January 2001 arXiv papers — page 12
Showing 1,101–1,200 of 2,489 papers
Solar neutrino problem accounting for self-consistent magnetohydrodynamics solution for solar magnetic fields
hep-phT. I. Rashba, O. G. Miranda, C. Penya-Garay, V. B. Semikoz
The analysis of the resonant spin-flavour (RSF) solutions to the solar neutrino problem in the framework of simplest analytic solutions to the solar magneto-hydrodynamics (MHD) equations is presented. We performed the global fit of the recent solar neutrino data, including event rates as well as day and night recoil electron spectra induced by solar neutrino
David Garcia
Higgs Yukawa couplings to down-type fermions receive, in the MSSM, supersymmetric quantum corrections that can be of order 1 for large values of tanβ, provided μ\sim MSUSY. Therefore, a sensitive prediction for observables driven by any of these couplings can only be obtained after an all-order resummation of the large corrections. We perform this necessary
A. Banfi, Yu. L. Dokshitzer, G. Marchesini, G. Zanderighi
We present the analysis of the 1/Q-suppressed non-perturbative (NP) contribution to the cumulative out-of-event-plane momentum distribution in e+e- annihilation in the near-to-planar three-jet region. It complements our previous study of the perturbative (PT) distributions resummed to single logarithmic accuracy. Due to inter-jet soft gluon radiation, the NP
K. Yamamoto, M. Tada, Y. Kishimoto, M. Shibata
We report on the present progress in development of the dark matter axion search experiment with Rydberg-atom-cavity detectors in Kyoto, CARRACK I and CARRACK II. The axion search has been performed with CARRACK I in the 8 % mass range around $ 10 μ{\rm eV} $, and CARRACK II is now ready for the search in the wide range $ 2 μ{\rm eV} - 50 μ{\rm eV} $. We hav
R. Godang, CLEO Collaboration
We have studied two-body charmless decays of the $B$ meson into the final states $ρ^0 ρ^0$, $K^{*0} ρ^0$, $K^{*0} K^{*0}$, $K^{*0} \bar{K^{*0}}$, $K^{*+} ρ^0$, $K^{*+} \bar{K^{*0}}$, and $K^{*+} K^{*-}$ using only decay modes with charged daughter particles. Using 9.7 million $B \bar{B}$ pairs collected with the CLEO detector, we place 90% confidence level u
C. Castanier, P. Gay, P. Lutz, J. Orloff
Feasibility of the measurement of the trilinear self-couplings of the Higgs boson is studied. Such a measurement would experimentally determine the structure of the Higgs potential. Full hadronic and semi-leptonic final states of the double-Higgs strahlung have been investigated.
L3 Collaboration
Open charm production in gamma-gamma collisions is studied with data collected at e+e- centre-of-mass energies from 189 GeV to 202 GeV corresponding to a total integrated luminosity of 410 pb-1. The charm cross section sigma(gamma gamma ---> c c~ X) is measured for the first time as a function of the two-photon centre-of-mass energy in the interval from 5 Ge
Asish Satpathy
The Belle detector at the KEK-B asymmetric $e^{+}e^{-}$ collider has recorded 6.2 fb$^{-1}$ data at the $Υ(4S)$ resonance by July 2000. Using this data sample, several new results on various B meson branching ratio measurements are presented. We also report on the measurement of the Standard Model CP violation parameter $\sin(2ϕ_{1})$, where $ϕ_{1}$ is one o
Eloy Ayón-Beato, Alberto García, Alfredo Macías, José M. Pérez-Sánchez
Scalar fields non--minimally coupled to (2+1)-gravity, in the presence of cosmological constant term, are considered. Non-minimal couplings are described by the term $ζR Ψ^2$ in the Lagrangian. Within a class of static circularly symmetric space-times, it is shown that the only existing physically relevant solutions are the anti-de Sitter space-time for $ζ=0
Thomas B. Bahder
A covariant and invariant theory of navigation in curved space-time with respect to electromagnetic beacons is written in terms of J. L. Synge's two-point invariant world function. Explicit equations are given for navigation in space-time in the vicinity of the Earth in Schwarzschild coordinates and in rotating coordinates. The restricted problem of dete
An Alternative to Matter Localization in the "Brane World": An Early Proposal and its Later Improvements
gr-qcMatej Pavsic
Here we place the Latex typeset of the paper M. Pavsic, Phys. Lett. A116 (1986) 1-5. In the paper we presented the picture that our spacetime is a 3-brane moving in a higher dimensional space. The dynamical equations were derived from the action which is just that for the usual Dirac-Nambu-Goto $p$-brane. We also considered the case where not only one, but m
Ting Chen, Ming-Yang Kao, Matthew Tepel, John Rush
The tandem mass spectrometry fragments a large number of molecules of the same peptide sequence into charged prefix and suffix subsequences, and then measures mass/charge ratios of these ions. The de novo peptide sequencing problem is to reconstruct the peptide sequence from a given tandem mass spectral data of k ions. By implicitly transforming the spectral
An Even Faster and More Unifying Algorithm for Comparing Trees via Unbalanced Bipartite Matchings
cs.CVMing-Yang Kao, Tak-Wah Lam, Wing-Kin Sung, Hing-Fung Ting
A widely used method for determining the similarity of two labeled trees is to compute a maximum agreement subtree of the two trees. Previous work on this similarity measure is only concerned with the comparison of labeled trees of two special kinds, namely, uniformly labeled trees (i.e., trees with all their nodes labeled by the same symbol) and evolutionar
Pierre Deransart, Jan-Georg Smaus
We consider prescriptive type systems for logic programs (as in Goedel or Mercury). In such systems, the typing is static, but it guarantees an operational property: if a program is "well-typed", then all derivations starting in a "well-typed" query are again "well-typed". This property has been called subject reduction. We show that
Wellington da Cruz, Marcelo Pagotto Carneiro
We consider the concept of fractons in the context of high-$T_{c}$ superconductivity. These objects, which carry rational or irrational quantum numbers, are classified into universal classes $h$ of particles or quasiparticles which obey specific fractal distribution function. We show that the relaxation time associated to Hall conductivity for the supercondu
Lev I. Deych, Alexey Yamilov, Alexander A. Lisyansky
Numerical study of the scaling of transmission fluctuations in the 1-D localization problem in the presence of absorption is carried out. Violations of single parameter scaling for lossy systems are found and explained on the basis of a new criterion for different types of scaling behavior derived by Deych et al [Phys. Rev. Lett., {\bf 84}, 2678 (2000)].
Giorgio Parisi
In this talk I will describe the deep influence Planck had on the development of statistical mechanics. At this end I will first outline the theoretical situation of statistical mechanics before Planck. I will then describe his main contributions to this field and the progresses obtained as an immediate consequence of his work. I will also outline the later
Brandon Carter, David Langlois, Reinhard Prix
Flow past a line vortex in a simple perfect fluid or superfluid gives rise to a transverse Magnus force that is given by the well known Joukowski lift formula. The problem of generalising this to multiconstituent superfluid models has been controversial since it was originally posed by the work of Iordanski in the context of the Landau 2-constituent model fo
D. N. Jayawardane, Chris J. Pickard, L. M. Brown, M. C. Payne
A comparison between experimental and theoretical electron Energy Loss Near Edge Structure (ELNES) of B and N K-edges in cubic boron nitride is presented. The electron energy loss spectra of cubic boron nitride particles were measured using a scanning transmission electron microscope. The theoretical calculation of the ELNES was performed within the framewor
Haijun Zhou, Yang Zhang
Force-induced structural transitions both in relatively random and in designed single-stranded DNA (ssDNA) chains are studied theoretically. At high salt conditions, ssDNA forms compacted hairpin patterns stabilized by base-pairing and base-pair stacking interactions, and a threshold external force is needed to pull the hairpinned structure into a random coi
M. Saint Jean, C. Even, C. Guthmann
In this paper we present new versatile "2D macroscopic Wigner islands" useful to investigate the various behaviors observed in mesoscopic confined systems. Our "Wigner islands" consist of electrostatically-interacting charged balls with millimetric size. We have experimentally determined the ground configurations for systems of N particles (N
Monte Carlo Study of the Finite Size Effects on the Magnetization of Maghemite Small Particles
cond-mat.mtrl-sciOscar Iglesias, Amilcar Labarta, Felix Ritort
Monte Carlo simulations of a model for $γ$-Fe$_2$O$_3$ (maghemite) single particle of spherical shape are presented aiming at the elucidation the specific role played by the finite size and the surface on the anomalous magnetic behaviour observed in small particle systems at low temperature. The influence of the finite-size effects on the equilibrium propert
Å. Ingerman, G. Johansson, V. S. Shumeiko, G. Wendin
We study coherent multiple Andreev reflections in quantum SNS junctions of finite length and arbitrary transparency. The presence of superconducting bound states in these junctions gives rise to great enhancement of the subgap current. The effect is most pronounced in low-transparency junctions, $D\ll1$, and in the interval of applied voltage $Δ/2<eV<Δ$, whe
Second Law of Thermodynamics, Macroscopic Observables within Boltzmann's Principle but without Thermodynamic Limit
cond-mat.stat-mechD. H. E. Gross
Boltzmann's principle S=k ln W allows to extend equilibrium thermo-statistics to ``Small'' systems without invoking the thermodynamic limit. The clue is to base statistical probability on ensemble averaging and not on time averaging. It is argued that due to the incomplete information obtained by macroscopic measurements thermodynamics handles en
The spectral and magnetic properties of $α$- and $γ$-Ce from the Dynamical Mean-Field Theory and Local Density Approximation
cond-mat.str-elM. B. Zölfl, I. A. Nekrasov, Th. Pruschke, V. I. Anisimov
We have calculated ground state properties and excitation spectra for Ce metal with the {\it ab initio} computational scheme combining local density approximation and dynamical mean-field theory (LDA+DMFT). We considered all electronic states, i.e. correlated f-states and non-correlated s-, p- and d-states. The strong local correlations (Coulomb interaction)
Influence of impurity scattering on tunneling conductance in normal metal- d -wave superconductor junctions
cond-mat.supr-conY. Tanaka, Y. Tanuma, S. Kashiwaya
Tunneling conductance spectra between a normal metal / d-wave superconductor junction under the presence of bulk impurities in the superconductor are studied. The quasiclassical theory has been applied to calculate the spatial variation of the pair potential and the effect of impurity scattering has been introduced by t-matrix approximation. The magnitude of
Weihong Zheng, J. Oitmaa
We use perturbative series expansions about a staggered dimerized ground state to compute the ground state energy, triplet excitation spectra and spectral weight for a one-dimensional model in which each site has an $S=\case 1/2$ spin ${\bf S}_i$ and a pseudospin ${\bf T}_i$, representing a doubly degenerate orbital. An explicit dimerization is introduced to
Keith Slevin, Tomi Ohtsuki
We analyze the scaling behavior of the higher Lyapunov exponents at the Anderson transition. We estimate the critical exponent and verify its universality and that of the critical conductance distribution for box, Gaussian and Lorentzian distributions of the random potential.
Jenny Greene, Charles D. Bailyn, Jerome A. Orosz
We present BVIJK photometry of the black-hole candidate GRO J1655-40 in full quiescence. We report a refined orbital period of 2.62191 +/- 0.00020 days. The light curves are dominated by ellipsoidal variations from the secondary star. We model the light curves with an upgraded code which includes a more accurate treatment of limb darkening. Previous models c
Timothy M. Brown, David Charbonneau, Ronald L. Gilliland, Robert W. Noyes
We have observed 4 transits of the planet of HD 209458 using the STIS spectrograph on HST. Summing the recorded counts over wavelength between 582 nm and 638 nm yields a photometric time series with 80 s time sampling and relative precision of about 1.1E-4 per sample. The folded light curve can be fit within observational errors using a model consisting of a
A Comprehensive Statistical Analysis of the Gas Distribution in Lyman-limit and Damped Lyman-alpha Absorption Systems
astro-phRino Bandiera, Edvige Corbelli
In this paper we show how to use data on Lyman-limit and Damped Lyman-alpha absorption systems to derive the hydrogen ionization fractions and the distribution of the face-on total gas column density. We consider axially symmetric, randomly oriented absorbers, ionized by an external background radiation field in order to relate the face-on total gas distribu
Peter Teuben, Piet Hut, Stuart Levy, Jun Makino
In dense clusters a bewildering variety of interactions between stars can be observed, ranging from simple encounters to collisions and other mass-transfer encounters. With faster and special-purpose computers like GRAPE, the amount of data per simulation is now exceeding 1TB. Visualization of such data has now become a complex 4D data-mining problem, combin
F. Masset, M. Snellgrove
We present new results related to the coupled evolution of a two giant planet system embedded in a protoplanetary disk, in which a Saturn mass protoplanet is trapped in an outer mean motion resonance with a Jupiter mass protoplanet. The gaps opened in the disk by the two planets overlap, therefore the two planet system exchanges angular momentum with the dis
Karl-Heinz Kampert
The study of high energy cosmic rays is a diversified field of observational and phenomenological physics addressing questions ranging from shock acceleration of charged particles in various astrophysical objects, via transport properties through galactic and extragalactic space, to questions of dark matter, and even to those of particle physics beyond the S
V. Buat-Menard, J. -M. Hameury, J. -P. Lasota
We show that the disc instability model can reproduce all the observed properties of Z Cam stars if the energy equation includes heating of the outer disc by the mass-transfer stream impact and by tidal torques and if the mass-transfer rate from the secondary varies by about 30% around the value critical for stability. In particular the magnitude difference
Limits on the cosmological abundance of supermassive compact objects from a search for multiple imaging in compact radio sources
astro-phP. N. Wilkinson, D. R. Henstock, I. W. A. Browne, A. G. Polatidis
Using Very Long Baseline Interferometry we have searched a sample of 300 compact radio sources for examples of multiple imaging produced by gravitational lensing; no multiple images were found with separations in the angular range 1.5--50 milliarcsec. This null result allows us to place a limit on the cosmological abundance of intergalactic supermassive comp
Multiwavelength Study of the Starburst Galaxy NGC 7714. II: The Balance between Young, Intermediate Age and Old Stars
astro-phAriane Lancon, Jeff D. Goldader, Claus Leitherer, Rosa M. Gonzalez Delgado
We combine existing multiwavelength data (incl. an HST/GHRS UV spectrum, an optical spectrum, far-IR, Xray and radio fluxes) with new HST/WFPC2 images, near-IR photometry and K band spectroscopy. We use these data to constrain the young, the intermediate age and the old stellar populations in the central 330 pc of the starburst galaxy NGC 7714. [...] We find
G. Conti, E. Mattaini, L. Chiappetti, D. Maccagni
The VIRMOS Consortium has the task to design and manufacture two spectrographs for ESO VLT, VIMOS (Visible Multi-Object Spectrograph) and NIRMOS (Near Infrared Multi-Object Spectrograph). This paper describes how the Mask Manufacturing Unit (MMU), which cuts the slit masks to be used with both instruments, meets the scientific requirements and manages the st
L. Lara, A. Alberdi, J. M. Marcaide
We present new results on the parsec-scale jet of the quasar 3C395, derived from VLBI polarization sensitive observations made in 1995.91 and 1998.50 at 8.4, 15.4 and 22.2 GHz. The observations show a complex one-sided jet extending up to 20 mas, with a projected magnetic field essentially aligned with the radio jet. The emission is strongly dominated, in to
M. Dadina, L. Bassani, M. Cappi, G. G. C. Palumbo
The Seyfert 2 Galaxy NGC 7172 was observed twice by BeppoSAX narrow field instruments approximately one year apart. As found in previous observations, the source is variable on short time scales (hours) by a factor of $\sim$30%, confirming the presence of a type 1 nucleus at the center. A strong flux variability (by a factor of 2) on a longer time scale was
M. Casse, E. Vangioni-Flam, J. Audouze
We review the main sources of LiBeB production and show that a primary mechanism is at work in the early Galaxy involving both ejection and acceleration of He, C and O at moderate energy, which by nuclear interaction with H and He produce light isotopes. The precise measurement of the Be abundance at [Fe/H] = -3.3 and of $^6Li$ in halo stars find an explanat
J. C. Testori, P. Reich, J. A. Bava, F. R. Colomb
We describe the equipment, observational method and reduction procedure of an absolutely calibrated radio continuum survey of the South Celestial Hemisphere at a frequency of 1420 MHz. These observations cover the area 0h < R.A. < 24h for declinations less than -10 degree. The sensitivity is about 50 mK T_B (full beam brightness) and the angular resolution (
Frank Eisenhauer
The stellar initial mass function (IMF) determines the relative number of stars born at a given mass. Despite the tremendous effort to establish a universal IMF, the astronomical literature offers a wealth of diverse evidence for IMF variations. This review was prepared for a controversial debate at the conference ``Starbursts -- Near and Far'' at Ri
B. R. Oppenheimer, D. A. Golimowski, S. R. Kulkarni, K. Matthews
We present the technique and results of a survey of stars within 8 pc of the Sun with declinations $\bfδ> -35\arcdeg$ (J2000.00). The survey, designed to find without color bias faint companions, consists of optical coronagraphic images of the 1\arcmin field of view centered on each star and infrared direct images with a 32\asc field of view. The images were
U. Lisenfeld, J. Braine, O. Vallejo, P. -A. Duc
Tidal Dwarf Galaxies (TDGs) are objects presently forming from gas which has been expelled from their parent galaxies during an interaction. We observed the CO emission of a sample of 11 TDGs, of which 8 were detected. The CO is found at the peak of the HI observations and has the same line velocity and width, indicating that the molecular gas is forming in
Particle Identification by Multifractal Parameters in Gamma-Astronomy with the HEGRA-Cherenkov-Telescopes
astro-phB. M. Schaefer, W. Hofmann, H. Lampeitl, M. Hemberger
Cherenkov images of air showers can also be classified using multifractal and wavelet parameters, as compared to the conventional Hillas image parameters. This technique was applied to the images recorded by the cameras of the stereoscopic imaging air Cherenkov-telescopes operated by the HEGRA collaboration. With respect to the identification of particles, t
Sergiy Silich, Guillermo Tenorio-Tagle
We evaluate the minimum energy input rate that starbursts require for expelling their newly processed matter from their host galaxies. Special attention is given to the pressure caused by the environment in which a galaxy is situated, as well as to the intrinsic rotation of the gaseous component. We account for these factors and for a massive dark matter dis
S. J. Peale
The probability of detecting a planetary companion of a lensing star during a microlensing event toward the Galactic center, averaged over all relevant event and galactic parameters, when the planet-star mass ratio $q=0.001$ has a maximum exceeding 10% at an orbit semimajor axis $a$ near 1.5 AU for a uniform distribution of impact parameters. The maximum pro
A study of possible temporal and latitudinal variations in the properties of the solar tachocline
astro-phSarbani Basu, H. M. Antia
Temporal variations of the structure and the rotation rate of the solar tachocline region are studied using helioseismic data from the Global Oscillation Network Group (GONG) and the Michelson Doppler Imager (MDI) obtained during the period 1995--2000. We do not find any significant temporal variation in the depth of the convection zone, the position of the
Measuring the brightness temperature distribution of extragalactic radio sources with space VLBI
astro-phS. J. Tingay
We have used VSOP space very long baseline interferometry observations to measure the brightness temperature distribution of a well-defined sub-set of the Pearson-Readhead sample of extragalactic radio sources. VLBI which is restricted to Earth-diameter baselines is not generally sensitive to emitting regions with brightness temperatures greater than approxi
Klaus Behrndt, Sergei Gukov, Marina Shmakova
Supersymmetric solutions, such as BPS domain walls or black holes, in four- and five-dimensional supergravity theories with eight supercharges can be described by effective quantum mechanics with a potential term. We show how properties of the latter theory can help us to learn about the physics of supersymmetric vacua and BPS solutions in these supergravity
Daniel M. Kaplan
Fermilab has long had the world's most intense antiproton source, but the opportunities for medium-energy antiproton physics have been limited, and those for low-energy antiproton physics nonexistent. The conclusion of E835 brings this era to an end. While the future of antiproton physics at Fermilab remains highly uncertain, developments are occurring t
Sergei Nayakshin, Demosthenes Kazanas
We point out that luminous magnetic flares, thought to occur in standard AGN accretion disks, cannot be located much higher than few pressure scale heights above the disk. Using this fact, we estimate the fraction of the disk surface illuminated by a typical flare. This fraction turns out to be very small for geometrically thin disks, which implies that the
Jesús Maíz-Apellániz
We have developed a method to calculate the fundamental parameters of the vertical structure of the Galaxy in the solar neighborhood from trigonometric parallaxes alone. The method takes into account Lutz-Kelker-type biases in a self-consistent way and has been applied to a sample of O-B5 stars obtained from the Hipparcos catalog. We find that the Sun is loc
Scott J. Kenyon, Mercedes Gomez
We describe an L-band photometric survey of 0.5 square deg of the Cha I dark cloud. The survey has a completeness limit of L < 11.0. Our survey detects 124 sources, including all known pre-main sequence stars with L < 11. The fraction of sources with near-IR excess emission is 58% +- 4% for K = 9-11. Cha I sources have bluer H-K and K-L colors than pre-main
Study of relativistic bound states in a scalar model using diagonalization/Monte Carlo methods
hep-phBugra Borasoy, Dean Lee
We use a recently proposed diagonalization/Monte Carlo computational scheme to study relativistic two-body and three-body bound states in 1+1 dimensional phi^6-phi^4 theory. We find that the approach is well-suited for calculating bound state energies and wavefunctions.
R. D. Ball, R. K. Ellis
We report on QCD radiative corrections to heavy quark production valid at high energy. The formulae presented will allow a matched calculation of the total cross section which is correct at $O(\as^3)$ and includes resummation of all terms of order $\as^3 [\as \ln (s/m^2)]^n$. We also include asymptotic estimates of the effect of the high energy resummation.
Roger Ellman
The mass equivalency [m*c^2 = h*f] applies to gravitational mass just as to inertial mass. From that, the gravitational mass has a corresponding, associated, equivalent frequency, f. Using that frequency a new result is obtained in which the significance of the Planck Length is clarified. The Planck Length is fundamental to gravitation and in effect superced
M. A. Pichowsky, A. Szczepaniak, J. T. Londergan
A unitary framework based on the Bakamjian-Thomas construction of relativistic quantum mechanics is used to describe two-pion scattering from threshold to 1400 MeV. The framework properly includes unitarity cuts for one-, two- and three-hadron states and provides an excellent description of the available data for pi pi phase shifts and inelasticities. The ro
Michael G. A. Crawford
A special relativistic perturbation to non-relativistic quantum mechanics is shown to lead to the special relativistic prediction for the rate of precession for quantum states in the Coulomb potential. This behavior is shown using SO(4) coherent states as examples. These states are localized on Kepler ellipses and precess in the presence of a relativistic pe
Doron Gepner, Boris Noyvert
SW(3/2,2) superconformal algebra is W algebra with two Virasoro operators. The Kac determinant is calculated and the complete list of unitary representations is determined. Two types of extensions of SW(3/2,2) algebra are discussed. A new approach to construction of W algebras from rational conformal field theories is proposed.
M. Rovinsky
Pour tout schéma simplicial complexe $X_{\bullet}$ il existe une application canonique $\nabla:H^{\ast}(X_{\bullet})\longrightarrow Ω^1_{{\mathbb C}/{\mathbb Q}}\otimes H^{\ast}(X_{\bullet})$, appelée la connexion de Gauß-Manin. Nous montrons qu'il existe une unique connexion fonctorielle sur toute structure de Hodge-Tate mixte ayant certaines propriétés
Negative Magnetoresistance Produced by Hall Fluctuations in a Ferromagnetic Domain Structure
cond-mat.mtrl-sciSergey V. Barabash, D. Stroud
We present a model for a negative magnetoresistance (MR) that would develop in a material with many ferromagnetic domains even if the individual domains have no magnetoresistance and even if there is no boundary resistance. The negative MR is due to a classical current-distortion effect arising from spatial variations in the Hall conductivity, combined with
Philip C. Argyres, K. Narayan
The spectrum of stable electrically and magnetically charged supersymmetric particles can change discontinuously as one changes the vacuum on the Coulomb branch of gauge theories with extended supersymmetry in four dimensions. We show that this decay process can be understood and is well described by semiclassical field configurations purely in terms of the
Soft X-ray AGN Luminosity Function from ROSAT Surveys II. Table of the binned Soft X-ray Luminosity Function
astro-phTakamitsu Miyaji, Guenther Hasinger, Maarten Schmidt
This is the second paper of our investigation of the 0.5-2 keV soft X-ray luminosity function (SXLF) of active galactic nuclei (AGN) using results from ROSAT surveys of various depth. The large dynamic range of the combined sample, from shallow large-area ROSAT All-Sky Survey (RASS)-based samples to the satellite's deepest pointed observation on the Lock
Gerard Clement, Alessandro Fabbri
We present an exact collapsing solution to 2+1 gravity with a negative cosmological constant minimally coupled to a massless scalar field, which exhibits physical properties making it a candidate critical solution. We discuss its global causal structure and its symmetries in relation with those of the corresponding continously self-similar solution derived i
René Messina, Christian Holm, Kurt Kremer
We investigate spherical macroions in the strong Coulomb coupling regime within the primitive model in salt-free environment. We first show that the ground state of an isolated colloid is naturally overcharged by simple electrostatic arguments illustrated by the Gillespie rule. We furthermore demonstrate that in the strong Coulomb coupling this mechanism lea
Igor A. Bandos, Jose A. de Azcarraga, Jose M. Izquierdo, Jerzy Lukierski
We provide a complete algebraic description of BPS states in M-theory in terms of primary constituents that we call BPS preons. We argue that any BPS state preserving $k$ of the 32 supersymmetries is a composite of (32-k) BPS preons. In particular, the BPS states corresponding to the basic M2 and M5 branes are composed of 16 BPS preons. By extending the M-al
Assessment of W1 and W2 theories for the computation of electron affinities, ionization potentials, heats of formation, and proton affinities
physics.chem-phS. Parthiban, Jan M. L. Martin
The performance of two recent {\em ab initio} computational thermochemistry schemes, W1 and W2 theory [J.M.L. Martin and G. de Oliveira, J. Chem. Phys. 111, 1843 (1999}], is assessed for an enlarged sample of thermochemical data consisting of the ionization potentials and electron affinities in the G2-1 and G2-2 sets, as well as the heats of formation in the
Stanley P. Owocki, David H. Cohen
Motivated by recent detections by the XMM and Chandra satellites of X-ray line emission from hot, luminous stars, we present synthetic line profiles for X-rays emitted within parameterized models of a hot-star wind. The X-ray line emission is taken to occur at a sharply defined co-moving-frame resonance wavelength, which is Doppler-shifted by a stellar wind
Gunter M. Schuetz, Jaime E. Santos
We investigate the nonequilibrium tube length fluctuations during the relaxation of an initially stretched, entangled polymer chain. The time-dependent variance $σ^2$ of the tube length follows in the early-time regime a simple universal power law $σ^2 = A \sqrt{t}$ originating in the diffusive motion of the polymer segments. The amplitude $A$ is calculated
I. A. Pshenichnov, J. P. Bondorf, I. N. Mishustin, A. Ventura
We study mutual dissociation of heavy nuclei in peripheral collisions at ultrarelativistic energies. Earlier this process was proposed for beam luminosity monitoring via simultaneous registration of forward and backward neutrons in zero degree calorimeters at Relativistic Heavy Ion Collider. Electromagnetic dissociation of heavy ions is considered in the fra
Jean Alexandre
A functional partial differential equation is set for the proper graphs generating functional of QED in external electromagnetic fields. This equation leads to the evolution of the proper graphs with the external field amplitude and the external field gauge dependence of the complete fermion propagator and vertex is derived non-perturbativally.
V. K. Dugaev, P. Bruno, J. Barnas
Weak localization corrections to conductivity of ferromagnetic systems are studied theoretically in the case when spin-orbit interaction plays a significant role. Two cases are analyzed in detail: (i) the case when the spin-orbit interaction is due to scattering from impurities, and (ii) the case when the spin-orbit interaction results from reduced dimension
K. Langfeld, H. Reinhardt, A. Schafke
Resorting to the the Laplace center gauge (LCG) and to the Maximal-center gauge (MCG), respectively, confining vortices are defined by center projection in either case. Vortex properties are investigated in the continuum limit of SU(2) lattice gauge theory. The vortex (area) density and the density of vortex crossing points are investigated. In the case of M
Single-Crystal High-Frequency EPR Investigation of a Tetranuclear Iron(III) Single-Molecule Magnet
cond-mat.mes-hallAugust Bouwen, Andrea Caneschi, Dante Gatteschi, Etienne Goovaerts
A high-frequency (95 GHz) EPR study is reported on single crystals of the planar tetranuclear complex Fe4(OCH3)6(dpm)6 (where Hdpm = dipivaloylmethane), which has been previously shown to present typical single-molecule magnet behaviour. The spectra, all originating from the S = 5 ground state, possess quasi-axial symmetry along the normal to the plane defin
J. R. Cudell, A. Le Yaouanc, C. Pittori
We show that, contrarily to recent claims, data from the Wilson (unimproved) fermionic action at three different beta values demonstrate the presence of a large Goldstone boson contribution in the quark pseudoscalar vertex, quantitatively close to our previous estimate based on the SW action with c_{SW}=1.769. We show that discretisation errors on Z_{S}^{MOM
Tanaka-Tagoshi Parametrization of post-1PN Spin-Free Gravitational Wave Chirps: Equispaced and Cardinal Interpolated Lattices For First Generation Interferometric Antennas
gr-qcR. P. Croce, Th. Demma, V. Pierro, I. M. Pinto
The spin-free binary-inspiral parameter-space introduced by Tanaka and Tagoshi to construct a uniformly-spaced lattice of templates at (and possibly beyond) $2.5PN$ order is shown to work for all first generation interferometric gravitational wave antennas. This allows to extend the minimum-redundant cardinal interpolation techniques of the correlator bank d
Marc-Thierry Jaekel, Serge Reynaud
The mean force exerted upon a perfect mirror moving in vacuum in a two dimensional spacetime has the same expression as the radiation reaction force computed in classical electron theory. It follows that unacceptable runaway solutions are predicted. We show that this instability problem does not appear when partially transmitting mirrors are studied. The mec
Polarized parton distributions from charged-current deep-inelastic scattering and future neutrino factories
hep-phStefano Forte, Michelangelo L. Mangano, Giovanni Ridolfi
We discuss the determination of polarized parton distributions from charged-current deep-inelastic scattering experiments. We summarize the next-to-leading order treatment of charged-current polarized structure functions, their relation to polarized parton distributions and scale dependence, and discuss their description by means of a next-to-leading order e
Tomohiro Harada, Hideki Maeda
We study the spherical collapse of a perfect fluid with an equation of state $P=kρ$ by full general relativistic numerical simulations. For $0<k\alt 0.036$, it has been known that there exists a general relativistic counterpart of the Larson-Penston self-similar Newtonian solution. The numerical simulations strongly suggest that, in the neighborhood of the c
Methods of Determination of the Energy and Mass of Primary Cosmic Ray Particles at Extensive Air Shower Energies
astro-phKarl-Heinz Kampert
Measurements of cosmic ray particles at energies above E = 5 x 10^{14} eV are performed by large area ground based air shower experiments. Only they provide the collection power required for obtaining sufficient statistics at the low flux levels involved. In this review we briefly outline the physics and astrophysics interests of such measurements and discus
T. Gollisch, C. Wetterich
We compute the free energy of helium-4 near the lambda transition based on an exact renormalization-group equation. An approximate solution permits the determination of universal and nonuniversal thermodynamic properties starting from the microphysics of the two-particle interactions. The method does not suffer from infrared divergences. The critical chemica
Solution of a class of one-dimensional reaction-diffusion models in disordered media
cond-mat.stat-mechM. Mobilia, P. -A. Bares
We study a one-dimensional class of reaction-diffusion models on a $10-$parameters manifold. The equations of motion of the correlation functions close on this manifold. We compute exactly the long-time behaviour of the density and correlation functions for {\it quenched} disordered systems. The {\it quenched} disorder consists of disconnected domains of rea
Kouji Nakamura
The initial data of the gravitational field produced by a loop thick string is considered. We show that a thick loop is not a geodesic on the initial hypersurface, while a loop conical singularity is. This suggests that there is the ``{\it critical thickness}'' of a string, at which the linear perturbation theory with a flat space background fails to
Youngman Kim, Young-Ho Song, Dong-Pil Min
We investigate the effects of pion and gluon exchanges on the formation of two-flavor color superconductivity at moderate density, $μ<1 GeV$. The chiral quark model proposed by Manohar and Georgi containing pions as well as gluons is employed to show that the pion exchange reduces substantially the value of the superconducting gap gotten with the gluon excha
G. R. Jin, D. L. Zhou, Yu-xi Liu, X. X. Yi
We implement the normal ordering technique to study the quantum dissipation of a single mode harmonic oscillator system. The dynamic evolution of the system is investigated for a reasonable initial state by solving the Schrödinger equation directly through the normal ordering technique. The decoherence process of the system for the cases $T=0K$ and $T\neq0K$
Ian Agol
Given a hyperbolic 3-manifold M containing an embedded closed geodesic, we estimate the volume of a complete hyperbolic metric on the complement of the geodesic in terms of the geometry of M. As a corollary, we show that the smallest volume orientable hyperbolic 3-manifold has volume >.32 .
Ulrich Gerland, Ralf Bundschuh, Terence Hwa
We describe quantitatively a RNA molecule under the influence of an external force exerted at its two ends as in a typical single-molecule experiment. Our calculation incorporates the interactions between nucleotides by using the experimentally-determined free energy rules for RNA secondary structure and models the polymeric properties of the exterior single
Andrei Khrennikov
We present the summary of the general discussion on the probabilistic foundations of quantum theory that took place during the round table at the Int. Conf. "Foundations of Probability and Physics", Växjö, Sweden-2000. It is possible to find at http://www.msi.vxu.se/aktuellt/konferens/Roundtable.html continuation of this Round Table. You can send you
Thomas Durt, Dagomir Kaszlikowski, Marek Zukowski
Predictions for systems in entangled states cannot be described in local realistic terms. However, after admixing some noise such a description is possible. We show that for two quNits (quantum systems described by N dimensional Hilbert spaces) in a maximally entangled state the minimal admixture of noise increases monotonically with N. The results are a dir
Krzysztof Sacha, Jakub Zakrzewski
The dynamics of Rydberg states of a hydrogen atom subject simultaneously to uniform static electric field and two microwave fields with commensurate frequencies is considered in the range of small fields amplitudes. In the certain range of the parameters of the system the classical secular motion of the electronic ellipse reveals chaotic behavior. Quantum me
Marc-Thierry Jaekel, Serge Reynaud
Moving mirrors are submitted to reaction forces by vacuum fields. The motional force is known to vanish for a single mirror uniformly accelerating in vacuum. We show that inertial forces (proportional to accelerations) arise in the presence of a second scatterer, exhibiting properties expected for a relative inertia: the mass corrections depend upon the dist
Marc-Thierry Jaekel, Serge Reynaud
The force experienced by a mirror moving in vacuum vanishes in the case of uniform velocity or uniform acceleration, as a consequence of spatial symmetries of vacuum. These symmetries do not subsist in a thermal field. We give a general expression of the corresponding viscosity coefficient valid at any temperature and for any reflectivity function. We show t
Max Tegmark, John Archibald Wheeler
As quantum theory celebrates its 100th birthday, spectacular successes are mixed with outstanding puzzles and promises of new technologies. This article reviews both the successes of quantum theory and the ongoing debate about its consequences for issues ranging from quantum computation to consciousness, parallel universes and the nature of physical reality.
Erhard Bieberich
In human consciousness perceptions are distinct or atomistic events despite being perceived by an apparently undivided inner observer. This paper applies both classical (Boolean) and quantum logic to analysis of the Liar paradox which is taken as a typical example of a self-referential negation in the perception space of an undivided observer. The conception
Marco Frasca
A formulation of quantum electrodynamics is given that applies to atoms in a strong laser field by perturbation theory in a non-relativistic regime. Dipole approximation is assumed. The dual Dyson series, here discussed by referring it to the Birkhoff theorem for singularly perturbed linear differential equations, can be applied and a perturbation series obt
M. Kolesik, J. V. Moloney, E. M. Wright
Polarization dynamics of femtosecond light pulses propagating in air is studied by computer simulation. A rich variety of dynamics is found that depends on the initial polarization state and power of the pulse. Effects of polarization on the plasma and supercontinuum generation are also discussed.
Lewis Keller, Rainer Pitthan, Sayed Rokni, Kathleen Thompson
A conceptual program to use NLC beams for test beams and fixed target physics is described. Primary undisrupted polarized beams would be the most simple to use, but for NLC, the disrupted beams are of good enough quality that they could also be used, after collimation of the low energy tails, for test beams and fixed target physics. Pertinent issues are: wha
A. Meucci, C. Giusti, F. D. Pacati
A consistent comparison between nonrelativistic and relativistic descriptions of the (e,e'p) reaction is presented. We use the nonrelativistic DWEEPY code and develop a fully relativistic model starting from the effective Pauli reduction for the scattering state and the relativistic mean field theory for the bound state. Results for the 16O(e,e'p) di