February 1995 arXiv papers — page 8

Tomaz Prosen

The paper presents exact surface of section reduction of quantum mechanics. The main theoretical result is a decomposition of the energy-dependent propagator G(E) = (E - H)^(-1) in terms of the propagators which (also or exclusively) act in Hilbert space of complex-valued functions over the configurational surface of section, which has one dimension less tha

Tomaz Prosen

The recently developed quantum surface of section method is applied to a search for extremely high-lying energy levels in a simple but generic Hamiltonian system between integrability and chaos, namely the semiseparable 2-dim oscillator. Using the stretch of 13,445 consecutive levels with the sequential number around $1.8\cdot 10^7$ (eighteen million) we hav

Thierry Foglizzo, Michel Tagger

We describe the effects of both magnetic buoyancy and differential rotation on a disc of isothermal gas embedded in a purely azimuthal magnetic field, in order to study the evolution and interplay of Parker and shearing instabilities. Both instabilities occur on the slow MHD branch of the dispersion relation, and can affect the same waves. We put a stress on

E. M. de Gouveia Dal Pino, A. Hetem, J. E. Horvath, C. A. W. de Souza

In this work, we analyse the temperature fluctuations of the cosmic microwave background radiation observed by COBE and show that the distribution can be fitted by a fractal distribution with a fractal dimension $ D= 1.43 \pm 0.07 $. This value is in close agreement with the fractal dimension obtained by Coleman and Pietronero (1992) and Luo and Schramm (199

M. Pettini, D. L. King, L. J. Smith, R. W. Hunstead

Measurements of element abundances in damped Lyman alpha systems are providing new means to investigate the chemical evolution of galaxies, particularly at early times. We review progress in this area, concentrating on recent efforts to extend the range of existing surveys to both higher and lower redshifts.

Grant Gussie

A novel explanation for the origin of the cometary globules within NGC 7293 (the "Helix" planetary nebula) is examined; that these globules originate as massive cometary bodies at large astrocentric radii. The mass of such hypothetical cometary bodies would have to be several orders of magnitude larger than any such bodies observed in our solar syste

Kingman Cheung, Tzu Chiang Yuan

At hadron colliders the dominant production mechanism of $(\bar bc)$ mesons with large transverse momentum is due to parton fragmentation. We compute the rates and transverse momentum spectra for production of S-wave and P-wave $(\bar b c)$ mesons at the Tevatron via the direct fragmentation of the bottom antiquark as well as the Altarelli-Parisi induced glu

Jonathan Gratus, Robin W Tucker

We analyse the massless wave equation on a class of two dimensional manifolds consisting of an arbitrary number of topological cylinders connected to one or more topological spheres. Such manifolds are endowed with a degenerate (non-globally hyperbolic) metric. Attention is drawn to the topological constraints on solutions describing monochromatic modes on b

R. Casalbuoni, A. Deandrea, S. De Curtis, D. Dominici

We discuss the possible symmetries of the effective lagrangian describing interacting pseudoscalar-, vector-, and axial-vector mesons. Specific choices of the parameters give rise to an $[SU(2)\otimes SU(2)]^3$ symmetry. This symmetry can be obtained either {\it á la} Georgi, with all states in the spectrum remaining massless, or in a new realization, implyi

Adam F. Falk, Alexander Kyatkin

A recent calculation by Chay and Rey has shown that instantons may make a significant contribution to the lepton energy spectrum near its endpoint. Using an ansatz borrowed from the study of high energy baryon number violating processes, we investigate whether these corrections could spoil the relation between the nonperturbative contributions to this spectr

Igor V. Dolgachev

We establish a relationship between mirror symmetry for K3 surfaces and Arnold's strange duality for K3 surfaces. We compute various examples of mirror families. Among them the mirror moduli family for the moduli space of degree 2n polarized K3 surfaces. It turns out to be related to the moduli space of elliptic curves with level n.

Bertrand Reulet, Michel Ramin, Helene Bouchiat, Dominique Mailly

We have measured the flux dependence of both real and imaginary conductance of $GaAs/GaAlAs$ isolated mesoscopic rings at 310 MHz. The rings are coupled to a highly sensitive electromagnetic superconducting micro-resonator and lead to a perturbation of the resonance frequency and quality factor. This experiment provides a new tool for the investigation of th

D. Diakonov, M. Polyakov, P. Sieber, J. Schaldach

We calculate the dissipation of the baryon number after the electroweak phase transition due to thermal fluctuations above the sphaleron barrier. We consider not only the classical Boltzmann factor but also fermionic and bosonic one-loop contributions. We find that both bosonic and especially fermionic fluctuations can considerably suppress the transition ra

M. S. Volkov, O. Brodbeck, G. Lavrelashvili, N. Straumann

It is proven that there are precisely $n$ odd-parity sphaleron-like unstable modes of the $n$-th Bartnik-McKinnon soliton and the $n$-th non-abelian black hole solution of the Einstein-Yang-Mills theory for the gauge group $SU(2)$.

F. Hussain, G. Thompson

These lecture notes begin with a brief survey of the physics of heavy quark systems. This discusion motivates the introduction of the Heavy Quark Effective theory (HQET) which captures a great deal of the intuition developed. A derivation of the HQET from QCD is presented as well as an analysis of its special properties. The effective theory can be seen to a

Mijo Batinic, Ivo Slaus, Alfred Svarc

The S-wave scattering length for eta-N elastic scattering is extracted from the S-wave T-matrix in a three coupled channel, multiresonance unitary model. Results are compared with values already reported in literature which are obtained applying multichannel, but single resonance -- no background models. A dispersion among the previously published values of

Yoonbai Kim, Sho Tsujimaru, Koichi Yamawaki

Spontaneous breakdown of the continuous symmetry is studied in the framework of discretized light-front quantization. We consider linear sigma model in 3+1 dimensions and show that the careful treatment of zero modes together with the regularization of the theory by introducing NG boson mass leads to the correct description of Nambu-Goldstone phase on the li

Clovis Wotzasek

The study of hidden symmetries within Dirac's formalism does not possess a systematic procedure due to the lack of first-class constraints to act as symmetry generators. On the other hand, in the Faddeev-Jackiw approach, gauge and reparametrization symmetries are generated by the null eigenvectors of the sympletic matrix and not by constraints, suggestin

B. Dutta, E. Keith

Although calculations of the $b\rightarrow sγ$ rate in supersymmetric grand unified models have always either ignored the gluino mediated contribution or found it to be negligible, we show that taking universal supersymmetry breaking masses at the Planck scale, rather than at the gauge unification scale as is customary, leads to the gluino contribution being

Takahiro Kawai, Henry P. Stapp

In two companion papers it was shown how to separate out from a scattering function in quantum electrodynamics a distinguished part that meets the correspondence-principle and pole-factorization requirements. The integrals that define the terms of the remainder are here shown to have singularities on the pertinent Landau singularity surface that are weaker t

C. A. Bertulani

The extraction of the photodissociation cross sections of $^8B$ from Coulomb dissociation experiments is investigated. A careful study is done on the contributions of the E1, E2 and M1 multipolarities to the breakup. A comparison with the data of a recent experiment is performed. It is shown that the extraction of the radiative capture cross sections $^7Be(p

C. A. Bertulani, H. Sagawa

We investigate the use of elastic and inelastic scatterings with secondary beams of radioactive nuclei as a mean to obtain information on ground state properties and transition matrix elements to continuum states. An eikonal model is developed for this purpose by using the folding potential. In particular we discuss possible signatures of halo wavefunctions

M. Kirchbach, D. O. Riska

The weak decay as well as the strong nucleon coupling constants of the isoscalar axial vector meson $f_1 (1285)$ are estimated within the octet quark model. It is shown that the empirical value for the coupling of $\overline{s}s$ quarkonium to nucleons can be understood by attributing the $f_1(1285)$-nucleon coupling to the $a_0πN$ triangle diagram.

Apoloniusz Tyszka

We consider families F of sequences converging to +infinity that F satisfies the following condition (C): (C): if an open set U in the real line is unbounded above then there exists a sequence belonging to F, which has an infinite number of terms belonging to U. For the functions f,g from {0,1,2,...} to {0,1,2,...} we define: f =< g if and only if {i: f(i) >

R. Jackiw

These days, as high energy particle colliders become unavailable for testing speculative theoretical ideas, physicists are looking to other environments that may provide extreme conditions where theory confronts physical reality. One such circumstance may arise at high temperature $T$, which perhaps can be attained in heavy ion collisions or in astrophysical

M. P. Grabowski, P. Mathieu

A class of quantum chains possessing a family of local conserved charges with a Catalan tree pattern is studied. Recently, we have identified such a structure in the integrable $SU(N)$-invariant chains. In the present work we find sufficient conditions for the existence of a family of charges with this structure in terms of the underlying algebra. Two additi

A. Cappelli, C. A. Trugenberger, G. R. Zemba

We review our recent work on the algebraic characterization of quantum Hall fluids. Specifically, we explain how the incompressible quantum fluid ground states can be classified by effective edge field theories with the W-infinity dynamical symmetry of ``quantum area-preserving diffeomorphisms&#39;&#39;. Using the representation theory of W-infinity, we show

H. J. de Vega, J. Ramírez Mittelbrunn, M. Ramón Medrano, N. Sánchez

We find exact solutions of the string equations of motion and constraints describing the {\em classical}\ splitting of a string into two. We show that for the same Cauchy data, the strings that split have {\bf smaller} action than the string without splitting. This phenomenon is already present in flat space-time. The mass, energy and momentum carried out by

R. S. Ward

In the continuum O(3) sigma model in two spatial dimensions, there are topological solitons whose size can be stabilized by adding Skyrme and potential terms. This paper describes a lattice version, namely a natural way of modifying the 2d Heisenberg model to achieve topological stability on the lattice.

V. Lemes, R. Renan, S. P. Sorella

The nonabelian generalization of a recently proposed abelian axial gauge model for tensor matter fields is obtained. In both cases the model can be derived from a $\vf^{4}-$type theory for antisymmetric fields obeying a complex self-dual condition.

D. Erdenebayar

An explicit orbifold example of the non-zero correlation functions related to the additional contribution to the induced mass term for Higgs particles at low energies is given. We verify that they form finite dimensional representations of the target space modular transformation $SL_2(Z)$. This action of the modular group is shown to be consistent with its a

Y. N. Srivastava, G. Vitiello, A. Widom

We derive the exact action for a damped mechanical system ( and the special case of the linear oscillator) from the path integral formulation of the quantum Brownian motion problem developed by Schwinger and by Feynman and Vernon. The doubling of the phase-space degrees of freedom for dissipative systems and thermal field theories is discussed and the initia

C. M. Yung, M. T. Batchelor

We study integrable vertex models and quantum spin chains with toroidal boundary conditions. An interesting class of such boundaries is associated with non-diagonal twist matrices. For such models there are no trivial reference states upon which a Bethe ansatz calculation can be constructed, in contrast to the well-known case of periodic boundary conditions.

M. T. Batchelor, R. J. Baxter, M. J. O&#39;Rourke, C. M. Yung

We consider the six-vertex model with anti-periodic boundary conditions across a finite strip. The row-to-row transfer matrix is diagonalised by the `commuting transfer matrices&#39; method. {}From the exact solution we obtain an independent derivation of the interfacial tension of the six-vertex model in the anti-ferroelectric phase. The nature of the corre

C. M. Yung, M. T. Batchelor

We find all the diagonal $K$-matrices for the $R$-matrix associated with the minimal representation of the exceptional affine algebra $G^{(1)}_2$. The corresponding transfer matrices are diagonalized with a variation of the analytic Bethe ansatz. We find many similarities with the case of the Izergin-Korepin $R$-matrix associated with the affine algebra $A^{

M. G. Olsson, S. Veseli

We use a $1S$ lattice QCD heavy-light wavefunction to generate a single parameter, model independent description of the Isgur-Wise function. Using recent data we find the zero-recoil slope to be $ξ&#39;(1)= -1.16\pm 0.17$, while the second derivative turns out to be $ξ&#39;&#39;(1)= 2.64\pm 0.74$.

G. K. Leontaris, N. D. Tracas

We discuss in detail the possibility of determining dynamicaly the gravitino mass $m_{3/2}$, which is related to the supersymmetry breaking scale, within the minimal supersymmetric standard model (MSSM). Using the complete MSSM spectrum, we minimize the vacuum energy including one-loop corrections and a cosmological term of ${\cal O}(m_{3/2}^4)$ induced by t

T. Watabe, Chr. V. Christov, K. Goeke

We calculate the electric quadrupole to magnetic dipole transition ratio $E2/M1$ for the reaction $γN \ra Δ(1232)$ in the chiral quark soliton model. The calculated $E2/M1$ ratio is in a good agreement with the very new experimental data. We obtain non-zero negative value for the electric quadrupole $N-Δ$ transition moment, which suggests an oblate deformed

S. Bellucci, C. Bruno

Within the Extended Nambu Jona-Lasinio model, we calculate the $O(p^6)$ counterterms entering the low-energy expansion of the $γγ\to π^0 π^0$ and the $η\to π^0 γγ$ amplitudes in Chiral Perturbation Theory. For $γγ\to π^0 π^0$ our results are compatible with both the experimental data and the two-loop calculation using meson resonance saturation. For the $η$

Jes Madsen

Low-baryon number lumps of strange quark matter, strangelets, are presently searched for in ultra-relativistic heavy-ion experiments at CERN and Brookhaven. This paper gives an overview of the physical properties of strangelets with emphasis on experimental signatures such as mass and charge. Direct solutions of the Dirac equation with MIT bag model boundary

Yasuhiro Okada

Flavor changing neutral current and CP violating processes are discussed in the minimal supergravity model. The constraint on charged Higgs mass from the new measurement of the inclusive branching ratio of the $b\rightarrow sγ$ process is obtained. The $B^0_d-\bar{B}^0_d$ mixing parameter ($x_d$) and the CP violating parameter in the $K^0-\bar{K}^0$ mixing (

P. Chauvet, J. L. Cervantes-Cota

The cosmic, general analitic solutions of the Brans--Dicke Theory for the flat space of homogeneous and isotropic models containing perfect, barotropic, fluids are seen to belong to a wider class of solutions --which includes cosmological models with the open and the closed spaces of the Friedmann--Robertson--Walker metric, as well as solutions for models wi

L. Berezansky, E. Braverman

The main result of the paper is that the oscillation (non-oscillation) of the impulsive delay differential equation $\dot {x}(t)+\sum_{k=1}^m A_k(t)x[h_k(t)]=0,~~t\geq 0$, $x(τ_j)=B_jx(τ_j-0), \lim τ_j = \infty$ is equivalent to the oscillation (non-oscillation) of the equation without impulses $\dot {x}(t)=\sum_{k=1}^m A_k(t) \prod_{h_k(t)<τ_j\leq t} B_j^{-

Florin Radulescu

Let $Γ$ be a fuchsian subgroup of \pslr. In this paper we consider the $Γ$-equivariant form of the Berezin&#39;s quantization of the upper half plane which will correspond to a deformation quantization of the (singular) space $\Bbb H/Γ$. Our main result is that the von Neumann algebra associated to the $Γ-$ equivariant form of the quantization is stable isom

J. Chen, R. Kobes, J. Wang

Clean metallic superlattice systems composed of alternating layers of superconducting and normal materials are considered, particularly aspects of the proximity effect as it affects the critical temperature. A simple model is used to address the question of when a finite--sized system theoretically approximates well a true infinite superlattice. The methods

Guido Minnen, Dale Gerdemann, Thilo Goetz

A novel approach to HPSG based natural language processing is described that uses an off-line compiler to automatically prime a declarative grammar for generation or parsing, and inputs the primed grammar to an advanced Earley-style processor. This way we provide an elegant solution to the problems with empty heads and efficient bidirectional processing whic

J. B. Hutchings, S. C. Morris

Observations with the PC2 CCD of the Hubble Space Telescope are described of two bright QSOs of redshift ~0.3. 1403+434 is IR-bright and radio-quiet, and 2201+315 is radio-loud with extended structure. Exposures were taken with the F702W and F555W filters. The images are deconvolved on their own and combined with 0.5 arcsec ground-based images. Both host gal

P. Goldoni, S. Mereghetti

We present the results of a ROSAT Position Sensitive Proportional Counter observation of the variable radio star \ls. The source has a power law spectrum with photon index 1.1 +/- 0.3 and a luminosity of 5.9 x 10^{33} erg/s in the 0.1 -2.4 keV range. Variability on a timescale of days is clearly visible in the ROSAT data, but no periodic pulsations have been

P. Goldoni, C. Musso, P. A. Caraveo, G. F. Bignami

After reviewing the multifrequency behaviour of the Isolated Neutron Stars detected so far, we analyze for each object the efficiency of conversion of the star&#39;s rotational energy loss into optical, X and gamma radiation. Although the number of pulsars detected at different wavelengths is rather limited, a pattern is seen to emerge from our analysis poin

F. Malbet, J. W. Yu, M. Shao

The need for high dynamic range imaging is crucial in many astronomical fields, such as extra-solar planet direct detection, extra-galactic science and circumstellar imaging. Using a high quality coronograph, dynamic ranges of up to $10^{5}$ have been achieved. However the ultimate limitations of coronographs do not come from their optical performances, but

Phillip Helbig

The general idea of determining cosmological parameters with gravitational lensing statistics is outlined, and then recent work---with an emphasis on applicability to all cosmological models, observational bias, better statistics and robustness testing through numerical simulations---is discussed with relevance to a scheme originally introduced by Kochanek t

C. J. Grillmair, K. C. Freeman, M. Irwin, P. J. Quinn

We examine the outer structure of 12 Galactic globular clusters using star-count analyses. Deep, two-color, photographic photometry is used to select and count stars with colors and magnitudes consistent with cluster-specific, color-magnitude sequences. The resulting reduction in the number of contaminating foreground stars allows us to push the star counts

M. H. van Kerkwijk, S. R. Kulkarni, K. Matthews, G. Neugebauer

We have obtained infrared spectra of the star suggested to be the counterpart of the soft gamma-ray repeater (SGR) 1806-20. We found strong emission lines similar to those seen in the spectra of the rare Luminous Blue Variables and B[e] stars. A He I absorption line is also seen, from which we infer a spectral type O9--B2. This classification, in combination

Rodrigo Ibata, Gerard Gilmore

We analyse velocity, chemical abundance and spatial distribution data for some 1500 K- and M- giants in the Galactic Bulge. The bulge has a well-determined linear rotation curve over the range $\rm 700pc \le R \le 3500pc$ with amplitude ${\rm \sim 25 km s^{-1} kpc^{-1}}$. The oblate isotropic bulge model of Kent (1992) is in reasonable agreement with our dat

Rodrigo Ibata, Gerard Gilmore

An observational survey of stars selected from the region of sky in the direction of the Galactic bulge is presented. We discuss the choice of tracer populations for this study. Digitised UK Schmidt plate photometry, calibrated with CCD photometry, is obtained in 18 regions over the bulge. Stars are selected for spectroscopic follow-up from within a carefull

J. G. Russo, A. A. Tseytlin

We consider a new 3-parameter class of exact 4-dimensional solutions in closed string theory and solve the corresponding string model, determining the physical spectrum and the partition function. The background fields (4-metric, antisymmetric tensor, two Kaluza-Klein vector fields, dilaton and modulus) generically describe axially symmetric stationary rotat

F. de Campos, M. A. Garcia-Jareno, Anjan S. Joshipura, J. Rosiek

R parity violation can induce mixing of the supersymmetric Higgs bosons with the sneutrinos at the tree level. We study the effect of this mixing on the decays of Higgs scalars as well as sneutrinos in an effective model where the violation of R parity is included in the minimal supersymmetric model through bilinear lepton number violating superpotential ter

I. I. Mazin, Victor M. Yakovenko

We discuss the origin of the neutron scattering peak at 41 meV observed in YBa$_2$Cu$_3$O$_7$ below $T_c$. The peak may occur due to spin-flip electron excitations across the superconducting gap which are enhanced by the antiferromagnetic interaction between Cu spins. In this picture, the experiment is most naturally explained if the superconducting order pa

I Batalin, R Marnelius, A Semikhatov

A geometric description is given for the Sp(2) covariant version of the field-antifield quantization of general constrained systems in the Lagrangian formalism. We develop differential geometry on manifolds in which a basic set of coordinates (`fields&#39;) have two superpartners (`antifields&#39;). The quantization on such a triplectic manifold requires int

X. de Hemptinne

Irreversibility of spontaneous macroscopic dynamics and its asymmetry with respect to the sign reversal of the variable $t$ is usually interpreted as a genuine property of complex isolated systems. Discussion of the kinetics involved in Joule&#39;s experiment concerning spontaneous expansion of a gas shows that the isolation hypothesis results from ambiguous

V. A. Saleev

A study of the $J/ψ$-meson production at large transverse momentum in high energy $γp$ collisions via the charm quark excitation in a photon is presented. Based on perturbative QCD and the nonrelativistic quark model, our calculation demonstrates that the charm content of a photon may be very important for the $J/ψ$ photoproduction at the large transverse mo

R. Ramachandran

The object of this brief review is to reconcile different points of view on how the spin of proton is made up from its constituents. On the basis of naive quark model with flavour symmetry such as isospin or SU(3) one finds a static description. On the contrary the local SU(3) colour symmetry gives a dynamical view. Both these views are contrasted and the ro

C. S. Kim, Jungil Lee, H. S. Song

We investigated how measurements of weak boson production at high energy $ep$ and $eγ$ collisions can provide important information on anomalous $WWγ$ couplings. We also considerd the sinlge muon production through the virtual $W$-decay at the Pohang Light Source (PLS) facility, and found this process is not adequate to be detected at the PLS until a large l

Giuseppe Vitiello

The quantum model of the brain proposed by Ricciardi and Umezawa is extended to dissipative dynamics in order to study the problem of memory capacity. It is shown that infinitely many vacua are accessible to memory printing in a way that in sequential information recording the storage of a new information does not destroy the previously stored ones, thus all

M. Flato, M. Gerstenhaber, A. A. Voronov

Cohomology and deformation theories are developed for Poisson algebras starting with the more general concept of a Leibniz pair, namely of an associative algebra $A$ together with a Lie algebra $L$ mapped into the derivations of $A$. A bicomplex (with both Hochschild and Chevalley-Eilenberg cohomologies) is essential.

V. S. Gerdjikov, N. A. Kostov

Zakharov-Shabat--Ablowitz-Kaup-Newel-Segur representation for Stokes-anti-Stokes stimulated Raman scattering is proposed. Periodical waves, solitons and self-similarity solutions are derived. Transient and bright threshold solitons are discussed.

T. Mart, C. Bennhold, C. E. Hyde-Wright

The few available data for the reactions $γp \rightarrow K^{0} Σ^{+}$ and $γn \rightarrow K^{+} Σ^{-}$ are compared to models developed for the processes $γp \rightarrow K^{+} Σ^{0}$ and $γp \rightarrow K^{+} Λ$. It is found that some of these phenomenological models overpredict the measurements by up to a factor of 100. Fitting the data for all of these rea

J. A. Niskanen

In a recent paper by C. J. Horowitz (Phys. Rev. C {\bf 48}, 2920 (1993)) a heavy meson exchange is incorporated into threshold NN --> d pi to enhance the grossly underestimated cross section. However, that calculation uses an unjustified assumption on the initial and final momenta, which causes an overestimate of this effect by a factor of 3--4. I point out

C. H. Chen, C. L. Wu, D. H. Feng, A. Arima

In this paper, eit is shown for a single-$j$ shell that the intrinsic excitations induced by the quadrupole-quadrupole interaction can be viewed as that due to the inverted surface-delta interaction whose multipole-pairing component with the largest spin is the dominant term and is attractive. This allow us to trace the origin of the recently introduced opti

Matti Pitkänen

There is some experimental evidence that some stars are older than the Universe in General Relativity based cosmology. In TGD based cosmology the paradox has explanation. Photons can be either topologically condensed on background spacetime surface or in &#39;vapour phase&#39; that is progate in $M^4_+\times CP_2$ as small surfaces. The time for propagation

Martin G. Harris

We consider a model of p independent Ising spins on a dynamical planar phi-cubed graph. Truncating the free energy to two terms yields an exactly solvable model that has a third order phase transition from a pure gravity region (gamma=-1/2) to a tree-like region (gamma=1/2), with gamma=1/3 on the critical line. We are able to make an order of magnitude estim

S. De Bievre, M. Degli Esposti, R. Giachetti

We present a unified framework for the quantization of a family of discrete dynamical systems of varying degrees of &#34;chaoticity&#34;. The systems to be quantized are piecewise affine maps on the two-torus, viewed as phase space, and include the automorphisms, translations and skew translations. We then treat some discontinuous transformations such as the

Qi-Zhou Chen, Xiang-Qian Luo, Shuo-Hong Guo

We investigate quantum chromodynamics in 2+1 dimensions ($\rm{QCD}_3$) using the Hamiltonian lattice field theory approach. The long wavelength structure of the ground state, which is closely related to the confinement phenomenon, is analyzed and its vacuum wave function is evaluated by means of the recently developed truncated eigenvalue equation method. Th

Olivier Piguet

Vector supersymmetry is typical of topological field theory. Its role in the construction of gauge invariant quantities is explained, as well as its role in the cancellation of the ultraviolet divergences. The example of the Chern-Simons theory in three dimensions is treated in details.

M. C. Diamantini, P. Sodano, C. A. Trugenberger

We investigate the non-perturbative structure of two planar $Z_p \times Z_p$ lattice gauge models and discuss their relevance to two-dimensional condensed matter systems and Josephson junction arrays. Both models involve two compact U(1) gauge fields with Chern-Simons interactions, which break the symmetry down to $Z_p \times Z_p$. By identifying the relevan

Igor Batalin, Robert Marnelius

The Sp(2)-symmetric Lagrangian quantization scheme is represented in a completely anticanonical form. Antifields are assigned to all field variables including former &#34;parametric&#34; ones π^{Aa}. The antibrackets (F, G)^a as well as the operators \triangle^a and V^a are extended to include the new anticanonical pairs π^{Aa}, \barϕ_A. A new version of the

Hiroaki Kanno, Yűji Ohta

We show that there is a series of topological string theories whose integrable structure is described by the Toda lattice hierarchy. The monodromy group of the Frobenius manifold for the matter sector is an extension of the affine Weyl group $\widetilde W (A_N^{(1)})$ introduced by Dubrovin. These models are generalizations of the topological $CP^1$ string t

Felix M. Lev

In our recent paper (hep-ph/9501348) we argued that the Bjorken variable $x$ in deep inelastic scattering cannot be interpreted as the light cone momentum fraction $ξ$ even in the Bjorken limit and in zero order of the perturbation theory. The purpose of the present paper is to qualitatively explain this fact using only a few simplest kinematical relations.

Qi-Zhou Chen, Xiang-Qian Luo, Shuo-Hong Guo, Xi-Yang Fang

We discuss how to extract the spectroscopy of quantum chromodynamics (QCD) in the pure gauge sector from the Hamiltonian lattice field theory approach. The recently developed truncated eigenvalue equation method is applied to the estimation of the scalar glueball $0^{++}$ and $0^{--}$ masses in the (2+1)-dimensional case. These masses reach the constant valu

K. Sailer, A. Schäfer, W. Greiner

Including the Haar measure we show that the effective potential of the regularized SU(2) Yang-Mills theory has a minimum at vanishing Wilson-line $W=0$ for strong coupling, whereas it develops two degenerate minima close to $W=\pm 1$ for weak coupling. This suggests that the non-abelian character of $SU(2)$ as contained in the Haar measure might be responsib

A. G. Morgan

The second order formalism for fermions provides a description of fermions that is very similar to that of scalars. We demonstrate that this second order formalism is equivalent to the standard Dirac formalism. We do so in terms of the conventional fermionic Feynman rules. The second order formalism has previously proven useful for the computation of fermion

Dongsheng Du, Chun Liu

A cyclic symmetry among the left-handed doublets of the three families is proposed. This symmetry can naturally result in a realistic hierarchical pattern of the fermion masses within the framework of supersymmetry with nonvanishing sneutrino vacuum expectation values.

Elizabeth Jenkins, Richard F. Lebed

The $I=0,1,2,3$ mass splittings of the spin-$1/2$ octet and spin-$3/2$ decuplet baryons are analyzed in the $1/\N$ expansion combined with perturbative flavor breaking. We show there is considerable experimental evidence that the baryon masses satisfy the hierarchy predicted by this expansion. Since flavor symmetry-breaking suppression factors alone are not

Jae-Kwon Kim

We report thermodynamic values of four-point renormalized coupling constant calculated by Monte Carlo simulations in the continuum limits of the lattice versions of the two-dimensional O(2) and O(3) non-linear sigma models. In each case the critical index of the coupling constant vanishes, which leads to hyperscaling (non-triviality).

ZEUS Collaboration

Two-jet production in deep-inelastic electron-proton scattering has been studied for $160<Q^2<1280$~GeV$^2$, $0.01<x<0.1$ and $0.04<y<0.95$ with the ZEUS detector at HERA. The kinematic properties of the jets and the jet production rates are presented. The partonic scaling variables of the two-jet system and the rate of two-jet production are compared to per

C. Dettmann, N. Frankel, N. Cornish

Fractal basin boundaries provide an important means of characterizing chaotic systems. We apply these ideas to general relativity, where other properties such as Lyapunov exponents are difficult to define in an observer independent manner. Here we discuss the difficulties in describing chaotic systems in general relativity and investigate the motion of parti

L. S. Finn

Recent work on the expected event rate of neutron star inspiral signals in the LIGO detector is summarized. The observed signals will be from inspirals at cosmological distances, and the important cosmological effects on the event rate and spectrum are discussed. This paper is a contribution to the proceedings of the 17th Texas Symposium held in Munich, 12-1

O. V. Babourova, B. N. Frolov, M. Yu. Koroliov

On the basis of the Lie derivative method in a metric-affine space-time it is shown that in the metric-affine gravitational theory the energy-momentum conservation law and therefore the equations of the matter motion are the consequence (as in the GR) of the gravitational field equations. The possi- bility of the detection of the space-time non-metric proper

Jysoo Lee

Using numerical and analytic methods, we study the behavior of granular particles contained in a vibrating box. We measure, by molecular dynamics (MD) simulation, several quantities which characterize the system. These quantities--the density and the granular temperature fields, and the vertical expansion--obey scaling in the variable $x = Af$. Here, $A$ and

Arianna Montorsi, David K. Campbell

We show that the exact ground state for a class of extended Hubbard models including bond-charge, exchange, and pair-hopping terms, is the Yang &#34;eta-paired&#34; state for any non-vanishing value of the pair-hopping amplitude, at least when the on-site Coulomb interaction is attractive enough and the remaining physical parameters satisfy a single constrai

Michel J. P. Gingras, David A. Huse

As a simplified model of randomly pinned vortex lattices or charge-density waves, we study the random-field XY model on square ($d=2$) and simple cubic ($d=3$) lattices. We argue, and confirm in simulations, that the spacing between topological defects (vortices) diverges more strongly than the Imry-Ma pinning length as the random field strength, $H$, is red

E. H. Lieb, J. P. Solovej, J. Yngvason

The quantum mechanical ground state of a 2D $N$-electron system in a confining potential $V(x)=Kv(x)$ ($K$ is a coupling constant) and a homogeneous magnetic field $B$ is studied in the high density limit $N\to\infty$, $K\to \infty$ with $K/N$ fixed. It is proved that the ground state energy and electronic density can be computed {\it exactly} in this limit

D. Shelton, A. M. Tsvelik

We study the 1D model of conduction electrons interacting with local vibronic modes. States in the conduction band are two-fold degenerate both in orbital index and spin. It is shown that such 1D system has a strong tendency to superconductivity. The superconducting pairing originates from coupling of two charge density waves; the scaling dimension of the or

A. M. Tsvelik

The exact solution of the boundary sine-Gordon model is studied in the region where the scaling dimension of the boundary field $1 < Δ< 1$. It is shown that at $Δ> 2/3$ the infrared fixed point belongs to the universality class of the underscreened anisotropic Kondo model. The boundary contribution to the specific heat scales as $C \sim T^{2Δ^{-1} - 2}$ at s

B. Normand, H. Kohno, H. Fukuyama

We consider the implications of spin-phonon coupling within the slave-boson, mean-field treatment of the extended t-J model of a high-temperature superconductor. In bilayer cuprates such as YBaCuO, where the $CuO_2$ plane is buckled, this interaction is linear in $O$ displacement along the c-axis, and the coupling constant is found to be large. The formation

F B Anders

The infinite-$U$ single impurity Anderson model for rare earth alloys is examined with a new set of self-consistent coupled integral equations, which can be embedded in the large $N$ expansion scheme ($N$ is the local spin degeneracy). The finite temperature impurity density of states (DOS) and the spin-fluctuation spectra are calculated exactly up to the or

Kai T. Hansen

We describe the structure of bifurcations in the unbounded classical Diamagnetic Kepler problem. We conjecture that this system does not have any stable orbits and that the non-wandering set is described by a complete trinary symbolic dynamics for scaled energies larger then $ε_c=0.328782\ldots$.

Kai T. Hansen, Predrag Cvitanovic

We investigate the Bunimovich stadium dynamics and find that in the limit of infinitely long stadium the symbolic dynamics is a subshift of finite type. For a stadium of finite length the Markov partitions are infinite, but the inadmissible symbol sequences can be determined exactly by means of the appropriate pruning front. We outline a construction of a se

Sandip K. Chakrabarti

We show that viscous, transonic accretion disks which start with sub-Keplerian angular momentum at the outer boundary reproduce the features of the so-called thick, thin, slim and other accretion disk models depending upon the accretion rates and viscosity parameters. These disks are advection dominated in the pre-shock region and rotation dominated in the p

Radoslaw Stompor, Krzysztof M. Gorski, Anthony J. Banday

The two-year COBE-DMR 53 and 90 GHz sky maps are used to determine the normalization of inflationary, cosmological constant dominated, cold dark matter models. Although the COBE-DMR data prefer a nearly critical value for the total density, low-density models with Omega_0 > 0.15 can not be rejected at a confidence level > 95%. We compare theoretical predicti