February 1995 arXiv papers — page 5

G. Bertsch, B. Mueller, J. Negele, J. Friar

We review the accomplishments of nuclear theory during the past five years and identify the future challenges and research opportunities. [Final, substantially revised version of the nuclear theory white paper]

Heidelberg-Moscow-Collaboration

Recent results of the Heidelberg-Moscow double beta decay experiment are presented. After 8.6 kg$\cdot$a of measuring time no signal is seen for the neutrinoless decay mode. A half-life limit of $T_{1/2}^{0νββ} > 5.1\cdot 10^{24}$~a is deduced which converts into a neutrino mass limit of $\langle m_{ν_e}\rangle < 0.68 $ eV (90\% CL). The experiment thus is t

Janet Hitzeman, Marc Moens, Claire Grover

We describe a method for analysing the temporal structure of a discourse which takes into account the effects of tense, aspect, temporal adverbials and rhetorical structure and which minimises unnecessary ambiguity in the temporal structure. It is part of a discourse grammar implemented in Carpenter&#39;s ALE formalism. The method for building up the tempora

F. Di Renzo, G. Marchesini, E. Onofri

We use a numerical method to obtain the weak coupling perturbative coefficients of local operators with lattice regularization. Such a method allows us to extend the perturbative expansions obtained so far by analytical Feynman diagrams calculations. In SU(3) lattice gauge theory in four dimensions we compute the first eight coefficients of the expectation v

Norbert Schörghofer, Leo Kadanoff, Detlef Lohse

We calculate static solutions of the &#39;GOY&#39; shell model of turbulence and do a linear stability analysis. The asymptotic limit of large Reynolds numbers is analyzed. A phase diagram is presented which shows the range of stability of the static solution. We see an unexpected oscillatory dependence of the stability range upon $\lg ν$, where $ν$ is the v

G. M. de Divitiis, R. Frezzotti, M. Guagnelli, M. Masetti

We propose to replace ordinary propagators in lattice operator correlations entering the determination of hadron masses with space-time smeared propagators. These are defined as the inverse of the quadratic operator in the fermion action times its hermitian conjugate. We obtain a cleaner determination of hadron masses, comparable to the effect of using smear

D. M. Christodoulou, I. Shlosman, J. E. Tohline

This paper has been removed by arXiv admin because it was an erroneous duplicate of astro-ph/9411031.

L. N. Lipatov

The Born amplitudes for quasi-multi-Regge kinematics of produced gluons are constructed in accordance with the Feynman rules including apart from usual Yang-Mills vertices also an infinite number of induced vertices. The new vertices describe the interaction of physical gluons produced in direct channels with the reggeized gluons propagating in crossing chan

P. Kanti, K. Tamvakis

We compute the external moduli and dilaton hair to $O(α&#39;)$ in the framework of the one-loop corrected superstring effective action for a rotating black hole background.

L. Accardi, I. Ya. Aref&#39;eva, I. V. Volovich

The master field for a subclass of planar diagrams, so called rainbow diagrams, for higher dimensional large N theories is considered. An explicit representation for the master field in terms of noncommutative random variables in the modified interaction representation in the Boltzmannian Fock space is given. A natural interaction in the Boltzmannian Fock sp

B. G. Englert, K. Wodkiewicz

The concept of intrinsic and operational observables in quantum mechanics is introduced. In any realistic description of a quantum measurement that includes a macroscopic detecting device, it is possible to construct from the statistics of the recorded raw data a set of operational quantities that correspond to the intrinsic quantum mechanical observable.

Henry P. Stapp

It is argued on the basis of certain mathematical characteristics that classical mechanics is not constitutionally suited to accomodate consciousness, whereas quantum mechanics is. These mathematical characteristics pertain to the nature of the information represented in the state of the brain, and the way this information enters into the dynamics.

Moshe Gai

Some problems in nuclear astrophysics are discussed with emphasize on the ones central to the field which were not solved over the last two decades, including Helium Burning in Massive stars (the 12C(a,g)16O reaction) and the 8B Solar Neutrino Flux Problem (the 7Be(p,g)8B reaction). We demonstrate that a great deal of progress was achieved by measuring the t

Saharon Shelah

We prove that double exponentiation is an upper bound to Ramsey theorem for colouring of pairs when we want to predetermine the order of the differences of successive members of the homogeneous set.

Saharon Shelah

The pcf theorem (of the possible cofinality theory) was proved for reduced products prod_{i< kappa} lambda_i/I, where kappa < min_{i< kappa} lambda_i. Here we prove this theorem under weaker assumptions such as wsat(I)< min_{i< kappa} lambda_i, where wsat(I) is the minimal theta such that kappa cannot be delivered to theta sets notin I (or even slightly weak

Arthur Apter, Saharon Shelah

We show that supercompactness and strong compactness can be equivalent even as properties of pairs of regular cardinals. Specifically, we show that if V models ZFC + GCH is a given model (which in interesting cases contains instances of supercompactness), then there is some cardinal and cofinality preserving generic extension V[G] models ZFC + GCH in which,

John T. Baldwin, Saharon Shelah

This paper is concerned with a class K of models and an abstract notion of submodel <=. Experience in first order model theory has shown the desirability of finding a `monster model&#39; to serve as a universal domain for K. In the original constructions of Jonsson and Fraisse, K was a universal class and ordinary substructure played the role of <=. Working

Saharon Shelah, Jindřich Zapletal

Complete Boolean algebras proved to be an important tool in topology and set theory. Two of the most prominent examples are B(kappa), the algebra of Borel sets modulo measure zero ideal in the generalized Cantor space {0,1}^kappa equipped with product measure, and C(kappa), the algebra of regular open sets in the space {0,1}^kappa, for kappa an infinite card

Pablo Arés Gastesi

In this paper we will use b-groups to construct coordinates for the Teichmüller spaces of 2-orbifolds. The main technical tool is the parametrization of triangle groups, which allows us to compute explicitly formulæ for generators of b-groups uniformizing orbifolds. In this way, we obtain a technique to pass from the abstract objects of deformation spaces to

F. Krahe

We study in detail the algebra of free ghost fields which we realize in a Hilbert-Fock space with positive metric. The investigation of causality clarifies the exact reason for the failure of the spin-statistics theorem and leads to the introduction of the Krein Operator. We study the charge algebra of the ghost fields which gives a representation of ${\rm g

M. A. Halasz, J. J. M. Verbaarschot

Recently, sum rules were derived for the inverse eigenvalues of the Dirac operator. They were obtained in two different ways: i) starting from the low-energy effective Lagrangian and ii) starting from a random matrix theory with the symmetries of the Dirac operator. This suggests that the effective theory can be obtained directly from the random matrix theor

M. T. Grisaru, D. Zanon

We discuss the dressing of one-loop sigma-model beta-functions by induced supergravity, for both N=1 and N=2 supersymmetric theories. We obtain exact results by a superconformal gauge argument, and verify them in the semi-classical limit by explicit perturbative calculations in the light-cone gauge. We find that for N=2 theories there is no dressing of the o

B. W. Harris, J. Smith

We have completed the ${\cal O}(α_s)$ QCD corrections to exclusive heavy quark-antiquark distributions in deep inelastic electroproduction and present here the differential distributions in the masses of charm-anticharm and bottom-antibottom pairs at the electron-proton collider HERA.

I. G. Dymnikova, M. Krawczyk

We consider first heavy particles with masses $M\sim M_{GUT}$ which arise in the Universe during phase transitions at the Grand Unification scale. Using statistical mechanics approach we show that they behave like ideal quantum degenerate Bose gas which has the temperature of the Hawking thermal radiation due to presence of the de Sitter event horizon. The e

A. Dobado, M. J. Herrero, J. R. Pelaez, E. Ruiz Morales

In the present work we study the predictions for $WZ$ and $ZZ$ production at LHC with the Electroweak Chiral Lagrangian (EChL) approach. Our analysis will be focused on the less favored case from the experimental point of view, in which the predictions for the gauge bosons scattering amplitudes are considered in the low energy range where, by construction of

Santiago Peris, Arcadi Santamaria

Using effective field theory techniques we discuss the QCD corrections to the large-$m_t$ contributions to the process $Z\rightarrow b \bar b$. In particular we obtain the $\a$ correction to the non-universal $\log m_t$ contribution to the $Zb\bar b$ vertex.

G. Raffelt, J. ~Silk

In the light of the $ν_μ\toν_e$ neutrino oscillations which may have been observed at the LSND experiment we explore the consequences of two inverted mass schemes where solar neutrino oscillations occur between $ν_e$ and $ν_τ$. The favored LSND value $Δm^2=6\,\eV^2$ leads to $m_{ν_e}\approx m_{ν_τ}\approx 2.5\,\eV$ and $m_{ν_μ}\approx0$ so that cosmology can

Teiji Kunihiro

After giving a short introduction to the Nambu-Jona-Lasinio model with an anomaly term, we show the importance of the scalar-scalar correlation in the low-energy hadron dynamics, which correlation may be summarized by a scalar-isoscalar meson, the sigma meson. The discussion is based on the chiral quark model with the sigma-meson degrees of freedom. Possible

Y. Achiman, T. Greiner

We present a systematic search for SUSY-SO(10) models which predict the neutrino properties. The models are based on the five sets of quark mass matrices, with texture zeros, discussed recently by Roberts, Ramond and Ross. We found 8 such neutrino textures three of which can solve the solar neutrino problem. The latter have tau-neutrino masses of few eV i.e.

Makoto Oka

I review hadronic processes involving strange hadrons, especially hyperons from the quark structure point of view. The strong interaction of quarks expects several important new features when the strangeness is introduced upon the non-strange degrees of freedom. I concentrate on the instanton induced interaction, effects of the Pauli principle for strangenes

S. Boettcher, M. Moshe

We use a one-dimensional random walk on $D$-dimensional hyper-spheres to determine the critical behavior of statistical systems in hyper-spherical geometries. First, we demonstrate the properties of such a walk by studying the phase diagram of a percolation problem. We find a line of second and first order phase transitions separated by a tricritical point.

Urs M. Heller

We investigate a version of SU(2) lattice gauge theory with a logarithmic action. The model is found to exhibit confinement, contrary to previous claims in the literature. Comparing ratios of physical quantities, like $\sqrtσ/T_c$, we find that the model belongs to the same universality class as the standard SU(2) lattice gauge theory with Wilson action. Lik

T. E. Gallivan, Arie Kapulkin

The nonuniversal behavior of two noncompact nonlinear sigma models is described. When these theories are defined on a lattice, the behavior of the order parameter (magnetization) near the critical point is sensitive to the details of the lattice definition. This is counter to experience and to expectations based on the ideas of universality.

W. Kummer, P. Widerin

General matterless--theories in 1+1 dimensions include dilaton gravity, Yang--Mills theory as well as non--Einsteinian gravity with dynamical torsion and higher power gravity, and even models of spherically symmetric d = 4 General Relativity. Their recent identification as special cases of &#39;Poisson--sigma--models&#39; with simple general solution in an a

I. A. Ikramov, F. Sharipov

We have found the sufficient conditions for the spectrum of matrix-valued Friedrichs model to be finite.

Z. R. Ashurova, Y. I. Zhuraev

We prove in this paper the uniqueness theorem for a certain class of harmonic functions defined in unbounded domain lying in a band.

A. B. Kuklov, A. Krakovsky, Joseph L Birman

The interaction of an edge dislocation made of half the superconducting plane with a magnetic interlayer vortex is considered within the framework of the Lawrence-Doniach model with negative as well as positive Josephson interlayer coupling. In the first case the binding energy of the vortex and the dislocation has been calculated by employing a variational

N. Kawashima, J. E. Gubernatis

We generalize the Fortuin-Kasteleyn (FK) cluster representation of the partition function of the Ising model to represent the partition function of quantum spin models with an arbitrary spin magnitude in arbitrary dimensions. This generalized representation enables us to develop a new cluster algorithm for the simulation of quantum spin systems by the worldl

F. Dominguez-Adame, E. Macia

We have numerically computed the reflectivity of X-ray incident normally onto Fibonacci multilayers, and compared the results with those obtained in periodic approximant multilayers. The constituent layers are of low and high refractive indices with the same thickness. Whereas reflectivity of periodic approximant multilayers changes only slightly with increa

M. Bowick, P. Di Francesco, O. Golinelli, E. Guitter

We study the folding of the regular triangular lattice in three dimensional embedding space, a model for the crumpling of polymerised membranes. We consider a discrete model, where folds are either planar or form the angles of a regular octahedron. These &#34;octahedral&#34; folding rules correspond simply to a discretisation of the 3d embedding space as a F

N. Schultka, E. Manousakis

The specific heat of the $x-y$ model is studied on cubic lattices of sizes $L \times L \times L$ and on lattices $L \times L \times H$ with $L \gg H$ (i.e. on lattices representing a film geometry) using the Cluster Monte Carlo method. Periodic boundary conditions were applied in all directions. In the cubic case we obtained the ratio of the critical exponen

Viktor Dotsenko, D. E. Feldman

We study the critical properties of the weakly disordered $p$-component ferromagnet in terms of the renormalization group (RG) theory generalized to take into account the replica symmetry breaking (RSB) effects coming from the multiple local minima solutions of the mean-field equations. It is shown that for $p < 4$ the traditional RG flows at dimensions $D=4

Eugene Demler, Shou-Cheng Zhang

Recent polarized neutron scattering experiments on $YBa_2 Cu_3 O_7$ have revealed a sharp spectral peak at the $(π,π)$ in reciprocal lattice centered around the energy transfer of $41\ meV$. We offer a theoretical explanation of this remarkable experiment in terms of a new collective mode in the particle particle channel of the Hubbard model. This collective

T. V. Shahbazyan, M. E. Raikh

The deviation of the energy position of a delocalized state from the center of Landau level is studied in the framework of the Chalker-Coddington model. It is demonstrated that introducing a weak Landau level mixing results in a shift of the delocalized state up in energy. The mechanism of a levitation is a neighboring - Landau level - assisted resonant tunn

Beryl Hoffman

This paper describes a combinatory categorial formalism called Multiset-CCG that can capture the syntax and interpretation of ``free&#39;&#39; word order in languages such as Turkish. The formalism compositionally derives the predicate-argument structure and the information structure (e.g. topic, focus) of a sentence in parallel, and uniformly handles word o

R. Badrinarayanan, Jorge V. Jose, G. Chu

We study the classical and quantum mechanics of a free particle that collides elastically with the walls of a circular disk with the radius varying periodically in time. The quasi-energy spectral properties of the model are obtained from evaluation of finite-dimensional approximations to the time evolution operator. As the scaled hbar is changed from large t

H. J. Haubold, A. M. Mathai

Four operating neutrino observatories confirm the long standing discrepancy between detected and predicted solar neutrino flux. Among these four experiments the Homestake experiment is taking data for almost 25 years. The reliability of the radiochemical method for detecting solar neutrinos has been tested recently by the GALLEX experiment. All efforts to so

D. M. Christodoulou, I. Shlosman, J. E. Tohline

We have previously introduced the parameter `alpha&#39; as an indicator of stability to m=2 nonaxisymmetric modes in rotating, self-gravitating, axisymmetric, gaseous and stellar systems. This parameter can be written as a function of the total rotational kinetic energy, the total gravitational potential energy, and as a function of the topology/connectednes

J. M. Martin-Mirones, E. Martinez-Gonzalez, J. I. Gonzalez-Serrano, J. L. Sanz

We have carried out spectroscopic observations of the high redshift ($z\approx 3.4$) radio galaxy 0902+34 at intermediate resolution with the William Herschel Telescope. The dynamical spectral ranges covered are 4600-5480 Åand 5920-7680 Åwith resolutions of 5.4 Åand 9.5 Å, respectively. We detect a continuum that is almost flat and resolve three emission lin

Sandra Di Rocco

A $k$-very ample line bundle L on a Del Pezzo Surface is numerically characterized. We find that the set of the exceptional curves and effective divisors with selfintersection zero, $\cal S$, plays a very important rule in checking the nefness and $k$-very ampleness of a line bundle on a Del pezzo Surface. We show that a line bundle L is nef if and only if i

Nagel K, Rasmussen S

We use a very simple description of human driving behavior to simulate traffic. The regime of maximum vehicle flow in a closed system shows near-critical behavior, and as a result a sharp decrease of the predictability of travel time. Since Advanced Traffic Management Systems (ATMSs) tend to drive larger parts of the transportation system towards this regime

Kai Nagel, Maya Paczuski

We study a single-lane traffic model that is based on human driving behavior. The outflow from a traffic jam self-organizes to a critical state of maximum throughput. Small perturbations of the outflow far downstream create emergent traffic jams with a power law distribution $P(t) \sim t^{-3/2}$ of lifetimes, $t$. On varying the vehicle density in a closed s

George Kirczenow, Brad L. Johnson

We present a theory of composite fermion edge states and their transport properties in the fractional and integer quantum Hall regimes. We show that the effective electro-chemical potentials of composite fermions at the edges of a Hall bar differ, in general, from those of electrons. An expression for the difference is given. Composite fermion edge states of

H. Hamidian, G. Semenoff, P. Suranyi, L. C. R. Wijewardhana

We use the epsilon expansion to explore a new universality class of second order quantum phase transitions associated with a four-dimensional Yukawa field theory coupled to a traceless Hermitean matrix scalar field. We argue that this class includes four-fermi models in $2<D<4$ dimensions with $SU(N_F)\times U(N)$ symmetry and a U(N) scalar, $SU(N_F)$ iso-ve

M. A. Stephanov

We discuss the relation between dimensional reduction in quantum field theories at finite temperature and a familiar quantum mechanical phenomenon that quantum effects become negligible at high temperatures. Fermi and Bose fields are compared in this respect. We show that decoupling of fermions from the dimensionally reduced theory can be related to the non-

Jan Cieśliński, Piotr Goldstein, Antoni Sym

We show that the theory of isothermic surfaces in $\E^3$ -- one of the oldest branches of differential geometry -- can be reformulated within the modern theory of completely integrable (soliton) systems. This enables one to study the geometry of isothermic surfaces in $\E^3$ by means of powerful spectral methods available in the soliton theory. Also the asso

Pablo M. Llatas, Shibaji Roy, Jose M. Sanchez de Santos

It is shown that two dimensional (2d) topological gravity in the conformal gauge has a larger symmetry than has been hitherto recognized; in the formulation of Labastida, Pernici and Witten it contains a twisted ``small&#39;&#39; N=4 superconformal symmetry. There are in fact two distinct twisted N=2 structures within this N=4, one of which is shown to be is

Suresh Manandhar

We provide a constraint based computational model of linear precedence as employed in the HPSG grammar formalism. An extended feature logic which adds a wide range of constraints involving precedence is described. A sound, complete and terminating deterministic constraint solving procedure is given. Deterministic computational model is achieved by weakening

Eli Eisenberg, Rachel Avigur, Nadav Shnerb

It has been previously shown, that classically chaotic kicked systems, whose unperturbed spectrum posseses one energy scale, admits a quantum anti-resonance (QAR) behavior. In this study we extend the conditions under which which this QAR occurs for the case of a two-sided kicked 1D infinite potential well. It is then shown by a perturbative argument that th

Hyun Seok Yang, Bum-Hoon Lee

We construct the BRST cohomology under a positive definite inner product and obtain the Hodge decomposition theorem at a non-degenerate state vector space $V$. The harmonic states isomorphic with a BRST cohomology class correspond to the physical Hilbert space with positive norm as long as the completeness of $Q_{BRST}$ is satisfied. We explicitly define ``c

Hyun Seok Yang, Bum-Hoon Lee

We find non-covariant local symmetries in the Abelian gauge theories. The Nöther charges generating these symmetries are nilpotent as BRST charges, and they impose constraints on the physical states.

D. Gaitsgory

The idea of the work is to find an invariant way to pass from deformation theory to cohomology, which does not use any explicit cocycles. The appropriate cohomology theory is based on considering sheaves on a certain site. An advantage of the approach is that it enables one to give a simultanious treatement to all types of algebras. As an application, we pro

Glyn Morrill

We show how categorial deduction can be implemented in higher-order (linear) logic programming, thereby realising parsing as deduction for the associative and non-associative Lambek calculi. This provides a method of solution to the parsing problem of Lambek categorial grammar applicable to a variety of its extensions.

S. Eidelman, F. Jegerlehner

The hadronic contributions to the anomalous magnetic moments of the leptons and to the effective fine structure constant at the Z-mass are reevaluated using all presently available $e^+ e^-$ data.

M. San Miguel, R. Montagne, A. Amengual, E. Hernandez-Garcia

A classification of dynamical systems in terms of their variational properties is reviewed. Within this classification, front propagation is discussed in a non-gradient relaxational potential flow. The model is motivated by transient pattern phenomena in nematics. A front propagating into an unstable homogenous state leaves behind an unstable periodic patter

R. A. Alanakyan, H. M. Asatrian, A. N. Ioannisian, S. A. Chatrchyan

In the framework of the left-right symmetric model the CP-parity violation has been studied in heavy Majorana neutrino decays $N\rightarrow e^{\mp} μ^{\pm} n$. The numerical estimates of CP-asymmetry for different masses of neutrino and $W_{R}^{\pm}$-boson were obtained. The possibility to detect this phenomenon at high energy colliders is mentioned.

G. Alejandro, F. D. Mazzitelli, C. Núñez

We consider static solutions of two dimensional dilaton gravity models as toy laboratories to address the question of the final fate of black holes. A non perturbative correction to the CGHS potential term is shown to lead classically to an extremal black hole geometry, thus providing a plausible solution to Hawking evaporation paradox. However, the full qua

Hoi-Kwong Lo

The Aharonov-Bohm effect has been invoked to probe the phase structure of a gauge theory. Yet in the case of non-Abelian gauge theories, it proves difficult to formulate a general procedure that unambiguously specifies the realization of the gauge symmetry, e.g. the unbroken subgroup. In this paper, we propose a set of order parameters that will do the job.

Hoi-Kwong Lo

In this Letter, we construct a set of order parameters for non-Abelian gauge theories which probe directly the unbroken group and are free of the deficiencies caused by quantum fluctuations and gauge fixing which have plagued all previous attempts. These operators can be used to map out the phase diagram of a non-Abelian gauge theory.

Vadim Kaplunovsky, Jan Louis

We investigate the field dependence of the gauge couplings of $N=1$ string vacua from the point of view of the low energy effective quantum field theory. We find that field-theoretical considerations severely constrain the form of the string loop corrections; in particular, the dilaton dependence of the gauge couplings is completely universal at the one-loop

Henry P. Stapp

It has recently been claimed that certain aspects of mental processing cannot be simulated by computers, even in principle. The argument is examined and a lacuna is identified.

Eli Eisenberg, Larry Horwitz

It is shown that the existence of a time operator in the Liouville space representation of both classical and quantum evolution provides a mechanism for effective entropy change of physical states. In particular, an initially effectively pure state can evolve under the usual unitary evolution to an effectively mixed state.

P. Zhuang, U. Heinz

We investigate the relationship between the covariant and the three-dimensional (equal-time) formulations of quantum kinetic theory. We show that the three-dimensional approach can be obtained as the energy average of the covariant formulation. We illustrate this statement in scalar and spinor QED. For scalar QED we derive Lorentz covariant transport and con

Erik Koelink, Walter Van Assche

Laurent polynomials related to the Hahn-Exton $q$-Bessel function, which are $q$-analogues of the Lommel polynomials, have been introduced by Koelink and Swarttouw. The explicit strong moment functional with respect to which the Laurent $q$-Lommel polynomials are orthogonal is given. The strong moment functional gives rise to two positive definite moment fun

Kevin Cattell, Michael J. Dinneen, Michael R. Fellows

Finite obstruction sets for lower ideals in the minor order are guaranteed to exist by the Graph Minor Theorem. It has been known for several years that, in principle, obstruction sets can be mechanically computed for most natural lower ideals. In this paper, we describe a general-purpose method for finding obstructions by using a bounded treewidth (or pathw

Bernhard Herwig

A class K of finite structures is said to have the extension property for automorphisms (EP) if for every A in K there exists an extension B in K such that every partial isomorphism on the structure A extends to an automorphism of B. Hrushovski proved EP for the class of all finite graphs. The main problem is to keep B finite. Hodges, Hodkinson, Lascar and S

A. Morozov

The theory of matrix models is reviewed from the point of view of its relation to integrable hierarchies. Determinantal formulas, relation to conformal field models and the theory of Generalized Kontsevich model are discussed in some detail. Attention is also paid to the group-theoretical interpretation of $τ$-functions which allows to go beyond the restrict

G. Bonelli, P. A. Marchetti, M. Matone

We find a volume form on moduli space of double punctured Riemann surfaces whose integral satisfies the Painlevé I recursion relations of the genus expansion of the specific heat of 2D gravity. This allows us to express the asymptotic expansion of the specific heat as an integral on an infinite dimensional moduli space in the spirit of Friedan-Shenker approa

Allen C. Hirshfeld, Uwe Sassenberg

The total twist number, which represents the first non-trivial Vassiliev knot invariant, is derived from the second order expression of the Wilson loop expectation value in the Chern-Simons theory. Using the well-known fact that the analytical expression is an invariant, a non-recursive formulation of the total twist based on the evaluation of knot diagrams

I. L. Buchbinder, B. R. Mistchuk, V. D. Pershin

The general BRST-BFV analysis of anomaly in the string theory coupled to background fields is carried out. An exact equation for c-valued symbol of anomaly operator is found and structure of its solutions is studied.

Mariano Cadoni, Marco Cavaglia&#39;

We present and discuss an euclidean solution of the low-energy effective string action that can be interpreded as a semiclassical decay process of the ground state of the theory.

G. Bimonte, R. Iengo, G. Lozano

We compute the $β$-function of a YM theory, broken to $U(1)$, by evaluating the coupling constant renormalization in the broken phase. We perform the calculation in the unitary gauge where only physical particles appear and the theory looks like a version of QED containing massive charged spin 1 particles. We consider an on-shell scattering process and after

Hiroyuki Hata, Yusuke Taniguchi

Color confinement by the mechanism of Kugo and Ojima can treat confinement of any quantized color carrying fields including dynamical quarks. However, the non-perturbative condition for this confinement has been known to be satisfied only in the pure-gauge model (PGM), which is a topological model without physical degrees of freedom. Here we analyze the Yang

Won T. Kim, Julian Lee

We show how a stress-energy pseudotensor can be constructed in two-dimensional dilatonic gravity theories (classical, CGHS and RST) and derive the expression for the ADM mass in these theories from it. We define the Bondi mass for these theories by using the pseudotensor formalism. The resulting expression is the generalization of the expression for the ADM

Q. P. Liu

We consider the Hamiltonian theory for the multi-component KP hierarchy. We show that the second Hamiltonian structures constructed by Sidorenko and Strampp[J. Math. Phys. {\bf 34}, 1429(1993)] are not Hamiltonian. A candidate for the second Hamiltonian Structures is proposed and is proved to lead to hereditary operators.

HIDENAGA YAMAGISHI, ISMAIL ZAHED

We find that various results of current algebra at tree level and beyond can be directly obtained from a master formula, without use of chiral perturbation theory or effective Lagrangians. Application is made to $ππ$ scattering, where it is shown that the bulk of the $ρ$ contribution can be determined in a model independent way.

P. Ball, M. Beneke, V. M Braun

We propose to resum exactly any number of one-loop vacuum polarization insertions into the scale of the coupling of lowest order radiative corrections. This makes maximal use of the information contained in one-loop perturbative corrections combined with the one-loop running of the effective coupling and provides a natural extension of the familiar BLM scale

C. Gerschel, J. Hüfner, E. Quack

The measured ratios $R(x,A_1/A_2)$ for $J/Ψ$, $Ψ&#39;$ and $μ^+μ^-$ production on two different targets $A_1, A_2$ as a function of the fractional momentum $x$ of the final state are well fit with a very simple functional form having three adjustable parameters. An empirical relation is found between the three parameters of the fit. The deduced $J/Ψ$ absorpt

Harald Fritzsch, Zhi-zong Xing

Within a specific texture of the quark mass matrix the notion of a maximal violation of the $CP$ symmetry can be defined. The experimental constraints from weak decays imply that in reality one is close to the case of maximal $CP$ violation, which vanishes as the mass of the $u$--quark approaches zero. The unitarity triangle of the Cabibbo--Kobayashi--Maskaw

J. Bernabe&#39;u, A. Pilaftsis

We suggest the use of a universality-breaking observable based on lepton asymmetries as derived from the left-right asymmetry and the $τ$ polarization at the $Z$ peak, which can efficiently constrain the parameter space of unified theories. The new observable is complementary to the leptonic partial width differences and it depends critically on the chiralit

Gad Eilam, Michael Gronau, Roberto R. Mendel

We study CP asymmetries in $B^{\pm}\to hπ^{\pm}$ decays, where the hadronic states $h=ρρ, K\Kbarπ$, $π^+π^-K^+K^-$, etc., and $h=π^+π^-, K^+K^-, 2(π^+π^-)$, etc., are taken on the resonances $η_c$ and $χ_{c0}$, respectively. The relatively large $η_c$ and $χ_{c0}$ decay widths, of about 10$-$15 MeV, provide the necessary absorptive phase in the interference

A. Efimov, M. Artuso, Min Gao, R. Mountain

We show that a multifaceted LiF radiator produces more Cherenkov light and has better resolution per photon than a flat radiator slab when used in a ring imaging Cherenkov counter. Such a system is being considered for the CLEO III upgrade.

S. M. Salamon

A linear constraint is given on the Betti numbers of a compact hyper-Kaehler manifold, using an index formula for c_1c_{n-1} on an almost complex manifold. The topology of some other manifolds with reduced holonomy is also discussed briefly.

F. Pazmandi, G. T. Zimanyi, R. T. Scalettar

A mean field theory of the localization transition for bosonic systems is developed. Localization is shown to be sensitive to the distribution of the random site energies. It occurs in the presence of a triangular distribution, but not a uniform one. The inverse participation ratio, the single site Green&#39;s function, the superfluid order parameter and the

SA Hattel, JM Wheatley

Monte Carlo simulations of the frustrated 2D XY model were carried out at small commensurate values of the frustration $f$. For $f=1/30$ a single transition was observed at which phase coherence (finite helicity modulus) and vortex lattice orientational order vanish together. For $f=1/56$ a new phase in which phase coherence is absent but orientational order

Frank Morawietz

This paper defines unification based ID/LP grammars based on typed feature structures as nonterminals and proposes a variant of Earley&#39;s algorithm to decide whether a given input sentence is a member of the language generated by a particular typed unification ID/LP grammar. A solution to the problem of the nonlocal flow of information in unification ID/L

I. M. Hook, R. G. McMahon, A. R. Patnaik, I. W. A. Browne

We report the discovery of a radio loud quasar with a redshift of 4.30. This object, which is the first radio selected quasar with a redshift greater than four, was discovered during an observational investigation into the evolution of the luminosity function of radio loud quasars. Here we describe results based on a sample of ~300, flat spectrum radio sourc

Zeljko Ivezic, Moshe Elitzur

The dynamical structure and infrared emission of winds around late-type stars are studied in a self-consistent model that couples the equations of motion and radiative transfer. Both the dynamics and IR spectrum of the solution are fully characterized by the flux averaged optical depth. Five types of dust grains are considered: astronomical silicate, SiC, cr

Michael R. Merrifield, Konrad Kuijken

We have used the Tremaine-Weinberg method to measure the angular speed of rotation for the bar in the SB0 galaxy NGC 936. With this technique, the bar&#39;s pattern speed, Omega_p, can be derived from the luminosity and stellar-kinematic information in long-slit spectral observations taken parallel to the major axis of the galaxy. The kinematic measurement r

G. A. Medina Tanco, J. E. Steiner

A sample of 45 symbiotic stars observed in the direction of the galactic bulge are classified in spectral type using TiO $λλ6180, 7100 Å$ and VO $λλ7865 Å$ absorption feature indices and visual comparison. The effective temperatures obtained are used together with K data from the literature to estimate the bolometric luminosity of the giant components if loc