July 1996 arXiv papers — page 8

Zurab Kakushadze, Gary Shiu, S. -H. Henry Tye

The rules for the free fermionic string model construction are extended to include general non-abelian orbifold constructions that go beyond the real fermionic approach. This generalization is also applied to the asymmetric orbifold rules recently introduced. These non-abelian orbifold rules are quite easy to use. Examples are given to illustrate their appli

M. G. Harris

The branching ratio is calculated for three different models of 2d gravity, using dynamical planar phi-cubed graphs. These models are pure gravity, the D=-2 Gaussian model coupled to gravity and the single spin Ising model coupled to gravity. The ratio gives a measure of how branched the graphs dominating the partition function are. Hence it can be used to e

Mikhail Vasiliev

We describe a model of massive matter fields interacting through higher-spin gauge fields in 2+1 dimensional space-time. The two main conclusions are that the parameter of mass $M$ appears as a module characterizing an appropriate vacuum solution of the full non-linear model and that $M$ affects a structure of a global vacuum higher-spin symmetry which leave

Thomas Schmitt

We discuss of the conceptual difficulties connected with the anticommutativity of classical fermion fields, and we argue that the "space" of all classical configurations of a model with such fields should be described as an infinite-dimensional supermanifold M. We discuss the two main approaches to supermanifolds, and we examine the reasons why many

E. Gava, T. Jayaraman, K. S. Narain, M. H. Sarmadi

We analyze in detail the description of type IIB theory on a Calabi-Yau three-fold near a conifold singularity in terms of intersecting D-branes. In particular we study the singularity structure of higher derivative $F$-terms of the form $F_g W^{2g}$ where $W$ is the gravitational superfield. This singularity is expected to be due to a one -loop contribution

Ramon Mendoza, Fernando Moraes

We outline a method of calculation of partition functions of orientable manifolds with fluctuating metric and perform the calculation for the specific case of the unit interval.

J. L. Petersen, J. Rasmussen, M. Yu

Based on our earlier work on free field realizations of conformal blocks for conformal field theories with $SL(2)$ current algebra and with fractional level and spins, we discuss in some detail the fusion rules which arise. By a careful analysis of the 4-point functions, we find that both the fusion rules previously found in the literature are realized in ou

M. Gasperini, G. Veneziano

A broad class of two-dimensional loop-corrected dilaton gravity models exhibit cosmological solutions that interpolate between the string perturbative vacuum and a background with asymptotically flat metric and linearly growing dilaton. The curvature singularities of the corresponding tree-level solutions are smoothed out, but no branch-change occurs. Thus,

Tohru Eguchi, Kentaro Hori

Making use of the exact solutions of the $N=2$ supersymmetric gauge theories we construct new classes of superconformal field theories (SCFTs) by fine-tuning the moduli parameters and bringing the theories to critical points. In the case of SCFTs constructed from pure gauge theories without matter $N=2$ critical points seem to be classified according to the

Donald L. Bennett

The Multiple Point Criticality Principle (MPCP) states that action parameters - in for example a field theory - take on values corresponding to the junction of a maximum number of phases in the phase diagram of a system that undergoes phase transitions. The phases to which physical significance is ascribed are normally regarded as artifacts of a regulation p

G. Krein

Effective chiral Lagrangians involving constituent quarks, Goldstone bosons and long-distance gluons are believed to describe the strong interactions in an intermediate energy region between the confinement scale and the chiral symmetry breaking scale. Baryons and mesons in such a description are bound states of constituent quarks. We discuss the combined us

F. Buccella, I. Dorusner, G. Miele, O. Pisanti

A quantum statistical parametrization of parton distributions has been considered. In this framework, the exclusion Pauli principle connects the violation of the Gottfried sum rule with the Ellis and Jaffe one, and implies a defect in the Bjorken sum rule. However, in terms of standard parametrizations of the polarized distributions a good description of the

Marc Sher

In Coleman-Weinberg symmetry breaking, all dimensionful parameters vanish and the symmetry is broken by loop corrections. Before Coleman-Weinberg symmetry breaking in the Standard Model was experimentally ruled out, it had already been excluded on cosmological grounds. In this Brief Report, the cosmological analysis is carried out for Coleman-Weinberg models

J. Feltesse, F. Kunne, E. Mirkes

The measurement of the polarized gluon distribution function $\Delta g(x)$ from photon gluon fusion processes in electron proton deep inelastic scattering producing two jets has been investigated. The study is based on the MEPJET simulation program. The size of the expected spin asymmetry and corresponding statistical uncertainties for a possible measurement

Emilio Torrente-Lujan

We consider interactions of fermions with the domain wall bubbles produced during a first order phase transition. A new exact solution of the Dirac equations is obtained for a wall profile incorporating a position dependent phase factor. The reflection coefficients are obtained.

M. Anselmino, M. Boglione, J. Hansson, F. Murgia

We discuss the production of polarized hadrons in polarized lepton nucleon interactions and show that the helicity density matrix of the hadron, when measurable, can give information on the spin structure of the nucleon and the spin dependence of the quark fragmentation process. Single spin asymmetries in the $\ell N^\uparrow \to hX$ process are also briefly

S. Frixione

I review the status of the comparison between theoretical predictions and experimental results for bottom production in hadronic collisions, and discuss the possible sources of the discrepancies found. The study of jets containing bottom quarks is proposed as a promising tool to investigate the $b$ production mechanism. I present next-to-leading order QCD pr

Hai-Yang Cheng, Chi-Yee Cheung, Chien-Wen Hwang

Within the light-front framework, form factors for $P\to P$ and $P\to V$ transitions ($P$: pseudoscalar meson, $V$: vector meson) due to the valence-quark configuration are calculated directly in the entire physical range of momentum transfer. The behavior of form factors in the infinite quark mass limit are examined to see if the requirements of heavy-quark

David Muller, Satya Nandi

We consider an extended gauge group for the electroweak interaction: SU(2)_1 \times SU(2)_2 \times U(1)_Y where the first and second generations of fermions couple to SU(2)_1 while the third generation couples to SU(2)_2. Bounds based on precision observables and heavy gauge boson searchesare placed on the new parameters of the theory, and the potential of t

P. Provero

The quantum fluctuations of the flux tube joining two static sources in the confining phase of a lattice gauge theory are described by an effective string theory. The predictions of the latter for ratios of Wilson loops of equal perimeter do not contain any free parameters, and can be computed exactly for large Wilson loops. We compare these predictions with

C. F. Baillie, W. Janke, D. A. Johnston

We perform extensive Monte Carlo simulations of the 10-state Potts model on quenched two-dimensional $Φ^3$ gravity graphs to study the effect of quenched coordination number randomness on the nature of the phase transition, which is strongly first order on regular lattices. The numerical data provides strong evidence that, due to the quenched randomness, the

E. S. Cheb-Terrab, L. G. S. Duarte, L. A. C. P. da Mota

A set of Maple V R.3/4 computer algebra routines for the analytical solving of 1st. order ODEs, using Lie group symmetry methods, is presented. The set of commands includes a 1st. order ODE-solver and routines for, among other things: the explicit determination of the coefficients of the infinitesimal symmetry generator; the construction of the most general

S. Demelio, S. Mignemi

The effective action for string theory which takes into account non-minimal coupling of moduli admits multi-black hole solutions. The euclidean continuation of these solutions can be interpreted as an instanton mediating the splitting and recombination of the throat of extremal magnetically charged black holes.

Claudio Furtado, Fernando Moraes

Point sources in (2+1)-dimensional gravity are conical singularities that modify the global curvature of the space giving rise to self-interaction effects on classical fields. In this work we study the electrostatic self-interaction of a point charge in the presence of point masses in (2+1)-dimensional gravity with a cosmological constant.

S. Giorgini, L. Pitaevskii, S. Stringari

By using a mean field approach, based on the Popov approximation, we calculate the temperature dependence of the condensate fraction of an interacting Bose gas confined in an anisotropic harmonic trap. For systems interacting with repulsive forces we find a significant decrease of the condensate fraction and of the critical temperature with respect to the pr

Vladimir N. Kostur, Philip B. Allen

The Rice-Sneddon model for BaBiO$_3$ is a nice model Hamiltonian for considering the properties of polarons and bipolarons in a three-dimensional oxide crystal. We use exact diagonalization methods on finite samples to study the stability and properties of polarons and bipolarons. Because polarons, when they form, turn out to be very well-localized, we are a

M. Houbiers, H. T. C. Stoof

We study the stability of a Bose condensate of atomic $^7$Li in a (harmonic oscillator) magnetic trap at non-zero temperatures. In analogy to the stability criterion for a neutron star, we conjecture that the gas becomes unstable if the free energy as a function of the central density of the cloud has a local extremum which conserves the number of particles.

Gerald Paetzold, Thorsten Hapke, Andreas Linke, Dieter W. Heermann

We study the deformation of nano--scale polymer films which are subject to external bending forces by means of computer simulation. The polymer is represented by a generalized bead--spring--model, intended to reproduce characteristic features of n--alkanes. The film is loaded by the action of a prismatic blade which is pressed into the polymer bulk from abov

Thorsten Hapke, Andreas Linke, Gerald Paetzold, Dieter W. Heermann

We study surface effects in amorphous polymer systems by means of computer simulation. In the framework of molecular dynamics, we present two different methods to prepare such surfaces. {\em Free} surfaces are stabilized solely by van--der--Waals interactions whereas {\em confined} surfaces emerge in the presence of repelling plates. The two models are compa

N. F. Schwabe, Ned S. Wingreen, R. J. Elliott

The Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between two magnetic $s$-$d$ spin impurities across a tunneling junction is studied when the system is driven out of equilibrium through biasing the junction. The nonequilibrium situation is handled with the Keldysh time-loop perturbation formalism in conjunction with appropriate coupling methods for tunne

Ivan Pontual, Fernando Moraes

In this work, it is shown that a non-zero vacuum energy density (the Casimir energy) for a scalar field appears in a continuous elastic solid due to the presence of a topological defect, the screw dislocation. An exact expression is obtained for this energy density in terms of the Burgers vector describing the defect, for zero and finite temperature.

Uwe C. Täuber

Columnar defects provide effective pinning centers for magnetic flux lines in high--$T_{\rm c}$ superconductors. Utilizing a mapping of the statistical mechanics of directed lines to the quantum mechanics of two--dimensional bosons, one expects an entangled flux liquid phase at high temperatures, separated by a second--order localization transition from a lo

Peter V. Coveney, Keir E. Novik

We investigate the dynamical behavior of binary fluid systems in two dimensions using dissipative particle dynamics. We find that following a symmetric quench the domain size R(t) grows with time t according to two distinct algebraic laws R(t) = t^n: at early times n = 1/2, while for later times n = 2/3. Following an asymmetric quench we observe only n = 1/2

Toine Andernach

The purpose of this paper is to present a method for automatic classification of dialogue utterances and the results of applying that method to a corpus. Superficial features of a set of training utterances (which we will call cues) are taken as the basis for finding relevant utterance classes and for extracting rules for assigning these classes to new utter

Antal van den Bosch, Walter Daelemans, Ton Weijters

Morphological analysis is an important subtask in text-to-speech conversion, hyphenation, and other language engineering tasks. The traditional approach to performing morphological analysis is to combine a morpheme lexicon, sets of (linguistic) rules, and heuristics to find a most probable analysis. In contrast we present an inductive learning approach in wh

Peh Li Shiuan, Christopher Ting Hian Ann

In this paper, we propose a novel strategy which is designed to enhance the accuracy of the parser by simplifying complex sentences before parsing. This approach involves the separate parsing of the constituent sub-sentences within a complex sentence. To achieve that, the divide-and-conquer strategy first disambiguates the roles of the link words in the sent

Wolchenkov Dmitriy

A short distance expansion method (SDE) that is well known in the quantum field theory for analysis of turbulent behaviour of stochastic magnetic hydrodynamics of incompressible conductive fluid is applied. As a result is shown that in an inertial range the turbulent spectra of magnetic hydrodynamics depend on a scale of arising of curls.

E. Gozzoli, M. Tosi, G. Marconi, A. Bragaglia

We present UBVI photometry for the old open cluster Collinder 261. From comparison of the observed colour-magnitude diagrams with simulations based on stellar evolutionary models we derive in a self consistent way reddening, distance, and age of the cluster: E(B-V)=0.25$-$0.34, (m-M)$_0$=11.7-12.0, and age=7$-$8 Gyr or 9$-$11 Gyr, depending on the adopted st

P. L. Nolan, the EGRET team

EGRET can now study six pulsars since the recent detection of PSR B1951+32. Careful analysis of the three brightest pulsars shows that gamma rays are emitted through essentially the entire rotation. This calls into question the previous interpretation of the Crab's low-level emission as due entirely to its nebula. The pulse light curves have either well-

E. Carretta, R. G. Gratton

We have obtained high-res, high S/N ratio CCD echelle spectra of 10 bright red giants in 3 GCs (47Tuc, NGC6752 and NGC6397) roughly spanning the range of metallicities of the galactic GC system; they reveal no evidence of star to star variation of [Fe/H] in these 3 GCs. A large set of high quality literature data (EWs from high-res CCD spectra) was re-analyz

Neven Bilic, Raoul D. Viollier

We study the phase transition of a system of self-gravitating neutrinos in the presence of a large radiation density background in the framework of the Thomas-Fermi model. We show that, by cooling a non-degenerate gas of massive neutrinos below some critical temperature, a condensed phase emerges, consisting of quasi-degenerate supermassive neutrino stars. T

Yun Wang, Edwin L. Turner

We consider an astrophysical system with a population of sources and a population of lenses. For each pair of source and lens, there is a thin on-axis tube-like volume behind the lens in which the radiation flux from the source is greatly increased due to gravitational lensing. Any objects (such as dust grains) which pass through such a thin tube will experi

Eriko Hironaka

Work of Laurent and Sarnak, following a conjecture of Lang, shows that the number of torsion points of order n on an algebraic subset of an affine complex torus is polynomial periodic. In this paper, we find bounds on the degree and period of this number as a function of n. Some examples, including the number of n torsion points on Fermat curves, are compute

B. Lindemann, A. Sopczak

This paper has been withdrawn.

H. Nowak, A. Sopczak

This paper has been withdrawn.

A. Sopczak

This paper has been withdrawn.

Alexander Berkovich, Barry M. McCoy, Anne Schilling

We present and prove Rogers-Schur-Ramanujan (Bose/Fermi) type identities for the Virasoro characters of the minimal model $M(p,p').$ The proof uses the continued fraction decomposition of $p'/p$ introduced by Takahashi and Suzuki for the study of the Bethe's Ansatz equations of the XXZ model and gives a general method to construct polynomial gene

C. M. Varma

A model of copper-oxygen bonding and anti-bonding bands with the most general two-body interactions allowable by symmetry is considered. The model has a continuous transition as a function of hole-density x and temperature T to a phase in which a current circulates in each unit cell. This phase preserves the translational symmetry of the lattice while breaki

R. S. Bhalerao

A phenomenological model for the nucleon structure functions is presented. Visualising the nucleon as a cavity filled with parton gas in equilibrium and parametrizing the effects due to the finiteness of the nucleon volume, we obtain a good fit to the data on the structure function $F_2^p$. The model then successfully predicts other unpolarized structure fun

Stefano Catani, Michael H. Seymour

We briefly describe a new general algorithm for carrying out QCD calculations to next-to-leading order in perturbation theory. The algorithm can be used for computing arbitrary jet cross sections in arbitrary processes and can be straightforwardly implemented in general-purpose Monte Carlo programs.

Anton Bovier, Veronique Gayrard

We give a comprehensive self-contained review on the rigorous analysis of the thermodynamics of a class of random spin systems of mean field type whose most prominent example is the Hopfield model. We focus on the low temperature phase and the analysis of the Gibbs measures with large deviation techniques. There is a very detailed and complete picture in the

Martin Bordemann, Stefan Waldmann

In this paper we develop a method of constructing Hilbert spaces and the representation of the formal algebra of quantum observables in deformation quantization which is an analog of the well-known GNS construction for complex $C^*$-algebras: in this approach the corresponding positive linear functionals (`states') take their values not in the field of c

Cheuk-Yin Wong, Lali Chatterjee

Final-state interaction and screening have a great influence on $q \bar q$ production cross sections, which are important quantities in many problems in quark-gluon plasma physics. They lead to an enhancement of the cross section for a $q \bar q$ color-singlet state and a suppression for a color-octet state. The effects are large near the production threshol

Elisa Ercolessi, Giovanni Landi, Paulo Teotonio-Sobrinho

Noncommutative lattices have been recently used as finite topological approximations in quantum physical models. As a first step in the construction of bundles and characteristic classes over such noncommutative spaces, we shall study their $K$-theory. We shall do it algebraically, by studying the algebraic $K$-theory of the associated algebras of `continuou

Elisa Ercolessi, Giovanni Landi, Paulo Teotonio-Sobrinho

Recently a new kind of approximation to continuum topological spaces has been introduced, the approximating spaces being partially ordered sets (posets) with a finite or at most a countable number of points. The partial order endows a poset with a nontrivial non-Hausdorff topology. Their ability to reproduce important topological information of the continuum

R. Pittau

In this paper, I present a technique to simplify the tensorial reduction of one-loop integrals with arbitrary internal masses, but at least two massless external legs. By applying the method to rank l tensor integrals, one ends up with at most rank 1 tensor functions with the initial number of denominators, plus tensor integrals with less denominators and ra

H. García-Compeán, A. Pérez-Lorenzana, A. Zepeda

We study topological defects arising in the Grand Unification Model $SU(6)_L\otimes SU(6)_c \otimes SU(6)_R \times Z_3$. We show that the model does not contain domain walls, while it produces massive magnetic monopoles and it may, depending on the symmetry breaking chain, give rise to the formation of strings. We also discuss their possible relation$ the or

Kenji Kajiwara, Yasuhiro Ohta

Two types of determinant representations of the rational solutions for the Painlevé II equation are discussed by using the bilinear formalism. One of them is a representation by the Devisme polynomials, and another one is a Hankel determinant representation. They are derived from the determinant solutions of the KP hierarchy and Toda lattice, respectively.

Hong-Chen Fu, Ryu Sasaki

We show that the binomial states (BS) of Stoler {\it et al.} admit the ladder and displacement operator formalism. By generalizing the ladder operator formalism we propose an eigenvalue equation which possesses the number and the squeezed states as its limiting solutions. The explicit forms of the solutions, to be referred to as the {\it generalized binomial

Ian C. Percival, Walter T. Strunz

In papers on primary state diffusion (Percival 1994, 1995), numerical estimates suggested that fluctuations in the space-time metric on the scale of the Planck time (10^-44s) could be detected using atom interferometers. In this paper we first specify a stochastic metric obtained from fluctuations that propagate with the velocity of light, and then develop t

Charilaos Aneziris

In this paper we summarise the work discussed in Ref. [1] and [2] (q-alg/9505003), in which we introduced a method helpful in solving the problem of knot classification. We also present results obtained since then.

K. L. Mitchell, P. C. Tandy

We study the self-energy amplitudes for the rho-omega meson system produced by an effective field theory model at the quark level characterized by a finite range quark-quark interaction and an isospin breaking bare quark mass difference $m_u - m_d$. Dynamical effects associated with confinement and dressing of quarks and the finite size of the produced $\bar

R. Guardiola, P. I. Moliner, J. Navarro, R. F. Bishop

We study the extension of our translationally invariant treatment of few-body nuclear systems to heavier nuclei. At the same time we also introduce state-dependent correlation operators. Our techniques are tailored to those nuclei that can be dealt with in $LS$ coupling, which includes all nuclei up to the shell closure at $A=40$. We study mainly $p$-shell n

A. Mengoni, T. Otsuka, T. Nakamura, M. Ishihara

We have investigated the implications of the neutron halo configuration, observed in the ground-state of some neutron-rich light nuclei, on neutron radiative transition processes. In particular, we have studied the influence of the neutron halo on the direct radiative capture (DRC) process. The energy dependence as well as the strength of E1 emission due to

Siwen Wang, Manoj K. Banerjee

Ohta proposed a solution for the well-known difficulty of satisfying the Ward-Takahashi identity for a photo-meson-baryon-baryon amplitude ($γ$MBB) when a dressed meson-baryon-baryon (MBB) vertex function is present. He obtained a form for the $γ$MBB amplitude which contained, in addition to the usual pole terms, longitudinal seagull terms which were determi

L. Beaulieu, D. R. Bowman, D. Fox, S. Das Gupta

Fragment production has been studied as a function of the source mass and excitation energy in peripheral collisions of $^{35}$Cl+$^{197}$Au at 43 MeV/nucleon and $^{70}$Ge+$^{nat}$Ti at 35 MeV/nucleon. The results are compared to the Au+Au data at 600 MeV/nucleon obtained by the ALADIN collaboration. A mass scaling, by $A_{source} \sim$ 35 to 190, strongly

John T. Baldwin, Saharon Shelah

Spencer and Shelah [ShSp:304] constructed for each irrational alpha between 0 and 1 the theory T^alpha as the almost sure theory of random graphs with edge probability n^{- alpha}. In [BlSh:528] we proved that this was the same theory as the theory T_alpha built by constructing a generic model in Baldwin and Shi. In this paper we explore some of the more sub

Saharon Shelah

One aim of this work is to get a universe in which weak versions of Martin axioms holds for some forcing notions of cardinality aleph_0, aleph_1 and aleph_2 while on aleph_2 club, the ``small'' brother of diamond, holds. As a consequence we get the consistency of ``there is no Gross space''. Another aim is to present a case of ``Historic iter

John T. Baldwin, Saharon Shelah

Let L contain only the equality symbol and let L^+ be an arbitrary finite symmetric relational language containing L . Suppose probabilities are defined on finite L^+ structures with ''edge probability'' n^{- alpha}. By T^alpha, the almost sure theory of random L^+-structures we mean the collection of L^+-sentences which have limit probabilit

S. N. Mayburov

We argue that correct account of the quantum properties of macroscopic objects which form reference frames (RF) demand the change of the standard space-time picture accepted in Quantum Mechanics. Galilean or Lorentz space-time transformations are shown to become incorrect in this case and for the description of transformations between different RF the specia

Jeremy S. Heyl, Lars Hernquist

We derive an analytic form for the Heisenberg-Euler Lagrangian in the limit where the component of the electric field parallel to the magnetic field is small. We expand these analytic functions to all orders in the field strength ($F_{μν}F^{μν}$) in the limits of weak and strong fields, and use these functions to estimate the pair-production rate in arbitrar

A. Mironov

Different group structures which underline the integrable systems are considered. In some cases, the quantization of the integrable system can be provided with substituting groups by their quantum counterparts. However, some other group structures keep non-deformed in the course of quantizing the integrable system although their treatment is to be changed. M

L. O. Buffon, D. Dalmazi, A. Zadra

We construct higher-spin N=1 super algebras as extensions of the super Virasoro algebra containing generators for all spins $s\ge 3/2$. We find two distinct classical (Poisson) algebras on the phase super space. Our results indicate that only one of them can be consistently quantized.

G. Aldazabal, A. Font, L. E. Ibanez, A. M. Uranga

We study heterotic $E_8\times E_8$ models that are dual to compactifications of F-theory and type IIA string on certain classes of elliptically fibered Calabi-Yau manifolds. Different choices for the specific torus in the fibration have heterotic duals that are most easily understood in terms of $E_8\times E_8$ models with gauge backgrounds of type $H\times

R. Poghossian

The symmetry algebra of $N=1$ Super-Liouville field theory in two dimensions is the infinite dimensional $N=1$ superconformal algebra, which allows one to prove, that correlation functions, containing degenerated fields obey some partial linear differential equations. In the special case of four point function, including a primary field degenerated at the fi

S. N. Roshchupkin, A. A. Zheltukhin

Tensionless null p-branes in arbitrary cosmological backgrounds are considered and their motion equations are solved. It is shown that an ideal fluid of null p-branes may be considered as a source of gravity for D-dimensional Friedmann- Robertson-Walker universes.

H. Reinhardt

The Yang-Mills functional integral is studied in an axial variant of 't Hooft's maximal Abelian gauge. In this gauge Gauß' law can be completely resolved resulting in a description in terms of unconstrained variables. Compared to previous work along this line starting with work of Goldstone and Jackiw one ends up here with half as many integratio

C. Chiou-Lahanas, G. A. Diamandis, B. C. Georgalas, A. Kapella-Economou

In this work we find static black hole solutions in the context of the two-dimensional dilaton gravity, which is modified by the addition of an $R^2$ term. This term arises from the one-loop effective action of a massive scalar field in its large mass expansion. The basic feature of this term is that it does not contribute to the Hawking radiation of the cla

Henryk Arodz, Leszek Hadasz

Excitations of a vortex are usually considered in a linear approximation neglecting their backreaction on the vortex. In the present paper we investigate backreaction of Proca type excitations on a straightlinear vortex in the Abelian Higgs model. We propose exact Ansatz for fields of the excited vortex. From initial set of six nonlinear field equations we o

Takehisa Fujita, Kenji Yamamoto, Yasuyuki Sekiguchi

We reexamine Bethe ansatz solutions of the massive Thirring model. We solve equations of periodic boundary conditions numerically without referring to the density of states. It is found that there is only one bound state in the massive Thirring model. The bound state spectrum obtained here is consistent with Fujita-Ogura's solutions of the infinite momen

I. V. Gorbunov, S. M. Kuzenko, S. L. Lyakhovich

We present new geometric formulations for the fractional spin particle models on the minimal phase spaces. New consistent couplings of the anyon to background fields are constructed. The relationship between our approach and previously developed anyon models is discussed.

S. Ramgoolam, L. Thorlacius

States obtained by projecting boundary states, associated with D-branes, to fixed mass-level and momentum generically define non-trivial cohomology classes. For on-shell states the cohomology is the standard one, but when the states are off-shell the relevant cohomology is defined using a BRST operator with ghost zero modes removed. The zero momentum cohomol

Itzhak Bars

The representation theory of the maximally extended superalgebra with 32 fermionic and 528 bosonic generators is developed in order to investigate non-perturbative properties of the democratic secret theory behind strings and other p-branes. The presence of Lorentz non-singlet central extensions is emphasized, their role for understanding up to 13 hidden dim

J. Blümlein, S. Riemersma, A. Vogt

A brief survey is given of recent results on the resummation of leading small-x terms for unpolarized and polarized non--singlet and singlet structure function evolution.

P. H. Chankowski, S. Pokorski

The simplest interpretation of the global success of the Standard Model is that new physics decouples well above the electroweak scale. Supersymmetric extension of the Standard Model offers the possibility of light chargino and the right-handed stop (with masses below $M_Z$), and still maintaining the successful predictions of the Standard Model. The value o

O. J. P. Eboli, E. M. Gregores, F. Halzen

The color-evaporation model quantitatively describes all data on photoproduction and hadroproduction of charmonium. Although the model is in part nonperturbative, the associated parameters can for instance be determined from the charmonium photoproduction data. At this point its predictions for the prompt production of $ψ$'s at the $Z$ pole are made with

Christopher D. Carone

I present a supersymmetric theory of flavor based on the discrete flavor group $(S_3)^3$. The model can account for the masses and mixing angles of the standard model, while maintaining sufficient sfermion degeneracy to evade the supersymmetric flavor problem. I demonstrate that the model has a viable phenomenology and makes one very striking prediction: the

Darwin Chang, W. -Y. Keung

We analyze the production of triple pseudoscalar Higgs bosons in the decay channel of $Z\rightarrow AAA$ for light pseudoscalar bosons when the corresponding scalar boson is too heavy to be produced by $Z$ decay. Analytic results are obtained both at the tree level and at the one--loop level. The branching fraction can be as large as $10^{-5}$ which should b

D. H. Brown, W. A. Worstell

We have performed a new evaluation of the hadronic contribution to $a_μ=(g-2)/2$ of the muon with explicit correlations of systematic errors among the experimental data on $σ( e^+e^- \to hadrons )$. Our result for the lowest order hadronic vacuum polarization contribution is $ a_μ^{had} = 702.6(7.8)(14.0) \times 10^{-10}$ where the the first error is statist

Elena Accomando, Alessandro Ballestrero

WPHACT (W W and Higgs Physics with PHACT) is a MC program and unweighted event generator which computes all Standard Model processes with four fermion in the final state at $e^+ e^-$ colliders. It is based on an helicity amplitude method which allows precise and fast evaluations of the matrix elements both for massless and massive fermions. Fermion masses fo

D. Ebert, R. N. Faustov, V. O. Galkin, A. P. Martynenko

In the framework of the relativistic quasipotential quark model the mass spectrum of baryons with two heavy quarks is calculated. The quasipotentials for interactions of two quarks and of a quark with a scalar and axial vector diquark are evaluated. The bound state masses of baryons with $J^P=\frac{1}{2}^+, \frac{3}{2}^+$ are computed.

J. A. Aguilar-Saavedra

The diagonalization of general mass matrices is a more delicate problem when eigenvalue degeneracies exist. In this case, often overlooked in the literature, some difficulties arise related to the freedom in the choice of basis in degenerate subspaces. Here two simple algorithms are developed to deal with quark and neutrino mass matrices with arbitrary degen

S. Bertolini

We discuss a new estimate of $\varepsilon '/\varepsilon$ in the kaon system. The present approach is based on the evaluation of the hadronic matrix elements of the \mbox{$ΔS =1$} effective quark lagrangian by means of the chiral quark model, with the inclusion of meson one-loop renormalization and NLO Wilson coefficients. The estimate here reviewed is fu

F. del Aguila, J. A. Aguilar-Saavedra, M. Zrałek

The invariant formulation of CP violation involves the generation of sets of invariant constraints for CP conservation, the manipulation of their expressions and the identification of complete and minimal subsets of such constraints. In this paper we present a collection of subroutines to deal with these three tasks in a fast, reliable and systematic way, wi

Marion Flanz, Emmanuel A. Paschos, Utpal Sarkar, Jan Weiss

A mechanism is presented, in which the mixing of right handed heavy Majorana neutrinos creates a $CP-$asymmetric universe. When these Majorana neutrinos subsequently decay more leptons than anti-leptons are produced. The lepton asymmetry created by this new mechanism can exceed by a few orders of magnitude any lepton asymmetry originating from direct decays.

N. G. Deshpande, B. Dutta, E. Keith

We discuss the production of lepton flavor violation and EDMs and the viability of the $b-τ$ unification hypothesis in SUSY grand unification with an intermediate gauge symmetry breaking scale.

Marcel Demarteau

A measurement of the mass of the $W$ boson is presented based on a sample of 5982 $W \rightarrow e ν$ decays observed in $p\overline{p}$ collisions at $\sqrt{s}$ = 1.8~TeV with the DØ detector during the 1992--1993 run. From a fit to the transverse mass spectrum, combined with measurements of the $Z$ boson mass, the $W$ boson mass is measured to be $M_W = 80

Robert L. Marsa, Matthew W. Choptuik

We examine the interactions of a black hole with a massless scalar field using a coordinate system which extends ingoing Eddington-Finkelstein coordinates to dynamic spherically symmetric-spacetimes. We avoid problems with the singularity by excising the region of the black hole interior to the apparent horizon. We use a second-order finite difference scheme

H. -M. Muller, S. E. Koonin

We perform Hartree-Fock calculations to show that quantum dots (i.e. two dimensional systems of up to twenty interacting electrons in an external parabolic potential) undergo a gradual transition to a spin-polarized Wigner crystal with increasing magnetic field strength. The phase diagram and ground state energies have been determined. We tried to improve th

A. S. Wills, A Harrison, S. A. M. Mentink, T. E. Mason

Deuteronium jarosite, (D_3O)Fe_3(SO_4)_2(OD)_6, contains a kagome lattice of Heisenberg spins, S=5/2, with a coverage of 97+-1%. DC and AC susceptibility measurements show strong in-plane antiferromagnetic exchange (θ_CW=-1500+-300K) and a spin-glass transition at T_f=13.8 K, while the magnetic contribution to the specific heat below T_f rises with T as T^2,