmitriev, V. Yu. Kachorovskii

We show that in a very strong magnetic field $B$ electron-phonon interaction gives rise to a splitting of Landau levels of a 2D electron into a series of infinitely degenerate sublevels. We provide both qualitative and quantitative description of this phenomenon. The cases of interaction with acoustic and polar optical phonons are considered. The energy dist

J. Hohlfeld, U. Conrad, E. Matthias

Femtosecond pump-probe second-harmonic generation (SHG) and transient linear reflectivity measurements were carried out on polycrystalline Cu, Ag and Au in air to analyze whether the electron temperature affects Fresnel factors or nonlinear susceptibilities, or both. Sensitivity to electron temperatures was attained by using photon energies near the interban

J. P. Bouchaud

Using results of Goldstone and Jaffe, we discuss the possibility of a low temperature instability of vortex tubes to a `folded' state, driven by the coupling to the normal electron states inside the cores. The basic mechanism is that a bended tube creates an effective potential for the electrons, which destabilizes the tube in a way reminiscent of the us

H. Mathur

Network models of dirty electronic systems are mapped onto an interacting field theory of lower dimensionality by intepreting one space dimension as time. This is accomplished via Feynman's interpretation of anti-particles as particles moving backwards in time. The method developed maps calculation of the moments of the Landauer conductance onto calculat

Lluis Marquez, Lluis Padro

We present an algorithm that automatically learns context constraints using statistical decision trees. We then use the acquired constraints in a flexible POS tagger. The tagger is able to use information of any degree: n-grams, automatically learned context constraints, linguistically motivated manually written constraints, etc. The sources and kinds of con

Hermann Riecke, Glen D. Granzow

Spatio-temporal chaos in parametrically driven waves is investigated in one and two dimensions using numerical simulations of Ginzburg-Landau equations. A regime is identified in which in one dimension the dynamics are due to double phase slips. In very small systems they are found to arise through a Hopf bifurcation off a mixed mode. In large systems they c

Wan Chen, C. R. Shrader, Mario Livio

We have collected the available data from the literature and from public data archives covering the past two decades for the long-term X-ray and optical light curves of X-ray nova (XN) outbursts, and carry out for the first time a systematic, statistical study of XN light curves which are classified into 5 morphological types. Basic light curve parameters, e

W. F. van Altena

Trigonometric parallax observations made with the Hubble Space Telescope's Fine Guidance Sensor #3 (HST FGS) of seven Hyades Cluster members in six fields of view have been analyzed along with their proper motions to determine the distance to the cluster. Knowledge of the Cluster's convergent point and mean proper motion are critical to the derivatio

ANTARES collaboration

The ANTARES collaboration propose to observe High Energy Cosmic Neutrinos using a Deep Sea Cherenkov detector. The sky survey with high energy neutrinos is complementary to the observations with photons. It is expected that this will shed a new light on the understanding of the origin of cosmics rays, on galactic and extra galactic sources. In this document,

B. Guiderdoni, E. Hivon, F. R. Bouchet

A new semi-analytic modelling of galaxy evolution in the IR/submm is hereafter outlined. This type of approach successfully reproduces the optical properties of galaxies. We illustrate a simple extension to the IR/submm wavelength range by taking the case of the SCDM model. We design a family of evolutionary scenarios with star formation histories reproducin

S. Degl'Innocenti, G. Fiorentini, B. Ricci

By using a phenomenological field theory of nucleon-nucleon interactions, Oberhummer et al. found a cross section of p+p $\to$ d + e$^+$ + $ν_e$ about 2.9 times that given by the potential approach and adopted in Standard Solar Model calculations. We show that a solar model with $S=2.9 S_{SSM}$ is inconsistent with helioseismic data, the difference between m

A. Celotti, Z. Kuncic, M. J. Rees, J. F. C. Wardle

The properties of thermal material coexisting with non-thermal emitting plasma and strong magnetic field in the powerful jets of Active Galactic Nuclei (AGN) are examined. Theoretical and observational constraints on the physical properties of this `cold' component are determined. While the presence of a thermal component occupying a fraction ~1.E-8 of t

A. Celotti, A. C. Fabian, M. J. Rees

The extreme variability event in the TeV emission of Mrk 421, recently reported by the Whipple team, imposes the tightest limits on the typical size of the TeV emitting regions in Active Galactic Nuclei (AGN). We examine the consequences that this imposes on the bulk Lorentz factor of the emitting plasma and on the radiation fields present in the central reg

T. Di Matteo, A. Celotti, A. C. Fabian

We discuss the role of thermal cyclo-synchrotron emission in a magnetically dominated corona above an accretion disk in an active galaxy or a galactic black hole candidate. The dissipation occurs in localized active regions around the central black hole. Cyclo-synchrotron radiation is found to be an important process. In the case of galactic black hole candi

Andreas Albrecht, Richard A. Battye, James Robinson

We calculate predictions from defect models of structure formation for both the matter and Cosmic Microwave Background (CMB) over all observable scales. Our results point to a serious problem reconciling the observed large-scale galaxy distribution with the COBE normalization, a result which is robust for a wide range of defect parameters. We conclude that s

I. G. Mitrofanov, M. L. Litvak, D. A. Ushakov

The cosmological origin of cosmic gamma-ray bursts is tested using the method of peak alignment for the averaging of time profiles. The test is applied to the basic cosmological model with standard sources, which postulates that difference between bright and dim bursts results from different cosmological red-shifts of their sources. The average emissivity cu

David Woods, Gregory G. Fahlman

A photometric survey of faint galaxies in three high Galactic latitude fields (each $\sim49~\rm{arcmin^{2}}$) with sub-arcsecond seeing is used to study the clustering properties of the faint galaxy population. Multi-color photometry of the galaxies has been obtained to magnitude limits of $V\sim25$, $R\sim25$ and $I\sim24$. Angular correlation analysis is a

W. G. Roberge

The alignment of interstellar dust grains is described by the joint distribution function for certain ``internal'' and ``external'' variables, where the former describe the orientation of a grain's axes with respect to its angular momentum, J, and the latter describe the orientation of J relative to the interstellar magnetic field. I show

Seth Rosenberg

Generalized quantum mechanics is used to examine a simple two-particle scattering experiment in which there is a bounded region of closed timelike curves (CTCs) in the experiment's future. The transitional probability is shown to depend on the existence and distribution of the CTCs. The effect is therefore acausal, since the CTCs are in the experiment&#3

John M. Pierre

We consider configurations of D6-branes with D0-brane charge given by recent work of Taylor and compute interaction potentials with various D-brane probes using a 1-loop open string calculation. These results are compared to a supergravity calculation using the solution given by Sheinblatt of an extremal black hole carrying 0-brane and 6-brane charge.

H. C. Rosu, J. L. Romero, J. Socorro

We connect the classical free damping cases by means of Rosner's construction in supersymmetric quantum mechanics. Starting with the critical damping, one can obtain in the underdamping case a chirping of instantaneous physical frequency ω^{2}(t) \propto ω_{u}^{2}sech^2(ω_{u}t), whereas in the overdamped case the "chirping" is of the (unphysical)

Erick J. Guerra, Ruth A. Daly

Outflow angles and bulk Lorentz factors for 43 sources that have proper motions compiled by Vermeulen & Cohen (1994) are computed on the basis of Doppler factors and observed apparent motions in the plane of the sky. These estimates of outflow angles and bulk Lorentz factors are discussed along with their agreement with orientation unified models of AGN. Int

Marcelo R. Ubriaco

We study the Bose-Einstein condensation of a gas with $SU_q(2)$ symmetry. We show, in the thermodynamic limit, that the boson interactions introduced by the quantum group symmetries enhance Bose-Einstein condensation giving a discontinuity in the heat capacity $C_v$ at the critical temperature $T_c$. The critical temperature and the gap in $C_v$ increase wit

Wei Lu

We present a parameterization of the non-collinear (virtual) Compton scattering tensor in terms of form factors, in which the Lorentz tensor associated with each form factor possesses manifest electromagnetic gauge invariance. The main finding is that in a well-defined form factor expansion of the scattering tensor, the form factors are either symmetric or a

Daniel Kabat, Soo-Jong Rey

We study the M(atrix) theory which describes the $E_8 \times E_8$ heterotic string compactified on $S^1$, or equivalently M-theory compactified on an orbifold $(S^1/\integer_2) \times S^1$, in the presence of a Wilson line. We formulate the corresponding M(atrix) gauge theory, which lives on a dual orbifold $S^1 \times (S^1 / \integer_2)$. Thirty-two real ch

J. Oswald, G. Span, F. Kuchar

We present a new theoretical approach for the integer quantum Hall effect, which is able to describe the inter-plateau transitions as well as the transition to the Hall insulator. We find two regimes (metallic and insulator like) of the top Landau level, in which the dissipative bulk current appears in different directions. The regimes are separated by a tem

Ursula Bassler, Gregorio Bernardi

The kinematic reconstruction of neutral current high Q^2 events at HERA is discussed in detail using as an example the recently published events of the H1 and ZEUS collaborations at Q^2 > 15000 GeV^2 and M > 180 GeV, which are more numerous than expected from Standard Model predictions. Taking into account the complete information of these events, the mass r

T. Nassar, O. Tirkkonen

We compute the finite size spectrum for the spin 1/2 XXZ chain with twisted boundary conditions, for anisotropy in the regime $0< γ<π/2$, and arbitrary twist $θ$. The string hypothesis is employed for treating complex excitations. The Bethe Ansatz equtions are solved within a coupled non-linear integral equation approach, with one equation for each type of s

Lars Bildsten, Deepto Chakrabarty, John Chiu, Mark H. Finger

We summarize five years of continuous monitoring of accretion-powered pulsars with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. Our 20-70 keV observations have determined or refined the orbital parameters of 13 binaries, discovered 5 new transient accreting pulsars, measured the pulsed flux history during outbursts

Zoltán Nagy, Zoltán Trócsányi

We present the next-to-leading order calculation of two four-jet event shape variables, the D parameter and acoplanarity differential distributions. We find large, more than 100% radiative corrections. The theoretical prediction for the D parameter is compared to L3 data obtained at the Z peak and corrected to hadron level.

J. J. Brainerd

The cosmological expansion cannot produce the reported correlations of the gamma-ray burst timescale and spectral energy with peak flux if the burst model reproduces the BATSE 3B peak-flux distribution for a non-evolving burst source density. Power law luminosity distribution models proportional to L^{-beta} produce acceptables fits to the data for most valu

B. Enriquez, G. Felder

We present a quantum version of the construction of the KZ system of equations as a flat connection on the spaces of coinvariants of representations of tensor products of Kac-Moody algebras. We consider here representations of a tensor product of Yangian doubles and compute the coinvariants of a deformation of the subalgebra generated by the regular function

The LUNA Collaboration, M. Junker, A. D&#39;Alessandro, S. Zavatarelli

We report on the results of the \hethet\ experiment at the underground accelerator facility LUNA (Gran Sasso). For the first time the lowest projectile energies utilized for the cross section measurement correspond to energies below the center of the solar Gamow peak ($E_{\rm 0}$=22 keV). The data provide no evidence for the existence of a hypothetical reson

T. Haugset, H. Haugerud

We consider systems of a small number of interacting bosons confined to harmonic potentials in one and two dimensions. By exact numerical diagonalization of the many-body Hamiltonian we determine the low lying excitation energies and the ground state energy and density profile. We discuss the dependence of these quantities on both interaction strength g and

Stephan Mertens, Christine Bessenrodt

The ground states of the Bernasconi model are binary +1/-1 sequences of length N with low autocorrelations. We introduce the notion of perfect sequences, binary sequences with one-valued off-peak correlations of minimum amount. If they exist, they are ground states. Using results from the mathematical theory of cyclic difference sets, we specify all values o

P. G. Silvestrov

The disintegration of quasiparticle in a quantum dot due to the electron interaction is considered. It was predicted recently that above the energy $\eps^{*} = Δ(g/\ln g)^{1/2}$ each one particle peak in the spectrum is split into many components ($Δ$ and $g$ are the one particle level spacing and conductance). We show that the observed value of $\eps^{*}$ s

Hongsu Kim, Sung Ku Kim

Instantons and their quantisation in pure Yang-Mills theory formulated in the background of de Sitter spacetime represented by spatially-closed ($k = 1$) Friedmann-Robertson-Walker metric are discussed. As for the classical treatment of the instanton physics, first, explicit instanton solutions are found and next, quantities like Pontryagin index and the sem

D. H. E. Gross, M. E. Madjet

Within the micro-canonical ensemble phase transitions of first order can be identified without invoking the thermodynamic limit. We show for the liquid-gas transition of sodium, potassium, and iron at normal pressure that the transition temperature, the latent heat as well as the interface surface tension approach for some 1000 atoms the experimental bulk va

Wolfgang Lueck, Thomas Schick

Suppose $\bar{M}$ is a compact connected odd-dimensional manifold with boundary, whose interior $M$ comes with a complete hyperbolic metric of finite volume. We will show that the $L^2$-topological torsion of $\bar{M}$ and the $L^2$-analytic torsion of the Riemannian manifold $M$ are equal. In particular, the $L^2$-topological torsion of $\bar{M}$ is proport

H. Frauenkron, P. Grassberger, HLRZ Juelich, Germany

We present Monte Carlo simulations of semidilute solutions of long self-attracting chain polymers near their Ising type critical point. The polymers are modeled as monodisperse self-avoiding walks on the simple cubic lattice with attraction between non-bonded nearest neighbors. Chain lengths are up to N=2048, system sizes are up to $2^{21}$ lattice sites and

Gustav Kramer, Cai-Dian Lu

Non-leptonic decays of B mesons into two mesons or meson resonances are studied on the basis of two versions of simple pole-dominance models involving scalar, vector, pseudoscalar and axial-vector poles. The results are compared with those obtained from the usual factorization model and used to obtain information on strong coupling constants between B meson

Nicolas J. Cerf

In analogy with its classical counterpart, a noisy quantum channel is characterized by a loss, a quantity that depends on the channel input and the quantum operation performed by the channel. The loss reflects the transmission quality: if the loss is zero, quantum information can be perfectly transmitted at a rate measured by the quantum source entropy. By u

J. F. Gunion, C. -H. Chen

We consider typical hadron collider detector signals sensitive to delayed decays of the lightest neutralino to photon plus goldstino and demonstrate the potential for substantially increasing the portion of the general parameter space of a gauge-mediated supersymmetry breaking model that can be probed at the Tevatron.

David A. Buote, A. C. Fabian

We present spectral analysis of ASCA data of 17 elliptical and 3 lenticular galaxies most of which have high L_x/L_B. Single-temperature models (MEKAL and Raymond-Smith) give unacceptable fits (chi^2_red > 1.5) in most cases and, in agreement with previous studies, give very sub-solar abundances, <Z> = 0.19 +/- 0.12 Z_sun (MEKAL). The spectra for approximate

Shigeki Matsutani

Recently I quantized an elastica with Bernoulli-Euler functional in two-dimensional space using the modified KdV hierarchy. In this article, I will quantize a Willmore surface, or equivalently a surface with the Polyakov extrinsic curvature action, using the modified Novikov-Veselov (MNV) equation. In other words, I show that the density of state of the part

E. A. Kochetov

A closed (in terms of classical data) expression for a transition amplitude between two generalized coherent states associated with a semisimple Lee algebra underlying the system is derived for large values of the representation highest weight, which corresponds to the quasiclssical approximation. Consideration is based upon a path-integral formalism adjuste

W. A. Hofer

The theoretical foundations of quantum mechanics and de Broglie-Bohm mechanics are analyzed and it is shown that both theories employ a formal approach to microphysics. By using a realistic approach it can be established that the internal structures of particles comply with a wave-equation. Including external potentials yields the Schrodinger equation, which

Robert J. Finkelstein

As one would anticipate from the realization of the q-commutators by difference operators, the states of maximum localization are smeared delta functions depending on q.

O. Babelon, M. Talon

We compute the symplectic structure of the spin Calogero model in terms of algebro-geometric data on the associated spectral curve.

Roger Picken

An invariant of knots is constructed from an integral for geometric braids due to Kohno and Kontsevich. It takes values in a quotient by a certain ideal of the algebra generated by chord diagrams over the circle.

M. Kozlov, A. Titov, N. Mosyagin, P. Souchko

We report results of ab initio calculation of the spin-rotational Hamiltonian parameters including P- and P,T-odd terms for the BaF molecule. The ground state wave function of BaF molecule is found with the help of the Relativistic Effective Core Potential method followed by the restoration of molecular four-component spinors in the core region of barium in

Shigeki Matsutani

In previous report (J. Phys. A (1997) 30 4019-4029), I showed that the Dirac field confined in a surface immersed in $R^3$ by means of a mass type potential is governed by the Konopelchenko-Kenmotsu-Weierstrass-Enneper equation. In this article, I quantized the Dirac field and calculated the gauge transformation which exhibits the gauge freedom of the parame

J. M. Speight

The topology and geometry of the moduli space, M_2, of degree 2 static solutions of the CP^1 model on a torus (spacetime T^2 x R) are studied. It is proved that M_2 is homeomorphic to the left coset space G/G_0 where G is a certain eight-dimensional noncompact Lie group and G_0 is a discrete subgroup of order 4. Low energy two-lump dynamics is approximated b

R. Banerjee, E. C. Marino

We describe two distinct approaches for bosonization in higher dimensions; one is based on a direct comparison of current correlation functions while the other relies on a Master lagrangean formalism. These are used to bosonise the Massive Thirring Model in three and four dimensions in the weak coupling regime but with an arbitrary fermion mass. In both appr