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May 2005 arXiv papers — page 17

Showing 1,601–1,700 of 3,731 papers

  1. R. Foot

    We show that the see-saw neutrino mass mechanism can coexist naturally with an extended gauge symmetry (i.e. without any gauge heirarchy problem) provided that the gauge symmetry contains gauged lepton number differences. The simplest such `natural' see-saw models are constructed and their implications for neutrino anomalies discussed.

  2. Vicente Azcoiti, Giuseppe Di Carlo, Angelo Galante, Victor Laliena

    We review a method for numerical simulations of lattice gauge theories at non-zero baryonic chemical potential we recently proposed. We first report on a test of the method using a solvable model and then present results for the phase structure of four flavour QCD. For the first time the region of chemical potential up to 1.4 T_C is explored, finding a first

  3. H1 Collaboration

    A measurement is presented of elastic deeply virtual Compton scattering γ* p \to γp made using e^+ p collision data corresponding to a luminosity of 46.5 pb^{-1}, taken with the H1 detector at HERA. The cross section is measured as a function of the photon virtuality, Q^2, the invariant mass of the γ* p system, W, and for the first time, differentially in th

  4. Makoto Tomoto

    We present the non-standard model Higgs boson searches at both DO and CDF experiments. We concentrate on three topics, reported by DO and CDF recently: the searches for the minimal supersymmetric Higgs boson using pp--> hbb --> bbbb and pp --> hX --> tau tau X, and for long-lived doubly charged Higgs boson.

  5. I. Vorobiev

    Exclusive rho rho production in two-photon collisions between a quasi-real, gamma, and a virtual, gamma*, photons is studied at LEP at centre-of-mass energies 89 GeV < sqrt{s} < 209 GeV with a total integrated luminosity of 854.7 pb-1. The cross sections of the gamma gamma* -> rho rho processes are determined as a function of the photon virtuality, Q^2, and

  6. G. Abbiendi

    Using the OPAL detector at LEP, the running of the effective QED coupling alpha(t) is measured for space-like momentum transfer, 2 \leq -t \leq 6 GeV^2, from the angular distribution of small-angle Bhabha scattering. This is currently the most significant direct observation of the running of the QED coupling in a single experiment and the first clear evidenc

  7. Brien C. Nolan, Raul Vera

    The study of the matching of stationary and axisymmetric spacetimes with Friedmann-Lemaitre-Robertson-Walker spacetimes preserving the axial symmetry is presented. We show, in particular, that any orthogonally transitive stationary and axisymmetric region in FLRW must be static, irrespective of the matter content. Therefore, previous results on static region

  8. Guangyu Li, Haibin Zhao

    In the experimental tests of gravity, there have been considerable interests in the possibility of intermediate-range gravity. In this paper, we use the earth-satellite measurement of earth gravity, the lunar orbiter measurement of lunar gravity, and lunar laser ranging measurement to constrain the intermediate-range gravity from lambda=1.2*10^{7}m - 3.8*10^

  9. Hiromi Saida

    When a black hole is put in an &#34;empty&#34; space (zero temperature space) on which there is no matter except the matter of the Hawking radiation (Hawking field), then an outgoing energy flow from the black hole into the empty space exists. By the way, an equilibrium between two arbitrary systems can not allow the existence of an energy (heat) flow from o

  10. D. Comelli

    Generalizations of gravitational Born-Infeld type lagrangians are investigated. Phenomenological constraints (reduction to Einstein-Hilbert action for small curvature, spin two ghost freedom and absence of Coulomb like Schwarschild singularity) select one effective lagrangian whose dynamics is dictated by the tensors g_{μν} and R_{μνρσ}(not R_{μν} or the sca

  11. Robert T. Jantzen

    The role of the Taub time gauge in cosmology is linked to the use of the densitized lapse function instead of the lapse function in the variational principle approach to the Einstein equations. The spatial metric variational equations then become the Ricci evolution equations, which are then supplemented by the Einstein constraints which result from the vari

  12. Paul G. ten Boom

    In addition to its long-term constancy, the Pioneer (spacecraft) anomaly appears to only exist for bodies whose mass is less than that of: planets, moons, comets, and heavy asteroids of known mass. Assuming the observational evidence is reliable, and not the result of an unknown systematic effect, a violation of the Weak Principle of Equivalence is implied.

  13. Marco Alberici

    A partially alternative derivation of the expression for the time dilation effect in a uniform static gravitational field is obtained by means of a thought experiment in which rates of clocks at rest at different heights are compared using as reference a clock bound to a free falling reference system (FFRS). Derivations along these lines have already been pr

  14. Dumitru Mihai Ionescu, Zhiyuan Yan

    In this correspondence, first-tier indirect (direct) discernible constellation expansions are defined for generalized orthogonal designs. The expanded signal constellation, leading to so-called super-orthogonal codes, allows the achievement of coding gains in addition to diversity gains enabled by orthogonal designs. Conditions that allow the shape of an exp

  15. David Eppstein, Michael T. Goodrich, Daniel S. Hirschberg

    We study practically efficient methods for performing combinatorial group testing. We present efficient non-adaptive and two-stage combinatorial group testing algorithms, which identify the at most d items out of a given set of n items that are defective, using fewer tests for all practical set sizes. For example, our two-stage algorithm matches the informat

  16. David R. Wood

    We give a simple proof of the following fundamental result independently due to Fary (1948) and Wagner (1936): Every plane graph has a drawing in which every edge is straight.

  17. Ignacio Melgar, Jaime Gomez, Juan Seijas

    The problem of known signal detection in Additive White Gaussian Noise is considered. In this paper a new detection algorithm based on Discrete Wavelet Transform pre-processing and threshold comparison is introduced. Current approaches described in [7] use the maximum value obtained in the wavelet domain for decision. Here, we use all available information i

  18. A. F. Albuquerque, A. S. T. Pires, M. E. Gouvea

    We present low-temperature dynamic properties of the quantum two-dimensional antiferromagnetic Heisenberg model with spin S=1/2. The calculation of the dynamic correlation function is performed by combining a projection operator formalism and the modified spin-wave theory (MSW), which gives a gap in the dispersion relation for finite temperatures. The so cal

  19. Sergei F. Lyuksyutov, Pavel B. Paramonov, Richard A. Vaia

    We are concerned with free energy analysis of the system comprising an AFM tip, water meniscus, and polymer film. Under applied electrostatic potential, the minimum in free energy is at a distance greater than the initial tip--substrate separation in the absence of potential. This equilibrium distance, t_0, mostly depends on the tip bias V and cantilever spr

  20. J. C. Phillips

    Minimalist theories of complex systems are broadly of two kinds: mean-field and axiomatic. So far all theories of properties absent from simple systems and intrinsic to complex systems, such as IP and SER, are axiomatic. SER is the prototypical complex temporal property of glasses, discovered by Kohlrausch 150 years ago, and now observed almost universally i

  21. J. C. Phillips

    Minimalist theories of complex systems are broadly of two kinds: mean-field and axiomatic. So far all theories of complex properties absent from simple systems and intrinsic to glasses are axiomatic. Stretched Exponential Relaxation (SER) is the prototypical complex temporal property of glasses, discovered by Kohlrausch 150 years ago, and now observed almost

  22. A. Özkan, N. Seferoğlu, B. Kutlu

    The static critical exponents of the three dimensional Blume-Capel model which has a tricritical point at}$D/J=2.82${\small value are estimated for the standard and the cooling algorithms which improved from Creutz Cellular Automaton. The analysis of the data using the finite-size scaling and power law relations reproduce their well-established values in the

  23. L. Barbier, D. Gratias

    6-d polyhedral models give a periodic description of aperiodic quasicrystals. There are powerful tools to describe their structural surface properties. Basis of the model for icosahedral quasicrystals are given. This description is further used to interpret high resolution STM images of the surface of i-AlPdMn which surface preparation was followed by He dif

  24. Ranjani Viswanatha, Sameer Sapra, Tanusri Saha-Dasgupta, D. D. Sarma

    We analyze the electronic structure of group III-V semiconductors obtained within full potential linearized augmented plane wave (FP-LAPW) method and arrive at a realistic and minimal tight-binding model, parameterized to provide an accurate description of both valence and conduction bands. It is shown that cation sp3 - anion sp3d5 basis along with the next

  25. D. H. E. Gross

    Equilibrium statistics of Hamiltonian systems is correctly described by the microcanonical ensemble. Classically this is the manifold of all points in the $N-$body phase space with the given total energy. Due to Boltzmann&#39;s principle, $e^S=tr(δ(E-H))$, its geometrical size is related to the entropy $S(E,N,...)$. This definition does not invoke any inform

  26. I. Weymann, J. Barnas

    Spin-dependent electronic transport through a quantum dot has been analyzed theoretically in the cotunneling regime by means of the second-order perturbation theory. The system is described by the impurity Anderson Hamiltonian with arbitrary Coulomb correlation parameter $U$. It is assumed that the dot level is intrinsically spin-split due to an effective mo

  27. C. Kirman, J. Lawrence, S. Hill, E-C. Yang

    We present high-frequency angle-dependent EPR data for crystals of [NixZn1-x(hmp)(t-BuEtOH)Cl]4 (x = 1 and 0.02). The x = 1 complex behaves as a single-molecule magnet at low temperatures, displaying hysteresis and exceptionally fast magnetization tunneling. We show that this behavior is related to a 4th-order transverse crystal-field interaction, which prod

  28. N. Tsujii, O. Suzuki, H. Suzuki, H. Kitazawa

    The Haldane system PbNi2V2O8 was investigated by the temperature dependent magnetization M(T) measurements at fields higher than H_c, with H_c the critical fields necessary to close the Haldane gap. It is revealed that M(T) for H > H_c exhibits a cusp-like minimum at T_{min}, below which M(T) increases with decreasing T having a convex curve. These features

  29. Yoshihiro Shimomura, Shin Miyahara, Nobuo Furukawa

    In order to study effects of frustration in an itinerant electron system, we investigate ground states of the antiferromagnetic double-exchange model on a triangular lattice. In this model, pseudo-spins are coupled to electron transfer integrals in such a way that antiparallel configurations of pseudo-spins gain kinetic energies. Although the antiferromagnet

  30. Sergey K. Nemirovskii

    Kinetics of merging and breaking down vortex loops is the important part of the whole vortex tangle dynamics. Another part is the motion of individual lines, which obeys the Biot-Savart law in presence of friction force and of applied external velocity fields if any. In the present work we evaluate the coefficients of the reconnection rates $A(l_{1},l_{2},l)

  31. Shi-Jie Yang

    We study target-searching processes on a percolation, on which a hunter tracks a target by smelling odors it emits. The odor intensity is supposed to be inversely proportional to the distance it propagates. The Monte Carlo simulation is performed on a 2-dimensional bond-percolation above the threshold. Having no idea of the location of the target, the hunter

  32. Debdutta Ray, Meghan P. Patankar, N. Periasamy, K. L. Narasimhan

    Photoelectronic properties of Alq3 were studied by photoconductivity measurements in thin film, sandwich (ITO/Alq3/LiF/Al) devices. We find that the photocurrent is dominated by bulk generation of carriers for incident photon energies greater than 2.75 eV. The quantum efficiency of photocarrier generation has been measured from carrier collection measurement

  33. Masaru Onoda, Naoto Nagaosa

    The role of the relaxation due to the impurity scattering and/or the contacts to leads/electrodes are studied for the spin Hall effect (SHE). Relaxation is essential to attain the steady state and also to the spin accumulation, but has been considered to be harmful for the intrinsic SHE (ISHE). These issues are examined quantitatively on two types of 2D mode

  34. Masaru Onoda, Naoto Nagaosa

    Spin current and accumulation generated by the electric field in spin Hall insulator (SHI) are investigated theoretically in terms of the Keldysh formalism. In contrast to the quantum Hall system, there are no massless edge modes in general. The spin current is generated near the contacts to the electrodes by the hybridization between the metallic states and

  35. B. Barbiellini, P. E. Mijnarends, S. Kaprzyk, A. Bansil

    We consider the shape of the magnetic Compton profile (MCP), $J_{mag}(p_z)$, in La$_{1.2}$Sr$_{1.8}$Mn$_2$O$_7$ for momentum transfer $p_z$ along the [110] direction and the associated reciprocal form factor $B(r)$ defined by taking the one-dimensional Fourier transform of $J_{mag}(p_z)$. $B(r)$ is shown to contain a prominent dip at $r\approx$ 1 $Å$, where

  36. B. Barbiellini, A. Bansil

    We discuss an efficient scheme for obtaining spin-polarized quasi-particle excitation energies within the general framework of the density functional theory (DFT). Our approach is to correct the DFT eigenvalues via the electrostatic energy of a majority or minority spin electron resulting from its interaction with the associated exchange and correlation hole

  37. J. Varalda, A. J. A. de Oliveira, D. H. Mosca, J. -M. George

    We report on resonant tunneling magnetoresistance via localized states through a ZnSe semiconducting barrier which can reverse the sign of the effective spin polarization of tunneling electrons. Experiments performed on Fe/ZnSe/Fe planar junctions have shown that positive, negative or even its sign-reversible magnetoresistance can be obtained, depending on t

  38. Tobias Herman, James Day, John Beamish

    We have investigated the adsorption and desorption of helium near its liquid-vapor critical point in silica aerogels with porosities between 95% and 98%. We used a capacitive measurement technique which allowed us to probe the helium density inside the aerogel directly, even though the samples were surrounded by bulk helium. The aerogel&#39;s very low therma

  39. E. J. Calegari, S. G. Magalhaes, A. A. Gomes

    The Roth&#39;s two-pole approximation has been used by the present authors to investigate the role of $d-p$ hybridization in the superconducting properties of an extended $d-p$ Hubbard model. Superconductivity with singlet $d_{x^2-y^2}$-wave pairing is treated by following Beenen and Edwards formalism. In this work, the Coulomb interaction, the temperature a

  40. F. Bass, V. Freilikher, O. Shefranova

    We study the influence of the space and time dispersion on the frequency dependence of the wave vectors of electromagnetic waves propagating in three-dimensional photonic crystals. Two types of structures are considered: media with weak periodic modulation of the permittivity, and photonic crystals composed of the periodically arranged identical resonant die

  41. Thomas Petermann, Paolo De Los Rios

    Supplementing a lattice with long-range connections effectively models small-world networks characterized by a high local and global interconnectedness observed in systems ranging from society to the brain. If the links have a wiring cost associated to their length l, the corresponding distribution q(l) plays a crucial role. Uniform length distributions have

  42. R. Hanson, L. H. Willems van Beveren, I. T. Vink, J. M. Elzerman

    We present a method for reading out the spin state of electrons in a quantum dot that is robust against charge noise and can be used even when the electron temperature exceeds the energy splitting between the states. The spin states are first correlated to different charge states using a spin dependence of the tunnel rates. A subsequent fast measurement of t

  43. L. Jiang, M. W. Wu

    We show that the bulk-inversion-asymmetry-type strain-induced spin-orbit coupling can be used to effectively modify the Dresselhaus spin splitting in (001) GaAs quantum wells with small well width and the resulting spin lifetime can be increased by two orders of magnitude to nanoseconds under right conditions. The efficiency of this strain manipulation of th

  44. C. Tannous, J. Gieraltowski, R. Valenzuela

    Recent measurements of the magnetoimpedance (at a fixed frequency of 1 MHz) of cobalt-rich wires subjected to torsion stress show an asymmetry as a function of torsion angle stemming from residual anisotropies induced during wire fabrication. We interpret these measurements with a simple model based on the competition between a circumferential magnetic aniso

  45. Navin Singh, Yashwant Singh

    The unzipping transition under the influence of external force of a dsDNA molecule has been studied using the Peyrard-Bishop Hamiltonian. The critical force $F_c(T)$ is found to depend on the potential parameters $k$, represents the stiffness of single strand of DNA and the potential depth $D$. We used constant extension ensemble to calculate the average for

  46. Kartik Sheth, Stuart N. Vogel, Michael W. Regan, Michele D. Thornley

    We present an analysis of the molecular gas distributions in the 29 barred and 15 unbarred spirals in BIMA SONG. For CO-bright galaxies, we confirm the conclusion by Sakamoto et al. (1999b) that barred spirals have higher molecular gas concentrations in the central kiloparsec. The SONG sample also includes 27 galaxies below the CO brightness limit used by Sa

  47. David J. Helfand, Robert H. Becker, Richard L. White

    We discovered independently the shell-type supernova remnant G12.82-0.02, recently reported by Brogan et al. (2005), which is coincident with the unidentified TeV gamma-ray source revealed in the HESS survey of the Galactic plane. Estimating the ambient starlight at the location of this source from the integrated Ly alpha luminosity of the nearby H II region

  48. István Szapudi

    In this lecture notes I concentrate on the classic and widely applicable characterization of higher order statistics by joint moments, a.k.a. higher order correlation functions, and directly related statistics. I put special emphasis on recent results, especially the connection of spatial statistics with symmetries.

  49. István Szapudi, Jun Pan, Simon Prunet, Tamás Budavári

    We present two related techniques to measure the two-point correlation function and the power spectrum with edge correction in any spatial dimensions. The underlying algorithm uses fast Fourier transforms for calculating the two-point function with an heuristically weighted edge corrected estimator. Once the correlation function is measured, we estimate the

  50. Lewis B. G. Knee, Bradley J. Wallace, Magdalen Normandeau

    We report the discovery of a system of unusual HI filaments which appear to be associated with molecular clouds in the Perseus spiral arm of our Galaxy. We investigate the hypothesis that this system is the result of a directed flow of dissociated gas from clouds trapped within an extended wind flow from massive stars. The Wolf-Rayet star WR 5 and the OIb(f)

  51. Knox S. Long, Cynthia S. Froning, Christian Knigge, William P. Blair

    We present time-resolved FUV spectra of the dwarf novae SS Cyg and WX Hyi in quiescence from observations using the Hopkins Ultraviolet Telescope on the Astro-1 and Astro-2 Space Shuttle missions and the Goddard High Resolution Spectrograph on the Hubble Space Telescope. Both dwarf novae are characterized by blue continua that extend to the Lyman limit punct

  52. A. P. S. Yadav, B. D. Wandelt

    Assuming linearity of the perturbations at the time of decoupling, we reconstruct the primordial scalar potential from the temperature and polarization anisotropies in the cosmic microwave background radiation. In doing so we derive an optimal linear filter which, when operated on the spherical harmonic coefficients of the anisotropy maps, returns an estimat

  53. G. D. Schmidt, P. Szkody, K. M. Vanlandingham, S. F. Anderson

    Discoveries of two new white dwarf plus M star binaries with striking optical cyclotron emission features from the Sloan Digital Sky Survey (SDSS) brings to six the total number of X-ray faint, magnetic accretion binaries that accrete at rates < 10^{-13} Msun/yr, or <1% of the values normally encountered in cataclysmic variables. This fact, coupled with dono

  54. O. Hernandez, H. Wozniak, C. Carignan, P. Amram

    The relevance of the Tremaine-Weinberg (TW) method is tested to measure the bar, spiral and inner structure pattern speeds using a gaseous velocity field. The TW method is applied to various simulated barred galaxies in order to demonstrate its validity in seven different configurations, including star formation or/and dark matter halo. The reliability of th

  55. H. Falcke, W. D. Apel, A. F. Badea

    The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10^20 eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within ~50 Mpc through interactions with the cosmic microwave background. As there are no sufficient powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from u

  56. H. E. S. S. collaboration, :, F. Aharonian

    We report the detection of TeV gamma-rays from the shell-type supernova remnant RX J0852.0-4622 with data of 3.2 h of live time recorded with H.E.S.S. in February 2004. An excess of (700 +/- 60) events from the whole remnant with a significance of 12 sigma was found. The observed emission region is clearly extended with a radius of the order of 1 degree and

  57. S. W. Campbell, Y. Fenner, A. I. Karakas, J. C. Lattanzio

    We are in the process of testing a popular theory that the observed abundance anomalies in the Globular Cluster NGC 6752 are due to `internal pollution&#39; from intermediate mass asymptotic giant branch stars. To this end we are using a chemical evolution model incorporating custom-made stellar evolution yields calculated using a detailed stellar evolution

  58. B. Fuhrmeister, J. H. M. M. Schmitt, P. H. Hauschildt

    We present semi-empirical model chromospheres computed with the atmosphere code PHOENIX. The models are designed to fit the observed spectra of five mid- to late-type M dwarfs. Next to hydrogen lines from the Balmer series we used various metal lines, e. g. from Fe {\sc i}, for the comparison between data and models. Our computations show that an NLTE treatm

  59. A. Bartkiewicz, M. Szymczak, R. J. Cohen, A. M. S. Richards

    We present the results of MERLIN polarization mapping of OH masers at 1665 and 1667 MHz towards the Cepheus A star-forming region. The maser emission is spread over a region of 6 arcsec by 10 arcsec, twice the extent previously detected. In contrast to the 22 GHz water masers, the OH masers associated with H II regions show neither clear velocity gradients n

  60. C. Giammanco, J. E. Beckman

    We present a detailed model capable of explaining quantitatively the temperature fluctuations observed in luminous, large HII regions. The model is based on two assumptions which we justify on the basis of observations: that the major fraction of the hydrogen in the clouds that form the HII regions is not photoionized and is essentially HI, this HII is light

  61. Rodrigo Gil-Merino, Geraint F. Lewis

    The multiply imaged, gravitationally lensed quasar, QSO 2237+0305, has been the subject of recent optical monitoring campaigns, with its light curves displaying uncorrelated variability attributed to gravitational microlensing by masses in the foreground galaxy. Based on these light curves, it has been claimed that the dominant microlensing population must b

  62. D. Gora, R. Engel, D. Heck, P. Homola

    The light intensity distribution in a shower image and its implications to the primary energy reconstructed by the fluorescence technique are studied. Based on detailed CORSIKA energy deposit simulations, a universal analytical formula is derived for the lateral distribution of light in the shower image and a correction factor is obtained to account for the

  63. M. Bondi, M-A. Perez-Torres, D. Dallacasa, T. W. B. Muxlow

    We report on 1.6 and 5.0 GHz observations of the ultraluminous infrared galaxy (ULIRG) Mrk 273, using the European VLBI Network (EVN) and the Multi-Element Radio-Linked Interferometer Network (MERLIN). We also make use of published 1.4 GHz VLBA observations of Mrk 273 by Carilli & Taylor (2000). Our 5 GHz images have a maximum resolution of 5-10 mas, which c

  64. Tetsu Kitayama, Naoki Yoshida

    We study the evolution of supernova (SN) remnants of the first stars, taking proper account of the radiative feedback of the progenitor stars on the surroundings. We carry out a series of one-dimensional hydrodynamic simulations with radiative cooling, starting from initial configurations that are drawn from the results of our earlier radiation hydrodynamic

  65. Yann Alibert, Olivier Mousis, Willy Benz

    We have developed an evolutionary turbulent model of the Jovian subnebula consistent with the extended core accretion formation models of Jupiter described by Alibert et al. (2005b) and derived from Alibert et al. (2004,2005a). This model takes into account the vertical structure of the subnebula, as well as the evolution of the surface density as given by a

  66. H. R. de Ruiter, P. Parma, A. Capetti, R. Fanti

    We present a study of the optical brightness profiles of early type galaxies, using a number of samples of radio galaxies and optically selected elliptical galaxies. For the radio galaxy samples--B2 of Fanaroff-Riley type I and 3C of Fanaroff-Riley type II-- we determined a number of parameters that describe a &#34;Nuker-law&#34; profile, which were compared

  67. R. Morganti, T. A. Oosterloo, C. N. Tadhunter, G. van Moorsel

    We present high-spatial resolution 21-cm HI VLA observations of the radio galaxy 3C305 (z=0.041). These new high-resolution data show that the ~1000 km/s broad HI absorption, earlier detected in low-resolution WSRT observations, is occurring against the bright, eastern radio lobe, about 1.6 kpc from the nucleus. We use new optical spectra taken with the WHT

  68. A. E. Rosaev

    The resonance perturbation of planetary ring by distant satellite is considered. The gravity interaction between rings particles is taken into account. The gravitation interaction between particles in rings can change shape of non-circular rings, so it is differ from keplerian ellipse. The shift between simple mean motion resonances and parametric resonance

  69. Craig J. Hogan

    The decoherence of quantum fluctuations into classical perturbations during inflation is discussed. A simple quantum mechanical argument, using a spatial particle wavefunction rather than a field description, shows that observable correlations from inflation must have a discrete spectrum, since they originate and freeze into the metric within a compact regio

  70. M. S. Dubrovin

    We present recent results from the CLEO Collaboration. The data used were collected from 1995 untill now at the Cornell Electron-positron Storage Ring (CESR). Measurements of the leptonic branching fractions for $J/ψ\to e^+ e^-, μ^+ μ^-$ and $Υ(1,2,3S) \to μ^+ μ^-$, search for $D^0-\bar{D^0}$ mixing using time dependent Dalitz plot analyses of the decay $D^0

  71. Partha Mukhopadhyay

    We explore a particular approach to study D-brane boundary states in Berkovits&#39; pure spinor formalism of superstring theories. In this approach one constructs the boundary states in the relevant conformal field theory by relaxing the pure spinor constraints. This enables us to write down the open string boundary conditions for non-BPS D-branes in type II

  72. Oded Schramm, David B. Wilson

    The purpose of this note is to describe a framework which unifies radial, chordal and dipolar SLE. When the definition of SLE(kappa;rho) is extended to the setting where the force points can be in the interior of the domain, radial SLE(kappa) becomes chordal SLE(kappa;rho), with rho=kappa-6, and vice versa. We also write down the martingales describing the R

  73. Roeland M. H. Merks, Erica D. Perryn, Abbas Shirinifard, James A. Glazier

    Blood vessels form either when dispersed endothelial cells (the cells lining the inner walls of fully-formed blood vessels) organize into a vessel network (vasculogenesis), or by sprouting or splitting of existing blood vessels (angiogenesis). Although they are closely related biologically, no current model explains both phenomena with a single biophysical m

  74. V. Koch, A. Majumder, J. Randrup

    The correlation between baryon number and strangeness elucidates the nature of strongly interacting matter, such as that formed transiently in high-energy nuclear collisions. This diagnostic can be extracted theoretically from lattice QCD calculations and experimentally from event-by-event fluctuations. The analysis of present lattice results above the criti

  75. Marianne Leitner

    In QED of two space dimensions, a quantum Hall effect occurs in the absence of any magnetic field. We give a simple and transparent explanation. In solid state physics, the Hall conductivity for non-degenerate ground state is expected to be given by an integer, the Chern number. In our field-free situation, however, the conductivity is $\pm 1/2$ in natural u

  76. Chad R. Galley, B. L. Hu

    We give a quantum field theoretical derivation of the scalar Abraham-Lorentz-Dirac (ALD) equation and the self-force for a scalar charged particle interacting with a quantum scalar field in curved spacetime. We regularize the causal Green&#39;s function using a quasi-local expansion in the spirit of effective field theory and obtain a regular expression for

  77. Martin Prescher, Fulvio Melia

    There is some evidence, though yet unconfirmed, that Sagittarius A*--the supermassive black hole at the Galactic center--emits its radio waves modulated with a ~100-day period. What is intriguing about this apparent quasi-periodicity is that, though the amplitude of the modulation increases with decreasing wavelength (from 3.6 to 1.3 cm), the quasi-period it

  78. J. Ambjorn, J. Jurkiewicz, R. Loll

    We provide detailed evidence for the claim that nonperturbative quantum gravity, defined through state sums of causal triangulated geometries, possesses a large-scale limit in which the dimension of spacetime is four and the dynamics of the volume of the universe behaves semiclassically. This is a first step in reconstructing the universe from a dynamical pr

  79. Arvind Rajaraman

    We examine the question of the supersymmetric completion of the $R^4$ term in type IIB supergravity by using superfield methods. We show that while there is an obstruction to constructing the full action, a subset of the terms in the action can be consistently analyzed independent of the other terms, and these can be obtained from the superfield. We find the

  80. Daniel Babich, Abraham Loeb

    We consider the polarization of 21cm line radiation from the epoch of reionization due to both intrinsically polarized emission and secondary mechanisms. We argue that Thomson scattering of the 21cm quadrupole by the reionized universe is likely to produce the largest effect. The 21cm quadrupole is sourced by baryonic density fluctuations and the fluctuation

  81. Ivan Spremo, Florian Schuetz, Peter Kopietz, Volodymyr Pashchenko

    For temperatures T well above the ordering temperature T*=3.0+-0.2K the magnetic properties of the metal-organic material Mn[C10H6(OH)(COO)]2x2H20 built from Mn^2+ ions and 3-hydroxy-2-naphthoic anions can be described by a S=5/2 quantum antiferromagnet on a distorted honeycomb lattice with two different nearest neighbor exchange couplings J2 \approx 2J1 \ap

  82. Lian-Ao Wu, Daniel A. Lidar

    When quantum communication networks proliferate they will likely be subject to a new type of attack: by hackers, virus makers, and other malicious intruders. Here we introduce the concept of &#34;quantum malware&#34; to describe such human-made intrusions. We offer a simple solution for storage of quantum information in a manner which protects quantum networ

  83. Lidia Pieri, Enzo Branchini, Stefan Hofmann

    Analytical calculations and recent numerical experiments have shown that a sizable of the mass in our Galaxy is in a form of clumpy, virialized substructures that, according to \cite{dms:05}, can be as light as $10^{-6} \msun$. In this work we estimate the gamma-rays flux expected from dark matter annihilation occurring within these minihalos, under the hypo

  84. E. B. Sonin

    The paper investigates theoretically effects of noise on low-bias parts of $IV$ curves of tunnel junctions. The analysis starts from the effect of shot noise from an additional (noise) junction on the Coulomb blockaded Josephson junction in high-impedance environment. Asymmetry of shot noise characterized by its odd moments results in asymmetry of the $IV$ c

  85. T. K. Pedlar, CLEO Collaboration

    Using 3.08 million psi(2S) decays observed in e^+e^- collisions by the CLEO detector, we present the results of a study of the psi(2S) decaying into baryon-antibaryon final states. We report the most precise measurements of the following eight modes: proton-antiproton, lambda-antilambda, Xi^- antiXi^-, Xi^0-antiXi^0 (first observation), Sigma+-antiSigma^+ (f

  86. Alejandro Perez, Carlo Rovelli

    The Immirzi parameter is a constant appearing in the general relativity action used as a starting point for the loop quantization of gravity. The parameter is commonly believed not to show up in the equations of motion, because it appears in front of a term in the action that vanishes on shell. We show that in the presence of fermions, instead, the Immirzi t

  87. Charles Livingston, Swatee Naik

    Let νbe any integer-valued additive knot invariant that bounds the smooth 4-genus of a knot K, |ν(K)| <= g_4(K), and determines the 4-ball genus of positive torus knots, ν(T_{p,q}) = (p-1)(q-1)/2. Either of the knot concordance invariants of Ozsvath-Szabo or Rasmussen, suitably normalized, have these properties. Let D_{\pm}(K,t) denote the positive or negati

  88. S. McGlynn, S. McBreen, L. Hanlon, B. McBreen

    GRB 040223 was observed by INTEGRAL and XMM-Newton. GRB 040223 has a peak flux of (1.6+/-0.13) x10^-8 ergs cm^-2 s^-1, a fluence of (4.4+/-0.4)x10^-7 ergs cm^-2 and a steep photon power law index of -2.3+/-0.2, in the energy range 20-200 keV. The steep spectrum implies it is an x- ray rich GRB with emission up to 200 keV and E_peak < 20 keV. If E_peak is < 1

  89. Finn Larsen

    A string theory description of near extremal black rings is proposed. The entropy is computed and the thermodynamic properties are derived for a large family of black rings that have not yet been constructed in supergravity. It is also argued that the most general black ring in N=8 supergravity has 21 parameters up to duality.

  90. Ramani S. Pilla, Catherine Loader

    Hansen (1982) proposed a class of &#34;generalized method of moments&#34; (GMMs) for estimating a vector of regression parameters from a set of score functions. Hansen established that, under certain regularity conditions, the estimator based on the GMMs is consistent, asymptotically normal and asymptotically efficient. In the generalized estimating equation

  91. Aaron Berndsen, Tirthabir Biswas, James M. Cline

    In the context of brane gas cosmology in superstring theory, we show why it is impossible to simultaneously stabilize the dilaton and the radion with a general gas of strings (including massless modes) and D-branes. Although this requires invoking a different mechanism to stabilize these moduli fields, we find that the brane gas can still play a crucial role

  92. S. Fratini, S. Ciuchi

    We study the electronic spectral properties in two examples of strongly interacting systems: a Mott-Hubbard insulator with additional electron-boson interactions, and a polaronic semiconductor. An approximate unified framework is developed for the high energy part of the spectrum, in which the electrons move in a random field determined by the interplay betw

  93. Richard W. Haymaker, Takayuki Matsuki

    We address the problem of determining the type I, type II or borderline dual superconductor behavior in maximal Abelian gauge SU(2) through the study of the dual Abrikosov vortex. We find that significant electric currents in the simulation data call into question the use of the dual Ginzburg Landau Higgs model in interpreting the data. Further, two definiti

  94. Henrique N. Sá Earp, Jiannis K. Pachos

    We present an explicit numerical method to obtain the Cartan-Khaneja-Glaser decomposition of a general element G of SU(2^N) in terms of its `Cartan&#39; and `non-Cartan&#39; components. This effectively factors G in terms of group elements that belong in SU(2^n) with n<N, a procedure that can be iterated down to n=2. We show that every step reduces to solvin

  95. Alessio Recati, Jean-Noël Fuchs, Claudia Sofia Peca, Wilhelm Zwerger

    We discuss the effective interactions between two localized perturbations in one-dimensional (1D) quantum liquids. For non-interacting fermions, the interactions exhibit Friedel oscillations, giving rise to a RKKY-type interaction familiar from impurity spins in metals. In the interacting case, at low energies, a Luttinger liquid description applies. In the

  96. Kazuyuki Furuuchi

    We analyze the reorganization of free field theory correlators to closed string amplitudes investigated in hep-th/0308184 hep-th/0402063 hep-th/0409233 hep-th/0504229 in the case of Euclidean thermal field theory and study how the dual bulk geometry is encoded on them. The expectation value of Polyakov loop, which is an order parameter for confinement-deconf

  97. Julián Candia

    We examine in detail the detectability of a signal of diffuse high energy neutrinos produced in the Milky Way by the interaction of cosmic rays (CRs) with the interstellar medium (ISM). We show that highly inhomogeneous galactic CR densities arise naturally from large scale drift effects and the inhomogeneous distribution of CR sources. In particular, the CR

  98. Bert van Es, Shota Gugushvili, Peter Spreij

    Given a sample from a discretely observed compound Poisson process, we consider estimation of the density of the jump sizes. We propose a kernel type nonparametric density estimator and study its asymptotic properties. An order bound for the bias and an asymptotic expansion of the variance of the estimator are given. Pointwise weak consistency and asymptotic

  99. M. S. Tomas

    We demonstrate that, according to a recently suggested Lorentz-force approach to the Casimir effect, the vacuum force on an atom embedded in a material cavity differs substantially from the force on an atom of the cavity medium. The force on an embedded atom is of the familiar (van der Waals and Casimir-Polder) type, however, more strongly modified by the ca

  100. Z. Akdeniz, P. Vignolo, M. P. Tosi

    We present mean-field calculations of the equilibrium state in a gaseous mixture of bosonic and spin-polarized fermionic atoms with repulsive or attractive interspecies interactions, confined inside a cigar-shaped trap under conditions such that the radial thickness of the two atomic clouds is approaching the magnitude of the s-wave scattering lengths. In th