Skip to content

September 2006 arXiv papers — page 19

Showing 1,8011,900 of 4,533 papers

  1. L. Machura, M. Kostur, P. Talkner, J. Luczka

    A novel transport phenomenon is identified that is induced by inertial Brownian particles which move in simple one-dimensional, symmetric periodic potentials under the influence of both a time periodic and a constant, biasing driving force. Within tailored parameter regimes, thermal equilibrium fluctuations induce the phenomenon of absolute negative mobility

  2. Romain Abraham, Jean-Francois Delmas

    We construct a continuous state branching process with immigration (CBI) whose immigration depends on the CBI itself and we recover a continuous state branching process (CB). This provides a dual construction of the pruning at nodes of CB introduced by the authors in a previous paper. This construction is a natural way to model neutral mutation. Using expone

  3. Claudio Cacciapuoti, Raffaele Carlone, Rodolfo Figari

    We consider a system realized with one spinless quantum particle and an array of $N$ spins 1/2 in dimension one and three. We characterize all the Hamiltonians obtained as point perturbations of an assigned free dynamics in terms of some ``generalized boundary conditions''. For every boundary condition we give the explicit formula for the resolvent o

  4. V. P. Psonis, Ch. C. Moustakidis, S. E. Massen

    We construct a class of nuclear equations of state based on a schematic potential model, that originates from the work of Prakash et. al. \cite{Prakash-88}, which reproduce the results of most microscopic calculations. The equations of state are used as input for solving the Tolman-Oppenheimer-Volkov equations for corresponding neutron stars. The potential p

  5. Gérard Henry Edmond Duchamp, Allan I. Solomon, Pawel Blasiak, Karol A. Penson

    We construct a three parameter deformation of the Hopf algebra $\mathbf{LDIAG}$. This new algebra is a true Hopf deformation which reduces to $\mathbf{LDIAG}$ on one hand and to $\mathbf{MQSym}$ on the other, relating $\mathbf{LDIAG}$ to other Hopf algebras of interest in contemporary physics. Further, its product law reproduces that of the algebra of polyze

  6. O. Kiriyama

    We calculate the effective potential of the 2SC/g2SC phases including vector condensates ($<gA_z^6>$ and $<gA_z^8>$) and study the gluonic phase and the single plane-wave Larkin-Ovchinnikov-Fulde-Ferrell state at nonzero temperature. Our analysis is performed within the framework of the gauged Nambu--Jona-Lasinio model. We compute potential curvatures with r

  7. Michael A. Ivanov

    In the sea of super-strong interacting gravitons, non-forehead collisions with gravitons deflect photons, and this deflection may differ for soft and hard radiations. As a result, the Hubble diagram would not be a universal function and it will have a different view for such sources as supernovae in visible light and gamma-ray bursts. Observations of these t

  8. A. I. Zhuk

    We investigate a possibility for construction of the conventional Friedmann cosmology for our observable Universe if underlying theory is multidimensional Kaluza-Klein model endowed with a perfect fluid. We show that effective Friedmann model obtained by dynamical compactification of the multidimensional one is faced with too strong variations of the fundame

  9. Florent Schaffhauser

    In this note, we state and give the main ideas of the proof of a real convexity theorem for group-valued momentum maps. This result is a quasi-Hamiltonian analogue of the O&#39;Shea-Sjamaar theorem in the usual Hamiltonian setting. We prove here that the image under the momentum map of the fixed-point set of a form-reversing involution defined on a quasi-Ham

  10. J. Anthony Tyson

    Starting around 2013, data from the Large Synoptic Survey Telescope (LSST) will be analyzed for a wide range of phenomena. By separately tracing the development of mass structure and rate of expansion of the universe, these data will address the physics of dark matter and dark energy, the possible existence of modified gravity on large scales, large extra di

  11. Jimmy Olsson, Olivier Cappé, Randal Douc, Eric Moulines

    This paper concerns the use of sequential Monte Carlo methods (SMC) for smoothing in general state space models. A well-known problem when applying the standard SMC technique in the smoothing mode is that the resampling mechanism introduces degeneracy of the approximation in the path space. However, when performing maximum likelihood estimation via the EM al

  12. Masahito Mochizuki, Masao Ogata

    Motivated by recently reported experimental phase diagrams, we study the effects of CoO6 distortion on the electronic structure in NaxCoO2.yH2O. We construct the multiband tight-binding model by employing the LDA result. Analyzing this model, we show the deformation of band dispersions and Fermi-surface topology as functions of CoO2-layer thickness. Consider

  13. Xiao-Qiang Xi, R. H. Yue, W. M. Liu

    The pairwise entanglement and local polarization of the ground state are discussed by studying the Heisenberg XX model in finite qubit case. The results show that: the ground state is composed by the micro state with the minimal total spin 0 (for even qubit) or 1/2 (for odd qubit), local polarization (LP) has intimate relation with the probability of the mic

  14. Sergey Grishkevich, Alejandro Saenz

    The influence of a tight isotropic harmonic trap on photoassociation of two ultracold alkali atoms forming a homonuclear diatomic is investigated using realistic atomic interaction potentials. Confinement of the initial atom pair due to the trap leads to a uniform strong enhancement of the photoassociation rate to most, but also to a strongly suppressed rate

  15. I. V. Dobrovolska, R. S. Tutik

    The explicit semiclassical treatment of the logarithmic perturbation theory for the bound-state problem of the radial Shrodinger equation with the screened Coulomb potential is developed. Based upon h-expansions and new quantization conditions a novel procedure for deriving perturbation expansions is offered. Avoiding disadvantages of the standard approach,

  16. Pedro Sancho

    We analyse some compositeness effects and their relation with entanglement. We show that the purity of a composite system increases, in the sense of the expectation values of the deviation operators, with large values of the entanglement between the components of the system. We also study the validity of Pauli&#39;s principle in composite systems. It is vali

  17. G. L. Klimchitskaya, V. M. Mostepanenko

    Casimir effect is the attractive force which acts between two plane parallel, closely spaced, uncharged, metallic plates in vacuum. This phenomenon was predicted theoretically in 1948 and reliably investigated experimentally only in recent years. In fact, the Casimir force is similar to the familiar van der Waals force in the case of relatively large separat

  18. Ari Belenkiy, Steve Shnider, Lawrence Horwitz

    We show that the method of stochastic reduction of linear superpositions can be applied to the process of disentanglement for the spin-0 state of two spin-1/2 particles. We describe the geometry of this process in the framework of the complex projective space

  19. Raffaele Romano

    Pure states are fundamental for the implementation of quantum technologies, and several methods for the purification of the state of a quantum system S have been developed in the past years. In this letter we present a new approach, based on the interaction of S with an auxiliary system P, having a wide range of applicability. Considering two-level systems S

  20. Janet Anders, Dagomir Kaszlikowski, Christian Lunkes, Toshio Ohshima

    We present a general argument showing that the temperature as well as other thermodynamical state variables can qualify as entanglement witnesses for spatial entanglement. This holds for a variety of systems and we exemplify our ideas using a simple free non-interacting Bosonic gas. We find that entanglement can exist at arbitrarily high temperatures, provid

  21. A. Romanelli, A. Auyuanet, R. Donangelo

    We study the quantum search algorithm as an open system. More specifically, we analyze the responses of that algorithm to an external monochromatic field, and to the decoherences introduced by the measurement process. We find that the search algorithm is robust with respect to many external interactions.

  22. Antonio Leon

    I propose here a new concept of information based on two relevant aspects of its expression. The first related to the undeniable fact that the expression of information modifies the physical state of its receiver. The second to the arbitrariness of such physical changes. In fact, these changes are not deducible from physical laws but from a code established

  23. A. Loinger

    General relativity includes geometrical optics. This basic fact has relevant consequences that concern the physical meaning of the discontinuity surfaces propagated in the gravitational field - as it was first emphasized by Levi-Civita.

  24. F. D. Stefani, K. Vasilev, N. Bocchio, F. Gaul

    We investigated the influence of the photonic mode density (PMD) on the triplet dynamics of individual chromophores on a dielectric interface by comparing their response in the presence and absence of a nearby gold film. Lifetimes of the excited singlet state were evaluated in ordet to measure directly the PMD at the molecules position. Triplet state lifetim

  25. Anatoly N. Panchenkov

    The study is devoted to the development of new effective tools and methods of ana-lytical hydrodynamics, including problems of existence, smoothness and structure of laminar and turbulent flows. The main problem is complex Navier-Stokes equations and turbulence in complex spaces. The necessity of introducing complex spaces in hydrodynamics is deter-mined by

  26. Esteban Moreno, F. J. Garcia-Vidal, Sergio G. Rodrigo, L. Martin-Moreno

    We theoretically study channel plasmon-polaritons (CPPs) with a geometry similar to that in recent experiments at telecom wavelengths (Bozhevolnyi et al., Nature 440, 508 (2006)). The CPP modal shape, dispersion relation, and losses are simulated using the multiple multipole method and the finite difference time domain technique. It is shown that, with the i

  27. Kwang-Hua W. Chu

    Upon using the hydrodynamic analog we can derive some families of stationary Beltrami field-like solutions from the free Maxwell equations in vacuum. These stationary electromagnetic fields are helical and/or column-like once they are represented in a suitable frame of reference. Possible dendritic and jelly-fish-like patterns of sprites are demonstrated.

  28. David W. Hogg

    Most introductory physics textbooks ask students to ignore air resistance but include no analysis of the appropriateness of that approximation. Indeed the approximation is inappropriate in many textbook problems. This short supplementary handout, appropriate for majors and non-majors alike, is designed to make up for this pervasive shortcoming (see also arXi

  29. Alberto Saa, Omar Teschke

    Surfaces formed by extracellular polymeric substances enclosing individual and some small communities of {\it Acidithiobacillus ferrooxidans} on plates of hydrophobic silicon and hydrophilic mica are analyzed by means of atomic force microscopy imaging. Accurate nanoscale descriptions of such coverage surfaces are obtained. The good agreement with the predic

  30. Berndt Müller

    This talk gives a theoretical perspective of the physics issues awaiting us when heavy ions will collide in the LHC.

  31. M. B. Barbaro, J. E. Amaro, J. A. Caballero, T. W. Donnelly

    We suggest that superscaling analyses of few-GeV inclusive electron scattering from nuclei, both in the quasielastic peak and in the region where the $Δ$-excitation dominates, allow one to make reliable predictions for charge-changing neutrino reactions at energies of a few GeV, relevant for neutrino oscillation experiments.

  32. A. N. Antonov, M. V. Ivanov, M. K. Gaidarov, E. Moya de Guerra

    Superscaling analyses of inclusive electron scattering from nuclei are extended from the quasielastic processes to the delta excitation region. The calculations of $(e,e^\prime)$ cross sections for the target nucleus $^{12}$C at various incident electron energies are performed using scaling functions $f(ψ^{\prime})$ obtained in approaches going beyond the me

  33. W. Florkowski, W. Broniowski, A. Kisiel, J. Pluta

    The effects of the freeze-out hypersurface and resonance decays on the pion correlation functions in relativistic heavy-ion collisions are studied with help of the hydro-inspired models with single freeze-out. The heavy-ion Monte-Carlo generator THERMINATOR is used to generate hadronic events describing production of particles from a thermalized and expandin

  34. J. Rizzo, M. Colonna, A. Ono

    Multifragmentation scenarios, as predicted by antisymmetrized molecular dynamics (AMD) or momentum-dependent stochastic mean-field (BGBD) calculations are compared. While in the BGBD case fragment emission is clearly linked to the spinodal decomposition mechanism, i.e. to mean-field instabilities, in AMD many-body correlations have a stronger impact on the f

  35. D. Bonatsos, D. Lenis, N. Pietralla, P. A. Terziev

    A gamma-soft analog of the confined beta-soft (CBS) rotor model is developed, by using a gamma-independent displaced infinite well beta-potential in the Bohr Hamiltonian, for which exact separation of variables is possible. Level schemes interpolating between the E(5) critical point symmetry (with R(4/2)=E(4)/E(2)= 2.20) and the O(5) gamma-soft rotor (with R

  36. Debabrata Pal, Sk. Golam Ali, B. Talukdar

    We derive a straightforward variational method to construct embedded soliton solutions of the third-order nonlinear Schödinger equation and analytically demonstrate that these solitons exist as a continuous family. We argue that a particular embedded soliton when perturbed may always relax to the adjacent one so as to make it fully stable.

  37. Ioana Dragomirescu, Adelina Georgescu

    Motion in the atmosphere or mantle convection are two among phenomena of natural convection induced by internal heat sources. They bifurcate from the conduction state as a result of its loss of stability. In spite of their importance, due to the occurrence of variable coefficients in the nonlinear partial differential equations governing the evolution of the

  38. Z. H. Dong

    By expressing the Holstein-Primakoff transformation in a symmetric form a modified spin-polaron technique utilized on triangular-lattice antiferromagnet is developed. With the technique, we have treated an extended t-J model, calculated the quasiparticle dispersion, and we also compared the the dispersion with that obtained by other method.

  39. Caucher Birkar, V. V. Shokurov

    Minimal log discrepancies (mld&#39;s) are related not only to termination of log flips, and thus to the existence of log flips but also to the ascending chain condition (acc) of some global invariants and invariants of singularities in the Log Minimal Model Program (LMMP). In this paper, we draw clear links between several central conjectures in the LMMP. Mo

  40. Omer Angel, Alexander E. Holroyd, Dan Romik, Balint Virag

    A sorting network is a shortest path from 12...n to n...21 in the Cayley graph of S_n generated by nearest-neighbour swaps. We prove that for a uniform random sorting network, as n->infinity the space-time process of swaps converges to the product of semicircle law and Lebesgue measure. We conjecture that the trajectories of individual particles converge to

  41. Sujith Vijay

    The well-known three distance theorem states that there are at most three distinct gaps between consecutive elements in the set of the first n multiples of any real number. We generalise this theorem to higher dimensions under a suitable formulation. The three distance theorem can be thought of as a statement about champions in a tournament. The players in t

  42. A. Brudnyi, Yu. Brudnyi

    If a metric subspace $M^{o}$ of an arbitrary metric space $M$ carries a doubling measure $μ$, then there is a simultaneous linear extension of all Lipschitz functions on $M^{o}$ ranged in a Banach space to those on $M$. Moreover, the norm of this linear operator is controlled by logarithm of the doubling constant of $μ$.

  43. Justin R. Peters

    Let $X$ be compact Hausdorff, and $ϕ: X \to X$ a continuous surjection. Let $\mathcal{A}$ be the semicrossed product algebra corresponding to the relation $fU = Uf\circ ϕ$. Then the C$^*$-envelope of $\mathcal{A}$ is the crossed product of a commutative C$^*$-algebra which contains $C(X)$ as a subalgebra, with respect to a homeomorphism which we construct. W

  44. Jean B. Lasserre

    We specialize Schmüdgen&#39;s Positivstellensatz and its Putinar and Jacobi and Prestel refinement, to the case of a polynomial $f\in R[X,Y]+R[Y,Z]$, positive on a compact basic semi algebraic set $K$ described by polynomials in $R[X,Y]$ and $R[Y,Z]$ only, or in $R[X]$ and $R[Y,Z]$ only (i.e. $K$ is a cartesian product). In particular, we show that the preor

  45. Odinette Renée Abib

    The purpose of the paper is to study the relationship between differential equations, Pfaffian systems and geometric structures, via the method of moving frames of E.Cartan. We show a local structure theorem. The Lie algebra aspects differential equations is studied too.

  46. Jimmy Lamboley, Michel Pierre

    In this paper, we describe the structure of shape derivatives around sets which are only assumed to be of finite perimeter in $\R^N$. This structure allows us to define a useful notion of positivity of the shape derivative and we show it implies its continuity with respect to the uniform norm when the boundary is Lipschitz (this restriction is essentially op

  47. Ngo Viet Trung

    We prove that the integral closures of the powers of a squarefree monomial ideal I equal the symbolic powers if and only if I is the edge ideal of a Fulkersonian hypergraph.

  48. Yang Su

    In this paper the singular hypersurfaces in $\mathbb{C}\mathrm{P}^4$ of degree $d$ with an isolated singularity are studied. If the singularity is of type $A_{2k+1}$, under the condition $d<(k+5)/2$, a classification of such hypersurfaces upto homeomorphism (which is diffeomorphism on the nonsingular part) is obtained. As an application, cubic hypersurfaces

  49. J. -L. Colliot-Th&#39;el`ene

    A connected reductive group G over a field k may be written as a quotient H/S, where the k-group H is an extension of a quasitrivial torus by a simply connected semisimple group, and S is a flasque k-torus, central in H (a flasque torus is a torus whose cocharacter group is an H^1-trivial Galois lattice). The flasque torus S is well-defined up to multiplicat

  50. Olivier Serman

    We prove that the forgetful morphism from the moduli space of orthogonal bundles to the moduli space of vector bundles over a smooth curve is an embedding. Our proof relies on an explicit description of a set of generators for the invariants on the representation space of a quiver under the action of a product of classical groups.

  51. Andrei Bytsko

    The spectral decomposition of regular sl_2-invariant R-matrices R(lambda) is studied by means of the method of reduction of the Yang-Baxter equation onto subspaces of a given spin. Restrictions on the possible structure of several highest coefficients in the spectral decomposition are derived. The origin and structure of the exceptional solution in the case

  52. Vladimir Turaev

    We discuss a topological approach to words introduced by the author. Words on an arbitrary alphabet are approximated by Gauss words and then studied up to natural modifications inspired by the Reidemeister moves on knot diagrams. This leads us to a notion of homotopy for words. We introduce several homotopy invariants of words and give a homotopy classificat

  53. N. Andruskiewitsch, M. Beattie

    In this note, the irreducible representations of a lifting of a quantum plane are determined. Both authors thank Hans-Jürgen Schneider for pointing out a mistake in the published version of the paper, that is corrected here.

  54. Francois Descouens, Alain Lascoux

    Using the action of the Yang-Baxter elements of the Hecke algebra on polynomials, we define two bases of polynomials in n variables. The Hall-Littlewood polynomials are a subfamily of one of them. For q=0, these bases specialize into the two families of classical Key polynomials (i.e. Demazure characters for type A). We give a scalar product for which the tw

  55. Yu Chen, Cathy Kriloff

    For a crystallographic root system, dominant regions in the Catalan hyperplane arrangement are in bijection with antichains in a partial order on the positive roots. For a noncrystallographic root system, the analogous arrangement and regions have importance in the representation theory of an associated graded Hecke algebra. Since there is also an analogous

  56. Mark Agranovsky

    We prove that generic homologically nontrivial $(2n-1)$-parameter family of analytic discs attached by their boundaries to a CR manifold $Ω$ in $\mathbb C^n, n \le 2$ tests CR functions: if a smooth function on $Ω$ extends analytically inside each analytic disc then it satisfies the tangential CR equations. In particular, we answer, in real analytic category

  57. Flaminio Flamini, Andreas Leopold Knutsen, Gianluca Pacienza

    In this paper, we study the Brill-Noether theory of the normalizations of singular, irreducible curves on a $K3$ surface. We introduce a {\em singular} Brill-Noether number $ρ_{sing}$ and show that if the Picard group of the K3 surface is ${\mathbb Z} [L]$, there are no $g^r_d$&#39;s on the normalizations of irreducible curves in $|L|$, provided that $ρ_{sin

  58. Jeffrey C. Lagarias, Eric Rains

    This paper studies the behavior under iteration of the maps T_{ab}(x,y) = (F_{ab}(x)- y, x) of the plane R^2, in which F_{ab}(x)= ax if x>0 and bx if x<0. These maps are area-preserving homeomorphisms of the plane that map rays from the origin into rays from the origin. Orbits of the map correspond to solutions of the nonlinear difference equation x_{n+2}= 1

  59. Fokko J. van de Bult

    Simultaneous eigenfunctions of two Askey-Wilson second order difference operators are constructed as formal matrix coefficients of the principal series representation of the modular double of the quantized universal enveloping algebra U_q(sl(2,C)). These eigenfunctions are shown to be equal to Ruijsenaars&#39; hypergeometric function under a proper parameter

  60. Jeffrey C. Lagarias, Eric Rains

    This paper studies the behavior under iteration of the maps T_{ab}(x,y) = (F_{ab}(x)-y,x) of the plane R^2, in which F_{ab}(x)=ax if x>=0 and bx if x<0. The orbits under iteration correspond to solutions of the nonlinear difference equation x_{n+2}= 1/2(a-b)|x_{n+1}| + 1/2(a+b)x_{n+1} - x_n. This family of piecewise-linear maps has the parameter space (a,b)\

  61. Joshua J. Friess, Steven S. Gubser, Georgios Michalogiorgakis, Silviu S. Pufu

    We investigate the stability against small deformations of strings dangling into AdS_5-Schwarzschild from a moving heavy quark-anti-quark pair. We speculate that emission of massive string states may be an important part of the evolution of certain unstable configurations.

  62. Massimo Giovannini

    Five-dimensional Gauss-Bonnet gravity, with one warped extra-dimension, allows classes of solutions where two scalar fields combine either in a kink-antikink system or in a trapping bag configuration. While the kink-antikink system can be interpreted as a pair of gravitating domain walls with opposite topological charges, the trapping bag solution consists o

  63. Alex Hamilton, Jeff Murugan

    The recently constructed Lunin-Maldacena deformation of $AdS_{5}\times S^{5}$ is known to support two inequivalent Penrose limits that lead to BPS pp-wave geometries. In this note, we construct new giant graviton solutions on these backgrounds. A detailed study of the spectra of small fluctuations about these solutions reveals a remarkably rich structure. In

  64. E Corrigan

    Some aspects of integrable field theories possessing purely transmitting defects are described. The main example is the sine-Gordon model and several striking features of a classical field theory containing one or more defects are pointed out. Similar features appearing in the associated quantum field theory are also reviewed briefly.

  65. G. Atondo-Rubio, J. A. Nieto, L. Ruiz, J. Silvas

    We develop a linearized five dimensional Kaluza-Klein theory as a gauge theory. By perturbing the metric around flat and the De Sitter backgrounds, we first discuss linearized gravity as a gauge theory in any dimension. In the particular case of five dimensions, we show that using the Kaluza-Klein mechanism, the field equations of our approach implies both l

  66. Boris Altshuler

    The conventional approach to calculation of the radion effective potential in the string theory inspired models with magnetic fluxbrane throat-like space-time compactified on a sphere gives the analytical expressions hopefully capable to describe early inflation. Potential is rather flat inside the throat, possesses steep slope for reheating in vicinity of t

  67. N. Caporaso, M. Cirafici, L. Griguolo, S. Pasquetti

    We study the relations between two-dimensional Yang-Mills theory on the torus, topological string theory on a Calabi-Yau threefold whose local geometry is the sum of two line bundles over the torus, and Chern-Simons theory on torus bundles. The chiral partition function of the Yang-Mills gauge theory in the large N limit is shown to coincide with the topolog

  68. Jennie D&#39;Ambroise, Floyd L. Williams

    We show that the Friedmann-Lemaitre-Robertson-Walker equations with scalar field and perfect fluid matter source are equivalent to a suitable non-linear Schrodinger type equation. This provides for an alternate method of obtaining exact solutions of the Einstein field equations for a homogeneous, isotropic universe.

  69. Xiaofeng Guo, Jun Li

    We present a QCD calculation of the coherent multiple scattering effect on single hadron production in semi-inclusive lepton-nucleus deep inelastic scattering (DIS). We show that the destructive interference of coherent multiple scattering leads to suppression in hadron productions. The suppression is similar to the expectations of energy loss calculations.

  70. L. Campanelli, M. Giannotti

    We study the effect of a uniform magnetic field on the dynamics of axions. In particular, we show that the Peccei-Quinn symmetry is explicitly broken by the presence of an external magnetic field. This breaking is induced by the non-conservation of the magnetic helicity and generates an electromagnetic contribution to the axion mass. We compute the magnetic

  71. Dominik Nickel, Reinhard Alkofer, Jochen Wambach

    The role of the strange quark mass for the phase structure of QCD at non-vanishing densities is studied by employing a recently developed self-consistent truncation scheme for the Dyson-Schwinger equations of the quark propagators in Landau gauge. Hereby the medium modification of the effective quark interaction by the polarization of gluons is implemented.

  72. Helmut Satz

    In statistical QCD, the thermal properties of the quark-gluon plasma can be determined by studying the in-medium behaviour of heavy quark bound states. The results can be applied to quarkonium production in high energy nuclear collisions, if these indeed form a fully equilibrated QGP. Modifications could arise if an initial charm excess persists in the colli

  73. I. N. Mishustin

    It is commonly accepted that strongly interacting matter has several phase transitions in different domains of temperature and baryon density. In this contribution I discuss two most popular phase transitions which in principle can be accessed in nuclear collisions. One of them, the liquid-gas phase transition, is well established theoretically and studied e

  74. Victor Flambaum, Michael Kuchiev

    The Coulomb problem for vector bosons W incorporates a known difficulty; the boson falls on the center. In QED the fermion vacuum polarization produces a barrier at small distances which solves the problem. In a renormalizable SU(2) theory containing vector triplet (W^+,W^-,gamma) and a heavy fermion doublet F with mass M the W^- falls on F^+, to distances r

  75. M. Beccaria, G. Macorini, F. M. Renard, C. Verzegnassi

    We compute the complete one loop electroweak effects in the MSSM for the eight processes of single top (and single antitop) production in the $t$-channel at hadron colliders, generalizing a previous analysis performed for the dominant $dt$ final state. The results are quite similar for all processes, showing an impressively large Standard Model effect and a

  76. Vishnu M. Bannur

    Here we present a self-consistent quasi-particle model for quark-gluon plasma and apply it to explain the non-ideal behaviour seen in lattice simulations. The basic idea, borrowed from electrodynamic plasma, is that the gluons acquire mass as it propagates through plasma due to collective effects and is approximately equal to the plasma frequency. The statis

  77. Wojciech Krolikowski

    A new option of parameter constraint is described for the recently proposed neutrino mass formula involving primarily three free parameters. The option implies the vanishing of a part of mass formula for the lowest mass neutrino, the part which may - in an intuitive model - be identified with its formal &#34;intrinsic selfenergy&#34;. However, its actual mas

  78. M. Sadzikowski

    We study the phase diagram of the strongly interacting matter at finite temperatures and densities including 2SC, uniform chiral and non-uniform chiral phases within the Nambu - Jona-Lasinio model in the mean field approximation.

  79. M. Nielsen, F. S. Navarra, M. E. Bracco

    Using the QCD sum rule approach we investigate the possible four-quark structure of the recently observed mesons $D_{sJ}^{+}(2317)$, firstly observed by BaBaR, X(3872), firstly observed by BELLE and $D_0^{*0}(2308)$ observed by BELLE. We use diquark-antidiquark currents and work in full QCD, without relying on $1/m_c$ expansion. Our results indicate that a f

  80. R. G. Jafarov, V. E. Rochev

    In present report we review some preliminary results of investigation of higher orders of mean-field expansion for Nambu--Jona-Lasinio model. We discuss first results of investigation of next-to-next-to-leading order of mean-field expansion equations for four-quark and three-quark Green functions. We have considered equations for Green functions of Nambu--Jo

  81. Sandhya Choubey

    Physics potential of future measurements of atmospheric neutrinos is explored. Observation of $Δm^2_{21}$ driven sub-dominant effects and $θ_{13}$ driven large matter effects in atmospheric neutrinos can be used to study the deviation of $θ_{23}$ from maximality and its octant. Neutrino mass hierarchy can be determined extremely well due to the large matter

  82. A. Freitas, P. Z. Skands

    In order to establish supersymmetry (SUSY) at future colliders, the identity of gauge couplings and the corresponding Yukawa couplings between gauginos, sfermions and fermions needs to be verified. Here a first phenomenological study for determining the Yukawa coupling of the SUSY-QCD sector is presented, using a method which combines information from LHC an

  83. Yuval Grossman, Alexander L. Kagan, Yosef Nir

    We analyze various theoretical aspects of CP violation in singly Cabibbo suppressed (SCS) D-meson decays, such as $D \to K K,ππ$. In particular, we explore the possibility that CP asymmetries will be measured close to the present level of experimental sensitivity of $O(10^{-2})$. Such measurements would signal new physics. We make the following points: (i) T

  84. Indranath Bhattacharyya

    The electron-neutrino bremsstrahlung process has been considered in the framework of electro-weak theory. The scattering cross section has been calculated in the center of mass frame and approximated to extreme relativistic as well as non-relativistic case. The rate of energy-loss via this type of bremsstrahlung process has been obtained both in non-degenera

  85. Stanislav Shcheredin, Edwin Laermann

    The Hypercube operator determines a variant of the approximate, truncated perfect fermion action. In this pilot study we are going to report on first experiences in dynamical QCD simulations with the Hypercube fermions. We apply this formulation in an investigation of the finite temperature transition for two flavours. On lattices of size $8^3\times 4$ we ex

  86. The BABAR Collaboration, B. Aubert

    We present branching fraction measurements of charged and neutral B decays to Dpi-, D*pi- and D**pi- with a missing mass method, based on a sample of 231 million Y(4S)-->BBar pairs collected by the BaBar detector at the PEP-II e+e- collider. One of the B mesons is fully reconstructed and the other one decays to a reconstructed charged pion and a companion ch

  87. Ghulam Shabbir, Shaukat Iqbal

    Direct integration technique is used to study the proper conformal vector fields in non conformally flat Bianchi type-1 space-times. Using the above mentioned technique we have shown that a very special class of the above space-time admits proper conformal vector fields.

  88. Piotr Faliszewski, Edith Hemaspaandra, Lane A. Hemaspaandra, Joerg Rothe

    We provide an overview of some recent progress on the complexity of election systems. The issues studied include the complexity of the winner, manipulation, bribery, and control problems.

  89. Pascal Weil

    Recognizable languages of finite words are part of every computer science cursus, and they are routinely described as a cornerstone for applications and for theory. We would like to briefly explore why that is, and how this word-related notion extends to more complex models, such as those developed for modeling distributed or timed behaviors.

  90. Bruno Courcelle, Pascal Weil

    Once the set of finite graphs is equipped with an algebra structure (arising from the definition of operations that generalize the concatenation of words), one can define the notion of a recognizable set of graphs in terms of finite congruences. Applications to the construction of efficient algorithms and to the theory of context-free sets of graphs follow n

  91. Joakim Bergli, Leonid Glazman

    The spin echo techniques aim at the elimination of the effect of a random magnetic field on the spin evolution. These techniques conventionally utlize the application of a permanent field which is much stronger than the random one. The strong field, however, may also modify the magnetic response of the medium containing the spins, thus altering their ``natur

  92. John W. Lawson, David H. Wolpert

    Novel assembly processes for nanocircuits could present compelling alternatives to the detailed design and placement currently used for computers. The resulting architectures however may not be programmable by standard means. In this paper, nanocomputers with unconventional architectures are programmed using adaptive methods. The internals of the device are

  93. K. P. S. Parmar, Y. Meheust, J. O. Fossum, K. D. Knudsen

    Oil suspensions of fluorohectorite clay particles exhibit a dramatic meso-structural ordering when submitted to a strong electric field. This is due to dipolar interaction between polarized fluorohectorite particles, which orientate and aggregate to form chains and/or bundle-like structures along the direction of the applied electric field. We have used sync

  94. V. F. Correa, T. P. Murphy, C. Martin, K. M. Purcell

    We report high magnetic field linear magnetostriction experiments on CeCoIn$_5$ single crystals. Two features are remarkable: (i) a sharp discontinuity in all the crystallographic axes associated with the upper superconducting critical field $B_{c2}$ that becomes less pronounced as the temperature increases; (ii) a distinctive second order-like feature obser

  95. K. P. S. Parmar, Y. Meheust, J. O. Fossum

    We have studied the effect of an external DC electric field (~kV/mm) on the rheological properties of colloidal suspensions consisting of aggregates of laponite particles in a silicone oil. Microscopy observations show that under application of an electric field greater than a triggering electric field E_c~0.6 kV/mm, laponite aggregates assemble into chain-

  96. Alexander L. Fetter

    A rapidly rotating Bose-Einstein condensate in a symmetric two-dimensional trap can be described with the lowest Landau-level set of states. In this case, the condensate wave function psi(x,y) is a Gaussian function of r^2 = x^2 + y^2, multiplied by an analytic function P(z) of the single complex variable z= x+ i y; the zeros of P(z) denote the positions of

  97. Charles W. Bauschlicher,, John W. Lawson

    We present current-voltage (I-V) curves computed using all-electron basis sets on the conducting molecule. The all-electron results are very similar to previous results obtained using effective core potentials (ECP). A hybrid integration scheme is used that keeps the all-electron calculations cost competitive with respect to the ECP calculations. By neglecti

  98. M. A. Anisimov, D. A. Fuentevilla

    We have developed a scaled parametric equation of state to describe and predict thermodynamic properties of supercooled water. The equation of state, built on the growing evidence that the critical point of supercooled liquid-liquid water separation exists, is universal in terms of theoretical scaling fields and is shown to belong to the Ising-model class of

  99. Juergen Koefinger, Nigel B. Wilding, Gerhard Kahl

    We have investigated the phase behaviour of a symmetrical binary fluid mixture for the situation where the chemical potentials $μ_1$ and $μ_2$ of the two species differ. Attention is focused on the set of interparticle interaction strengths for which, when $μ_1=μ_2$, the phase diagram exhibits both a liquid-vapor critical point and a tricritical point. The c

  100. G. A. Levin, P. N. Barnes, N. Amemiya

    We report the magnetization losses in an experimental multifilament coated conductor. A 4 mm wide and 10 cm long YBCO coated conductor was subdivided into eight 0.5 mm wide filaments by laser ablation and subjected to post-ablation treatment. As the result, the hysteresis loss was reduced, as expected, in proportion to the width of the filaments. However, th