November 1994 arXiv papers — page 8

Nicholas B. Tufillaro

Analysis of effects of noise and drift on chaotic synchronization. To appear in Physics Letters.

Nicholas B. Tufillaro

Some misleading statements in a recent paper in PRE are corrected.

Nicholas B. Tufillaro

The (forced) periodic orbit spectrum is calculated for a chaotic time series (BZ reaction).

Nicholas B. Tufillaro

Prunning front is calculated for a bouncing ball system and the results are compared to a braid analysis. To Appear in Physical Review E.

L. Ya. Glozman, D. O. Riska

The fine structure of the low energy part of the nucleon and strange hyperon spectra, which are formed of single states without parity doublets, may be understood in terms of an $SU(3)$ flavor-symmetric quark-quark interaction that describes chiral pseudoscalar boson exchange. The model predicts the fine structure splittings within 10-30\% of their empirical

A. A. Gvozdev, A. V. Kuznetsov, N. V. Mikheev, L. A. Vassilevskaya

The decays $μ\rightarrow e γ$, $μ\rightarrow e γγ$, and $μ\rightarrow e e \bar e$ are analysed in the framework of the Pati-Salam type quark-lepton symmetry $SU(4)_V \otimes SU(2)_L \otimes G_R$ where the effects of mixing in the quark-lepton currents are taken into account. It is shown that the $μ\rightarrow e γγ$ and $μ\rightarrow e e \bar e$ decays via th

K. Bresser

All bicovariant first order differential calculi on the quantum group GLq(3,C) are determined. There are two distinct one-parameter families of calculi. In terms of a suitable basis of 1-forms the commutation relations can be expressed with the help of the R-matrix of GLq(3,C). Some calculi induce bicovariant differential calculi on SLq(3,C) and on real form

Hideaki Aoyama, Toshiyuki Harano

The complex-time method for quantum tunneling is studied. In one-dimensional quantum mechanics, we construct a reduction formula for a Green function in the number of turning points based on the WKB approximation. This formula yields a series, which can be interpreted as a sum over the complex-time paths. The weights of the paths are determined.

Tadashi YOSHIKAWA

We discuss the effects of isospin breaking which appear in the vertex corrections for $Zb \bar{b}$, $Zτ^+τ^-$ and $Wντ$ in a one-family technicolor model without exact custodial symmetry. By means of the effective lagrangian approach we compute the vertex corrections for $Zb\bar{b}$, $Zττ$ and $Wτν$ taking account of the contributions from technivectormesons

Frank Cuypers, Karol Kolodziej

We study the incidence of genuine quartic vector boson couplings in the reactions e-e- -> e-e-ZZ, e-νZW, ννWW. We find that a linear collider operated in the e-e- mode will provide bounds on these couplings which are competitive with those to be obtained in the e+e- mode.

John L. Friedman, Michael S. Morris

We study the massless scalar field on asymptotically flat spacetimes with closed timelike curves (CTC's), in which all future-directed CTC's traverse one end of a handle (wormhole) and emerge from the other end at an earlier time. For a class of static geometries of this type, and for smooth initial data with all derivatives in $L_2$ on ${\cI}^{-}$,

Norman Cruz, Jorge Zanelli

The hydrostatic equilibrium of a $2+1$ dimensional perfect fluid star in asymptotically anti-de Sitter space is discussed. The interior geometry matches the exterior $2+1$ black-hole solution. An upper mass limit is found, analogous to Buchdahl's theorem in 3+1, and the possibility of collapse is discussed. The case of a uniform matter density is solved

S. Carlip, J. E. Nelson

We compare three approaches to the quantization of (2+1)-dimensional gravity with a negative cosmological constant: reduced phase space quantization with the York time slicing, quantization of the algebra of holonomies, and quantization of the space of classical solutions. The relationships among these quantum theories allow us to define and interpret time-d

D. Cule, Y. Shapir

The discrete Gaussian model for the surface of a crystal deposited on a disordered substrate is studied by Monte Carlo simulations. A continuous transition is found from a phase with a thermally-induced roughness to a glassy one in which the roughness is driven by the disorder. The behavior of the height-height correlations is consistent with the one-step re

I. R. Aitchison, P. Ao, D. J. Thouless, X. -M. Zhu

We show that the low frequency, long wavelength dynamics of the phase of the pair field for a BCS-type s-wave superconductor at T=0 is equivalent to that of a time-dependent non-linear Schrödinger Lagrangian (TDNLSL), when terms required by Galilean invariance are included. If the modulus of the pair field is also allowed to vary, the system is equivalent to

Robert Gassler

A differential form vanishing on the tangent space at smooth points of a reduced embedded analytic germ is called conormal. For proving that a conormal one--form of a hypersurface vanishes at its singularities we state a Bertini--type theorem.

Benjamin Grinstein

Introductory lectures (delivered at TASI, June 1994) on heavy quarks and heavy quark effective field theory. Applications to inclusive semileptonic decays and to interactions with light mesons are covered in detail.

V. Schechtman, H. Terao, A. Varchenko

In this note we strenghten a theorem by Esnault-Schechtman-Viehweg which states that one can compute the cohomology of a complement of hyperplanes in a complex affine space with coefficients in a local system using only logarithmic global differential forms, provided certain "Aomoto non-resonance conditions" for monodromies are fulfilled at some &#34

Allan Ramsay

Krifka [1993] has suggested that focus should be seen as a means of providing material for a range of semantic and pragmatic functions to work on, rather than as a specific semantic or pragmatic function itself. The current paper describes an implementation of this general idea, and applies it to the interpretation of {\em only} and {\em not}.

Ulli Wolff

In pure SU(2) gauge theory we compute the two-loop coefficient in the relation between the lattice bare coupling and the running coupling defined through the Schroedinger functional. This result is required to relate the latter to the MSbar-coupling in our programme to compute alpha_s. In addition it allows us to implement O(a) improvement of the Schroedinge

Axel Bender, Reinhard Alkofer

The Dyson-Schwinger equation for the quark self energy is solved in rainbow approximation using an infrared (IR) vanishing gluon propagator that introduces an IR mass scale $b$. There exists a $b$ dependent critical coupling indicating the spontaneous breakdown of chiral symmetry. If one chooses realistic QCD coupling constants the strength and the scale of

Tobias Hurth

We present the causal construction of perturbative Yang-Mills theories in four(3+1)-dimensional space-time. We work with free quantum fields throughout. The inductive causal method by Epstein and Glaser leads directly to a finite perturbation series and does not rely on an intermediary regularization of the theory. The causal method naturally separates the p

Fumiharu Kato

In this paper, we give a criterion for the existence of logarithmic embeddings -- which was first introduced by Steenbrink -- for general normal crossing varieties. Using this criterion, we also give a new proof of the theorem of Kawamata--Namikawa which states a criterion for the existence of the log structures of semistable type.

Itzhak Bars

Two dimensional classical string theory is solved in any curved spacetime. The complete spacetime required to describe the classical string motions turns out to be larger than the global space required by complete particle geodesics. The solutions are fully classified by their behavior in the asymptotically flat region of spacetime. When the curvature is smo

J. A. Caballero, E. Garrido, E. Moya de Guerra, P. Sarriguren

We study the properties of the spin dependent one body density in momentum space for odd--A polarized deformed nuclei within the mean field approximation. We derive analytic expressions connecting intrinsic and laboratory momentum distributions. The latter are related to observable transition densities in {\bf p}--space that can be probed in one nucleon knoc

E. Garrido, J. A. Caballero, E. Moya de Guerra, P. Sarriguren

We present results for response functions and asymmetries in the nuclear reactions 37\vec{Ar}(\vec{e},e'n)36Ar and 37\vec{K}(\vec{e},e' p)36Ar at quasifree kinematics. We compare PWIA results obtained using deformed HF wave functions with PWIA and DWIA results obtained assuming a spherical mean field. We show that the complex structure of the deforme

C. Ciofi degli Atti, E. Pace, G. Salmè

The theory of quasi-elastic inclusive scattering of polarized leptons off polarized $^3$He is critically reviewed and the origin of different expressions for the polarized nuclear response function appearing in the literature is explained. The sensitivity of the longitudinal asymmetry upon the neutron form factors is thoroughly investigated and the role play

Wolgang Eholzer, Nils-Peter Skoruppa

We describe the construction of vector valued modular forms transforming under a given congruence representation of the modular group SL$(\bold Z)$ in terms of theta series. We apply this general setup to obtain closed and easily computable formulas for conformal characters of rational models of $W$-algebras.

F. Ravanini, M. Stanishkov, R. Tateo

We give evidence, by use of the Thermodynamic Bethe Ansatz approach, of the existence of both massive and massless behaviours for the $ϕ_{2,1}$ perturbation of the $M_{3,5}$ non-unitary minimal model, thus resolving apparent contradictions in the previous literature. The two behaviours correspond to changing the perturbing bare coupling constant from real va

Florian Nill, Hans-Werner Wiesbrock

Given an irreducible inclusion of infinite von-Neumann-algebras $\cn \subset \cm$ together with a conditional expectation $ E : \cm \rightarrow \cm $ such that the inclusion has depth 2, we show quite explicitely how $\cn $ can be viewed as the fixed point algebra of $\cm$ w.r.t. an outer action of a compact Kac-algebra acting on $\cm$. This gives an alterna

Dimitra Karabali

We discuss how a large class of incompressible quantum Hall states can be characterized as highest weight states of different representations of the \Winf algebra. Second quantized expressions of the \Winf generators are explicitly derived in the cases of multilayer Hall states, the states proposed by Jain to explain the hierarchical filling fractions and th

Luis J Boya, Alejandro Rivero

We build a toy model of the Wilson-Kogut renormalization group in one dimensional Quantum Mechanics. With it, we show how the RG flow in the space of 1-D S matrices of finite range defines, as renormalized interactions, the known four parametric set of contact interactions, thus providing a suitable framework for its study.

Hendrik Grundling

For a manifold M we define a structure on the group action of Diff(M) on the smooth functions on M which reduces to the usual differential geometry upon differentiation at zero along the one-parameter groups of Diff(M). This ``integrated differential geometry'' generalises to all group actions on associative algebras, including noncommutative ones, a

H. -C. Cheng, L. J. Hall

In the minimal supersymmetric standard model, assuming universal scalar masses at large energies, there are four intragenerational relations between the masses of the squarks and sleptons for each light generation. In this paper we study the scalar mass relations which follow only from the assumption that at large energies there is a grand unified theory whi

R. N. Mohapatra, S. Nussinov

If the upper limit on the effective (Majorana) neutrino mass from neutrinoless double beta decay experiments is confirmed to be much less than an electron-volt, then one way to reconcile it with the degenerate neutrino mass pattern suggested recently to explain the observed deficit of solar and atmospheric neutrinos as well as neutrinos as HDM is to postulat

S. Dimopoulos, L. J. Hall

In a class of supersymmetric grand unified theories, including those based on the gauge group $SO(10)$, there are new contributions to the electric dipole moments of the neutron and electron, which arise as a heavy top quark effect. These contributions arise from CKM-like phases, not from phases of the supersymmetry breaking operators, and can be reliably co

Bruce A. Campbell, Keith A. Olive

We consider the effects of the time dependence of couplings due to their dependence on a dilaton field, as occurs in superstring theory, as well as in gravity theories of the Jordan-Brans-Dicke type. Because the scale parameters of couplings set by dimensional transmutation depend exponentially on the dilaton vev, we may obtain stringent limits on the shift

A. Bramon, E. Shabalin

The branching ratios of weak decays of $η$ mesons are estimated in the framework of the Standard Model. To observe such decays, $η$ meson sources with $N_η > 10^{13}$ per year are needed.

B. Ancochea, A. Bramon

Quantum interference effects between past and future events (neutral kaon transitions, including CP violating decays) are discussed for entangled kaon pairs produced through $ϕ\to K^0 \bar{K^0}$ in $ϕ$-factories. Contrasting with the exciting conclusions of other recent analyses, we predict the inexistence of such an observable effect.

A. Bramon, A. Grau, G. Pancheri

The accuracy of effective chiral lagrangians including vector-mesons as (hidden symmetry) gauge fields is shown to be improved by taking into account SU(3)-breaking in the vector-meson sector. The masses, $M_V$, and couplings to the photon field and pseudoscalar pairs, $f_{Vγ}$ and $g_{VPP}$, are all consistently described in terms of two parameters, which a

A. Denner, S. Dittmaier, R. Schuster

We investigate the sensitivity of the reaction $γγ\to W^+W^-$ to the Higgs sector based on the complete one-loop corrections in the minimal Standard Model and the gauged non-linear $σ$-model. While this sensitivity is very strong for the suppressed cross-section of equally polarized photons and longitudinal W bosons, it is only marginal for the dominant mode

B. ~Ehrnsperger, A. ~Schäfer

We reanalyse hyperon beta decay data to extract the corresponding F and D values. We show that flavour symmetry breaking effects lead naturally to a reduction of the $F/D$ ratio. For proton and neutron our analyses suggests $F/D = 0.49 \pm 0.08$ instead of $F/D = 0.575 \pm 0.016$ which is generally used to analyse the spin data. Our smaller $F/D$ value allow

P. W. Stephenson

We investigate point-to-point correlation functions for various mesonic and baryonic channels using the ${\cal O}(a)$-improved Wilson action due to Sheikholeslami and Wohlert. We consider propagators to both time slices 0 and 1. We find that discretisation effects are more pronounced than those reported with unimproved Wilson fermions, but that the same proc

Frithjof Karsch

Modifications of hadron masses and some of their basic properties with temperature or nuclear density are considered as one possible signature for the formation of dense hadronic matter in nuclear collisions. We discuss here some basic results on the temperature dependence of hadron properties obtained from calculations of hadron correlation functions, the c

F. ~Karsch, E. Laermann, M. Lütgemeier

We establish a close relation between the spatial string tension of the (3+1)-dimensional $SU(3)$ gauge theory at finite temperature ($σ_s$) and the string tension of the 3-dimensional $SU(3)$ gauge theory ($σ_3$) which is similar to what has been found previously for $SU(2)$. We obtain $\sqrt{σ_3} = (0.554 \pm 0.004) g_3^2$ and $\sqrt{σ_s} = (0.586 \pm 0.04

F. Karsch, E. Meggiolaro, L. Turko

Using the monomer--dimer representation of the lattice Schwinger model, with $N_f =1$ Wilson fermions in the strong--coupling regime ($β=0$), we evaluate its partition function, $Z$, exactly on finite lattices. By studying the zeroes of $Z(k)$ in the complex plane $(Re(k),Im(k))$ for a large number of small lattices, we find the zeroes closest to the real ax

James T. Wheeler

The gauge bundle of the 4-dim conformal group over an 8-dim base space, called biconformal space, is shown have a consistent interpretation as a scale-invariant phase space. Specifically, we show that a classical Hamiltonian system generates a differential geometry which is necessarily biconformal, and that the classical Hamiltonian dynamics of a point parti

Xing Zhuge, Joan M. Centrella, Stephen L. W. McMillan

We calculate the gravitational radiation produced by the merger and coalescence of inspiraling binary neutron stars using 3-dimensional numerical simulations. The stars are modeled as polytropes and start out in the point-mass limit at wide separation. The hydrodynamic integration is performed using smooth particle hydrodynamics (SPH) with Newtonian gravity,

Franz Embacher

Recently, it has been shown that an infinite succession of classical signature changes (''signature oscillations'') can compactify and stabilize internal dimensions, and simultaneously leads, after a coarse graining type of average procedure, to an effective (''physical'') space-time geometry displaying the usual Lorentzian me

R. Resta, S. Sorella

The ferroelectric polarization of perovskite oxides is much larger than implied by displacement of static ionic charges. We use an explicitly correlated scheme to investigate the phenomenon; charge transport is evaluated as a geometric quantum phase. Both covalence and electron-electron interaction enhance polarization in the weakly correlated regime. At hig

S. Wiseman, E. Domany

The critical behaviour of a bond-disordered Ashkin-Teller model on a square lattice is investigated by intensive Monte-Carlo simulations. A duality transformation is used to locate a critical plane of the disordered model. This critical plane corresponds to the line of critical points of the pure model, along which critical exponents vary continuously. Along

G. F. Mazenko, R. A. Wickham

The theory of growth kinetics developed previously is extended to the asymmetric case of off-critical quenches for systems with a conserved scalar order parameter. In this instance the new parameter $M$, the average global value of the order parameter, enters the theory. For $M=0$ one has critical quenches, while for sufficiently large $M$ one approaches the

Gang Su, Bao-Heng Zhao

We show that in the translation invariant case and in the antiferromagnetic phase, the reduced density matrix $ρ_2$ has no off-diagonal long-range order of on-site electron pairs for the single-band Hubbard model on a cubic lattice away from half filling at finite temperatures both for the positive coupling and for the negative coupling. In these cases the m

Atle Ro

A theory of interlanguage (IL) lexicons is outlined, with emphasis on IL lexical entries, based on the HPSG notion of lexical sign. This theory accounts for idiosyncratic or lexical transfer of syntactic subcategorisation and idioms from the first language to the IL. It also accounts for developmental stages in IL lexical grammar, and grammatical variation i

J. D. Bryngelson, J. N. Onuchic, N. D. Socci, P. G. Wolynes

The understanding, and even the description of protein folding is impeded by the complexity of the process. Much of this complexity can be described and understood by taking a statistical approach to the energetics of protein conformation, that is, to the energy landscape. The statistical energy landscape approach explains when and why unique behaviors, such

Bernd A. Berg, Ulrich H. E. Hansmann, Yuko Okamoto

We comment on a recent article by Hao and Scheraga.

Robert H. Brandenberger

An introduction to modern cosmology is given, focusing on theories for the origin of structure in the Universe. After a brief review of the theory of growth of cosmological perturbations and a summary of some important observational results, most of the article is devoted to discussions of the inflationary Universe scenario and of topological defect models o

Ramesh Narayan, Matthias Bartelmann

We propose a new technique, which we call the lens parallax method, to determine simultaneously the redshift distribution of the faint blue galaxies and the mass distribution of foreground clusters of galaxies. The method is based on gravitational lensing and uses the fact that the mean angular size of the faint blue galaxies is a well-determined function of

Luis Masperi, Sandra Savaglio

It is shown that the axion concentrated in electroweak strings which are consequently stabilized may produce a rotation of the polarization angle of radiation from extragalactic sources larger than that caused by a background field, and that axionic walls attached to global strings have an effect which depends on the frequency. We discuss the validity of the

Jeffrey A. Willick, Stephane Courteau, Sandra M. Faber, David Burstein

We have combined five Tully-Fisher (TF) redshift-distance samples for peculiar velocity analysis: the cluster data of Han, Mould and coworkers (1991-93, HM) and Willick (1991, W91CL), and the field data of Aaronson et al. (1992), Willick (1991), Courteau & Faber (1992), and Mathewson et al. (1992), totaling over 3000 spiral galaxies. We treat the cluster dat

Y. P. Jing, H. J. Mo, G. Boerner, L. Z. Fang

We investigate, using high resolution N-body simulations, the density profiles and the morphologies of galaxy clusters in three models of structure formation. We show that these properties are closely related to the occurrence of a significant merging event to a cluster in the recent past. The three models are: (1) the standard CDM model (SCDM) with $Ω_0 = 1

J. W. Moffat

A nonsymmetric gravitational theory (NGT) is presented which is free of ghost poles, tachyons and higher-order poles and there are no problems with asymptotic boundary conditions. An extended Birkhoff theorem is shown to hold for the spherically symmetric solution of the field equations. A static spherically symmetric solution in the short-range approximatio

D. Dalmazi, A. de Souza Dutra

We discuss a relativistic free particle with fractional spin in 2+1 dimensions, where the dual spin components satisfy the canonical angular momentum algebra $\left\{ S_μ, S_ν\right\}\,=\,ε_{μνγ}S^γ$. It is shown that it is a general consequence of these features that the Poincarè invariance is broken down to the Lorentz one, so indicating that it is not pos

S. Kalyana Rama

Alternatives to Einstein's theory of general relativity can be distinguished by measuring the parametrised post Newtonian parameters. Two such parameters $β$ and $γ$, equal to one in Einstein theory, can be obtained from static spherically symmetric solutions. For the graviton-dilaton system, as in Brans-Dicke or low energy string theory, we find that if

R. Longo, K. -H. Rehren

A subtheory of a quantum field theory specifies von~Neumann subalgebras $å(\oo)$ (the `observables' in the space-time region $\oo$) of the von~Neumann algebras $\bb(\oo)$ (the `fields' localized in $\oo$). Every local algebra being a (type $\III_1$) factor, the inclusion $å(\oo) \subset \bb(\oo)$ is a subfactor. The assignment of these local subfacto

C. Stephen Hellberg, Efstratios Manousakis

The phase diagram of the two-dimensional t-J model is determined accurately at low electron density by a combination of analytic and numerical techniques. The ground state exhibits three phases in the limit of zero electron density: an unpaired state at small J/t, a gas of s-wave pairs for 2 < J/t < 3.4367, and a phase separated state at larger interaction s

S. A. Larin, T. van Ritbergen, J. A. M. Vermaseren

We present the analytical $α_{s}^3$ correction to the $Z^{0}$ decay rate into hadrons. We calculate this correction up to (and including) terms of the order $(m_Z^2/m_{top}^2)^3$ in the large top quark mass expansion. We rely on the technique of the large mass expansion of individual Feynman diagrams and treat its application in detail. We convert the obtain

Maxim Braverman

We introduce a notion of elliptic differential graded Lie algebra. The class of elliptic algebras contains such examples as the algebra of differential forms with values in endomorphisms of a flat vector bundle over a compact manifold, etc. For elliptic differential graded algebra we construct a complete set of deformations. We show that for several deformat

Kazuo Fujikawa

An index relation $dim\ ker\ a^{\dagger}a - dim\ ker\ aa^{\dagger} = 1$ is satisfied by the creation and annihilation operators $a^{\dagger}$ and $a$ of a harmonic oscillator. A hermitian phase operator, which inevitably leads to $dim\ ker\ a^{\dagger}a - dim\ ker\ aa^{\dagger} = 0$, cannot be consistently defined. If one considers an $s+1$ dimensional trunc

D. F. Wang, C. Gruber

The integrability of the one dimensional chiral Hubbard model is discussed in the limit of strong interaction, U=+\infty. The system is shown to be integrable in sense of existence of an infinite number of constants of motion. The system is related to a chiral Kondo lattice model at strong interaction J=+\infty

Emanuel Knill

Hamidoune&#39;s connectivity results for hierarchical Cayley digraphs are extended to Cayley coset digraphs and thus to arbitrary vertex transitive digraphs. It is shown that if a Cayley coset digraph can be hierarchically decomposed in a certain way, then it is optimally vertex connected. The results are obtained by extending the methods used by Hamidoune.

Jussi Kalkkinen

We study the noncommutative geometry of a two-leaf Parisi--Sourlas supermanifold in Connes&#39; formalism using different $K$-cycles over the Grassmann algebra valued functions on the supermanifold. We find that the curvature of the trivial noncommutative vector bundle defines in the simplest case the super Yang--Mills action coupled to a scalar field. By co

J. Jezierski

The asymptotic conformal Yano--Killing tensor proposed in J. Jezierski, On the relation between metric and spin-2 formulation of linearized Einstein theory [GRG, in print (1994)] is analyzed for Schwarzschild metric and tensor equations defining this object are given. The result shows that the Schwarzschild metric (and other metrics which are asymptotically

Nguyen Suan Han

Closed expressions for the Green function and amplitude of the scalar particle scattering in the external gravitational field $g_{μν}(x)$ are found in the form of functional integrals. It is shown that, as compared with the scattering on the vector potential, the tensor character of the gravitational field leads to a more rapid increase of the cross section

Nguyen Suan Han, Hoang Ngoc Long, Dang Van Soa

We consider the conversion of gravitons into photons in the $ TE_{mo} $ mode. Cross sections in different directions are given.

Johan van de Leur

To every partition $n=n_1+n_2+\cdots+n_s$ one can associate a vertex operator realization of the Lie algebras $a_{\infty}$ and $\hat{gl}_n$. Using this construction we obtain reductions of the $s$--component KP hierarchy, reductions which are related to these partitions. In this way we obtain matrix KdV type equations. We show that the following two constrai

Johan van de Leur

Adler, Shiota and van Moerbeke obtained for the KP and Toda lattice hierarchies a formula which translates the action of the vertex operator on tau--functions to an action of a vertex operator of pseudo-differential operators on wave functions. This relates the additional symmetries of the KP and Toda lattice hierarchyto the $W_{1+\infty}$--, respectively $W

Johan Van De Leur

We study the BKP hierarchy and its $n$--reduction, for the case that $n$ is odd. This is related to the principal realization of the basic module of the twisted affine Lie algebra $\hat{sl}_n^{(2)}$. We show that the following two statements for a BKP $τ$ function are equivalent: (1) $τ$ is is $n$--reduced and satisfies the string equation, i.e. $L_{-1}τ=0$,

Xuemin Jin

The self-energies of $Δ$ isobar propagating in nuclear matter are calculated using the finite-density QCD sum-rule methods. The calculations show that the Lorentz vector self-energy for the $Δ$ is significantly smaller than the nucleon vector self-energy. The magnitude of the $Δ$ scalar self-energy is larger than the corresponding value for the nucleon, whic

Mark B. Wise

Recent progress in the theory of hadrons containing a single heavy quark is reviewed. Particular attention is paid to those aspects that bear on the determination of the magnitudes of the Cabibbo--Kobayashi--Maskawa matrix elements $V_{cb}$ and $V_{ub}$.}

J. P. Vary, T. J. Fields, H. J. Pirner

We examine QED$_{1+1}$ (the massive Schwinger model) to extend existing perturbation results in $m_f/m_b$, and compare our results with lattice and DLCQ calculations. (Based on a talk presented by J.P. Vary at ``Theory of Hadrons and Light-Front QCD&#39;&#39;, Polona Zgorzelisko, Poland, August 1994.)

S. Dawson, G. Valencia

We bound anomalous gauge boson couplings using LEP data for the $Z\rightarrow {\overline f} f$ partial widths. We use an effective field theory formalism to compute the one-loop corrections resulting from non-standard model three and four gauge boson vertices. We find that measurements at LEP constrain the three gauge boson couplings at a level comparable to

Michael Martin Nieto, Michael H. Holzscheiter

We describe the origin, development, and status of the Los Alamos antiproton catching trap. Originally designed for the antiproton gravity experiment, it now is clear that this device can be a source of low-energy antiprotons for a wide range of physics, both on site, at CERN, and also off site.

M. Knecht, B. Moussallam, J. Stern

The $ππ$ interaction is studied at one loop order in the framework of Generalized Chiral Perturbation theory

Kazuo Fujikawa

A vector-like extension of the standard model for heavier quarks and leptons with $SU(2)\times U(1)$ gauge symmetry and only one Higgs doublet is examined. This scheme incorporates infinitely many fermions and avoids the appearance of a strongly interacting sector. The model is perturbatively well controllable, and constraints such as $b\rightarrow sγ$ and G

Mark A. Scheel, Stuart L. Shapiro, Saul A. Teukolsky

We discuss a number of long-standing theoretical questions about collapse to black holes in the Brans-Dicke theory of gravitation. Using a new numerical code, we show that Oppenheimer-Snyder collapse in this theory produces black holes that are identical to those of general relativity in final equilibrium, but are quite different from those of general relati

Mark A. Scheel, Stuart L. Shapiro, Saul A. Teukolsky

We present a new numerical code that evolves a spherically symmetric configuration of collisionless matter in the Brans-Dicke theory of gravitation. In this theory the spacetime is dynamical even in spherical symmetry, where it can contain gravitational radiation. Our code is capable of accurately tracking collapse to a black hole in a dynamical spacetime ar

U. Zuelicke, A. J. Millis

We derive expressions for the universal contribution to the specific heat of a three-dimensional metal near a zero-temperature phase transition with dynamic exponent $z=2,3$, or 4. The results allow a quantitative comparison of theory to data. We illustrate the application of our results by analyzing data for Ce$_{1-x}$Lu$_x$Cu$_2$Si$_2$, which has been clai

Koo-Chul Lee

We extend the circle theorem on the zeros of the partition function to a continuum system. We also calculate the exact zeros of the partition function for a finite system where the probability distribution for the order parameter is given by two asymmetric Gaussian peaks. For the temperature driven first order transition in the thermodynamic limit, the locus

Ralph Grishman, Catherine Macleod, Adam Meyers

We describe the design of Comlex Syntax, a computational lexicon providing detailed syntactic information for approximately 38,000 English headwords. We consider the types of errors which arise in creating such a lexicon, and how such errors can be measured and controlled.

Antonio Politi, Alessandro Torcini

The mechanisms of information transmission are investigated in a lattice of coupled continuous maps, by analyzing the propagation of both finite and infinitesimal disturbances. Two distinct regimes are detected: in the former case, both classes of perturbations spread with the same velocity; in the latter case, finite perturbations propagate faster than infi

A. J. Connolly, A. S. Szalay, M. A. Bershady, A. L. Kinney

Classification of galaxy spectral energy distributions in terms of orthogonal basis functions provides an objective means of estimating the number of significant spectral components that comprise a particular galaxy type. We apply the Karhunen-Loève transform to derive a spectral eigensystem from a sample of ten galaxy spectral energy distributions. These sp

Reuven Ramaty, Benzion Kozlovsky, Richard E. Lingenfelter

We show that the 4.44 and 6.13 MeV line emission observed with COMPTEL from Orion is consistent with gamma ray spectra consisting of a mixture of narrow and broad lines or spectra containing only broad lines. We employed several accelerated particle compositions and showed that the current COMPTEL data in the 3--7 MeV region alone cannot distinguish between

Sandip K. Chakrabarti

We present a theoretical model for the ionized disk in M87 which includes spiral shock waves. The line emission profiles computed from this model at various positions on the disk are found to be in agreement with the recent Hubble Space Telescope results. Based on this model, we find that the ionized disk comprises two-armed giant spiral shock waves which ex

A. Giovagnoli, M. Tosi

Numerical models for the chemical evolution of the Galaxy have been computed with the new stellar yields published by Maeder (1992). These metallicity dependent yields represent an important improvement in the chemical evolution of galaxies but there are still uncertainties in the stellar evolution which prevent completely satisfactory results. {}From the co

Kohji Tomisaka

Fragmentation process in a cylindrical magnetized cloud is studied with the nested grid method. The nested grid scheme use 15 levels of grids with different spatial resolution overlaid subsequently, which enables us to trace the evolution from the molecular cloud density $\sim 100 {\rm cm}^{-3}$ to that of the protostellar disk $\sim 10^{10} {\rm cm} ^{-3}$

Hugues Sicotte

We start by pedagigically reviewing the problem of large scale magnetic fields. We explain the acquisition of angular momentum in the general context of Dark Matter models and we use this result to derive a dynamical mechanism for magnetic field generation. This mechanism does not produce any magnetic field for standard CDM, but it does for a large class of

G. Ellingsrud, S. A. Strømme

We outline a strategy for computing intersection numbers on smooth varieties with torus actions using a residue formula of Bott. As an example, Gromov-Witten numbers of twisted cubic and elliptic quartic curves on some general complete intersection in projective space are computed. The results are consistent with predictions made from mirror symmetry computa

Philip C. Argyres, Alon E. Faraggi

We present an exact description of the metric on the moduli space of vacua and the spectrum of massive states for four dimensional N=2 supersymmetric SU(n) gauge theories. The moduli space of quantum vacua is identified with the moduli space of a special set of genus n-1 hyperelliptic Riemann surfaces.

Christopher D. Carone, Hitoshi Murayama

We discuss the phenomenology of a light U(1) gauge boson, $γ_B$, that couples only to baryon number. We assume that the new U(1) gauge symmetry is spontaneously broken and that the $γ_B$ mass is smaller than $m_Z$. Nevertheless, we show that the model survives the current experimental constraints. In addition, we argue that evidence for the existence of such