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May 2002 arXiv papers — page 7

Showing 601–700 of 3,036 papers

  1. L. M. Volkova, S. A. Polyshchuk, S. A. Magarill, F. E. Herbeck

    We establish the empirical correlation between Tc and crystal chemical parameters in diborides. Our results suggest that Tc of diborides can be higher 77K.

  2. Y. K. Ng, E. Brogt, C. Chiosi, G. Bertelli

    A new method, AMORE - based on a genetic algorithm optimizer, is presented for the automated study of colour-magnitude diagrams. The method combines several stellar population synthesis tools developed in the last decade by or in collaboration with the Padova group. Our method is able to recover, within the uncertainties, the parameters -- distance, extincti

  3. A. Del Popolo

    I derive the mass-temperature relation and its time evolution for clusters of galaxies in different cosmologies by means of two different models. The first one is a modification and improvement of a model by Del Popolo & Gambera(1999), namely based upon a modification of the top-hat model in order to take account of angular momentum acquisition by protostruc

  4. A. Konopelko

    Since their discovery at radio wavelengths pulsars have been persistent targets for widespread multi-wave observations throughout optics, radio, X-rays, and high-energy gamma-rays. Observations with the EGRET gamma-ray telescope, on board Compton GRO satellite, confirmed the expectation of a pulsed high-energy emission up to a few GeV. Presently, at least se

  5. Eric G. Blackman

    Some recent results and open issues in magnetic dynamo theory are addressed. The distinction between small-scale and mean-field dynamo (MFD) action in forced turbulent flows is emphasized. Though useful, the MFD has been controversial. This is partly due to concerns about its need for helically forced turbulence, but mainly because simple "textbook"

  6. Peter B. Gilkey, Raina Ivanova, Tan Zhang

    We study the higher order Jacobi operator in pseudo-Riemannian geometry. We exhibit a family of manifolds so that this operator has constant Jordan normal form on the Grassmannian of subspaces of signature (r,s) for certain values of (r,s). These pseudo-Riemannian manifolds are new and non-trivial examples of higher order Osserman manifolds.

  7. Hideki Maeda, Jun-ichirou Koga, Kei-ichi Maeda

    We investigate spherically symmetric self-similar solutions in Brans-Dicke theory. Assuming a perfect fluid with the equation of state $p=(γ-1)μ(1 \le γ<2)$, we show that there are no non-trivial solutions which approach asymptotically to the flat Friedmann-Robertson-Walker spacetime if the energy density is positive. This result suggests that primordial bla

  8. Dongsu Bak, Nobuyoshi Ohta, Mohammad M. Sheikh-Jabbari

    After reviewing the supertubes and super brane-antibrane systems in the context of matrix model, we look for more general higher-dimensional configurations. For D3-bar{D3}, we find a non-trivial configuration with E cdot B not equal to 0 and describe the worldvolume gauge theory. We present the string probe of D3-bar{D3} system and study the decoupling limit

  9. T. Roy Choudhury, R. Srianand

    In this article, we explore the possibility of using the properties of gamma ray bursts (GRBs) to probe the physical conditions in the epochs prior to reionization. The redshift distribution of GRBs is modelled using the Press-Schechter formalism with an assumption that they follow the cosmic star formation history. We reproduce the observed star formation r

  10. A. M. Perelomov

    In the paper by F. Calogero and author [Commun. Math. Phys. 59 (1978) 109-116] the formula for frequencies of small oscillations of the Sutherland system ($A_l$ case) was found. In present note the generalization of this formula for the case of arbitrary root system is given.

  11. Sutapa Ghosh, Soma Mandal, Somenath Chakrabarty

    It is shown explicitly that a ferromagnetic transition of neutron star (NS) / proto-neutron star (PNS) matter in the $β$-equilibrium condition with $σ-ω-ρ$ exchange type of mean field approximation can actually occur if and only if the neutrinos remain trapped within the system, and perhaps it is also necessary for the neutrinos / anti-neutrinos to carry som

  12. V. A. Kuz&#39;menko

    Two alternative hypotheses try to explain the origin of the continuum. The present communication gives new argument in favor of the dimer hypothesis. This argument is based on the existence of the wide component of line in absorption spectrum of polyatomic molecules.

  13. Sudhir Raniwala

    Measurements of azimuthal distribution of inclusive photons using the fine granularity preshower photon multiplicity detector (PMD) at CERN SPS are used to obtain anisotropy in the azimuthal distributions. These results are used to estimate the anisotropy in the neutral pion distributions. The results are compared with results of charged particle data, both

  14. I. Kogan, A. M. Perelomov, G. W. Semenoff

    We examine the stability of ringlike configurations of N charges on a plane interacting through the potential $V(z_1,...,z_N)=\sum_i |z_i|^2-\sum_{i<j} ln|z_i-z_j|^2$. We interpret the equilibrium distributions in terms of a shell model and compare predictions of the model with the results of numerical simulations for systems with up to 100 particles.

  15. Sayan Kar

    The space of couplings of a given theory is the arena of interest in this article. Equipped with a metric ansatz akin to the Fisher information matrix in the space of parameters in statistics (similar metrics in physics are the Zamolodchikov metric or the O&#39;Connor--Stephens metric) we investigate the geometry of theory space through a study of specific e

  16. V. I. Kuvshinov, A. V. Kuzmin

    Chaos criterion for quantum field theory is proposed. Its correspondence with classical chaos criterion in semi-classical regime is shown. It is demonstrated for real scalar field that proposed chaos criterion can be used to investigate stability of classical solutions of field equations.

  17. Yosuke Uehara

    We propose a new mechanism to generate the neutrino Majorana mass in TeV-scale gravity models. The black hole violates all non-gauged symmetries and can become the origin of lepton number violating processes. The fluctuation of higher-dimensional spacetime can result in the production of a black hole, which emits 2 neutrinos. If neutrinos are Majorana partic

  18. H. L. Harney

    As a coauthor of the article mentioned in the title, I discuss the criticism in the comment of Aalseth et al. Part of the criticism is justified.

  19. Shuntaro Mizuno, Kei-ichi Maeda, Kohta Yamamoto

    We study the dynamics of a scalar field in the brane cosmology. We assume that a scalar field is confined in our 4-dimensional world. As for the potential of the scalar field, we discuss three typical models: (1) a power-law potential, (2) an inverse-power-law potential, and (3) an exponential potential. We show that the behavior of the scalar field is very

  20. Qing-hua Xu, Zuo-tang Liang

    We extend the calculations of the spin alignments of vector mesons in $e^+e^-$ annihilation in a recent Rapid Communication to deeply inelastic lepton-nucleon scatterings. We present the results for different mesons in the current fragmentation regions of $μ^- N$$ \to$$ μ^- VX$ at high energies and $ν_μN $$\to$$ μ^- VX$ at both high and low energies. We also

  21. P. Azzurri

    We review here the measurements of W-pair production and W decay rates performed by the four LEP experiments at ECM from 161 to 209 GeV, and their relevance in support of the standard electroweak model.

  22. Carlo Rovelli, Simone Speziale

    A Planck-scale minimal observable length appears in many approaches to quantum gravity. It is sometimes argued that this minimal length might conflict with Lorentz invariance, because a boosted observer could see the minimal length further Lorentz contracted. We show that this is not the case within loop quantum gravity. In loop quantum gravity the minimal l

  23. Regina Barzilay, Lillian Lee

    An important component of any generation system is the mapping dictionary, a lexicon of elementary semantic expressions and corresponding natural language realizations. Typically, labor-intensive knowledge-based methods are used to construct the dictionary. We instead propose to acquire it automatically via a novel multiple-pass algorithm employing multiple-

  24. C. Reichhardt, C. J. Olson Reichhardt

    We examine the charge transport through disordered arrays of metallic dots using numerical simulations. We find power law scaling in the current-voltage curves for arrays containing no voids, while for void-filled arrays charge bottlenecks form and a single scaling is absent, in agreement with recent experiments. In the void-free case we also show that the s

  25. Wei-Xing Zhou, Didier Sornette

    We apply two non-parametric methods to test further the hypothesis that log-periodicity characterizes the detrended price trajectory of large financial indices prior to financial crashes or strong corrections. The analysis using the so-called (H,q)-derivative is applied to seven time series ending with the October 1987 crash, the October 1997 correction and

  26. I. S. Elfimov, S. Yunoki, G. A. Sawatzky

    We introduce a path to a possibly new class of magnetic materials whose properties are determined entirely by the presence of a low concentration of specific point defects in their crystal structure. Using model Hamiltonian and ab-initio band structure methods we demonstrate that even large band gap nonmagnetic materials as simple as CaO can exhibit extraord

  27. A. A. Ovchinnikov, M. Ya. Ovchinnikova

    Influence of a spiral spin structure on the superconducting (SC) pairing in the most probable active $γ$ band of $Sr_2RuO_4$ is studied in the mean field approximation. Such structure with &#34;incommensurate&#34; vector $Q=2π(1/3,1/3)$ has been proposed as that which removes the nesting instability in $\alfa, \betta$ bands. The model pairing interaction of

  28. Weinan E, Weiqing Ren, Eric Vanden-Eijnden

    A novel and powerful method is presented for the study of rare switching events in complex systems with multiscale energy landscapes. The method performs an umbrella sampling of the equilibrium distribution of the system in hyperplanes normal to the effective transition pathway, i.e. the transition pathway of a coarse-grained potential which need not to be k

  29. Weinan E, Weiqing Ren, Eric Vanden-Eijnden

    We present a new and efficient method for computing the transition pathways, free energy barriers, and transition rates in complex systems with relatively smooth energy landscapes. The method proceeds by evolving strings, i.e. smooth curves with intrinsic parametrization whose dynamics takes them to the most probable transition path between two metastable re

  30. Y. S. Lee, Jaejun Yu, J. S. Lee, T. W. Noh

    Optical conductivity spectra $σ_1(ω)$ of paramagnetic CaRuO$_3$ are investigated at various temperatures. At T=10 K, it shows a non-Fermi liquid behavior of $σ_1(ω)\sim 1/ω^{\frac 12}$, similar to the case of a ferromagnet SrRuO$_3$. As the temperature ($T$) is increased, on the other hand, $σ_1(ω)$ in the low frequency region is progressively suppressed, de

  31. D. C. Mei, L. Zhang, Z. J. Jiang, B. Z. Dai

    Using the sample of radio selected BL Lacertae objects (RBLs) and X-ray selected BL Lacertae objects (XBLs) presented by Sambruna et al. (1996), we calculated the luminosities of radio, optical and X-ray of each source and made the statistical analysis among the luminosities at different wave-bands, broad-band spectral indices from radio to X-ray ($α_{\rm rx

  32. B. Uyaniker, W. Reich, A. Yar, R. Kothes

    The Cygnus Loop is classified as a middle-aged supernova remnant (SNR) located below the Galactic equator (l=74, b=-8.6) and 770 pc away from us. Its large size and little confusion with Galactic emission makes it an ideal test ground for evolutionary and structural theories of SNRs. New radio continuum mapping of the Cygnus Loop at 2695 MHz with the Effelsb

  33. M. Plionis

    The following review presents an attempt to discuss various issues of current interest in Observational Cosmology, the selection of which as well as the emphasis given, reflects my own preference and biases. After presenting some Cosmological basics, for which I was aided by excellent text-books, I emphasize on attempts to determine some of the important cos

  34. David Garfinkle, Carsten Gundlach

    We find the perturbation spectrum of a family of spherically symmetric and continuously self-similar (CSS) exact solutions that appear to be relevant for the critical collapse of scalar field matter in 2+1 spacetime dimensions. The rate of exponential growth of the unstable perturbation yields the critical exponent. Our results are compared to the numerical

  35. Ping Sun, Gabriel Kotliar

    We develop the extended dynamical mean field theory (E-DMFT) with a view towards realistic applications. {\bf 1)} We introduce an intuitive derivation of the E-DMFT formalism. By identifying the Hartree contributions before the E-DMFT treatment, it allows to handle systems in symmetry breaking phases within a simple formalism. {\bf 2)} We make a new implemen

  36. Charles Sauerbier

    Three algorithms are presented that determine the existence of satisfying assignments for 3SAT Boolean satisfiability expressions. One algorithm is presented for determining an instance of a satisfying assignment, where such exists. The algorithms are each deterministic and of polynomial complexity. The algorithms determining existence are complete as each p

  37. Christian W. Bauer, Dan Pirjol, Iain W. Stewart

    We describe in some detail the derivation of a power counting formula for the soft-collinear effective theory (SCET). This formula constrains which operators are required to correctly describe the infrared at any order in the Lambda_QCD/Q expansion (lambda expansion). The result assigns a unique lambda-dimension to graphs in SCET solely from vertices, is gau

  38. Marie Ericsson, Erik Sjöqvist, Johan Brännlund, Daniel K. L. Oi

    We generalize the notion of relative phase to completely positive maps with known unitary representation, based on interferometry. Parallel transport conditions that define the geometric phase for such maps are introduced. The interference effect is embodied in a set of interference patterns defined by flipping the environment state in one of the two paths.

  39. Martin White, Lars Hernquist, Volker Springel

    We present results on the thermal and kinetic Sunyaev-Zel&#39;dovich (SZ) effects from a sequence of high resolution hydrodynamic simulations of structure formation, including cooling, feedback and metal injection. These simulations represent a self-consistent thermal model which incorporates ideas from the `pre-heating&#39; scenario while preserving good ag

  40. Antony Lewis, Sarah Bridle

    We present a fast Markov Chain Monte-Carlo exploration of cosmological parameter space. We perform a joint analysis of results from recent CMB experiments and provide parameter constraints, including sigma_8, from the CMB independent of other data. We next combine data from the CMB, HST Key Project, 2dF galaxy redshift survey, supernovae Ia and big-bang nucl

  41. A. F. Kostko, M. A. Anisimov, J. V. Sengers

    We have performed accurate dynamic light-scattering measurements near critical demixing points of solutions of polystyrene in cyclohexane with polymer molecular weight ranging from 200,000 to 11.4 million. Two dynamic modes have been observed, &#39;&#39;slow&#39;&#39; and &#39;&#39;fast&#39;&#39;, that result from a coupling between diffusive relaxation of c

  42. Ernesto P. Borges

    We analyze the cumulative distribution of total personal income of USA counties, and gross domestic product of Brazilian, German and United Kingdom counties, and also of world countries. We verify that generalized exponential distributions, related to nonextensive statistical mechanics, describe almost the whole spectrum of the distributions (within acceptab

  43. Amand Faessler, Th. Gutsche, M. A. Ivanov, J. G. Korner

    We study the exclusive rare decay B -> K l(bar) l. We calculate the relevant form factors within a relativistic constituent quark model, for the first time without employing the impulse approximation. The calculated form factors are used to evaluate differential decay rates and polarization observables. We present results on the q2-dependence of a set of obs

  44. Veronika E. Hubeny, Mukund Rangamani, Erik Verlinde

    We investigate Penrose limits of two classes of non-local theories, little string theories and non-commutative gauge theories. Penrose limits of the near-horizon geometry of NS5-branes help to shed some light on the high energy spectrum of little string theories. We attempt to understand renormalization group flow in these theories by considering Penrose lim

  45. Pietro Massignan, Michele Modugno

    We present a 1D effective model for the evolution of a cigar-shaped Bose-Einstein condensate in time dependent potentials whose radial component is harmonic. We apply this model to investigate the dynamics and expansion of condensates in 1D optical lattices, by comparing our predictions with recent experimental data and theoretical results. We also discuss n

  46. Malte Henkel

    Statistical systems displaying a strongly anisotropic or dynamical scaling behaviour are characterized by an anisotropy exponent theta or a dynamical exponent z. For a given value of theta, we construct local scale transformations which can be viewed as scale transformations with a space-time-dependent dilatation factor. Two distinct types of local scale tra

  47. A. Glatz, T. Nattermann, V. Pokrovsky

    The viscous motion of an interface driven by an ac external field of frequency omega_0 in a random medium is considered here for the first time. The velocity exhibits a smeared depinning transition showing a double hysteresis which is absent in the adiabatic case omega_0 --> 0. Using scaling arguments and an approximate renormalization group calculation we e

  48. V. Corato, P. Silvestrini, L. Stodolsky, J. Wosiek

    We examine the realization of a quantum CNOT gate by adiabatic operations.The principles of such systems and their analysis are briefly discussed and a model consisting of two weakly coupled double- potential well qubits is studied numerically. Regions of the parameter space with suitable well-defined sets of wavefunctions are found, in which then an adiabat

  49. Bert Janssen, Yolanda Lozano

    We argue that the dielectric effect, mostly studied for systems of coincident D-branes, is also extendible to configurations of multiple gravitational waves. We provide some evidence that Matrix string theory has an alternative interpretation as describing also, in the static gauge, multiple Type IIA gravitational waves. Starting with the linearised action o

  50. Ayres Freitas, Dominik Stöckinger

    Well-known and newly developed renormalization schemes for $\tanβ$ are analyzed in view of three desirable properties: gauge independence, process independence, and numerical stability in perturbation theory. Arguments are provided that no scheme can meet all three requirements, and as an illustration, a ``No-Go-Theorem&#39;&#39; for the renormalization of $

  51. L. Vanzi, L. K. Hunt, T. X. Thuan

    We have obtained near-infrared images and spectra of three blue compact dwarf galaxies of intermediate sub-solar metallicity Tol~35, Tol~3 and UM 462. This work is part of a larger project aimed to study the star formation and the stellar populations of low metallicity galaxies in the near-infrared. In this frame work galaxies of intermediate metallicity rep

  52. P. D. Ditlevsen, M. H. Jensen, P. Olesen

    Few rigorous results are derived for fully developed turbulence. By applying the scaling properties of the Navier-Stokes equation we have derived a relation for the energy spectrum valid for unforced or decaying isotropic turbulence. We find the existence of a scaling function $ψ$. The energy spectrum can at any time by a suitable rescaling be mapped onto th

  53. H. C. Spruit, G. Kanbach

    We present coordinated X-ray and optical observations of the X-ray transient KV UMa (= XTE J1118+480) at high time resolution. The optical variation associated with spikes in the X-rays consist of a dip preceding the spike by 0-5 s, and a peak following it. The cross-correlation function between X-rays and optical has the same shape. It rises sharply, within

  54. E. Peled, D. Shahar, Y. Chen, D. L. Sivco

    We present an experimental study of mesoscopic, two-dimensional electronic systems at high magnetic fields. Our samples, prepared from a low-mobility InGaAs/InAlAs wafer, exhibit reproducible, sample specific, resistance fluctuations. Focusing on the lowest Landau level we find that, while the diagonal resistivity displays strong fluctuations, the Hall resis

  55. T. Sanuki, M. Fujikawa, K. Abe, K. Anraku

    We report new measurements of the atmospheric muons at mountain altitude. The measurement was carried out with the BESS detector at the top of Mt. Norikura, Japan. The altitude is 2,770 m above sea level. Comparing our results and predictions given by some interaction models, a further appropriate model has been investigated. These studies would improve accu

  56. Yurii V. Brezhnev

    Based on Burnside&#39;s parametrization of the algebraic curve $y^2=x^5-x$ we provide remaining attributes of its uniformization: Fuchsian equations and their solutions, accessory parameters, monodromies, conformal maps, fundamental polygons, etc. As a generalization, we construct the zero genus uniformization of arbitrary curves. For hyperelliptic curves al

  57. Uma Mahanta, Prasanta Das

    The paper is being withdrawn because of some theoretical inconsistencies.

  58. Santosh Ansumali, Iliya V. Karlin, Hans Christian Öttinger

    We derive minimal discrete models of the Boltzmann equation consistent with equilibrium thermodynamics, and which recover correct hydrodynamics in arbitrary dimensions. A simple analytical procedure of constructing the equilibrium for the nonisothermal hydrodynamics is established. A new discrete velocity model is proposed for the simulation of the Navier-St

  59. Jun Nishimura, Toshiyuki Okubo, Fumihiko Sugino

    We advocate a method to improve systematically the self-consistent harmonic approximation (or the Gaussian approximation), which has been employed extensively in condensed matter physics and statistical mechanics. We demonstrate the {\em convergence} of the method in a model obtained from dimensional reduction of SU($N$) Yang-Mills theory in $D$ dimensions.

  60. H. Yoshioka, Y. Okamura

    Tomonaga-Luttinger-liquid theory is formulated for metallic carbon nanotubes with open boundaries. Both cases of single- and multi-wall nanotubes are discussed. Based on this theory, spatial variation of the charge density from an edge is investigated with taking account of the shift of the chemical potential which expresses the carrier injection to the nano

  61. Thomas Becher, Stephan Braig, Matthias Neubert, Alexander L. Kagan

    The presence of a light b-squark (with mass about 4 GeV) and gluino (with mass about 15 GeV) might explain the observed excess in b-quark production at the Tevatron. Though provocative, this model is not excluded by present data. The light supersymmetric particles can induce large flavor-changing effects in radiative decays of B mesons. We analyse the decays

  62. Xi Dai, Ziqiang Wang

    The variational approach of Gunnarsson and Schönhammer to the Anderson impurity model is generalized to study d-wave superconductors in the presence of dilute spin-1/2 impurities. We show that the local moment is screened when the hybridization exceeds a nonzero critical value at which the ground state changes from a spin doublet to a spin singlet. The elect

  63. Brett Little, Alexander Knebe, Ranty Islam

    In this paper we are exploring the differences between a Warm Dark Matter model and a CDM model where the power on a certain scale is reduced by introducing a narrow negative feature (&#34;dip&#34;). This dip is placed in a way so as to mimic the loss of power in the WDM model: both models have the same integrated power out to the scale where the power of th

  64. Jelena Stajic, Andrew Iyengar, K. Levin, B. R. Boyce

    In this paper we compare two broad classes of theories for the pseudogap in cuprate superconductors. The comparison in made in reference to measurements of the superfluid density, $ρ_s(T,x)$, in $YBa_2CuO_{7- δ}$ films having a wide range of stoichiometries, $δ$, or, hole doping, $x$. The theoretical challenge raised by these (and previous) data is to unders

  65. Eric E. Mamajek, Michael R. Meyer, James Liebert

    We present results of a spectroscopic survey of X-ray- and proper motion-selected samples of late-type stars in the Lower Cen-Cru (LCC) and Upper Cen-Lup (UCL) subgroups of the nearest OB association: Sco-Cen. The primary goals of the survey are to determine the star-formation history of the OB subgroups, and to assess the frequency of accreting stars in a s

  66. M. H. S. Amin, S. N. Rashkeev, M. Coury, A. N. Omelyanchouk

    We report self-consistent quasiclassical calculations of spontaneous currents and magnetic moments in finite size unconventional superconducting systems, namely: (i) in isolated d-wave superconductor islands where, in addition to the dominant order parameter (with a d_{x^2-y^2} symmetry), a subdominant order parameter of s or d_{xy} symmetry is added; (ii) i

  67. A. C. de la Torre, D. Goyeneche

    The quantum mechanical formalism for position and momentum of a particle in a one dimensional cyclic lattice is constructively developed. Some mathematical features characteristic of the finite dimensional Hilbert space are compared with the infinite dimensional case. The construction of an unbiased basis for state determination is discussed.

  68. M. Kozuma, D. Akasmatsu, L. Deng, E. W. Hagley

    We report experimental investigationd of optical pulse group velocity reduction and probe pulse regeneration using a Raman scheme. The new scheme which does not rely on the on-one-photon resonance electromagnetically induced transparency (EIT), has many advantages over the conventional method which critically relys on the transparency window created by an EI

  69. G. Auberson, G. Mahoux, S. M. Roy, Virendra Singh

    We derive ``Bell inequalities&#39;&#39; in four dimensional phase space and prove the following ``three marginal theorem&#39;&#39; for phase space densities $ρ(\overrightarrow{q},\overrightarrow{p})$, thus settling a long standing conjecture : ``there exist quantum states for which more than three of the quantum probability distributions for $(q_1,q_2)$, $(p

  70. Mark S. Byrd, Daniel A. Lidar

    Strong and fast &#34;bang-bang&#34; (BB) pulses have been recently proposed as a means for reducing decoherence in a quantum system. So far theoretical analysis of the BB technique relied on model Hamiltonians. Here we introduce a method for empirically determining the set of required BB pulses, that relies on quantum process tomography. In this manner an ex

  71. Howard Barnum

    I consider the tradeoff between the information gained about an initially unknown quantum state, and the disturbance caused to that state by the measurement process. I show that for any distribution of initial states, the information-disturbance frontier is convex, and disturbance is nondecreasing with information gain. I consider the most general model of q

  72. Gerhard C. Hegerfeldt, Dirk Seidel

    Explicit expressions are determined for the photon correlation function of ``blinking&#39;&#39; quantum systems, i.e. systems with different types of fluorescent periods. These expressions can be used for a fit to experimental data and for obtaining system parameters therefrom. For two dipole-dipole interacting $V$ systems the dependence on the dipole coupli

  73. B. Militello, A. Messina, A. Napoli

    The possibility of revealing non-classical behaviours in the dynamics of a trapped ion via measurements of the mean value of suitable operators is reported. In particular we focus on the manifestation known as `` Parity Effect\rq\rq which may be observed \emph{directly measuring} the expectation value of an appropriate correlation operator. The experimental

  74. Reginald T. Cahill, Kirsty Kitto

    We report a re-analysis of the old results from the Michelson-Morley interferometer experiments that were designed to detect absolute motion. We build upon a recent (1998) re-analysis of the original data by Munera, which revealed small but significant effects after allowing for several systematic errors in the original analyses. The further re-analysis here

  75. Kevin H. Knuth

    The problem of mixed signals occurs in many different contexts; one of the most familiar being acoustics. The forward problem in acoustics consists of finding the sound pressure levels at various detectors resulting from sound signals emanating from the active acoustic sources. The inverse problem consists of using the sound recorded by the detectors to sepa

  76. A. Semparithi, V. Charulatha, S. Keshavamurthy

    Highly excited vibrational states of an isolated molecule encode the vibrational energy flow pathways in the molecule. Recent studies have had spectacular success in understanding the nature of the excited states mainly due to the extensive studies of the classical phase space structures and their bifurcations. Such detailed classical-quantum correspondence

  77. Anandhan Jayaraman, Andrew Belmonte

    We present an experimental study of the motion of a solid sphere falling through a wormlike micellar fluid. While smaller or lighter spheres quickly reach a terminal velocity, larger or heavier spheres are found to oscillate in the direction of their falling motion. The onset of this instability correlates with a critical value of the velocity gradient scale

  78. H. Fujii

    Attenuation of the singlet quark--anti-quark bound state passing through a random external SU(N) color field at high energy is studied within the eikonal framework as a model for the absorption of a quarkonium by nuclear target. For a thick target of length L the penetration probability is suppressed non-exponentially and behaves asymptotically $\propto 1/LN

  79. Yongseok Oh, Taesoo Song, Su Houng Lee, Cheuk-Yin Wong

    The $J/ψ$ dissociation by $π$ and $ρ$ mesons is examined in meson exchange model and compared to the quark interchange model. We found that the main difference between the predictions of the two models could be resolved by the form factors and the contact interactions in meson exchange model calculations. By adopting covariant form factors and adjusting the

  80. R. J. Furnstahl, J. Piekarewicz, Brian D. Serot

    In an effective hadronic theory constructed to describe long-range nuclear physics, the dynamics of the vacuum can be expanded in terms with zero or a finite number of derivatives acting on the fields. Thus vacuum dynamics can always be absorbed in the (infinite number of) counterterm parameters necessarily present in the effective lagrangian. These finite p

  81. Olivier Brodier, Peter Schlagheck, Denis Ullmo

    We present evidence that tunneling processes in near-integrable systems are enhanced due to the manifestation of nonlinear resonances and their respective island chains in phase space. A semiclassical description of this &#34;resonance-assisted&#34; mechanism is given, which is based on a local perturbative description of the dynamics in the vicinity of the

  82. Jon Jacobsen, Anandhan Jayaraman, Andrew Belmonte

    We study a class of integrodifferential equations and related ordinary differential equations for the initial value problem of a rigid sphere falling through an infinite fluid medium. We prove that for creeping Newtonian flow, the motion of the sphere is monotone in its approach to the steady state solution given by the Stokes drag. We discuss this property

  83. T. Iliescu, P. Fischer

    The rational large eddy simulation (RLES) model is applied to turbulent channel flows. This approximate deconvolution model is based on a rational (subdiagonal Pade&#39;) approximation of the Fourier transform of the Gaussian filter and is proposed as an alternative to the gradient (also known as the nonlinear or tensor-diffusivity) model. We used a spectral

  84. Paul P Martin, David Woodcock

    This article develops an alcove geometric approach to the representation theory of certain affine Hecke algebra quotients generalizing the blob algebra; and gives an exposition of some new representations of these algebras.

  85. Mirko Primc

    J. Lepowsky and R. L. Wilson initiated the approach to combinatorial Rogers-Ramanujan type identities via the vertex operator constructions of representations of affine Lie algebras. In a joint work with Arne Meurman this approach is developed further in the framework of vertex operator algebras. The main ingredients of that construction are defining relatio

  86. Harald Hengelbrock

    For a Fano manifold M, complex conjugation defines a real involution on the quantum cohomology ring. For the Grassmannian we identify this involution with an explicit transformation on Schubert classes defined over the integers. It is a composition of a power of the cyclic action recently defined by Agnihotri and Woodward with Poincare duality. The existence

  87. Marius Buliga

    Elementary sub-Riemannian geometry on the Heisenberg group H(n) provides a compact picture of symplectic geometry. Any Hamiltonian diffeomorphism on $R^{2n}$ lifts to a volume preserving bi-Lipschitz homeomorphisms of H(n), with the use of its generating function. Any curve of a flow of such homeomorphisms deviates from horizontality by the Hamiltonian of th

  88. J. Stephany, A. Restuccia

    A covariant quantization method for physical systems with reducible constraints is presented.

  89. John M. Cornwall, Noah Graham

    Euclidean d=3 SU(2) Yang-Mills-Chern-Simons (YMCS) theory, including Georgi-Glashow (GGCS) theory, may have solitons in the presence of appropriate mass terms. For integral CS level k and for solitons carrying integral CS number, YMCS is gauge-invariant and consistent. However, individual solitons such as sphalerons and linked center vortices with CS number

  90. Karim A. Malik

    Two approaches to the study of cosmological perturbations in the brane-world scenario are compared: the first uses the 5D equations directly whereas the second approach projects them onto the 4D brane and then uses the effective 4D equations.

  91. G. Karl, J. J. Simpson

    We generalize the notion of democratic mixing matrices for neutrinos and propose a scheme in which the electron neutrino is a superposition of three different mass eigenstates with equal weights. This scheme accounts for the recent SNO results as well as atmospheric muon neutrino and electron neutrino data. The outcomes of reactor neutrino and accelerator ex

  92. Stefano Forte, Jose I. Latorre, Lorenzo Magnea, Andrea Piccione

    We determine the strong coupling alpha_s(M_Z) from scaling violations of truncated moments of the nonsinglet deep inelastic structure function F_2. Truncated moments are determined from BCDMS and NMC data using a neural network parametrization which retains the full experimental information on errors and correlations. Our method minimizes all sources of theo

  93. Alain Romeyer

    The European collaboration ANTARES aims at operating a large deep-sea neutrino telescope in the Mediterranean sea. The detection of high-energy cosmic neutrino can improve our knowledge on the most powerful astrophysical sources in the Universe and about the origins of cosmic rays. A first Monte-Carlo study for the ANTARES sensitivity to diffuse neutrino flu

  94. Kingman Cheung, Chung-Hsien Chou

    In models of large extra dimensions, the fundamental Planck scale can be as low as TeV. Thus, in hadronic collisions interesting objects like black holes, string balls, or $p$-branes can be produced. In scenarios of fat brane or universal extra dimensions, the SM particles are allowed to propagate in the extra spatial dimensions, which leads to the enhanceme

  95. F. Krauss

    A method is suggested to combine tree level QCD matrix for the production of multi jet final states and the parton shower in hadronic interactions. The method follows closely an algorithm developed recently for the case of $e^+e^-$ annihilations.

  96. Alakabha Datta, David London

    We describe a new method for obtaining the CP phase alpha via measurements of B_{d,s} -> K(*) Kbar(*) decays. This method is particularly appropriate for hadron colliders since some of the branching ratios are small [O(10^{-6})], and since B_s decays are involved. By comparing the value of alpha extracted from this method with that obtained in B -> pi pi or

  97. Riccardo Barbieri, Guido Marandella, Michele Papucci

    We revisit in some more detail a recent specific proposal for the breaking of the electroweak symmetry and of supersymmetry by a compact extra dimension. Possible mass terms for the Higgs and the matter hypermultiplets are considered and their effects on the spectrum analyzed. Previous conclusions are reinforced and put on firmer ground.

  98. W. Bernreuther

    In these lecture notes an introduction is given to some ideas and attempts to understand the origin of the matter-antimatter asymmetry of the universe. After the discussion of some basic issues of cosmology and particle theory the scenarios of electroweak baryogenesis, GUT baryogenesis, and leptogenesis are outlined.

  99. Tomislav Ivezic

    In the usual Clifford algebra formulation of electrodynamics the Faraday bivector field $F$ is expressed in terms of \QTR{em}{the observer dependent} relative vectors $\QTR{bf}{E}$ and $\QTR{bf}{B.}$ In this paper we present \QTR{em}{the observer independent}decomposition of $F$ by using the vectors (grade-1) of electric $E$ and magnetic $B$ fields and we de

  100. J. Nemchik

    Within a light-cone QCD formalism which incorporates color transparency (CT), coherence length (CL) effects and gluon shadowing (GS) we study electroproduction of charmonia off nuclei. In contrast to production of light vector mesons (rho^0, phi^0) when at small and medium energies CT and the onset of CL effects are not easily separated, in production of cha