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January 2001 arXiv papers — page 12

Showing 1,101–1,200 of 2,489 papers

  1. T. 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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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

  11. Matej 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

  12. 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

  13. Ming-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

  14. 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

  15. 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

  16. 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)].

  17. 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

  18. 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

  19. 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

  20. 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

  21. 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

  22. Oscar 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

  23. 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

  24. D. H. E. Gross

    Boltzmann&#39;s principle S=k ln W allows to extend equilibrium thermo-statistics to ``Small&#39;&#39; 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

  25. M. 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)

  26. Y. 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

  27. 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

  28. 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.

  29. 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

  30. 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

  31. Rino 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

  32. 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

  33. 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

  34. 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

  35. 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

  36. P. 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

  37. Ariane 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

  38. 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

  39. 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

  40. 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

  41. 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

  42. 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 (

  43. 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&#39;&#39; at Ri

  44. 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

  45. 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

  46. B. 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

  47. 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

  48. 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

  49. Sarbani 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

  50. S. 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

  51. 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

  52. Daniel M. Kaplan

    Fermilab has long had the world&#39;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

  53. 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

  54. 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

  55. 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

  56. Bugra 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.

  57. 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.

  58. 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

  59. 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

  60. 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

  61. 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.

  62. 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&#39;il existe une unique connexion fonctorielle sur toute structure de Hodge-Tate mixte ayant certaines propriétés

  63. Sergey 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

  64. 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

  65. Takamitsu 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&#39;s deepest pointed observation on the Lock

  66. 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

  67. 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

  68. 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

  69. S. 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

  70. 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

  71. 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

  72. 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

  73. 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.

  74. 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

  75. 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

  76. August 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

  77. 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

  78. R. 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

  79. 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

  80. Stefano 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

  81. 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

  82. Karl-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

  83. 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

  84. M. 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

  85. 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}&#39;&#39; of a string, at which the linear perturbation theory with a flat space background fails to

  86. 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

  87. 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 $T\neq0K$

  88. 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 .

  89. 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

  90. 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. &#34;Foundations of Probability and Physics&#34;, 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

  91. 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

  92. 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

  93. 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

  94. 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

  95. 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.

  96. 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

  97. 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

  98. 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.

  99. 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

  100. A. Meucci, C. Giusti, F. D. Pacati

    A consistent comparison between nonrelativistic and relativistic descriptions of the (e,e&#39;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&#39;p) di