April 1993 arXiv papers — page 2

Jiang-Bei Fan, Ming Yu

Modules over affine Lie superalgebras ${\cal G}$ are studied, in particular, for ${\cal G}=\hat{OSP(1,2)}$. It is shown that on studying Verma modules, much of the results in Kac-Moody algebra can be generalized to the super case. Of most importance are the generalized Kac-Kazhdan formula and the Malikov-Feigin-Fuchs construction, which give the weights and

T. Eguchi, Y. Yamada, S. -K. Yang

We discuss topological Landau-Ginzburg theories coupled to the 2-dimensional topological gravity. We point out that the basic recursion relations for correlation functions of the 2-dimesional gravity have exactly the same form as the Gauss-Manin differential equations for the period integrals of superpotentials. Thus the one-point functions on the sphere of

R. F. Werner

We consider the Statistical Mechanics of systems of particles satisfying the $q$-commutation relations recently proposed by Greenberg and others. We show that although the commutation relations approach Bose (resp.\ Fermi) relations for $q\to1$ (resp.\ $q\to-1$), the partition functions of free gases are independent of $q$ in the range $-1<q<1$. The partitio

A. Petermann

Following a suggestion made by Tseytlin, we investigate the case when one replaces the transverse part of the bosonic action by an $n=2$ supersymmetric sigma-model with a symmetric homogeneous Kählerian target space. As conjectured by Tseytlin, the metric is shown to be exactly known since the beta function is known to reduce to its one-loop value.

J. Lopez, D. V. Nanopoulos, G. Park, H. Pois

We explore the one-loop electroweak radiative corrections in the minimal $SU(5)$ and the no-scale flipped $SU(5)$ supergravity models via explicit calculation of vacuum polarization contributions to the $ε_{1,2,3}$ parameters. Experimentally, $ε_{1,2,3}$ are obtained from a global fit to the LEP observables, and $M_W/M_Z$ measurements. We include $q^2$-depen

I. Pesando

We show that non-oriented coloured polymers (self--avoiding walks with different types of links) are in the same universality class of the ordinary self--avoiding walks, while the oriented coloured are not.

D. Poilblanc, J. Riera, E. Dagotto

The formation of bound states of holes in an antiferromagnetic spin-1/2 background is studied using numerical techniques applied to the ${\rm t-J}$ Hamiltonian on clusters with up to 26 sites. An analysis of the binding energy as a function of cluster size suggests that a two hole bound state is formed for couplings larger than a ``critical&#39;&#39; value $

Penny D. Sackett, Andrew Gould

If massive compact halo objects (\ms) are detected in ongoing searches, then \tsmctlmc, the ratio of the optical depth toward the Small and Large Magellanic Clouds, will be a robust indicator of the flattening of the Galactic dark matter halo. For a spherical halo, \tsmctlmc\ is about 1.45, independent of details of the shape of the Galactic rotation curve,

Hume A. Feldman, Nick Kaiser, John A. Peacock

We develop a general method for power spectrum analysis of three dimensional redshift surveys. We present rigorous analytical estimates for the statistical uncertainty in the power and we are able to derive a rigorous optimal weighting scheme under the reasonable (and largely empirically verified) assumption that the long wavelength Fourier components are Ga

James F. Lynch

A variant of Kauffman&#39;s model of cellular metabolism is presented. It is a randomly generated network of boolean gates, identical to Kauffman&#39;s except for a small bias in favor of boolean gates that depend on at most one input. The bias is asymptotic to 0 as the number of gates increases. Upper bounds on the time until the network reaches a state cyc

Edward Frenkel, Andras Szenes

We give a new interpretation and proof of the dilogarithm identities, associated to the affine Kac-Moody algebra sl(2)^, using the path description of the corresponding crystal basis. We also discuss connections with algebraic K-theory.

T. Goldman

A purely left-chiral model of the weak interactions is used to show that the total parity-violating asymmetry in quark-quark scattering must grow with increasing energy. In the absence of other new physics, non-observation of a large asymmetry can therefore be used to infer an upper bound on the mass scale for new right-chiral weak vector bosons. Applying th

Kikuo Harigaya

Effects on C$_{60}$ by thermal fluctuations of phonons, misalignment of C$_{60}$ molecules in a crystal, and other intercalated impurities (remaining C$_{70}$, oxygens, and so on) are simulated by disorder potentials. The Su-Schrieffer-Heeger--type electron-phonon model for doped C$_{60}$ is solved with gaussian bond disorders and also with site disorders. S

Philip A. Carinhas

Typical nuclear equations of state and a quark bag model, surprisingly, allow compact stars with alternate layers of neutrons and quarks. One can determine on the basis of the Gibbs free energy which phase, nuclear or quark, is energetically favorable. Using the nuclear equation of state of Wiringa, and a quark equation of state given by Freedman and McLerra

Noboru Kawamoto

Recent numerical results on the fractal structure of two-dimensional quantum gravity coupled to $c=-2$ matter are reviewed. Analytic derivation of the fractal dimensions based on the Liouville theory and diffusion equation is also discussed. Excellent agreements between the numerical and theoretical results are obtained. Some problems on the non-universal na

H. Lu, C. N. Pope, X. J. Wang

We construct BRST operators for certain higher-spin extensions of the Virasoro algebra, in which there is a spin-$s$ gauge field on the world sheet, as well as the spin-2 gauge field corrresponding to the two-dimensional metric. We use these BRST operators to study the physical states of the associated string theories, and show how they are related to certai

Edwin Langmann

We discuss the restricted linear group in infinite dimensions modeled by the Schatten class of rank $2p=4$ which contains $(3+1)$-dimensional analog of the loop groups and is closely related to Yang-Mills theory with fermions in $(3+1)$-dimensions. We give an alternative to the construction of the ``highest weight&#39;&#39; representation of this group found

Wai-Keung Tang

We studies the high energy elastic scattering of quark anti-quark with an exchange of a mesonic state in the $t$ channel with $-t/Λ^{2} \gg 1$. Both the normalization factor and the Regge trajectory can be calculated in PQCD in cases of fixed (non-running) and running coupling constant. The dependence of the Regge trajectory on the coupling constant is highl

L. Diosi, B. Lukacs

Karolyhazy&#39;s hazy space-time model, invented for breaking down macroscopic interferences, employs wave-like gravity disturbances. If so, then electric charges would radiate permanently. Here we discuss the observational consequences of the radiation. We find that such radiation is excluded by common experimental situations.

O. Golinelli, Th. Jolicoeur, R. Lacaze

We investigate the magnetic field behaviour of an antiferromagnetic Heisenberg spin-1 chain with the most general single-ion anisotropy. We discuss the regime in which the magnetic field is below the transition value. The splitting of the Haldane triplet is obtained as a function of a field applied in an arbitrary orientation by means of a Lancz\H os exact d

R. Sekhar Chivukula, Vassilis Koulovassilopoulos

The one-Higgs-doublet standard model is necessarily incomplete because of the triviality of the scalar symmetry-breaking sector. If the Higgs mass is approximately 600 GeV or higher, there must be additional dynamics at a scale $Λ$ which is less than a few TeV. In this case the properties of the Higgs resonance can differ substantially from those predicted b

W. Broniowski, M. Lutz, A. Steiner

Instead of using a simple reggeon-exchange model, we provide a model-independent estimate of high-energy contribution to the Adler-Weisberger sum-rule. Results and conclusions of the paper remain unchanged.

Ken-ichiro Arita

A semiclassical analysis is made of the origin of an undulating pattern in the smoothed level density for a reflection-asymmetric superdeformed oscillator potential. It is suggested that, when the octupole-type deformation increases, an interference effect between two families of periodic orbit with the ratio of periods approximately 2:1 becomes stronger and

Markus A. Luty, Martin White

We consider the predictions of chiral perturbation theory for $SU(3)$ breaking in weak semileptonic and $s$-wave nonleptonic hyperon decays. By defining an expansion sensitive only to $SU(3)$ breaking, we show that the leading corrections give rise to moderate corrections to $SU(3)$ relations ($\lsim 20\%$), even though the {\it chiral} symmetry $SU(3) \time

David Bowser-Chao, Kingman Cheung, Scott Thomas

The detection of an intermediate mass charged Higgs boson at $\gamgam$ colliders via the modes $\gamgam \to H^+ H^- \to ντ^+ \barν τ^-,~ c \bar{s} \bar{c} s,~$ and $ ντ^+ \bar{c}s + c \bar{s} \barν τ^-$ is considered. $W^+ W^-$ boson pair production is the dominant background for these modes. The three modes may be used in a complementary fashion to detect a

B. V. Danilin, M. V. Zhukov, J. S. Vaagen, I. J. Thompson

The electric dipole response of the halo nucleus $^{11}$Li is calculated in a hyperspherical three-body formulation, and is studied as a function of the interaction employed for $n-^9$Li to reflect the Pauli principle. Strength concentrations at lower energies are found but no narrow resonances. Only one possible scenario of $^{11}$Li structure is in close c

Theodore J. Allen, Andrew J. Bordner, Dennis B. Crossley

We examine the quantization of the motion of two charged vortices in a Ginzburg--Landau theory for the fractional quantum Hall effect recently proposed by the first two authors. The system has two second-class constraints which can be implemented either in the reduced phase space or Dirac-Gupta-Bleuler formalism. Using the intrinsic formulation of statistics

R. Cuerno, A. González--Ruiz

Elliptic diagonal solutions for the reflection matrices associated to the elliptic $R$ matrix of the eight vertex free fermion model are presented. They lead through the second derivative of the open chain transfer matrix to an XY hamiltonian in a magnetic field which is invariant under a quantum deformed Clifford--Hopf algebra.

M. Chaichian, R. Gonzales Felipe, C. Montonen

The statistics of $q$-oscillators, quons and to some extent, of anyons are studied and the basic differences among these objects are pointed out. In particular, the statistical distributions for different bosonic and fermionic $q$-oscillators are found for their corresponding Fock space representations in the case when the hamiltonian is identified with the

Jakub Rembielinski, Kordian A. Smolinski

We described a $q$-deformation of a quantum dynamics in one dimension. We prove that there exists only one essential deforamtion of quantum dynamics.

Spenta R. Wadia

We review some aspects of the non-perturbative formulation of 2-dim. string theory in terms of non-relativistic fermions. We derive the bosonization using $W_\infty$ coherent states in the path-integral formulation. We discuss the classical limit and indicate the precise nature of the truncation of the full theory that leads to collective field theory. As ap

Marialuisa Frau, Marco A. R-Monteiro, Stefano Sciuto

All classical Lie algebras can be realized à la Schwinger in terms of fermionic oscillators. We show that the same can be done for their $q$-deformed counterparts by simply replacing the fermionic oscillators with anyonic ones defined on a two dimensional lattice. The deformation parameter $q$ is a phase related to the anyonic statistical parameter. A crucia

Vittorio Del Duca, Wai-Keung Tang

The theory of the perturbative pomeron, due to Lipatov and collaborators, is used to compute the probability of observing parton-parton elastic scattering and rapidity gaps between jets in hadron collisions at very high energies.

V. Barger, M. S. Berger, P. Ohmann, R. J. N. Phillips

In minimal SUSY-GUT models with $M_{SUSY}\ltap 1$ TeV, the renormalization group equations have a solution dominated by the infrared fixed point of the top Yukawa coupling. This fixed point predicts $m_t=(200\; {\rm GeV})\sin β$; combined with the LEP results it excludes $m_t\ltap 130$ GeV. For $m_t$ in the range 130-160 GeV, we discuss the sensitivity of th

Paul H. Frampton, James T. Liu, Daniel Ng, B. Charles Rasco

The 331 model offers an explanation of flavor by anomaly cancellation between three families. It predicts three exotic quarks, $Q=D$, $S$, $T$, and five extra gauge bosons comprising an additional neutral $Z_2$ and four charged dileptonic gauge bosons $(Y^{--},Y^-)$, $(Y^{++},Y^+)$. Production of $Q\overline{Q}$, $QY$, $YY$ and $Z_2$ at the SSC is calculated

Satchidananda Naik

The coefficient of the O(a)-improved Sheikholeslami-Wohlert action for Wilson fermions are perturbatively determined at one-loop level and estimated at two-loop level.

Makoto Kaburagi, Isao Harada, Takashi Tonegawa

Low-lying excited states of the spin-1 antiferromagnetic Heisenberg chain with an impurity bond are investigated in terms of domain-wall excitations by means of analytical methods as well as a method of numerical diagonalization. It is shown that 1) the impurity bond brings about a massive triplet mode in the Haldane gap, 2) the triplet state comprises three

L. Brey, J. J. Palacios, C. Tejedor

Coulomb effects on the edge states of a two dimensional electron gas in the presence of a high magnetic field are studied for different widths of the boundaries. Schrödinger and Poisson equations are selfconsistently solved in the integer Quantum Hall regime. Regions of flat bands at the Fermi level appear for smooth interfaces in order to minimize the elect

J. J. Palacios, L. Martin-Moreno, C. Tejedor

We study lateral tunneling through a quantum box including electron-electron interactions in the presence of a magnetic field which breaks single particle degeneracies. The conductance at zero temperature as a function of the Fermi energy in the leads consists of a set of peaks related to changing by one the electron occupancy in the box. We find that the po

David R. Morrison

We study moduli spaces of nonlinear sigma-models on Calabi-Yau manifolds, using the one-loop semiclassical approximation. The data being parameterized includes a choice of complex structure on the manifold, as well as some ``extra structure&#39;&#39; described by means of classes in H^2. The expectation that this moduli space is well-behaved in these ``extra

Claudio Corianò

We show that the leading double spectral density in sum rules for Compton-like processes can be obtained by simple properties of the Borel transform, extending an approach widely used in the literature on sum rules, and known to be valid only for the spectral densities of form factors. The extension is illustrated in the scalar case, where it is shown to be

Joakim Hallin

(some errors corrected, slightly extended)

Yasuhiro Ohta, Kenji Kajiwara, Junkichi Satsuma

The relativistic Toda lattice equation is decomposed into three Toda systems, the Toda lattice itself, Bäcklund transformation of Toda lattice and discrete time Toda lattice. It is shown that the solutions of the equation are given in terms of the Casorati determinant. By using the Casoratian technique, the bilinear equations of Toda systems are reduced to t

J. Engel, E. Kolbe, K. Langanke, P. Vogel

We examine several phenomena beyond the scope of Fermi-gas models that affect the quasielastic scattering (from oxygen) of neutrinos in the 0.1 -- 3.0 GeV range. These include Coulomb interactions of outgoing protons and leptons, a realistic finite-volume mean field, and the residual nucleon-nucleon interaction. None of these effects are accurately represent

S. Skorik, V. Spiridonov

Properties of the simplest class of self-similar potentials are analyzed. Wave functions of the corresponding Schrödinger equation provide bases of representations of the $q$-deformed Heisenberg-Weyl algebra. When the parameter $q$ is a root of unity the functional form of the potentials can be found explicitly. The general $q^3=1$ and the particular $q^4=1$

Terry Gannon, Q. Ho-Kim

Using the self-dual lattice method, we make a systematic search for modular invariant partition functions of the affine algebras $g\*{(1)}$ of $g=A_2$, $A_1+A_1$, $G_2$, and $C_2$. Unlike previous computer searches, this method is necessarily complete. We succeed in finding all physical invariants for $A_2$ at levels $\le 32$, for $G_2$ at levels $\le 31$, f

B. Harms, Y. Leblanc

We consider modifications to general relativity due to non-local string effects by using perturbation theory about the 4-dimensional Schwarzschild black hole metric. In keeping with our interpretation in previous works of black holes as quantum p-branes we investigate non-local effects due to a critical bosonic string compactified down to 4 dimensions. We sh

Jens Erler

I show that anomaly cancellation conditions are sufficient to determine the two most important topological numbers relevant for Calabi-Yau compactification to six dimensions. This reflects the fact that K3 is the only non-trivial CY manifold in two complex dimensions. I explicitly construct the Green-Schwarz counterterms and derive sum rules for charges of a

R. Emparan, M. A. Valle Basagoiti

We calculate the perturbative correction to every cluster coefficient of a gas of anyons through second order in the anyon coupling constant, as described by Chern-Simons field theory.

C. Kounnas

We propose two new realizations of the N=4, $\hat{c}=4$ superconformal system based on the compact and non-compact versions of parafermionic algebras. The target space interpretation of these systems is given in terms of four-dimensional target spaces with non-trivial metric and topology different from the previously known four-dimensional semi-wormhole real

Hiroshi Shirokura

We show the factorization of correlation functions of tachyon operators in 2D string theory using the discretized approach of Moore. Our demonstration of the factorization is more general than that of the paper of Sakai and Tanii. We obtain the rules for the factorization of tachyon amplitudes. Our results can be understood in terms of the operator product e

Stefano Frixione Michelangelo L. Mangano Paolo Nason, Giovanni Ridolfi

Using a recent next-to-leading-order calculation of the photoproduction double differential cross section for heavy quarks, we study the possibility of extracting the gluon density of the proton from heavy-quark photoproduction data. We discuss the theoretical uncertainties connected with this method, and we conclude that they are well under control in a wid

T. G. Rizzo

The possibility that the interactions of the third generation of quarks and leptons may violate universality by a small amount remains an open experimental question. The model of Li and Ma, which naturally accommodates such violations, is found to be highly constrained by newly obtained, high precision electroweak and $τ$-lepton data once full Standard Model

Luis Urrutia, N. Morales

Starting from the expression for the superdeterminant of (xI-M), where M is an arbitrary supermatrix, we propose a definition for the corresponding characteristic polynomial and we prove that each supermatrix satisfies its characteristic equation. Depending upon the factorization properties of the basic polynomials whose ratio defines the above mentioned det

Michael P. Ryan, Sergio Hojman

Contribution to the Misner Festshrift, no abstract.

R. Beig, N. Ó Murchadha

An earlier construction by the authors of sequences of globally regular, asymptotically flat initial data for the Einstein vacuum equations containing trapped surfaces for large values of the parameter is extended, from the time symmetric case considered previously, to the case of maximal slices. The resulting theorem shows rigorously that there exists a lar

M. D. Johnson, G. S. Canright

We have tested Haldane&#39;s ``fractional-Pauli-principle&#39;&#39; description of excitations around the $ν= 1/3$ state in the FQHE, using exact results for small systems of electrons. We find that Haldane&#39;s prediction $β= \pm 1/m$ for quasiholes and quasiparticles, respectively, describes our results well with the modification $β_{qp} = 2-1/3$ rather t

G. Beylkin

Wavelet based algorithms in numerical analysis are similar to other transform methods in that vectors and operators are expanded into a basis and the computations take place in this new system of coordinates. However, due to the recursive definition of wavelets, their controllable localization in both space and wave number (time and frequency) domains, and t

Yu Chen, Hirotada Ohashi, Mamoru Akiyama

We systematically derived hydrodynamic equations and transport coefficients for a class of multi-speed lattice Boltzmann models in D dimensions, using the multi-scale technique. The constitutive relation of physical fluid is recovered by a modified equilibrium distribution in Maxwell-Boltzmann type. With the use of the rest particles and the particle reservo

Sanjay K. Ghosh, S. C. Phatak, Pradip K. Sahu

An exact numerical calculation of neutrino emissivity of two and three flavour quark matter have been carried out. We find that the neutrino emissivity obtained from the Iwamoto formula is in qualitative agreement with our calculation for two flavour quark matter. For three flavour case, on the other hand we find that the Iwamoto formula overestimates the nu

Sanjay K. Ghosh, Pradip K. Sahu

The nonlinear chiral extension of colour dielectric model has been used in the present work to study the properties of quark stars. Assuming that the square of meson fields develop nonzero expectation value, the thermodynamic potential for charge neutral interacting two and three flavour quark matter, in beta equilibrium, has been calculated up to second ord

Anatol N. Kirillov

We prove an inequality for the Kostka-Foulkes polynomials $K_{λ,μ}(q)$. As a corollary, we obtain a nontrivial lower bound for the Kostka numbers and a new proof of the Berenstein-Zelevinsky weight-multiplicity-one-criterium.

Debajyoti Choudhury, Probir Roy, Rahul Sinha

We relate all $C$-- and $P$--invariant anomalous triple vector--boson couplings to the oblique electroweak parameters. LEP constraints on the latter then yield the strongest and most general simultaneous bounds to date on the former. Even if the oblique parameters assume their Standard Model values precisely, these bounds would not shrink to zero---thus unde

Jemal Guven

This is a revised version of gr-qc/9304033

Carsten Grosse-Knetter, Ingolf Kuss, Dieter Schildknecht

We examine dimension-six extensions of the standard electroweak Lagrangian which are invariant under local \suu -transformations. The dimension-four trilinear and quadrilinear effective interactions of the vector bosons with one another are found to coincide with the vector boson interactions previously derived from global SU(2) weak isospin symmetry broken

Denjoe O'Connor, C. R. Stephens

We discuss the relationship between geometry, the renormalization group (RG) and gravity. We begin by reviewing our recent work on crossover problems in field theory. By crossover we mean the interpolation between different representations of the conformal group by the action of relevant operators. At the level of the RG this crossover is manifest in the flo

A. N. Schellekens

Recent work on the classification of conformal field theories with one primary field (the identity operator) is reviewed. The classification of such theories is an essential step in the program of classification of all rational conformal field theories, but appears impossible in general. The last managable case, central charge 24, is considered here. We foun

R. D. Tangerman, J. A. Tjon

We consider a Pauli particle in a Coulomb field. The supersymmetric Hamiltonian is constructed, by explicitly giving the two supercharges $Q_{1}$ and $ Q_{2}$ in the full three-dimensional space and which together with the Hamiltonian, are shown to constitute an $S(2)$ superalgebra. This offers an alternative way of grouping the energy eigenstates into irred

K. Behrndt

We investigate a solution of the Weyl invariance conditions in open string theory in 4 dimensions. In the closed string sector this solution is a combination of the SU(2) Wess--Zumino--Witten model and a Liouville theory. The investigation is carried out in the $σ$ model approach where we have coupled all massless modes (especially an abelian gauge field via

G. Grignani, G. Nardelli

Following the general method discussed in Refs.[1,2], Liouville gravity and the 2 dimensional model of non-Einstenian gravity ${\cal L} \sim curv^2 + torsion^2 + cosm. const.$ can be formulated as ISO(1,1) gauge theories. In the first order formalism the models present, besides the Poincaré gauge symmetry, additional local symmetries. We show that in both mo

G. Grignani, G. Nardelli

In the first order form, the model considered by Strobl presents, besides local Lorentz and diffeomorphism invariances, an additional local non-linear symmetry. When the model is realized as a Poincaré gauge theory according to the procedure outlined in Refs.[1,2], the generators of the non-linear symmetry are responsible for the ``nasty constraint algebra&#

Klaus Kirsten, Guido Cognola, Luciano Vanzo

We consider a self-interacting scalar field theory in a slowly varying gravitational background field. Using zeta-function regularization and heat-kernel techniques, we derive the one-loop effective Lagrangian up to second order in the variation of the background field and up to quadratic terms in the curvature tensors. Specializing to different spacetimes o

E. Elizalde, S. Naftulin, S. D. Odintsov

The one-loop effective action corresponding the general model of dilaton gravity given by the Lagrangian $L=-\sqrt{g} \left[ \frac{1}{2}Z(Φ) g^{μν} \partial_μΦ\partial_νΦ+ C(Φ) R + V (Φ)\right]$, where $Z(Φ)$, $ C(Φ)$ and $V (Φ)$ are arbitrary functions of the dilaton field, is found. The question of the quantum equivalence of classically equivalent dilaton

P. Elmfors, H. Umezawa

The thermal Bogoliubov transformation in thermo field dynamics is generalized in two respects. First, a generalization of the $α$--degree of freedom to tilde non--conserving representations is considered. Secondly, the usual $2\times2$ Bogoliubov matrix is extended to a $4\times4$ matrix including mixing of modes with non--trivial multiparticle correlations.

V. Dotsenko, G. Harris, E. Marinari, E. Martinec

We analyze the behavior of the ensemble of surface boundaries of the critical clusters at $T=T_c$ in the $3d$ Ising model. We find that $N_g(A)$, the number of surfaces of given genus $g$ and fixed area $A$, behaves as $A^{-x(g)}$ $e^{-μA}$. We show that $μ$ is a constant independent of $g$ and $x(g)$ is approximately a linear function of $g$. The sum of $N_

Scott Axelrod, I. M. Singer

In a previous paper [\AS], we used superspace techniques to prove that perturbation theory (around a classical solution with no zero modes) for Chern--Simons quantum field theory on a general $3$-manifold $M$ is finite. We conjectured (and proved for the case of $2$-loops) that, after adding counterterms of the expected form, the terms in the perturbation th

Hai-Yang Cheng, B. Tseng

Cabibbo-allowed nonleptonic weak decays of charmed baryons $\lamc,~\xin,~\xip$ and $Ω_c^0$ into an octet baryon and a pseudoscalar meson are analyzed. The nonfactorizable contributions are evaluated under pole approximation, and it turns out that the $s$-wave amplitudes are dominated by the low-lying $\halfm$ resonances, while $p$-wave ones governed by the g

Mariano Quirós

We describe in detail, in the context of the simple scalar $ϕ^4$ theory, the prescription for resummation of daisy and superdaisy diagrams in the effective potential using the solution of the gap equations in the infrared limit. We find that the latter procedure is consistent provided we neglect logarithmic terms from the finite-temperature self energies and

N. N. Nikolaev

I present a new determination of the total cross section for proton-proton collisions from the recent Akeno results on absorption of the cosmic ray protons in the p-Air collisions. Extrapolation to the SSC energy suggests $\sigma_{tot}(p-p) \approx (160-170) mb$. I also comment on a possible sensitivity of the p-Air cross section determinations to assumption

A. L. Kataev, V. T. Kim

We consider in detail various theoretical uncertainties of the perturbative predictions for the decay width of $H^0\rightarrow b\overline{b}$ process in the region $50\ GeV< M_H\leq 2M_W$. We calculate the order $O(α_s^2)$-contributions to the expression for $Γ_{Hb\overline{b}}$ through the pole quark mass and demonstrate that they are important for the elim

R. Casalbuoni, A. Deandrea, N. Di Bartolomeo, R. Gatto

Although no asymptotic heavy quark spin symmetry, and even more no flavor symmetry, are expected for systems such as quarkonium, a numerical discussion shows that for some processes and in a preasymptotic region which may roughly include charmonium and bottomonium, the use of the spin-symmetry may be useful in conjunction with chiral symmetry for light hadro

P. Binetruy, E. A. Dudas, F. Pillon

The dynamical breakdown of the $SU(2) \times U(1)$ symmetry triggered by a top-antitop condensate is studied in a supersymmetric version of the gauged Nambu-Jona-Lasinio model. An effective potential approach is used to investigate the vacuum structure and the equivalence with the minimal supersymmetric standard model. The role of the soft supersymmetry brea

UKQCD Collaboration, GS Bali, K Schilling, A Hulsebos

We present a study of the $SU(3)$ glueball spectrum for all $J^{PC}$ values at lattice spacings down to $a^{-1}=3.73 (6)$ GeV ($β=6.4$) using lattices of size up to $32^4$. We extend previous studies and show that the continuum limit has effectively been reached. The number of clearly identified $J^{PC}$ states has been substantially increased. There are no

Jemal Guven

A manifestly covariant equation is derived to describe the perturbations in a domain wall on a given background spacetime. This generalizes recent work on domain walls in Minkowski space and introduces a framework for examining the stability of relativistic bubbles in curved spacetimes.

Piotr T. Chrusciel

A Theorem is proved which reduces the problem of completeness of orbits of Killing vector fields in maximal globally hyperbolic, say vacuum, space--times to some properties of the orbits near the Cauchy surface. In particular it is shown that all Killing orbits are complete in maximal developements of asymptotically flat Cauchy data, or of Cauchy data prescr

T. Jungwirth, L. Smrcka

The effect of strong magnetic fields parallel to GaAs/AlGaAs interface on the subband structure of a 2D electron layer is ivestigated theoretically. The system with two levels occupied in zero magnetic field is considered and the magnetic field induced depletion of the second subband is studied. The confining potential and the electron dispersion relations a

Philippe Christe, Malte Henkel

This is an introduction to conformal invariance and two-dimensional critical phenomena for graduate students and condensed-matter physicists. After explaining the algebraic foundations of conformal invariance, numerical methods and their application to the Ising, Potts, Ashkin-Teller and XY models, tricritical behaviour, the Yang-Lee singularity and the XXZ

S. Succi, R. Benzi

It is shown that the Lattice Boltzmann equation for hydrodynamics can be extended in such a way as to describe non-relativistic quantum mechanics.

D. W. Grunau, T. Lookman, S. Y. Chen, A. S. Lapedes

The lattice Boltzmann (LB) method is used to study the kinetics of domain growth of a binary fluid in a number of geometries modeling porous media. Unlike the traditional methods which solve the Cahn-Hilliard equation, the LB method correctly simulates fluid properties, phase segregation, interface dynamics and wetting. Our results, based on lattice sizes of

Allen Back, John Guckenheimer, Mark Myers

This paper establishes a general framework for describing hybrid dynamical systems which is particularly suitable for numerical simulation. In this context, the data structures used to describe the sets and functions which comprise the dynamical system are crucial since they provide the link between a natural mathematical formulation of a problem and the cor

P. Gosdzinsky

Supersymmetric radiative corrections to the partial width $Γ(τ\rightarrow e ν\barν)$ and the masses of the $W$ and $Z$ gauge bosons are calculated in different renormalization schemes. The importance of the non-universal contributions is analyzed.

N. Tufillaro, CNLS, T-13, Lanl

Braid theory is used to calcualte the topological entropy of data from the belousov-Zhabotinskii reaction, the results agree well with one-dimensional theory to the order of approximation considered.

H. Rosu, E. Canessa

Davydov&#39;s model of solitons in alpha-helix protein chains is shown to display features of self-organized criticality (SOC), i.e., power law behaviour of correlations in space and 1/f-noise, as a consequence of considering random peptide group displacements from their (periodic) equilibrium positions along a chain. This may shed light on a basic mechanism

C. J. Benesh, T. Goldman, G. J. Stephenson

We calculate order $α_s$ color magnetic corrections to the valence quark distributions of the proton using the Los Alamos Model Potential wavefunctions. The spin-spin interaction breaks the model SU(4) symmetry, providing a natural mechanism for the difference between the up and down distributions. For a value of $α_s$ sufficient to produce the $N-Δ$ mass sp

N. N. Nikolaev

Colour transparency is a cute and indispensable property of QCD as the gauge theory of strong interaction. CT tests of QCD consist of production of the perturbative small-sized hadronic state and measuring the strngth of its non-perturbative diffraction nteraction in a nuclear matter. The energy depenednce of the final- state interaction in a nuclear matter

B. Mosconi, J. Pauschenwein, P. Ricci

Outgoing nucleon polarization in exclusive deuteron electrodisintegration is studied at the quasi-elastic peak in the standard theory with emphasis on the effect of nucleonic and pionic relativistic corrections. The cases of polarized beam or/and polarized target are considered. Sizeable relativistic effects are pointed out in several polarization components

M. Yu. Lashkevich

Usual coset construction $\SU{k}\times\SU{l}/\SU{k+l}$ of Wess--Zumino conformal field theory is presented as a coset construction of minimal models. This new coset construction can be defined rigorously and allows one to calculate easily correlation functions of a number of primary fields.

Carles Ayala

We explore the implications of recent work by Brézin and Zinn-Justin, applying the renormalization group techniques from critical phenomena to the scaling limit of matrix models in two-dimensional quantum gravity. They endeavor to get the lowest order fixed points of the theory giving insight upon the critical points of the theory. We show that at leading or

Arne L. Larsen

A general family of charge-current carrying cosmic string models is investigated. In the special case of circular configurations in arbitrary axially symmetric gravitational and electromagnetic backgrounds the dynamics is determined by simple point particle Hamiltonians. A certain &#34;duality&#34; transformation relates our results to previous ones, obtaine

H. J. de Vega, G. Giavarini

We present a thorough analysis of the Non Intersecting String (NIS) model and its exact solution. This is an integrable $q$-states vertex model describing configurations of non-intersecting polygons on the lattice. The exact eigenvalues of the transfer matrix are found by analytic Bethe Ansatz. The Bethe Ansatz equations thus found are shown to be equivalent