June 1996 arXiv papers — page 9

Yuval Grossman, Harry J. Lipkin

A unique description avoiding confusion is presented for all flavor-oscillation experiments in which particles of a definite flavor are emitted from a localized source. The probability for finding a particle with the wrong flavor must vanish at the position of the source for all times. This condition requires flavor-time and flavor-energy factorizations whic

Frank X. Lee, Derek B. Leinweber

The lattice QCD field is currently undergoing a revolution in the manner in which improvements of the approach are being implemented. We are examining the utility of order-a^2-improved tadpole-improved actions for the light fermion sector. The masses of the low-lying hadrons are calculated using the order-a^2-improved gluon action and the order-a^2-improved

R. G. Edwards, Ivan Horváth, A. D. Kennedy

The theoretical justification of the Hybrid Monte Carlo algorithm depends upon the molecular dynamics trajectories within it being exactly reversible. If computations were carried out with exact arithmetic then it would be easy to ensure such reversibility, but the use of approximate floating point arithmetic inevitably introduces violations of reversibility

NA22 Collaboration

Taking into account the anisotropy of phase space in multiparticle production, a self-affine analysis of factorial moments was carried out on the NA22 data for $\p^+\Pp$ and $\PK^+\Pp$ collisions at 250 GeV/$c$. Within the transverse plane, the Hurst exponents measuring the anisotropy are consistent with unit value (i.e. no anisotropy). They are, however, on

Slava G. Turyshev, John D. Anderson, Ronald W. Hellings

Due to its relatively large eccentricity and proximity to the Sun, Mercury's orbital motion provides one of the best solar-system tests of relativistic gravity. We emphasize the number of feasible relativistic gravity tests that can be performed within the context of the parameterized weak field and slow motion approximation - a usefulframework for testi

Claes R Cramer, Bernard S. Kay

We use the image sum method to reproduce Sushkov's result that for a massless automorphic field on the initial globally hyperbolic region $IGH$ of Misner space, one can always find a special value of the automorphic parameter $α$ such that the renormalized expectation value $\langleα|T_{ab}|α\rangle$ in the {\it Sushkov state} ``$\langleα|\cdot|α\rangle$

Valeriy V. Ginzburg, Noel A. Clark

We propose an exactly solvable self-consistent kinetic model of polymerization-induced phase separation (PIPS) via spinodal decomposition. Using modified Cahn-Hilliard and Glotzer-Coniglio theories for early and late stages of spinodal decomposition, we find scaling regimes and compare the obtained results with existing experimental and theoretical informati

R. Allub, B. Alascio

We study a simplified model of the electronic structure of compounds of the type of La$_{1-x}$Sr$_x$MnO$_3$. The model represents each Mn$^{4+}$ ion by a spin S=1/2, on which an electron can be added to produce Mn$^{3+}$. We include two strong intratomic interactions in the Hamiltonian: exchange ($J$% ) and Coulomb ($U$). Finally, to represent the effect of

Ji Li, A. G. Rojo, Leonard M. Sander

We examine the island size distribution function and spatial correlation function of a model for island growth in the submonolayer regime in both 1 and 2 dimensions. In our model the islands do not grow in shape, and a fixed number of adatoms are added, nucleate, and are trapped at islands as they diffuse. We study the cases of various critical island sizes

Biplab Chattopadhyay

A phenomenological lattice model of high $T_c$ cuprates including order parameter phase fluctuations is considered within the BCS approximation, to interpret the experimental data from ARPES measurements on Bi2212 samples. A Kosterlitz-Thouless (KT) transition temperature $T_c^{KT}$ is estimated below the mean field transition $T_c^{MF}$, phase boundaries be

Qimiao Si, J. Lleweilun Smith

We study the competition between intersite and local correlations in a spinless two-band extended Hubbard model by taking an alternative limit of infinite dimensions. We find that the intersite density fluctuations suppress the charge Kondo energy scale and lead to a Fermi liquid to non-Fermi liquid transition for repulsive on-site density-density interactio

Per Dahlqvist

We investigate the topological zeta function for unimodal maps in general and dynamical zeta functions for the tent map in particular. For the generic situation, when the kneading sequence is aperiodic, it is shown that the zeta functions have a natural boundary along its radius of convergence, beyond which the function lacks analytic continuation. We make a

Eugene A. Magnier, You-Hua Chu, Sean D. Points, Una Hwang

We have used optical echelle spectra along with ROSAT and ASCA X-ray spectra to test the hypothesis that the southern portion of the N44 X-ray bright region is the result of a blowout structure. Three pieces of evidence now support this conclusion. First, the filamentary optical morphology corresponding with the location of the X-ray bright South Bar suggest

Daksh Lohiya, Shobhit Mahajan, A. Mukherjee, Annu Batra

Primordial nucleosynthesis is considered a success story of the standard big bang (SBB) cosmology. The cosmological and elementary particle physics parameters are believed to be severely constrained by the requirement of correct abundances of light elements. We demonstrate nucleosynthesis in a class of models very different from SBB. In these models the cosm

Y. -N. Chin, C. Henkel, J. B. Whiteoak, T. J. Millar

Nine HII regions of the LMC were mapped in 13CO(1--0) and three in 12CO(1--0) to study the physical properties of the interstellar medium in the Magellanic Clouds. For N113 the molecular core is found to have a peak position which differs from that of the associated HII region by 20 arcsec. Toward this molecular core the 12CO and 13CO peak Tmb line temperatu

Lennox L. Cowie, Antoinette Songaila, Esther M. Hu, J. G. Cohen

We present the results of spectroscopic studies with the LRIS spectrograph on Keck of two of the Hawaii deep survey fields. The 393 objects observed cover an area of 26.2 square arcmin and constitute a nearly complete sample down to K = 20, I = 23, and B = 24.5. The rest-frame K-band luminosity function and its evolution with redshift are described. Comparis

Stephen Holland, Gregory G. Fahlman, Harvey B. Richer

We present deep V & I WFPC2 photometry in two fields in the M31 halo 32' and 50' from the center of M31 along the SE minor axis at the locations of the M31 GCs G302 and G312 respectively. The M31 halo LFs are not consistent with a single high-metallicity population but are consistent with a mix of 50% to 75% metal-rich stars and 25% to 50% metal-poor

Robert Lazarsfeld

The purpose of this note is to point out an elementary but somewhat surprising connection between the work of Buser and Sarnak on lengths of periods of abelian varieties and the Seshadri constants measuring the local positivity of theta divisors. The link is established via symplectic blowing up, in the spirit of McDuff and Polterovich. As an application of

Shin-ichi Tadaki

A two-dimensional cellular automaton model of traffic flow with open boundaries are investigated by computer simulations. The outflow of cars from the system and the average velocity are investigated. The time sequences of the outflow and average velocity have flicker noises in a jamming phase. The low density behavior are discussed with simple jam-free appr

T. E. Mason, A. Schroder, G. Aeppli, H. A. Mook

We have used inelastic neutron scattering to examine the magnetic fluctuations at intermediate frequencies in the simplest high temperature superconductor, La_{2-x}Sr_{x}Cu_{4}. The suppression of the low energy magnetic response in the superconducting state is accompanied by an increase in the response at higher energies. Just above a threshold energy of ~7

O. Babelon, D. Bernard, F. A. Smirnov

The form factor bootstrap approach allows to construct the space of local fields in the massive restricted sine-Gordon model. This space has to be isomorphic to that of the corresponding minimal model of conformal field theory. We describe the subspaces which correspond to the Verma modules of primary fields in terms of the commutative algebra of local integ

Samuel L. Braunstein

This paper is withdrawn as it is equivalent to the paper quant-ph/9605035 by Gilles Brassard.

K. Huitu, J. Maalampi, A. Pietila, M. Raidal

We have investigated production of doubly charged Higgs particles $Δ_{L,R}^{++}$ via WW fusion process in proton-proton collisions at LHC energies in the framework of the left-right symmetric model. The production cross section of the right-triplet Higgs is for representative values of model parameters at femtobarn level. The discovery reach depends on the m

Fred James, Jiri Hoogland, Ronald Kleiss

This is basically a review of the field of Quasi-Monte Carlo intended for computational physicists and other potential users of quasi-random numbers. As such, much of the material is not new, but is presented here in a style hopefully more accessible to physicists than the specialized mathematical literature. There are also some new results: On the practical

J. J. Lodder

Starting from the unmixed Lagrangian, the electro-weak radiative corrections are recomputed using symmetrical generalised functions. All gauge bosons acquire an indeterminate mass. Electro-weak mixing is obtained by diagonalization of the mass matrix. The W/Z mass ratio follows automatically. The Higgs mechanism is not needed to generate the vector boson mas

W. A. Rodrigues, J. -Y. Lu

We present the theory, the experimental evidence, and fundamental physical consequences concerning the existence of families of undistorted progressive waves (UPWs) of arbitrary speeds $0\leq v < \infty$, which are solutions of the homogeneous wave equation, Maxwell equations, and Dirac and Weyl equations.

Alon E. Faraggi, Marco Matone

By defining a prepotential function for the stationary Schrödinger equation we derive an inversion formula for the space variable $x$ as a function of the wave-function $ψ$. The resulting equation is a Legendre transform that relates $x$, the prepotential ${\cal F}$, and the probability density. We invert the Schrödinger equation to a third-order differentia

Ary W. Espinosa Müller, Adelio R. Matamala Vásquez

A new totally algebraic formalism based on general, abstract ladder operators has been proposed. This approach heavily grounds in the superoperator formalism of Primas. However it is necessary to introduce many improvements in his formalism. In this regard, it has been introduced a new set of superoperators featured by their algebraic structure. Also, two le

A. K. Motovilov

Systems of three and four quantum particles in the boundary-condition model are considered. The Faddeev-Yakubovsky approach is applied to construct the Fredholm-type integral equations for these systems in framework of the Potential theory. The boundary-value problems are formulated for the Faddeev-Yakubovsky components of wave functions.

V. Van der Sluys, J. Ryckebusch, M. Waroquier

The reduced (e,e$&#39;$p) cross section is calculated for kinematics that probe high missing momenta. The final-state interaction is handled within a non-relativistic many-body framework. One- and two-body nuclear currents are included. Electron distortion effects are treated in an exact distorted wave calculation. It is shown that at high missing momenta th

Koichi Saito, Kazuo Tsushima, Anthony W. Thomas

Relativistic Hartree equations for spherical nuclei have been derived from a relativistic quark model of the structure of bound nucleons which interact through the (self-consistent) exchange of scalar ($\sigma$) and vector ($\omega$ and $\rho$) mesons. The coupling constants and the mass of the $\sigma$-meson are determined from the properties of symmetric n

Jouni Parkkonen

We consider the following question: Which parameters in the extension of a rational pleating ray across the boundary of $\Cal M$, the Maskit embedding of the Teichmüller space of once punctured tori correspond to a Kleinian group? Using methods of Keen and Series and Wright we prove a local result, stating that on each rational ray there is a sequence of par

Lutz Weis, Dirk Werner

We prove the norm identity $\|Id+T\| = 1+\|T\|$, which is known as the Daugavet equation, for operators $T$ on $C(S)$ not fixing a copy of $C(S)$, where $S$ is a compact metric space without isolated points.

Yuri A. Abramovich, Anthony W. Wickstead

The following theorem is essentially due to L.~Kantorovich and B. Vulikh and it describes one of the most important classes of Banach lattices between which each continuous operator is regular. {\bf Theorem 1.1.} {\sl Let $E$ be an arbitrary L-space and $F$ be an arbitrary Banach lattice with Levi norm. Then ${\cal L}(E,F)={\cal L}^r(E,F),\ (\star) $ that is

M. Alimohammadi, M. Khorrami

Using the simple path integral method we calculate the $n$-point functions of field strength of Yang-Mills theories on arbitrary two-dimensional Riemann surfaces. In $U(1)$ case we show that the correlators consist of two parts , a free and an $x$-independent part. In the case of non-abelian semisimple compact gauge groups we find the non-gauge invariant cor

A. Johansen

We analyse the critical behaviour of anomalous currents in N=1 four-dimensional supersymmetric gauge theories in the context of electric-magnetic duality. We show that the anomalous dimension of the Konishi superfield is related to the slope of the beta function at the critical point. We construct a duality map for the Konishi current in the minimal SQCD. As

R. Casadio, B. Harms, Y. Leblanc, P. H. Cox

This work describes new perturbative solutions to the classical, four-dimensional Kerr--Newman dilaton black hole field equations. Our solutions do not require the black hole to be slowly rotating. The unperturbed solution is taken to be the ordinary Kerr solution, and the perturbation parameter is effectively the square of the charge-to-mass ratio $(Q/M)^2$

Paul S. Norridge

We use the Cutkosky rules as a tool for determining the infinities present in graviton scattering amplitudes. We are able to confirm theoretical derivations of counterterms in Einstein-Maxwell theory and to determine new results in the Dirac-Einstein counter-Lagrangian.

L. A. Ferreira, J. L. Miramontes, J. Sanchez Guillen

The solutions of a large class of hierarchies of zero-curvature equations that includes Toda and KdV type hierarchies are investigated. All these hierarchies are constructed from affine (twisted or untwisted) Kac-Moody algebras~$\ggg$. Their common feature is that they have some special ``vacuum solutions&#39;&#39; corresponding to Lax operators lying in som

H. Kleinert

There exists a simple rule by which path integrals for the motion of a point particle in a flat space can be transformed correctly into those in curved space. This rule arose from well-established methods in the theory of plastic deformations, where crystals with defects are described mathematically by applying nonholonomic coordinate transformations to idea

Eric D. Williams

A quantum mechanical system describing bosons in one space dimension with a kinetic energy of arbitrary order in derivatives and a delta function interaction is studied. Exact wavefunctions for an arbitrary number of particles and order of derivative are constructed. Also, equations determining the spectrum of eigenvalues are found.

HoSeong La

Considering the linearized gravity with matter fields, the effective potential of the ``conformal dilaton&#39;&#39; in the string frame is generated semiclassically by one-loop contribution of heavy matter fields. This in turn generates a nontrivial potential for the physical dilaton in the Einstein frame with the trace of the graviton in the Einstein frame

D. Diakonov, V. Petrov, P. Pobylitsa, M. Polyakov

At large N_c the nucleon can be viewed as a soliton of the effective chiral lagrangian. This picture of nucleons allows a consistent nonperturbative calculation of the leading-twist parton distributions at a low normalization point. We derive general formulae for the polarized and unpolarized distributions (singlet and non-singlet) in the chiral quark-solito

Shoichi Sasaki, Hideo Suganuma, Hiroshi Toki

The chiral phase transition at finite temperature is studied by using the Schwinger-Dyson equation in the dual Ginzburg-Landau theory, in which the dual Higgs mechanism plays an essential role on both the color confinement and the spontaneous chiral-symmetry breaking. At zero temperature, the quark condensate is strongly correlated with the string tension, w

George Sterman

I review the treatment of high-energy QCD in Minkowski space, with an emphasis on factorization theorems as extensions of the operator product expansion. I discuss how the factorization properties of high-energy cross sections and amplitudes lead to evolution equations that resum large logarithms for two-scale problems.

A. Frink, B. A. Kniehl, D. Kreimer, K. Riesselmann

The Standard-Model Higgs boson with mass $ M_H >> 2M_Z $ decays almost exclusively to pairs of $W$ and $Z$ bosons. We calculate the dominant two-loop corrections of $ O( G_F^2 M_H^4 )$ to the partial widths of these decays. In the on-mass-shell renormalization scheme, the correction factor is found to be $ 1 + 14.6 % (M_H/TeV)^2 + 16.9 % (M_H/TeV)^4 $, where

B. Machet

I study, in the leptonic sector, the role of the $SU(2)_V$ custodial symmetry $\ti{\cal G}$ which was shown in ref. [1] to control the quantization of the electric charge in the $J=0$ mesonic sector. The electroweak theory is considered, according to ref. [2], as a purely vectorial model which interacts with a ``hidden&#39;&#39; sector of composite scalars.

N. Armesto, M. A. Braun

The pomeron-pomeron interaction is studied in the perturbative approach of BFKL-Bartels. The total pomeron-pomeron cross-section is proportional to $α_{s}^{4}s^Δ/\sqrt {t_{1}t_{2}}$ where $\sqrt{s}$ is the c.m. energy and $t_{1,2}$ are the virtualities of the colliding pomerons. Upon calculating the coefficient the cross-section is found to be of the order 2

S. M. H. Wong

We show the evolution of a gluon plasma towards equilibrium starting at some early moment when the momentum distribution in the central region is momentaneously isotropic. Using HIJING results for Au+Au collision as initial input, we consider thermalization and chemical equilibration simultaneously at both LHC and RHIC energies. Thermalization is shown to be

J. D. Kim, C. W. Kim, Jewan Kim, Dae-Gyu Lee

The concepts of effective and dynamical neutrino mixing matrices are introduced in order to describe the behavior of neutrinos in matter. The former relates weak eigenstates to mass eigenstates, whereas the latter relates weak eigenstates to energy eigenstates in matter. It is shown that the dynamical mixing angles enable us to express the neutrino survival

T. Matolcsi, W. A. Rodrigues

recent theoretical results show the existence of arbitrary speeds ($0\leq v <\infty$) solutions of the wave equations of mathematical physics. Some recent experiments confirm the results for sound waves. The question arises naturally: What is the appropriate spacetime model to describe superluminal phenomena? In this paper we present a spacetime model that i

R. B. Mann, G. Papadopoulos

We construct a supersymmetric extension of the $I\big(ISO(2,1)\big)$ Chern-Simons gravity and show that certain particle-like solutions and the adS black-hole solution of this theory are supersymmetric.

Eric Poisson

Among the expected sources of gravitational waves for the Laser Interferometer Space Antenna (LISA) is the capture of solar-mass compact stars by massive black holes residing in galactic centers. We construct a simple model for such a capture, in which the compact star moves freely on a circular orbit in the equatorial plane of the massive black hole. We con

Carsten Gundlach

Lecture given at the workshop &#34;Mathematical aspects of theories of gravitation&#34;, Stefan Banach International Mathematical Centre, 7 March 1996. A mini-introduction to critical phenomena in gravitational collapse is combined with a more detailed discussion of the regularity of the ``critical spacetimes&#39;&#39; dominating these phenomena.

A. K. Motovilov

The spectral problem $(A + V(z))ψ=zψ$ is considered where the main Hamiltonian $A$ is a self-adjoint operator of sufficiently arbitrary nature. The perturbation $V(z)=-B(A&#39;-z)^{-1}B^{*}$ depends on the energy $z$ as resolvent of another self-adjoint operator $A&#39;$. The latter is usually interpreted as Hamiltonian describing an internal structure of ph

C. M. Varma

The paramagnetic insulator to ferromagnetic metal transition in Lanthanum manganites and the associated magnetoresistive phenomena is treated by considering the localization due to random hopping induced by slowly fluctuating spin configurations and electron-electron interactions. The transition temperature and its variation with composition is derived. The

Viktor K. Horváth, Imre M. Jánosi, Péter J. Vella

We measured experimentally the static friction force $F_s$ on the surface of a glass rod immersed in dry sand. We observed that $F_s$ is extremely sensitive to the closeness of packing of grains. A linear increase of the grain-density yields to an exponentially increasing friction force. We also report on a novel periodicity of $F_s$ during gradual pulling o

Subir Sachdev

A systematic method for the computation of finite temperature ($T$) crossover functions near quantum critical points close to, or above, their upper-critical dimension is devised. We describe the physics of the various regions in the $T$ and critical tuning parameter ($t$) plane. The quantum critical point is at $T=0$, $t=0$, and in many cases there is a lin

Walter Stephan

The single-polaron band structure of the Holstein model in one and two dimensions is studied using a new form of resummed strong-coupling perturbation theory. Well converged results are obtained for phonon frequencies of the order of the hopping integral and strong to intermediate electron-phonon coupling. The polaron band structure at intermediate coupling

Serge Galam, Alain Mauger

A power law is postulated for both site and bond percolation thresholds. The formula writes $p_c=p_0[(d-1)(q-1)]^{-a}d^{\ b}$, where $d$ is the space dimension and $q$ the coordination number. All thresholds up to $d\rightarrow \infty$ are found to belong to only three universality classes. For first two classes $b=0$ for site dilution while $b=a$ for bond d

Serguei B. Isakov, Stéphane Ouvry

We consider the equations of state for systems of particles with exclusion statistics in a harmonic well. Paradygmatic examples are noninteracting particles obeying ideal fractional exclusion statistics placed in (i) a harmonic well on a line, and (ii) a harmonic well in the Lowest Landau Level (LLL) of an exterior magnetic field. We show their identity with

Hae-Young Kee, Jongbae Hong

The temperature and pressure effects on the resistivity of the manganese oxides are studied analytically via the Kondo lattice model with a strong Hund&#39;s coupling. We obtain analytically the single-particle density of states on the Bethe lattice in the large connectivity limit using the analytical variant of the dynamic Lanczos method. From the density o

Lydéric Bocquet, Jarosław Piasecki

In this paper, the first microscopic approach to the Brownian motion is developed in the case where the mass density of the suspending bath is of the same order of magnitude as that of the Brownian (B) particle. Starting from an extended Boltzmann equation, which describes correctly the interaction with the fluid, we derive systematicaly via the multiple tim

Sidney van den Bergh

Available data on the luminosities of supernovae of Type Ia (SNe Ia) that have been calibrated by Cepheids are collected and discussed. The objects in the present sample show a range of ~20 in luminosity. The data strongly confirm the suspicion that SNe Ia in early-type systems are, on average, fainter than those that occur in late-type galaxies. Historical

C. N. A. Willmer, D. C. Koo, N. ELlman, M. J. Kurtz

We report 328 redshifts, b$_J$ magnitudes and b$_J$--r$_F$ colors of galaxies measured in a redshift survey of a 4$^\circ$ $\times$ 0.67$^\circ$ slice close to the north Galactic pole. The faintest galaxies in this survey have a magnitude of b$_J$ $\sim$ 20.5. The redshifts present external errors of the order of 70 \kms, and we estimate that the mean photom

M. U. SubbaRao, A. J. Connolly, A. S. Szalay, D. C. Koo

The determination of the galaxy luminosity function is an active and fundamental field in observational cosmology. In this paper we propose a cost effective way of measuring galaxy luminosity functions at faint magnitudes. Our technique employs the use of galaxy redshifts estimated from their multicolor photometry (Connolly et al. 1995). Associated with the

R. A. Araya, A. K. Harding

The spectrum of the transient X-ray binary pulsar A0535+26 obtained by OSSE in February 1994 shows an absorption feature at 110 keV but does not confirm a feature at around 55 keV, as previously reported by other instruments. If the 110 keV feature is due to cyclotron scattering at the first harmonic, then the magnetic field required is about $10^{13}$ Gauss

Joao Magueijo

We investigate which of the exotic Doppler peak features found for textures and cosmic strings are generic novelties pertaining to defects. We find that the ``out of phase&#39;&#39; texture signature is an accident. Generic defects, when they generate a secondary peak structure similar to inflation, apply to it an additive shift. It is not necessary for this

Yasuyuki Kachi

We shall investigate a flipping contraction g : X -> Y from a 4-fold X with at most isolated complete intersection singularities. If Y has an anti-bi-canonical divisor (=bi-elephant) with only rational singularities, then g carries an inductive structure chained up by blow-ups (La Torre Pendente), and in particular the flip exists. This naturally contains Mi

Roberto Casadio, Benjamin Harms

By promoting an invariant subgroup $H$ of $ISO(2,1)$ to a gauge symmetry of a WZWN action, we obtain the description of a bosonic string moving either in a curved 4-dimensional space--time with an axion field and curvature singularities or in 3-dimensional Minkowski space--time.

E. I. Ganzha

In this paper we solve positively the problem of (local) density of solutions of the (2+1)-dimentional integrable system describing triply orthogonal curvilinear coordinates in R^3 (a (2+1)-dimensional generalization of the 3-wave system) obtainable from a given initial solution with consecutive Bäcklund transformations (called Ribaucour transformations in c

E. I. Ganzha

In this paper we solve positively the problem of (local) density of the &#34;potentials&#34; M(x,y) of the Moutard equation, u_{xy} = M(x,y) u, u=u(x,y), (used in many papers for construction of exact solutions of (2+1)-dimensional integrable systems) obtainable from a given initial potential with consecutive Moutard transformations.

E. T. Ganzha, S. P. Tsarev

The usual superposition formulas for Baecklund transformations of (2+1)-dimensional integrable systems include quadratures unlike the well known case of (1+1)-dimensional inegrable systems where the fourth solution is found with algebraic operations. In the present paper we show how in the case of (2+1)-dimensional integrable systems one can find an extended

Lowell S. Brown, Ronald S. Steinke

We examine Compton scattering of electrons on black body photons in the case where the electrons are highly relativistic, but the center of mass energy is small in comparison with the electron mass. We derive the partial lifetime of electrons in the LEP accelerator due to this form of scattering in the vacuum beam pipe and compare it with previous results.

H. David Politzer

For a non-self-interacting Bose gas with a fixed, large number of particles confined to a trap, as the ground state occupation becomes macroscopic, the condensate number fluctuations remain micrscopic. However, this is the only significant aspect in which the grand canonical description differs from canonical or microcanonical in the thermodynamic limit. Gen

W. Henderson, E. Y. Andrei, M. J. Higgins, S. Bhattacharya

Strong metastability and history dependence are observed in DC and pulsed transport studies of flux-line lattices in 2H-$NbSe_{2}$, leading to the identification of two distinct states of the lattice with different spatial ordering. The metastability is most pronounced upon crossing a transition line marked by a large jump in the critical current (the peak e

Carsten Gundlach, Jorge Pullin

We suggest that ``free evolution&#39;&#39; integration schemes for the Einstein equations (that do not enforce constraints) may contain exponentially growing modes that render them useless in numerical integrations of black hole spacetimes, independently of how the equations are differenced. As an example we consider the evolution of Schwarzschild and Reissn

Christer Samuelsson

An asymptote is derived from Turing&#39;s local reestimation formula for population frequencies, and a local reestimation formula is derived from Zipf&#39;s law for the asymptotic behavior of population frequencies. The two are shown to be qualitatively different asymptotically, but nevertheless to be instances of a common class of reestimation-formula-asymp

Alejandro Cabo, Aurora Perez Martinez

A thermodynamic stability criterion for the spontaneous breaking of the translation invariance of many particle systems is derived. It simply requires the positive character of the wavevector dependent dielectric function as generalising the same condition for macroscopic dielectric constants. Its application to the Single Mode Approximation (SMA) for the de

Neil Cornish, Norm Frankel

Like a fairy-tale princess, trajectories around black holes can be sensitive to small disturbances. We describe how a small disturbance can lead to erratic orbits and an increased production of gravitational waves.

Gungwon Kang

We have shown that the dynamics of the scalar field $ϕ(x)= ``G^{-1}(x)&#34;$ in Brans-Dicke theories of gravity makes the surface area of the black hole horizon {\it oscillatory} during its dynamical evolution. It explicitly explains why the area theorem does not hold in Brans-Dicke theory. However, we show that there exists a certain non-decreasing quantity

M. E. Carrington, U. Heinz

We study 3-point functions at finite temperature in the closed time path formalism. We give a general decomposition of the eight component tensor in terms of seven vertex functions. We derive a spectral representation for these seven functions in terms of two independent real spectral functions. We derive relationships between the seven functions and obtain

Vladimir Hinich

To any non-negatively graded dg Lie algebra $g$ over a field $k$ of characteristic zero we assign a functor $Σ_g: art/k \to Kan$ from the category of commutative local artinian $k$-algebras with the residue field $k$ to the category of Kan simplicial sets. There is a natural homotopy equivalence between $Σ_g$ and the Deligne groupoid corresponding to $g$. Th

Toralf Gruner, Dirk-Gunnar Welsch

Using a recently developed formalism of quantization of radiation in the presence of absorbing dielectric bodies, the problem of photon tunneling through absorbing barriers is studied. The multilayer barriers are described in terms of multistep complex permittivities in the frequency domain which satisfy the Kramers--Kronig relations. From the resulting inpu

A. H. Bougourzi, M. Couture, M. Kacir

The exact form factors of the Heisenberg models $XXX$ and $XXZ$ have been recently computed through the quantum affine symmetry of $XXZ$ model in the thermodynamic limit. We use them to derive an exact formula for the contribution of two spinons to the dynamical correlation function of $XXX$ model at zero temperature.

D. Lacroix, R. Peschanski

We re-analyze the conditions for the phenomenon of intermittency (self-similar fluctuations) to occur in models of multifragmentation. Analyzing two different mechanisms, the bond-percolation and the ERW (Elattari, Richert and Wagner) statistical fragmentation models, we point out a common quasi-gaussian shape of the total multiplicity distribution in the cr

G. Chalmers, W. Siegel

We provide an action for self-dual Yang-Mills theory which is a simple truncation of the usual Yang-Mills action. Only vertices that violate helicity conservation maximally are included. One-loop amplitudes in the self-dual theory then follow as a subset of the Yang-Mills ones. In light-cone gauges this action is almost identical to previously proposed actio

M. Frau, A. Lerda, S. Sciuto, G. R. Zemba

We describe the recently introduced method of algebraic bosonization of the $(1+1)$-dimensional Luttinger systems by discussing in detail the specific case of the Calogero-Sutherland model, and mentioning the hard-core Bose gas. We also compare our findings with the exact Bethe Ansatz results.

Anna Tollsten

We find a general p-1-brane solution to supergravity coupled to a p+1-form field strength using the ``standard ansatz&#39;&#39; for the fields. In addition to the well-known elementary and solitonic p-1-brane solutions, which are the only ones preserving half of the supersymmetry (for the cases where the supersymmetry transformations are known), there are ot

Michio Kaku

String duality requires the presence of solitonic $p$-branes. By contrast, the existence of fundamental supermembranes is problematic, since they are probably unstable. In this paper, we re-examine the quantum stability of fundamental supermembranes in 11 dimensions. Previously, supermembranes were shown to be unstable by approximating them with SU(n) super

Ali Chamseddine, Alain Connes

A universal formula for an action associated with a noncommutative geometry, defined by a spectal triple $(\Ac ,\Hc ,D)$, is proposed. It is based on the spectrum of the Dirac operator and is a geometric invariant. The new symmetry principle is the automorphism of the algebra $\Ac $ which combines both diffeomorphisms and internal symmetries. Applying this t

Sang-Jun Kim, Choonkyu Lee

We make an all-order analysis to establish the precise correspondence between nonrelativistic Chern-Simons quantum field theory and an appropriate first-quantized description. Physical role of the field-theoretic contact term in the context of renormalized perturbation theory is clarifed through their connection to self-adjoint extension of the Hamiltonian i

Tomoko Uesugi, Akio Sugamoto, Azusa Yamaguchi

The electroweak baryogenesis is studied in the charge transport mechanism with the vector-like quark model. Introducing an extra vector-like up-type quark and a singlet Higgs scalar with the mass of the order of a few hundred GeV, the baryon number generation from the bubble wall is estimated. We show that this scenario is consistent with the measurement of

J. Bijnens, U. -G. Meißner

These are short proceedings of the workshop on ``The Standard Model at Low Energies&#39;&#39; held at ECT* in Trento, Italy, from April 29 to May 10, 1996. The workshop concentrated on Chiral Perturbation Theory in its various settings. Included are a one page contribution with references per speaker and a listing of some review papers of relevance to the fi

A. Arhrib, G. Moultaka

We study the 1-loop corrections to the charged Higgs production both in the Minimal Supersymmetric Standard Model (MSSM) and in a more general type II two-Higgs-doublet model (THDM-II). We consider the full set of corrections (including soft photon contributions as well as box diagrams), and define a parametrization that allows a comparison between the two m

Thomas Mannel

In this series of lectures the basic ideas of the $1/m_Q$ expansion in QCD ($m_Q$ is the mass of a heavy quark) are outlined. Applications to exclusive and inclusive decays are given.

Per Osland, Ya. M. Shnir

Dyon loops give a contribution to the matrix element for light-by-light scattering that violates parity and time-reversal symmetry. This effect induces an electric dipole moment for the electron, of order $M^{-2}$, where $M$ is the dyon mass. The current limit on the electric dipole moment of the electron yields the lower mass bound $M>{\cal O}(1)~\mbox{TeV}

G. Lazarides, C. Panagiotakopoulos, N. D. Vlachos

We perform a numerical investigation of the field evolution in the smooth hybrid inflationary model. We find that for almost all the examined initial values we do get an adequate amount of inflation. Our results show that the model is &#39;&#39;natural&#39;&#39; and satisfactory.

Wen-Chin Wu, A. Griffin

We quantize the recent hydrodynamic analysis of Stringari for the low-energy collective modes of a trapped Bose gas at $T=0$. This is based on the time-dependent Gross-Pitaevskii equation, but omits the kinetic energy of the density fluctuations. We diagonalize the hydrodynamic Hamiltonian in terms of the normal modes associated with the amplitude and phase

L. S. Borkowski

In ordinary metals, antiferromagnetic exchange between conduction electrons and a magnetic impurity leads to screening of the impurity spin below the Kondo temperature, $T_K$. In systems such as semimetals, small-gap semiconductors and unconventional superconductors, a reduction in available conduction states near the chemical potential can greatly depress $