February 2000 arXiv papers — page 19

T. S. Kosmas, Sergey Kovalenko

The exotic neutrinoless $μ^- - e^-$ nuclear conversion is studied within the conventional extensions of the standard model as well as in the minimal supersymmetric (SUSY) models with and without R-parity conservation. The dependence of the $μ^- - e^-$ conversion rates on the nucleon and nuclear structure is consistently taken into account. Using our calculat

André Gusso

We investigate the possibility that four-fermion contact interactions give rise to the observed deviation from the Standard Model prediction for the weak charge of Cesium, through one-loop contributions. We show that the presence of loops involving the third generation quarks can explain such deviation.

Vladimir Visnjic

The generation structure in the quark and lepton spectrum is explained as originating from the excitation spectrum S_n of SU(2)_W doublet scalar fields, whose ground state S_1 is the Standard Model Higgs field. There is only one basic family of SU(2)_W doublet left-handed fermions, nu_L, e_L, u_L, d_L, whose bound states with S_n manifest themselves as the g

V. Gimenez, L. Giusti, G. Martinelli, F. Rapuano

By combining the first unquenched lattice computation of the B-meson binding energy and the two-loop contribution to the lattice HQET residual mass, we determine the (\bar{MS}) (b)-quark mass, (\bar{m}_{b}(\bar{m}_{b})). The inclusion of the two-loop corrections is essential to extract (\bar{m}_{b}(\bar{m}_{b})) with a precision of ({\cal O}(Λ^{2}_{QCD}/m_{b

S. Fujimoto, S. Kato, T. Suzuki

A quantum perfect lattice action in four dimensions can be derived analytically as a renormalized trajectory when we perform a block spin transformation of monopole currents in a simple but non-trivial case of quadratic monopole interactions. The spectrum of the lattice theory is identical to that of the continuum theory. The perfect monopole action is trans

S. Cecchini, I. D'Antone, L. Degli Esposti, G. Giacomelli

Increasing interest towards the observation of the highest energy cosmic rays has motivated the development of new detection techniques. The properties of the Cherenkov photon pulse emitted in the atmosphere by these very rare particles indicate low-cost semiconductor detectors as good candidates for their optical read-out. The aim of this paper is to evalua

Jeffrey A. Appel

The most recent results on CP violation and mixing in the charm system are reviewed as a guide to the future. While no surprising results are reported so far, charm provides a unique window to physics beyond the Standard Model. The results reported here come from four sources: ALEPH at LEP, E791 and FOCUS/E831 at Fermilab, and CLEO II.V at CESR. Results beyo

A. E. Asratyan, G. V. Davidenko, A. G. Dolgolenko, V. S. Kaftanov

A conceptual scheme of a hybrid-emulsion spectrometer for investigating various channels of neutrino oscillations is proposed. The design emphasizes detection of $τ$ leptons by detached vertices, reliable identification of electrons, and good spectrometry for all charged particles and photons. A distributed target is formed by layers of low-Z material, emuls

John N. Bahcall

I summarize the current state of solar neutrino research and then give my answer to the question: What should we do next?

N. Wex

Small-eccentricity binary pulsars with white dwarf companions provide excellent test laboratories for various effects predicted by alternative theories of gravity, in particular tests for the emission of gravitational dipole radiation and the existence of gravitational Stark effects. We will present new limits to these effects. The statistical analysis prese

Christiane Lechner, Sascha Husa, Peter C. Aichelburg

We present a class of numerical solutions to the SU(2) nonlinear $σ$-model coupled to the Einstein equations with cosmological constant $Λ\geq 0$ in spherical symmetry. These solutions are characterized by the presence of a regular static region which includes a center of symmetry. They are parameterized by a dimensionless ``coupling constant'' $β$,

V. V. Kuzmichev

A highly excited Friedmann universe filled with a scalar field and radiation has been considered. On the basis of a direct solution to the quantum-mechanical problem with a well-defined time variable, it has been shown that such a universe can have features (energy density, scale factor, Hubble constant, density parameter, matter mass, equivalent number of b

V. V. Kuzmichev

The classical and quantum models of the Friedmann universe originally filled with a scalar field and radiation have been studied. The radiation has been used to specify a reference frame that makes it possible to remove ambiguities in choosing the time coordinate. Solutions to the Einstein and Schroedinger equations have been studied under the assumption tha

A. G. Agnese, M. La Camera

We employ a theorem due to Campbell to build some simple 4-dimensional cosmological models which originate from solutions describing waves propagating along the extra-dimension of a 5-dimensional Ricci-flat space. The dimensional reduction is performed in the Jordan frame according to the induced-matter theory of Wesson.

Jorge Pullin

News: TGG session in the April meeting, by Cliff Will NRC report, by Beverly Berger MG9 Travel Grant for US researchers, by Jim Isenberg Research Briefs: How many coalescing binaries are there?, by Vicky Kalogera Recent developments in black critical phenomena, by Pat Brady Optical black holes?, by Matt Visser ``Branification:'' an alternative to com

Sandro S. e Costa

In a paper presented a few years ago, De Lorenci et al. showed, in the context of canonical quantum cosmology, a model which allowed space topology changes (Phys. Rev. D 56, 3329 (1997)). The purpose of this present work is to go a step further in that model, by performing some calculations only estimated there for several compact manifolds of constant negat

G. G. Varzugin

The initial-value problem for cylindrical gravitational waves is studied through the development of the inverse scattering method scheme. The inverse scattering transform in this case can be viewed as a transformation of the Cauchy data to the data on the symmetry axis. Riemann-Hilbert problem, which serves as inverse transformation, is formulated in two dif

Eric M. Collins, Nicholas Kioussis, Say Peng Lim, Bernard R. Cooper

We present an ab initio based method which gives clear insight into the interplay between the hybridization, the coulomb exchange, and the crystal-field interactions, as the degree of 4f localization is varied across a series of strongly correlated cerium systems. The results for the ordered magnetic moments, magnetic structure, and ordering temperatures are

D. Schmeltzer

We introduce a new method to analysis the many-body problem with disorder. The method is an extension of the real space renormalization group based on the operator product expansion. We consider the problem in the presence of interaction, large elastic mean free path, and finite temperatures. As a result scaling is stopped either by temperature or the length

P. M. Gehring, S. E. Park, G. Shirane

Neutron inelastic scattering measurements of the polar TO phonon mode dispersion in the cubic relaxor Pb(Zn_1/3Nb_2/3)_0.92Ti_0.08O_3 at 500K reveal anomalous behavior in which the optic branch appears to drop precipitously into the acoustic branch at a finite value of the momentum transfer q=0.2 inverse Angstroms, measured from the zone center. We speculate

Ping Sun, D. Schmeltzer

The one dimensional spin-1/2 Heisenberg antiferromagnet in a weak magnetic field h is studied using the bosonization method. We derive a set of renormalization group equations. The fixed point is reached when the field is scaled to the value at which the system is quarter-filled. As the magnetic field varies, a continuum line of fixed points is formed. We co

E. Lidorikis, C. M. Soukoulis

We examine numerically the time-dependent properties of nonlinear bistable multilayer structures for constant wave illumination. We find that our system exhibits both steady-state and self-pulsing solutions. In the steady state regime, we examine the dynamics of driving the system between different transmission states by injecting pulses, and we find the opt

Hernan A. Makse, David L. Johnson, Lawrence M. Schwartz

3D Computer simulations and experiments are employed to study random packings of compressible spherical grains under external confining stress. Of particular interest is the rigid ball limit, which we describe as a continuous transition in which the applied stress vanishes as (ϕ-ϕ_c)^β, where ϕis the (solid phase) volume density. This transition coincides wi

E. Lidorikis, M. M. Sigalas, C. M. Soukoulis, E. N. Economou

By using two ab initio numerical methods we study the effects that disorder has on the spectral gaps and on wave localization in two-dimensional photonic band gap materials. We find that there are basically two different responses depending on the lattice realization (solid dielectric cylinders in air or vise versa), the wave polarization, and the particular

L. C. Malacarne, R. S. Mendes

Besides of complexities concerning to football championships, it is identified some regularities in them. These regularities refer to goal distributions by goal-players and by games. In particular, the goal distribution by goal-players it well adjusted by the Zipf-Mandelbrot law, suggesting a conection with an anomalous decay.

C. Raghu, Indranil Rudra, S. Ramasesha, Diptiman Sen

Motivated by recent work on Heisenberg antiferromagnetic spin systems on various lattices made up of triangles, we examine the low-energy properties of a chain of antiferromagnetically coupled triangles of half-odd-integer spins. We derive the low-energy effective Hamiltonian to second order in the ratio of the coupling J_2 between triangles to the coupling

Nelson Alves, Ulrich H. E. Hansmann

We report on multicanonical simulations of the helix-coil transition of a polypeptide. The nature of this transition was studied by calculating partition function zeros and the finite-size scaling of various quantities. Estimates for critical exponents are presented.

R. J. McQueeney, A. R. Bishop, Ya-Sha Yi, Z. G. Yu

The in-plane oxygen vibrations in La2NiO4 are investigated for several hole-doping concentrations both theoretically and experimentally via inelastic neutron scattering. Using an inhomogeneous Hartree-Fock plus RPA numerical method in a two-dimensional Peierls-Hubbard model, it is found that the doping induces stripe ordering of localized charges, and that t

M. Fleischhauer

Local field effects on the rate of spontaneous emission and Lamb shift in a dense gas of atoms are discussed taking into account correlations of atomic center-of-mass coordinates. For this the exact retarded propagator in the medium is calculated in independent scattering approximation and employing a virtual-cavity model. The resulting changes of the atomic

V. M. Krasnov, A. Yurgens, D. Winkler, P. Delsing

We present intrinsic tunneling spectroscopy measurements on small Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ mesas. The tunnel conductance curves show both sharp peaks at the superconducting gap voltage and broad humps representing the $c$-axis pseudo-gap. The superconducting gap vanishes at $T_c$, while the pseudo-gap exists well above $T_c$. Our observation implies tha

S. Stramaglia, A. Refice, L. Guerriero

The use of Mean-Field theory to unwrap principal phase patterns has been recently proposed. In this paper we generalize the Mean-Field approach to process phase patterns with arbitrary degree of undersampling. The phase unwrapping problem is formulated as that of finding the ground state of a locally constrained, finite size, spin-L Ising model under a non-u

Petrica I. Cristea

A new and simple analytical charge-control model of the two-dimensional electron gas of a double-heterojunction AlGaAs/GaAs/AlGaAs HEMT is described. It is found that, despite its simplicity, the charge-control model gives an accurate description of the device operation for a wide range of physical parameters. The validity of the analytical model is supporte

Karol I. Wysokinski

I address here the question of the mutual interplay of strong correlations and disorder in the system. I consider random version of the Hubbard model. Diagonal randomness is introduced {\it via} random on-site energies and treated by the coherent potential approximation. Strong, short ranged, electron - electron interactions are described by the slave boson

Evgueny Kochetov, Marcin Mierzejewski

A simple version of the Bardeen-Cooper-Schrieffer (BCS)-type mean-field theory for the t-J model is developed. The present approach rigorously treats the constraint of no doubly occupied states and invokes two local order parameters to implement spontaneous breaking of the global U(1)\times U(1) symmetry. This is achieved by identifying the Hubbard operators

Koji Hukushima

The fixed-point structure of three-dimensional bond-disordered Ising models is investigated using the numerical domain-wall renormalization-group method. It is found that, in the +/-J Ising model, there exists a non-trivial fixed point along the phase boundary between the paramagnetic and ferromagnetic phases. The fixed-point Hamiltonian of the +/-J model nu

Hong Xu, Marc Baus

The recently proposed universal relations between the moments of the polydispersity distributions of a phase-separated weakly polydisperse system are analyzed in detail using the numerical results obtained by solving a simple density functional theory of a polydisperse fluid. It is shown that universal properties are the exception rather than the rule.

Juergen Dietel

We reconsider the theory of the half-filled Landau level with impurities using the Chern-Simons formulation and study Ward identities for the Chern-Simons theory. From these we get conductivity diagrams with impurities which obey the continuity equation. We calculate the conductivity of these diagrams for which we obtain log(Tτ) divergent conductivity diagra

Arkajyoti Misra, Bikas K. Chakrabarti

The phase diagram of the dynamic magnetization-reversal transition in pure Ising systems under a pulsed field competing with the existing order can be explained satisfactorily using the classical nucleation theory. Indications of single-domain and multi-domain nucleation and of the corresponding changes in the nucleation rates are clearly observed. The natur

J. S. Gallagher, N. L. Homeier, C. J. Conselice, WFPC-2IDT

We present preliminary results from a Hubble Space Telescope (HST) WFPC2 investigation of spatial and temporal distributions of star clusters in the clumpy irregular galaxy NGC 7673 and the starburst spirals NGC 3310 and Haro 1. We compare the spectral energy distributions of star clusters in the large clumps in NGC 7673 to model calculations of stellar clus

E. M. de Gouveia Dal Pino, A. Lazarian

We here investigate the possibility that the ultra-high energy cosmic ray (UHECR) events observed above the GZK limit are mostly protons accelerated in econnection sites just above the magnetosphere of newborn millisecond pulsars which are originated by accretion induced collapse (AIC).

Patrick Cseresnjes, Christophe Alard, Jean Guibert

We report the detection of $\sim$ 1500 RR Lyrae of Bailey type ab located in the Sagittarius dwarf galaxy (Sgr). These variables have been detected on two ESO Schmidt fields centred on (l,b)=(3.1 deg,-7.1 deg) and (6.6 deg, -10.8 deg), covering an area of $\sim$50 square degree. We present a surface density map of Sgr based on the spatial distribution of the

Alan H. Guth

The basic workings of inflationary models are summarized, along with the arguments that strongly suggest that our universe is the product of inflation. The mechanisms that lead to eternal inflation in both new and chaotic models are described. Although the infinity of pocket universes produced by eternal inflation are unobservable, it is argued that eternal

H. Monteiro, C. Morisset, R. Gruenwald, S. M. Viegas

We use a 3D photoionization modeling tool to study the morpho-kinematic properties of the Planetary Nebula (PN) NGC 3132. We show that it is possible to reproduce the low resolution observations (spectra and images) with an ellipsoidal shell. However, high resolution observations, as those showing a density variation along the nebula and the [O III]5007 velo

J. M. Eppley, R. B. Partridge

We used the 1.4 GHz NRAO NVSS survey to search for ghost images of radio sources, expected in cosmologies with a positive cosmological constant and positive space curvature. No statistically significant evidence for ghost images was found, placing constraints on the values of L, the space curvature or the duration of the radio-luminous phase of extragalactic

K. J. Orford

Reviews statistical methods for 1- and 2-dimensional analysis of cosmic ray data including recent Bayesian analyses.

A. Meiksin

It is shown how wavelets may be used to analyse the absorption properties of the Lya forest. The Discrete Wavelet Transform of a QSO spectrum is used to decompose the light fluctuations that comprise the forest into orthogonal wavelets. It is demonstrated that most of the signal is carried by the moderate to lower frequency wavelets in high resolution spectr

A. Henden, U. Munari

We present accurate UBVRI photometric comparison sequences around 20 symbiotic stars. The sequences extend over wide brightness and color ranges, and are suited to cover quiescence as well as outburst phases. The sequences are intended to assist both present time photometry as well as measurement of photographic plates from historical archives. The types of

Gaspar Galaz

(Abridged) We present near-IR photometry of a selected sample of southern hemisphere E+A galaxies. The sample includes 50 galaxies from nearby and distant clusters as well as E+A galaxies from the field. The photometry includes J, H and Ks apparent magnitudes and colors. Observed colors are obtained from the apparent total magnitudes and compared to spectrop

L. Portinari, C. Chiosi

We develop a numerical chemical model allowing for radial flows of gas, with the aim to analyse the possible role of gas flows in the chemical evolution of the Galactic Disc. The dynamical effects of the Galactic Bar on the radial gas profile of the Disc are especially addressed.

Ya. V. Pavlenko

Theoretical aspects of modeling of spectra of late M- and L-dwarfs are discussed. We show, that the processes of formation of spectra of M- and L-dwarfs are basically different. Instead of the case of M-dwarfs, atoms of Ti and V should be depleted into grains in the atmospheres of L-dwarfs. Overall shape of the L-dwarf spectra is governed by the K I + Na I r

Matthew R. Bate

We investigate the formation of binary stellar systems. We consider a model where a `seed' protobinary system forms, via fragmentation, within a collapsing molecular cloud core and evolves to its final mass by accreting material from an infalling gaseous envelope. This accretion alters the mass ratio and orbit of the binary, and is largely responsible fo

G. Hebrard, D. Pequignot, A. Vidal-Madjar, J. R. Walsh

The detection and first identification of the deuterium Balmer emission lines, D-alpha and D-beta, in the core of the Orion Nebula is reported. Observations were conducted at the 3.6m Canada-France-Hawaii Telescope, using the Echelle spectrograph Gecko. These lines are very narrow and have identical 11 km/s velocity shifts with respect to H-alpha and H-beta.

T. A. Oosterloo, R. Morganti, A. Tzioumis, J. Reynolds

We present 21-cm HI line and 13-cm continuum observations, obtained with the Australian Long Baseline Array, of the Seyfert 2 galaxy IC 5063. This object appears to be one of the best examples of Seyfert galaxies where shocks produced by the radio plasma jet influence both the radio as well as the near-infrared emission. The picture resulting from the new ob

Nicolas Regnault

Type Ia supernovae (SNIa) have been used as approximate standard candles to measure cosmological parameters such as the Hubble constant and the deceleration parameter. These measurements rely on empirical correlations between peak luminosities and other features that can be observed in the supernovae spectra and their light curves. Such correlations deserve

M. Kusunose, F. Takahara, H. Li

Blazars are known to emit a broad band emission from radio to gamma-rays with rapid time variations, particularly, in X- and gamma-rays. Synchrotron radiation and inverse Compton scattering are thought to play an important role in emission and the time variations are likely related to the acceleration of nonthermal electrons. As simultaneous multiwavelength

T. T. Ishii, T. T. Takeuchi, H. Hirashita, K. Yoshikawa

We constructed a model of infrared and sub-mm (hereafter IR) galaxy number count and estimated history of the IR luminosity density. We treat the evolutionary change of galaxy luminosities as a stepwise nonparametric form, in order to explore the most suitable evolutionary history which reproduces the present observational results. We found the evolutionary

Tom Abel, Greg L. Bryan, Michael L. Norman

Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and evolution of pregalactic structure. In particular the efficiency of primordial star formation and the primordial IMF are of special interest. We present results from hig

H. Li, M. Kusunose

Multiwavelength observations of blazars such as Mrk 421 and Mrk 501 show that they exhibit strong short time variabilities in flare-like phenomena. Based on the homogeneous synchrotron self-Compton (SSC) model and assuming that time variability of the emission is initiated by changes in the injection of nonthermal electrons, we perform detailed temporal and

Rychard J. Bouwens, Joseph Silk

We present simple models for disk evolution based on two different approaches: a forward approach based on predictions generic to hierarchical models for structure formation (e.g., Mo, Mao, & White 1998) and a backwards approach based on detailed modeling of the Milky Way galaxy (e.g., Bouwens, Cayon, & Silk 1997). We normalize these models to local observat

Ignas Snellen, Richard Schilizzi, George Miley, Ger de Bruyn

This paper describes an investigation of the early evolution of extragalactic radio sources using samples of faint and bright Gigahertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio galaxies. Correlations found between their peak frequency, peak flux density and angular size provide strong evidence that synchrotron self absorption is the cause

Ignas Snellen, Richard Schilizzi, Huib-Jan van Langevelde

We present the data and analysis of VLBI observations at 1.6, 5 and 15 GHz of a sample of faint Gigahertz Peaked Spectrum (GPS) sources selected from the Westerbork Northern Sky Survey (WENSS). The 5 GHz observations involved a global array of 16 stations and yielded data on the total sample of 47 sources. A subsample of 26 GPS sources with peak frequencies

Stanley J. Brodsky, Einan Gardi, Georges Grunberg, Johan Rathsman

We investigate the relation between a postulated skeleton expansion and the conformal limit of QCD. We begin by developing some consequences of an Abelian-like skeleton expansion, which allows one to disentangle running-coupling effects from the remaining skeleton coefficients. The latter are by construction renormalon-free, and hence hopefully better behave

Shi-Lin Zhu

We derive the light cone QCD sum rule for the $ηNN$ coupling constant $g_{ηNN} $. The contribution from the excited states and the continuum is subtracted cleanly through the double Borel transform with respect to the two external momenta, $p_1^2$, $p_2^2=(p-q)^2$. Our result is $α_{ηNN}=(0.3\pm 0.15)$, which favors small values used in literatures.

M. Nishino, H. Onishi, K. Yamaguchi, S. Miyashita

We study effect of inhomogeneities of the lattice in the S=1/2 bond-alternating chain by using a quantum Monte Carlo method and an exact diagonalization method. We adopt a defect in the alternating order as the inhomogeneity and we call it `bond impurity'. Local magnetic structures induced by the bond impurities are investigated both in the ground state

T. M. Aliev, A. Ozpineci, M. Savci

Influence of the fourth generation, if ever exists, on the experimentally measurable quantities such as invariant dilepton mass distribution, lepton forward-backward asymmetry, and the ratio (Gamma_L/Gamma_T) of the decay widths when K* meson is longitudinally and transversally polarized, is studied. Using the experimental results on the branching ratios for

M. M. Sharma, A. R. Farhan, S. Mythili

Shell effects in nuclei about the stability line are investigated within the framework of the Relativistic Hartree-Bogoliubov (RHB) theory with self-consistent finite-range pairing. Using 2-neutron separation energies of Ni and Sn isotopes, the role of $σ$- and $ω$-meson couplings on the shell effects in nuclei is examined. It is observed that the existing s

HERMES Collaboration, K. Ackerstaff

Production and decay angular distributions were extracted from measurements of exclusive electroproduction of the rho^0(770) meson over a range in the virtual photon negative four-momentum squared 0.5< Q^2 <4 GeV^2 and the photon-nucleon invariant mass range 3.8< W <6.5 GeV. The experiment was performed with the HERMES spectrometer, using a longitudinally po

Alexander Friedland

We point out that for solar neutrino oscillations with the mass-squared difference of Delta m^2 ~ 10^-10 - 10^-9 eV^2, traditionally known as ``vacuum oscillation&#39;&#39; range, the solar matter effects are non-negligible, particularly for the low energy pp neutrinos. One consequence of this is that the values of the mixing angle theta and pi/2-theta are n

A. C. Manoharan

It is natural to consider a quantum system in the continuum limit of space-time configuration. Incorporating also, Einstein&#39;s special relativity, leads to the quantum theory of fields. Non-relativistic quantum mechanics and classical mechanics are special cases. By studying vacuum expectation values (Wightman functions W(n; z) where z denotes the set of

M. W. Mitchell, R. Y. Chiao

The mediated photon-photon interaction due to the resonant Kerr nonlinearity in an inhomogeneously broadened atomic vapor is considered. The time-scale for photon-photon scattering is computed and found to be determined by the inhomogeneous broadening and the magnitude of the momentum transfer. This time can be shorter than the atomic relaxation time. Effect

M. W. Mitchell, Cindy I. Hancox, R. Y. Chiao

Temporal and angular correlations in atom-mediated photon-photon scattering are measured. Good agreement is found with the theory presented in Part~I.

Elliott H. Lieb, Jakob Yngvason

The ground state energy per particle of a dilute, homogeneous, two-dimensional Bose gas, in the thermodynamic limit is shown rigorously to be $E_0/N = (2π\hbar^2ρ/m){|\ln (ρa^2)|^{-1}}$, to leading order, with a relative error at most ${\rm O} (|\ln (ρa^2)|^{-1/5})$. Here $N$ is the number of particles, $ρ=N/V$ is the particle density and $a$ is the scatteri

Richard Paul Horja

We study aspects related to Kontsevich&#39;s homological mirror symmetry conjecture in the case of Calabi-Yau complete intersections in toric varieties. In a 1996 lecture at Rutgers University, Kontsevich indicated how his proposal implies that the groups of automorphisms of the two types of categories involved in the homological mirror symmetry conjecture s

Shyamoli Chaudhuri, Eric G. Novak

We give a path integral derivation of the annulus diagram in a supersymmetric theory of open and closed strings with Dbranes. We compute the pair correlation function of Wilson loops in the generic weakly coupled supersymmetric flat spacetime background with Dbranes. We obtain a -u^4/r^9 potential between heavy nonrelativistic sources in a supersymmetric gau

2 Collaboration

About 11 200 e^+e^- -> omega -> pi^+pi^-pi^0 events selected in the center of mass energy range from 760 to 810 MeV were used for the measurement of the ωmeson parameters. The following results have been obtained: sigma _{0}=(1457 \pm 23 \pm 19)nb, m_ω=(782.71 \pm 0.07 \pm 0.04) MeV/c^{2}, Γ_ω=(8.68 \pm 0.23 \pm 0.10) MeV, Γ_{e^+e^-}\cdot Br (ω-> pi^+pi^-pi^

Enrico Montanari, Mirco Calura

The behaviour of a &#34;test&#34; electromagnetic field in the background of an exact gravitational plane wave is investigated in the framework of Einstein&#39;s general relativity. We have expressed the general solution to the de Rham equations as a Fourier-like integral. In the general case we have reduced the problem to a set of ordinary differential equa

E. Barkai, V. Fleurov, J. Klafter

We introduce a Lévy-Lorentz gas in which a light particle is scattered by static point scatterers arranged on a line. We investigate the case where the intervals between scatterers $\{ξ_i \}$ are independent random variables identically distributed according to the probability density function $μ(ξ)\sim ξ^{-(1 + γ)}$. We show that under certain conditions th

Boaz Kol, Amnon Aharony

Cylindrical lattice Diffusion Limited Aggregation (DLA), with a narrow width N, is solved using a Markovian matrix method. This matrix contains the probabilities that the front moves from one configuration to another at each growth step, calculated exactly by solving the Laplace equation and using the proper normalization. The method is applied for a series

Chandan Dasgupta, Oriol T. Valls

Properties of the free energy landscape in phase space of a dense hard sphere system characterized by a discretized free energy functional of the Ramakrishnan-Yussouff form are investigated numerically. A considerable number of glassy local minima of the free energy are located and the distribution of an appropriately defined ``overlap&#39;&#39; between mini

L. P. Rokhinson, L. J. Guo, S. Y. Chou, D. C. Tsui

We studied transport through ultra-small Si quantum dot transistors fabricated from silicon-on-insulator wafers. At high temperatures, 4K<T<100K, the devices show single-electron or single-hole transport through the lithographically defined dot. At T<4K, current through the devices is characterized by multidot transport. From the analysis of the transport in

H. R. Schmitt, A. L. Kinney

We present the results of broad-band B and I imaging observations for a sample of 88 Seyfert galaxies (29 Seyfert 1&#39;s and 59 Seyfert 2&#39;s), selected from a mostly isotropic property, the flux at 60$μ$m. We also present the B and I imaging results for an additional sample of 20 Seyfert galaxies (7 Seyfert 1&#39;s and 13 Seyfert 2&#39;s), selected from

A. L. Kinney, H. R. Schmitt, C. J. Clarke, J. E. Pringle

We present the study of the relative angle between the accretion disk (or radio jet) and the galaxy disk for a sample of Seyfert galaxies selected from a mostly isotropic property, the 60$μ$m flux. For each galaxy we have a pair of points ($i$,$δ$), which are the inclination of the galaxy relative to the line of sight and the angle between the jet projected

Noam Soker

I propose that the relatively high eccentricity found in some tidally strongly interacting binary systems, where the mass-losing star is an evolved giant star, e.g., an asymptotic giant branch star, is caused by an enhanced mass loss rate during periastron passages. Tidal interaction by itself will circularize the orbits of these systems in a relatively shor

M. Kawasaki, K. Kohri, Naoshi Sugiyama

The late-time entropy production by the massive particle decay induces the various cosmological effects in the early epoch and modify the standard scenario. We investigate the thermalization process of the neutrinos after the entropy production by solving the Boltzmann equations numerically. We find that if the large entropy are produced at t $\sim$ 1 sec, t

T. Matos, F. S. Guzman

Recently it has been proposed that the main contributor to the dark energy of the Universe is a dynamical, slow evolving, spatially inhomogeneous scalar field called quintessence. We investigate the behavior of this scalar field at galactic level by assuming that it is the dark matter compossing the halos of galaxies. Using an exact solution of the Einstein&

Martin Gremm

We discuss thick domain walls interpolating between spaces with naked singularities and give arguments based on the $AdS$/CFT correspondence why such singularities may be physically meaningful. Our examples include thick domain walls with Minkowski, de Sitter, and anti-de Sitter geometries on the four-dimensional slice. For flat domain walls we can solve the

Christopher P. Herzog

Recently D'Hoker et al. (1999) computed 4-point correlation functions of axion and dilaton fields in type IIB SUGRA on AdS_5 x S^5. We reproduce from a CFT point of view all power law singular terms in these AdS 4-point amplitudes. We also calculate a corresponding 4-point function in the weak coupling limit, g_{YM}^2 N -> 0. Comparison reveals the existence

P. Kielanowski, S. R. Juárez W., J. G. Mora H.

We analyze the two loop renormalization group equations in the standard model and its extensions for the coupling constants and the quark Yukawa couplings. The key point of our analysis is the observed hierarchy of the quark masses and the CKM matrix. For the one loop evolution we find the explicit solution for the evolution of the Yukawa couplings and show

Ken-Ichi Aoki, Kaoru Takagi, Haruhiko Terao, Masashi Tomoyose

The order parameters of dynamical chiral symmetry breaking in QCD, the dynamical mass of quarks and the chiral condensates, are evaluated by numerically solving the Non-Perturbative Renormalization Group (NPRG) equations. We employ an approximation scheme beyond ``the ladder&#39;&#39;, that is, beyond the (improved) ladder Schwinger-Dyson equations. The chir

Jason R. Cooke, Gerald A. Miller

We consider the ground state in a model with scalar nucleons and a meson using the formalism of light-front dynamics. Light-front potentials for two-nucleon bound states are calculated using two approaches. First, light-front time-ordered perturbation theory is used to calculate one- and two-meson-exchange potentials. These potentials give results that agree

Jens Lieberum

We prove that the LMO-invariant of a 3-manifold of rank one is determined by the Alexander polynomial of the manifold, and conversely, that the Alexander polynomial is determined by the LMO-invariant. Furthermore, we show that the Alexander polynomial of a null-homologous knot in a rational homology 3-sphere can be obtained by composing the weight system of

Anders Johansen, Didier Sornette

Contrary to common belief, both the Earth&#39;s human population and its economic output have grown faster than exponential, i.e., in a super-Malthusian mode, for most of the known history. These growth rates are compatible with a spontaneous singularity occuring at the same critical time 2052 +- 10 signaling an abrupt transition to a new regime. The degree

W. Hunziker, I. M. Sigal, A. Soffer

We give a new derivation of the minimal velocity estimates for unitary evolutions with some optimal bounds.

Steve Zelditch

This paper concerns the inverse spectral problem for analytic simple surfaces of revolution. By `simple&#39; is meant that there is precisely one critical distance from the axis of revolution. Such surfaces have completely integrable geodesic flows with global action-angle variables and possess global quantum Birkhoff normal forms (Colin de Verdiere). We pro

Thierry Mignon

Let $d,m_1,...,m_r$ be ($r+1$) positive integers, and $P_1,...,P_r$ be $r$ general points in the projective plane ; let $m$ be a positive integer. We prove that there exists a bound $d_0(m)$ such that : If $m_i < m$ ($0<i<r+1$), and $d > d_0(m)$ then the linear system $L$ of plane curves of degree $d$ having a multiplicity at least $m_i$ at each point $P_i$

Daniela Bigatti, Leonard Susskind

These TASI lectures review the Holographic principle. The first lecture describes the puzzle of black hole information loss that led to the idea of Black Hole Complementarity and subsequently to the Holographic Principle itself. The second lecture discusses the holographic entropy bound in general space-times. The final two lectures are devoted to the ADS/CF

Sergei V. Shabanov

The physical phase space in gauge systems is studied. Effects caused by a non-Euclidean geometry of the physical phase space in quantum gauge models are described in the operator and path integral formalisms. The projection on the Dirac gauge invariant states is used to derive a necessary modification of the Hamiltonian path integral in gauge theories of the

S. A. Bulgadaev

It is shown that 3D vector van der Waals (conformal) nonlinear $σ$-model (NSM) on a sphere $S^2$ has two types of topological excitations reminiscent vortices and instantons of 2D NSM. The first, the hedgehogs, are described by homotopic group $π_2(S^2) = \mathbb {Z}$ and have the logarithmic energies. They are an analog of 2D vortices. The energy and intera

E787 collaboration

A search for additional evidence for the rare kaon decay K^+ --> pi^+ nu nubar has been made with a new data set comparable in sensitivity to the previous exposure that produced a single event.

S. Yi, L. You

We study the ground state properties of trapped atomic condensates with electric field induced dipole-dipole interactions. A rigorous method for constructing the pseudo potential in the spirit of ladder approximation is developed for general non-spherical (polarized) particles interacting anisotropically. We discuss interesting features not previously consid