October 1995 arXiv papers — page 6

L. Schuelke, B. Zheng

The dynamic process for the two dimensional three state Potts model in the critical domain is simulated by the Monte Carlo method. It is shown that the critical point can rigorously be located from the universal short-time behaviour. This makes it possible to investigate critical dynamics independently of the equilibrium state. From the power law behaviour o

Paul J. M. Bastiaansen, Hubert J. F. Knops

Monte Carlo or Molecular Dynamics calculations of surfaces of Lennard-Jones systems often indicate, apart from a gradual disordering of the surface called surface melting, the presence of a phase transition at the surface, but cannot determine the nature of the transition. In the present paper, we provide for a link between the continuous Lennard-Jones syste

Mark Rakowski, Siddhartha Sen

The quantum kinetic equation used in the study of weak turbulence is reconsidered in the context of a theory with a generic quartic interaction. The expectation value of the time derivative of the mode number operators is computed in a perturbation expansion which places the large diagonal component of the quartic term in the unperturbed Hamiltonian. Althoug

Haye Hinrichsen, Sven Sandow, Ingo Peschel

We discuss a new mechanism leading to a matrix product form for the stationary state of one-dimensional stochastic models. The corresponding algebra is quadratic and involves four different matrices. For the example of a coagulation-decoagulation model explicit four-dimensional representations are given and exact expressions for various physical quantities a

Jose-Luis Mozos, Hong Guo

We have performed numerical simulations of dendritic growth at very low undercoolings in two spatial dimension using a phase-field model. In this regime of growth, the dendrites present sharp corners in the tip region while the trailing region is parabolic, and the corresponding side-branching structures resemble the shape of the tip. The scaling $vρ^2\sim c

Atsushi Yamagata

This is the first Monte Carlo study of the hard-sphere lattice gas with nearest neighbour exclusion on the body-centred cubic lattice. We estimate the critical activity to be $0.7223 \pm 0.0003$. This result confirms that there is a re-entrant phase transition of an antiferromagnetic Ising model in an external field and a Blume-Emery-Griffiths model on the b

Rolf Ragnarsson, J. Lewis Ford, Christian D. Santangelo, Eberhard Bodenschatz

We report experimental results on the rift formation between two freezing wax plates. The plates were pulled apart with constant velocity, while floating on the melt, in a way akin to the tectonic plates of the earth's crust. At slow spreading rates, a rift, initially perpendicular to the spreading direction, was found to be stable, while above a critica

Christine Done, Julian Krolik

We derive both total flux and velocity-resolved response functions for the CIV 1549 emission line from the data obtained in the 1993 NGC 5548 monitoring campaign. These response functions imply: 1.) the emission region stretches from inside 1 lt-d to outside 10 lt-d, and is probably better described as round than flat; 2.) the velocity field is dominated by

F. De Paolis, G. Ingrosso, Ph. Jetzer

We study different models of dark matter distribution for the halo of our galaxy. In particular, we consider Eddington and King-Michie models, which [C[C, which include anisotropy in the velocity space, and compute in a self-consistent way the amount of dark matter present in the halo. Assuming that the dark matter is in form of MACHOs, we find for each mode

Benoit Tremblay, David Merritt, T. B. Williams

We have obtained radial velocities of 68 planetary nebulae surrounding the SB0 galaxy NGC 3384 in the Leo I group, using the CTIO 4 m telescope and the Rutgers Fabry-Perot interferometer. The PN system exhibits a well-ordered rotation field aligned with the photometric axes of the galaxy. The rotation curve is flat from about 2 kpc until at least 7 kpc. Our

Eric J. Bakker, Henny J. G. L. M. Lamers, L. B. F. M. Waters, Ton Schoenmaker

We present a list of post-AGB stars showing molecular line absorption and emission in the optical spectrum. Two objects show CH+, one in emission and one in absorption, and ten stars show C2 and CN in absorption. The Doppler velocities of the C2 lines and the rotational temperatures indicate that the line forming region is the AGB remnant. An analysis of the

M. Bellazzini, E. Vesperini, F. Fusi Pecci, F. R. Ferraro

The Halo Galactic Globular Clusters (GCs) lying inside the solar circle (\inn, \r $< 8 Kpc$, \feh$<-0.8$) are shown to keep no record of the strong correlation between GC absolute integrated magnitudes and core parameters (concentration and central density) clearly detected for the Halo GCs lying outside this circle (\out) as well as (at lower statistical si

S. Andreon, E. Davoust, R. Michard, J. -L. Nieto

We present the results of an isophotal shape analysis of three samples of galaxies in the Coma cluster. Quantitative morphology, together with structural and photometric parameters, is given for each galaxy. Special emphasis has been placed on the detailed classification of early-type galaxies. The three samples are: i) a sample of 97 early-type galaxies bri

Peter R. Eisenhardt, Lee Armus, David W. Hogg, B. T. Soifer

We present an image of the redshift 2.3 IRAS source FSC10214+4724 at 0.8 microns obtained with the HST WFPC2 Planetary Camera. The source appears as an unresolved (< 0.06&#34;) arc 0.7&#34; long, with significant substructure along its length. The arc is centered near an elliptical galaxy 1.18&#34; to the north. An unresolved component 100 times fainter than

Steven Duplij

We found another N=1 odd superanalog of complex structure (the even one is widely used in the theory of super Riemann surfaces). New N=1 superconformal-like transformations are similar to anti-holomorphic ones of nonsupersymmetric complex function theory. They are dual to the ordinary superconformal transformations subject to the Berezinian addition formula

Edward Witten

The recent discovery of an explicit conformal field theory description of Type II $p$-branes makes it possible to investigate the existence of bound states of such objects. In particular, it is possible with reasonable precision to verify the prediction that the Type IIB superstring in ten dimensions has a family of soliton and bound state strings permuted b

O. Le Fevre, D. Hudon, S. J. Lilly, D. Crampton

We have used the projected two-point correlation function, $w(r_p)$, to investigate the spatial distribution of the 591 galaxies with secure redshifts between $0 \leq z \leq 1.3$ in the five CFRS fields. The slope of the two-point correlation function for the sample as a whole is $γ=1.64\pm0.05$, very similar to the local slope, and $γ$ is therefore not stro

J. Bonca, J. E. Gubernatis

We used methods of Bayesian statistical inference and the principle of maximum entropy to analytically continue imaginary-time Green&#39;s function generated in quantum Monte Carlo simulations to obtain the real-time Green&#39;s functions. For test problems, we considered chains of harmonic and anharmonic oscillators whose properties we simulated by a hybrid

Nathan A. Lindop, Henrik Jeldoft Jensen

The motion of an elastic body over a rough surface is simulated in one dimension using Newtonian dynamics. We drive the body by prescribing a constant velocity. We extract the friction force from the work done by the applied force in order to maintain the motion of the body. A positive amount of work is needed because energy is converted into the internal el

H. W. Lee, Y. S. Myung, Jin Young Kim

We discuss the two-dimensional (2D), $ε<2$ extremal ground states of charged black hole. Here $ε$ is the dilaton coupling parameter for the Maxwell term. The complete analysis of stability is carried out for all these extremal black holes. It is found that they are all unstable. To understand this instability, we study the non-extremal charged black hole wit

Fumihiko Sugino, Tamiaki Yoneya

We present detailed discussions on the stochastic Hamiltonians for non-critical string field theories on the basis of matrix models. Beginning from the simplest $c=0$ case, we derive the explicit forms of the Hamiltonians for the higher critical case $k=3$ (which corresponds to $c=-22/5$) and for the case $c=1/2$, directly from the double-scaled matrix model

Yūichi Chikashige, Tadashi Kon

We study gravitational quantum mechanics violating (QMV) effects to masses of Nambu-Goldstone bosons, taking majoron as an example. We show a supersymmetric majoron has either mass of O(keV) for the dimension five potential or smaller mass for effective potentials with higher dimensions. We extend the Dashen&#39;s formula for pseudo Nambu-Goldstone bosons to

C. S. Kim, J. H. Lin

In this letter, we have taken a particular Lagrangian, which was introduced to resolve U(1) problem, as an effective QCD Lagrangian, and have derived a formula of the quark content of the nucleon spin. The difference between quark content of the proton (\Delta\Sigma_p) and that of the neutron (\Delta\Sigma_n) is evaluated by this formula. Neglecting the high

Lev Kofman, Andrei Linde, Alexei A. Starobinsky

At the first stage of reheating after inflation, parametric resonance may rapidly transfer most of the energy of an inflaton field $ϕ$ to the energy of other bosons. We show that quantum fluctuations of scalar and vector fields produced at this stage are much greater than they would be in a state of thermal equilibrium. This leads to cosmological phase trans

Pilar Hernandez, Raman Sundrum

We discuss the problem of formulating the continuum limit of chiral gauge theories ($χ$GT) in the absence of an explicitly gauge-invariant regulator for the fermions. A solution is proposed which is independent of the details of the regulator, wherein one considers two cutoff scales, $Λ_f >> Λ_b$, for the fermions and the gauge bosons respectively. Our recen

S. Simula

Inclusive electron scattering off few-nucleon systems is investigated at $x>1$ and high momentum transfer, including the contributions from quasi-elastic and deep inelastic scattering processes. It is shown that at $x>1$ the inclusive cross section is dominated by the process of virtual photon absorption on a pair of correlated nucleons both in case of quasi

M. Henningson

We consider the spectrum of BPS saturated states in $N = 2$ gauge theories in four dimensions. This spectrum may be discontinuous across real codimension one submanifolds of marginal stability in the moduli space of vacua. An example, which can be treated with semiclassical methods in the weak coupling limit, is the decay of quark-soliton bound states. For a

Victor O. Rivelles

We present several forms in which the BRST transformations of QCD in covariant gauges can be cast. They can be non-local and even not manifestly covariant. These transformations may be obtained in the path integral formalism by non standard integrations in the ghost sector or by performing changes of ghost variables which leave the action and the path integr

Curtis G. Callan,, Juan M. Maldacena, Amanda W. Peet

We show that polarization dependent string-string scattering provides new evidence for the identification of the Dabholkar-Harvey (DH) string solution with the heterotic string itself. First, we construct excited versions of the DH solution which carry arbitrary left-moving waves yet are annihilated by half the supersymmetries. These solutions correspond in

S. Ansoldi, A. Aurilia, E. Spallucci

The string quantum kernel is normally written as a functional sum over the string coordinates and the world--sheet metrics. As an alternative to this quantum field--inspired approach, we study the closed bosonic string propagation amplitude in the functional space of loop configurations. This functional theory is based entirely on the Jacobi variational form

Mu-In Park, Young-Jai Park

According to the experimental data, it is still controversial whether the neutrinos, especially the electron-neutrino and muon-neutrino, can be considered as the fermionic spinorial tachyons, and there is still no reliable report on the existence of the right-handed neutrinos. In this letter, we show that the neutrinos with the single handedness can not be t

Anjan Kundu

A lattice regularized Lax operator for the nonultralocal modified Korteweg de Vries (mKdV) equation is proposed at the quantum level with the basic operators satisfying a $q$-deformed braided algebra. Finding further the associated quantum $R$ and $Z$-matrices the exact integrability of the model is proved through the braided quantum Yang--Baxter equation, a

N. D. Lambert

We calculate the beta-functions of the general massive (p,q) supersymmetric sigma model to two loop order using (1,0) superfields. The conditions for finiteness are discussed in relation to (p,q) supersymmetry. We also calculate the effective potential using component fields to one loop order and consider the possibility of perturbative breaking of supersymm

J. Sonnenschein, S. Theisen, S. Yankielowicz

We give a simple proof of the relation $Λ\p_artialΛ\F= {i\over2π}b_1\langle\Trϕ^2\rangle$, which is valid for $N=2$ supersymmetric QCD with massless quarks. We consider $SU(N_c)$ gauge theories as well as $SO(N_c)$ and $SP(N_c)$. Aa analogous relation which corresponds to massive hypermultiplets is written down. We also discuss the generalizations to $N=1$ m

Y. S. Myung, Jin Young Kim

We consider the perturbation of tachyon about the extremal ground state of a two-dimensional (2D) electrically charged black hole. It is found that the presenting potential to on-coming tachyonic wave takes a double-humped barrier well. This allows an exponentially growing mode with respect to time. This extremal ground state is classically unstable. We conc

Y. S. Myung

We discuss the stability of the extremal ground states of a two-dimensional (2D) charged black hole which carries both electric ($Q_E$) and magnetic ($Q_M$) charges. The method is first to find the physical field and then to derive the equation of the Schrödinger type. It is found that the presenting potential to an on-coming tachyon (as a spectator) takes a

H. W. Lee, Y. S. Myung, Jin Young Kim

We obtain the $ε<2$ new extremal ground states of a two-dimensional (2D) charged black hole where $ε$ is the dilaton coupling parameter for the Maxwell term. The stability analysis is carried out for all these extremal black holes. It is found that the shape of potentials to an on-coming tachyon (as a spectator) take all barrier-well types. These provide the

Jin Young Kim, H. W. Lee, Y. S. Myung

The charged 2D black hole is visualized as presenting an potential barrier $V^{OUT}(r^*)$ to on-coming tachyon wave. Since this takes the complicated form, an approximate form $V^{APP}(r^*)$ is used for scattering analysis. We calculate the reflection and transmission coefficients for scattering of tachyon off the charged 2D black hole. The Hawking temperatu

Y. S. Myung

We found an infinite number of potentials surrounding 2d black hole. According to the transmission ${\cal T}$ and reflection ${\cal R}$ coefficients for scattering of string fields off 2d black hole, we can classify an infinite number of potentials into three : graviton-dilaton, tachyon and the other types. We suggest that the discrete states from all the Vi

H. W. Lee, Y. S. Myung, Jin Young Kim

We study the propagation of string fields (metric $G_{μν}$, Mawxell gauge potential $A_μ$, dilaton $Φ$, and tachyon $T$) in a two-dimensional (2D) charged black hole. It is shown that the tachyon is a propagating field both inside and outside the black hole. This becomes infinitely blueshifted at the inner horizon. We confirm that the inner horizon is unstab

Tonnis A. ter Veldhuis

Models with dynamical supersymmetry breaking are interesting because they may provide a solution to both the gauge hierarchy and the fine-tuning problems. However, because of strongly interacting dynamics, it is in general impossible to analyze them quantitatively. One of the few models with calculable dynamical supersymmetry breaking is a model with SU(5) g

C. E. M. Wagner

We discuss the impact of the recent precision measurements at LEP on the minimal supersymmetric standard model. We show that the values of $\tanβ$ necessary to induce large positive corrections to $R_b$ are the same as the ones preferred by the unification of the bottom and $τ$ Yukawa couplings in the MSSM for the current measured value of $M_t$. We discuss

G. K. Leontaris, S. Lola

Extensions of the Standard Model with additional U(1) symmetries can describe the hierarchy of fermion masses and mixing angles, including neutrinos. The neutrino masses and mixings are determined up to a discrete ambiguity corresponding to the representation content of the Higgs sector responsible for the Majorana mass matrix. The solar and the atmospheric

Aron M. Bernstein, Barry R. Holstein

This paper gives an overview of a Workshop on Chiral Dynamics: Theory and Experiment which was held at MIT July 25-29, 1994; its unique feature was the equal mixture of theory and experiment. The purpose of the workshop was to bring together many of the active participants to assess the status of the field and to explore fruitful future directions. The found

Johan Bijnens, Elisabetta Pallante

Using two different methods inspired by duality transformations we present the equivalence between effective Lagrangians for massive vector mesons using a vector field and an antisymmetric tensor field. This completes the list of explicit field transformations between the various effective Lagrangian methods to describe massive vector and axial vector mesons

P. Colangelo, G. Corcella, G. Nardulli

We give an estimate of the $C$-even $B^0 \bar{B^0}$ background coming from the radiative decay $Υ(4S)\to B^0\bar B^0γ$ at $B$-factories. Our result $B(Υ(4S)\to B^0\bar B^0γ) \simeq 3 \times 10^{-9}$ shows that such background could be safely neglected in the analyses of $CP$ violating effects.

Meng Ta-chung

The special role played by singly polarized high-energy hadron-hadron collisions in Spin Physics is discussed: In such processes, the measured and the calculated quantities can be and have been directly compared with each other --- without data-extrapolation and without sum rules. It is in this kind of processes, where significant asymmetries (up to 30-40\%)

Hisashi Kikuchi

The one-loop induced magnetic dipole moments of a neutrino are examined in a background of degenerate electrons in the standard model. For the nonrelativistic neutrino, they are enhanced by a factor \( (8\pF/3\mnu) \), where \pF\ is the electron Fermi momentum and \mnu\ the neutrino mass. For the relativistic neutrino, they enhance the flavor-changing but he

N. Kitazawa

The deviation of the experimental value of $R_b \equiv Γ_b/Γ_h$ from the standard-model prediction can be naturally explained in the extended technicolor scenario.The diagonal extended technicolor gauge boson which flavor-diagonally couples with both the ordinary fermions and the techni-fermions plays an important role in order to have the appropriate radiat

J. P. Ma

We analyse inclusive photoproduction of polarized $^3P_1$ quarkonium in the framework of QCD. To separate nonperturbative and perturbative parts in the density matrix of the produced quarkonium we use a method , which is equivalent to the diagramatic expansion widely used in analysing deeply inelastic scatterings. A systematic expansion in a small velocity $

Claudio Coriano&#39;, A. R. White

Using reggeon diagrams as a partial implementation of $t$-channel unitarity, $O(g^4)$ corrections to the BFKL evolution equation have been obtained. We describe the spectrum and holomorphic factorization properties of the resulting scale-invariant kernel. For a gauge theory, $t$-channel unitarity can be studied directly in the complex $j$-plane by implementi

C. Coriano`, R. R. Parwani, A. R. White

We summarize recent work on the evaluation of the scale invariant next-to-leading order Lipatov kernel, constructed via transverse momentum diagrams. At zero momentum transfer the square of the leading-order kernel appears together with an additional component, now identified as a new partial-wave amplitude, having a separate, holomorphically factorizable, s

Claudio Coriano`, Alan R. White

In a non-abelian gauge theory the $t$-channel multiparticle unitarity equations continued in the complex j-plane can be systematically expanded around $j=1$. The combination of Ward identity constraints with unitarity is sufficient to produce directly many results obtained by Regge limit leading-log and next-to-leading log momentum space calculations. The $O

Hitoshi Murayama, Marek Olechowski, Stefan Pokorski

The supersymmetric SO(10) GUT with $t$--$b$--$τ$ Yukawa coupling unification has problems with correct electroweak symmetry breaking, experimental constraints (especially $b\rightarrow sγ$) and neutralino abundance, if the scalar masses are universal at the GUT scale. We point out that non-universality of the scalar masses at the GUT scale generated both by

B. Beinlich, F. Karsch, E. Laermann

Finite cut-off effects strongly influence the thermodynamics of lattice regularized QCD at high temperature in the standard Wilson formulation. We analyze the reduction of finite cut-off effects in formulations of the thermodynamics of $SU(N)$ gauge theories with three different $O(a^2)$ and $O(a^4)$ improved actions. We calculate the energy density and pres

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

We perform simulations of an absolute value version of the Villain model on phi3 and phi4 Feynman diagrams, ``thin&#39;&#39; 3-regular and 4-regular random graphs. The phi4 results are in excellent quantitative agreement with the exact calculations by Dorey and Kurzepa for an annealed ensemble of thin graphs, in spite of simulating only a single graph of eac

Joe Kiskis

This paper shows that there are no {\em physical} walls in the deconfined, high-temperature phase of $Z(2)$ lattice gauge theory. In a Hamiltonian formulation, the interface in the Wilson lines is not physical. The line interface and its energy are interpreted in terms of physical variables. They are associated with a difference between two partition functio

S. Adler, M. S. Atiya, I-H. Chiang, J. S. Frank

An upper limit on the branching ratio for the decay $K^+ \! \rightarrow \! π^+ ν\overlineν$ is set at $2.4 \times 10^{-9}$ at the 90\% C.L. using pions in the kinematic region $214~{\rm MeV}/c < P_π< 231~{\rm MeV}/c$. An upper limit of $5.2 \times 10^{-10}$ is found on the branching ratio for decays $K^+ \! \rightarrow \! π^+ X^0$, where $X^0$ is any massles

Anton K. Rebhan

It is shown how quantum field theory at finite temperature can be used to set up self-consistent and gauge invariant equations for cosmological perturbations sustained by an ultrarelativistic plasma. While in the collisionless case, the results are equivalent to those obtained from the Einstein-Vlasov equations, weak self-interactions in the plasma turn out

A. O. Barvinsky, A. G. Mirzabekian, V. V. Zhytnikov

The class of effective actions exactly reproducing the conformal anomaly in 4D is considered. It is demonstrated that the freedom within this class can be fixed by the choice of the conformal gauge. The conformal invariant part of the generic one-loop effective action expanded in the covariant series up to third order in the curvature is rewritten in the new

G. Blumberg, Branko P. Stojkovic, M. V. Klein

We show that in quasi-two-dimensional $d$-wave superconductors Van Hove singularities close to the Fermi surface lead to novel magnetic quasi-particle excitations. We calculate the temperature and doping dependence of dynamical magnetic susceptibility for YBCO and show that the proposed excitations are in agreement with inelastic neutron scattering experimen

Ronald Dickman

Continuous phase transitions are studied in a two dimensional nonequilibrium model with an infinite number of absorbing configurations. Spreading from a localized source is characterized by nonuniversal critical exponents, which vary continuously with the density phi in the surrounding region. The exponent delta changes by more than an order of magnitude, an

P. Dalmas de Reotier, A. Yaouanc

We provide a theoretical framework to compute the zero field muon spin relaxation rate of a Heisenberg ferromagnet at low temperature. We use the linear spin wave approximation. The rate, which is a measure of the spin lattice relaxation induced by the magnetic fluctuations along the easy axis, allows one to estimate the magnon stiffness constant.

Yoshiaki Ono

We investigate magnetization as functions of external magnetic field $H$ in the $U$-infinite Anderson lattice model within the leading order approximation in the $1/N$-expansion. At $T=0$, at $H=H_M$ where the Zeeman energy is equal to a certain characteristic energy in the system, the magnetization curve has a kink and the differential susceptibility $dM/dH

Craig Savage

This paper introduces and reviews light forces, atom cooling and atom trapping. The emphasis is on the physics of the basic processes. In discussing conservative forces the semi-classical dressed states are used rather than the usual quantized field dressed states.

Eyal Maoz

Observations of line emission from water masers near the center of the galaxy NGC 4258 have recently provided compelling evidence for rotating disk of gas, viewed nearly edge-on, surrounding a massive black hole (Miyoshi etal. 1995). We show that the disk is only marginally stable to radial perturbations - a stability regime where weak non-axisymmetric distu

David Merritt, Karl Gebhardt

In spite of the promise of new techniques for constraining the mass distribution in galaxy clusters, much remains to be learned from galaxy orbital velocities. This article reviews the theory of potential estimation in hot dynamical systems like galaxy clusters. An analysis is presented of the Coma cluster, based on a sample of about 1500 galaxies with proba

Kim Griest

We review some recent determinations of the amount of dark matter on galactic and larger scales, with special attention to the dark matter in the Milky Way. We then briefly review the motivation for and basic physics of several dark matter candidates, and then go into more depth for two candidates, the neutralino from supersymmetry, and the baryonic Macho ca

Michael C. Liu, James R. Graham, A. M. Ghez, M. Meixner

We present arcsecond resolution mid-infrared (8--13 $μ$m) images and photometry of four young stellar objects (YSOs)~--- L1551-IRS5, HL~Tau, AS~205, and AS~209 (V1121~Oph)~--- taken with the Berkeley Mid-Infrared Camera. For AS~205, a known T Tauri binary, we also present near-infrared JHK images and HKL$^{\prime}$ speckle imaging data. All three single star

Boris Shulgin, Alexander Neiman, Vadim Anishchenko

The nonlinear response of noisy bistable systems driven by strong amplitude periodical force is investigated by physical experiment. The new phenomenon of locking of the mean switching frequency between states of bistable system is found. It is shown that there is an interval of noise intensities in which the mean switching frequency remains constant and coi

Chung-Yi Wu, Tsung-Wen Yeh, Hsiang-nan Li

We compute various form factors involved in $B\to D^{(*)}$ transitions based on the perturbative QCD formalism, which includes Sudakov effects from the resummation of large radiative corrections in a heavy-light system. A two-parameter model wave function for $D^{(*)}$ mesons is fixed using data of the nonleptonic decays $B\to D^{(*)}π$, from which the ratio

L. Del Debbio, M. Faber, J. Greensite, S. Olejnik

We show that the hypothesis of abelian dominance in maximal abelian gauge, which is known to work for Wilson loops in the fundamental representation, fails for Wilson loops in higher group representations. Monte Carlo simulations are performed on lattice $SU(2)$ gauge theory, in $D=3$ dimensions, in the maximal abelian gauge, in the confined phase. It is wel

Florin Constantinescu, Mirko Luedde

From the braid-valued Burau module over the braid group we construct the Yang-Baxter matrices yielding the Alexander- and the Jones knot invariants. This generalises an observation of V. F. R. Jones.

Mirko Luedde

W.~Magnus' representations of submonoids $ E \leq \mbox{End}(F) $ of the endomorphisms of a free group $ F $ of finite rank are generalised by identifying them with the first homology group of $ F $ with particular coefficient modules. By considering a suitable free resolution of the integers over the semidirect product of free groups, a class of representat

P. A. Henning, E. Poliatchenko, T. Schilling, J. Bros

Causality requires, that the (anti-) commutator of two interacting field operators vanishes for space-like coordinate differences. This implies, that the Fourier transform of the spectral function of this quantum field should vanish in the space-like domain. We find, that this requirement imposes some constraints on the use of resummed propagators in high te

Gilad Lifschytz, Miguel E. Ortiz

The semiclassical approximation is studied on hypersurfaces approaching the union of future null infinity and the event horizon on a large class of four dimensional black hole backgrounds. Quantum fluctuations in the background geometry are shown to lead to a breakdown of the semiclassical approximation in these models. The boundary of the region where the s

N. P. Landsman

The ADM approach to canonical general relativity combined with Dirac&#39;s method of quantizing constrained systems leads to the Wheeler-DeWitt equation. A number of mathematical as well as physical difficulties that arise in connection with this equation may be circumvented if one employs a covariant Hamiltonian method in conjunction with a recently develop

I. L. Buchbinder, V. D. Pershin, G. B. Toder

A non-gauge dynamical system depending on parameters is considered. It is shown that these parameters can have such values that corresponding canonically quantized theory will be gauge invariant. The equations allowing to find these values of parameters are derived. The prescription under consideration is applied to obtaining the equation of motion for tachy

Jintai Ding

This is an extension of quantum spinor construction in \cite{DF2}. We define quantum affine Clifford algebras based on the tensor category and the solutions of q-KZ equations, construct quantum spinor representations of $U_q(\hat{\frak gl}(n))$ and explain classical and quantum boson-fermion correspondence.

T. Ioannidou, R. S. Ward

The integrable (2+1)-dimensional chiral equations are related to the self-dual Yang-Mills equation. Previously-known nonlocal conservation laws do not yield finite conserved charges, because the relevant spatial integrals diverge. We exhibit infinite sequences of conserved quantities that do exist, and have a simple explicit form.

R. S. Ward

One usually expects localized solitons in integrable systems to interact trivially. There is an integrable (2+1)-dimensional chiral equation which admits multi-soliton solutions with trivial dynamics. This paper describes how to generate explicit solutions representing nontrivial soliton interactions: in particular, a head-on collision of two solitons result

Patricio Perez

Some contributions of physics towards the understanding of consciousness are described. As recent relevant models, associative memory neural networks are mentioned. It is shown that consciousness and quantum physics share some properties. Two existing quantum models are discussed.

J. Rodrigues, A. Henneman, P. J. Mulders

We present examples for the calculation of the distribution and fragmentation functions using the representation in terms of non-local matrix elements of quark field operators. As specific examples, we use a simple spectator model to estimate the leading twist quark distribution functions and the fragmentation functions for a quark into a nucleon or a pion.

P. J. Mulders

Inclusive and semi-inclusive deep inelastic leptoproduction offers possibilities to study details of the quark and gluon structure of the hadrons involved. In many of these experiments polarization is an essential ingredient. We also emphasize the dependence on transverse momenta of the quarks, which leads to azimuthal asymmetries in the produced hadrons.

Peter K. Silaev, Slava G. Turyshev

The spacetime singularities play a useful role in gravitational theories by distinguishing physical solutions from non-physical ones. The problem, we studying in this paper is: are these singularities stable? To answer this question, we have analyzed the general problem of stability of the family of the static spherically symmetric solutions of the standard

N. Kaloper, R. Madden, K. A. Olive

We reexamine the graceful exit problem in the Pre-Big-Bang inflationary scenario. The dilaton-gravity action is generalized by adding the axion and a general axion/dilaton potential. We provide a phase space analysis of the dynamics which leads us to extend the previous no-go theorem and rule out the branch change necessary for graceful exit in this context.

Marc Henneaux

A crucial property of the standard antifield-BRST cohomology at non negative ghost number is that any cohomological class is completely determined by its antifield independent part. In particular, a BRST cocycle that vanishes when the antifields are set equal to zero is necessarily exact.\ \ This property, which follows from the standard theorems of homologi

C. Duval, P. A. Horváthy, L. Palla

It is shown that the non-relativistic `Dirac&#39; equation of Lévy-Leblond, we used recently to describe a spin $1/2$ field interacting non-relativistically with a Chern-Simons gauge field, can be obtained by lightlike reduction from $3+1$ dimensions. This allows us to prove that the system is Schrödinger symmetric. A spinor representation of the Schrödinger

I. Antoniadis, J. Iliopoulos, T. N. Tomaras

The non-local one-loop contribution to the gravitational effective action around de Sitter space is computed using the background field method with pure trace external gravitational fields and it is shown to vanish. The calculation is performed in a generic covariant gauge and the result is verified to be gauge invariant.

Kazuo Fujikawa

A path integral with BRST symmetry can be formulated by summing the Gribov-type copies in a very specific way if the functional correspondence between $τ$ and the gauge parameter $ω$ defined by $τ(x) = f( A_μ^ω)$ is ``globally single valued&#39;&#39;, where $f( A_μ^ω) = 0 $ specifies the gauge condition. A soluble gauge model with Gribov-type copies recently

Katsusada Morita, Yoshitaka Okumura

We incorporate Sogami&#39;s idea in the standard model into our previous formulation of non-commutative differential geometry by extending the action of the extra exterior derivative operator on spinors defined over the discrete space-time; four dimensinal Minkovski space multiplyed by two point discrete space. The extension consists in making it possible to

S. Chernyshev, M. A. Nowak, I. Zahed

Heavy hadrons are analyzed in a random and dilute gas of instantons. We derive the instanton-induced interactions between heavy and light quarks at next to leading order in the heavy quark mass and in the planar approximation, and discuss their effects on the hadronic spectrum. The role of these interactions in the formation of exotic hadrons is also discuss

I. I. Bigi

Phenomenological models of heavy flavour decays differ significantly in their predictions of global features of $B_c$ decays, like the $B_c$ lifetime or the relative weight of $c\ra s$ and $b\ra c$ transitions. The $1/m_Q$ expansion which is directly based on QCD allows predictions on the pattern to be expected, namely $τ(B_c)$ to lie well below 1 psec with

Mikulas Gintner, Stephen Godfrey

We performed a detailed analysis of the process $e^+e^-\to \ell νq\bar{q}&#39;$ to determine its sensitivity to anomalous trilinear gauge boson couplings of the $WWγ$ and $WWZ$ vertices and how the sensitivity varies with energy and integrated luminosity. We included all tree level Feynman diagrams that contribute to this final state and used a maximum likel

Ulrich Nierste

I describe in detail the calculation of the coefficients eta_3 and eta_1 of the low-energy Delta S=2 -hamiltonian describing K^0-K^0-bar-mixing in the next-to-leading order of renormalization group improved (RG) perturbation theory. First a general introduction into the application of the operator expansion and of RG methods to weak processes is presented. T

A. P. Martynenko, V. A. Saleev

We calculate fragmentation functions for a b-quark to fragment into color-singlet P-wave bound states $\bar c b$ in the Heavy Quark Effective Theory with the exact account of $O(1/m_b)$ corrections. We demonstrate an agreement of the obtained results with the corresponding calculations carried out in quantum chromodynamics.

Marc Sher

Bounds on R-parity violating couplings in the supersymmetric standard model are reviewed, and some new bounds arising from non-observation of certain rare B-decays (such as $B \rightarrow K^+K^-$) are presented. The focus is on baryon-number violating couplings, but it is also noted that many products of lepton- number violating and baryon-number violating c

C. Boros, Liang Zuo-tang

It is shown that the existence of left-right asymmetry in single-spin inclusive Lambda production, together with the characteristic features of the data, should be considered as another clear signature for the existence of orbiting valence quarks in polarized nucleons. Predictions for other hyperons are made. It is pointed out that measurements of such asymm

Jan Stern

Precise measurement of the $ππ$-phase shift $δ^0_0(E)$ at very low energies would provide, for the first time, the experimental evidence in favour of or against the existence of a large quark condensate in the QCD vacuum, which is standardly postulated as the mechanism of the spontaneous breakdown of chiral symmetry in QCD. The contribution of Da$ϕ$ne to thi

P. J. Mulders

Inclusive and semi-inclusive deep inelastic leptoproduction offers possibilities to study details of the quark and gluon structure of hadrons. In many of these experiments polarization is an essential ingredient. We also emphasize the dependence on transverse momenta of the quarks, which leads to azimuthal asymmetries in the produced hadrons.