August 2004 arXiv papers — page 15

C. V. Giuraniuc, J. P. L. Hatchett, J. O. Indekeu, M. Leone

Scale-free networks with topology-dependent interactions are studied. It is shown that the universality classes of critical behavior, which conventionally depend only on topology, can also be explored by tuning the interactions. A mapping, $γ' = (γ- μ)/(1-μ)$, describes how a shift of the standard exponent $γ$ of the degree distribution $P(q)$ can absorb

Taoufik Bouziane

In this paper, we prove the existence of energy minimizers in each free homotopy class of maps between polyhedra with target space without focal points. Our proof involves a careful study of some geometric properties of riemannian polhyedra without focal points. Among other things, we show that on the relevant polyhedra, there exists a convex supporting func

J. A. Valiente Kroon

The Conformal Einstein equations and the representation of spatial infinity as a cylinder introduced by Friedrich are used to analyse the behaviour of the gravitational field near null and spatial infinity for the development of data which are asymptotically Euclidean, conformally flat and time asymmetric. Our analysis allows for initial data whose second fu

M. L. Walker

We utilise a non-local gauge transform which renders the entire action of SUSY QED invariant and respects the SUSY algebra modulo the gauge-fixing condition, to derive two- and three-point ghost-free SUSY Ward identities in SUSY QED. We use the cluster decomposition principle to find the Green's function Ward identities and then takes linear combinations

S. K. Roushon

This article has two purposes. In \cite{R3} (math.KT/0405211) we showed that the FIC (Fibered Isomorphism Conjecture for pseudoisotopy functor) for a particular class of 3-manifolds (we denoted this class by \cal C) is the key to prove the FIC for 3-manifold groups in general. And we proved the FIC for the fundamental groups of members of a subclass of \cal

Branislav Sazdovic

It is well known that space-time coordinates and corresponding Dp-brane world-volume become non-commutative, if open string ends on Dp-brane with Neveu-Schwarz background field $B_{μν}$. In this paper we extend these considerations including the dilaton field $Φ$, linear in coordinates $x^μ$. In that case the conformal part of the world-sheet metric appears

Ziemowit Popowicz

The Kaup - Kupershmidt equation is generalized to the system of equations in the same manner as the Korteweg - de Vries equation is generalized to the Hirota - Satsuma equation. The Gelfan - Dikii - Lax and Hamiltonian formulatiohn for this generalization is given. The same construction is repeated for the constrainded Kadomtsev - Pietviashvili - Lax operato

Michael Blank

We study phase transitions of a system of particles on the one-dimensional integer lattice moving with constant acceleration, with a collision law respecting slower particles. This simple deterministic ``particle-hopping'' traffic flow model being a straightforward generalization to the well known Nagel-Schreckenberg model covers also a more recent s

Anirudh Pradhan, Kashika Srivastava, Amrit Lal Ahuja

Exact solutions of the Einstein's field equations describing a spherically symmetric cosmological model without a big bang or any other kind of singularity recently obtained by Dadhich and Patel (2000) are revisited. The matter content of the model is a shear-free perfect fluid with isotropic pressure and a radial heat flux. Three different exact solutio

Takahiro Mori, Hikaru Kawamura

Spatio-temporal correlations of earthquakes are studied numerically on the basis of the one-dimensional spring-block (Burridge-Knopoff) model. As large events approach, the frequency of smaller events gradually increases, while, just before the mainshock, it is dramatically suppressed in a close vicinity of the epicenter of the upcoming mainshock, a phenomen

Damir Becirevic, Giovanni Villadoro

We compute the 1-loop chiral corrections to the bag parameters which are needed for the discussion of the SUSY K-Kbar mixing problem in both finite and infinite volume. We then show how the bag parameters can be combined among themselves and with some auxiliary quantities and thus sensibly reduce the systematic errors due to chiral extrapolations as well as

D. F. Anagnostopoulos, S. Biri, D. Gotta, A. Gruber

Narrow X-ray lines from helium-like argon emitted from a dedicated ECR source have been used to determine the response function of a Bragg crystal spectrometer equipped with large area spherically bent silicon (111) or quartz (10$\bar{1}$) crystals. The measured spectra are compared with simulated ones created by a ray-tracing code based on the expected theo

Masayoshi Kaneda

This paper is a revision and an enlargement of the previous version titled "Extreme points of the unit ball of a quasi-multiplier space" which had been circulated since 2004. We study extreme points of the unit ball of an operator space by introducing the new notion (approximate) "quasi-identities". Then we characterize an operator algebra wi

Sudeep Das, Pankaj Jain, John P. Ralston, Rajib Saha

Radiation propagating over cosmological distances can probe light weakly interacting pseudoscalar (or scalar) particles. The existence of a spin-0 field changes the dynamical symmetries of electrodynamics. It predicts spontaneous generation of polarization of electromagnetic waves due to mode mixing in the presence of background magnetic field.We illustrate

Baosheng Yuan, Kan Chen, Bing-Hong Wang

We study the organization and dynamics of growing directed networks. These networks are built by adding nodes successively in such a way that each new node has $K$ directed links to the existing ones. The organization of a growing directed network is analyzed in terms of the number of ``descendants'' of each node in the network. We show that the dist

C. H. Lee, H. Matsuhata, H. Yamaguchi, C. Sekine

X-ray and electron diffraction measurements on the metal-insulator (M-I) transition compound PrRu$_4$P$_{12}$ have revealed the emergence of a periodic ordering of charge density around the Pr atoms. It is found that the ordering is associated with the onset of a low temperature insulator phase. These conclusions are supported by the facts that the space gro

E. Barradas-Guevara, Olga Felix-Beltran, J. Hernandez-Sanchez, A. Rosado

The vertex H+-W-+h0, involving the gauge bosons W-+, the charged (H+-) and the lightest neutral (h0) Higgs bosons, arises within the context of many extensions of the SM, and it can be used to probe the Higgs sector of such extensions via the decay H+- -> W+- h0. We discuss the strength of this vertex for an extension of the MSSM with an additional complex H

Srijit Goswami, Mark Friesen, J. L. Truitt, Charles Tahan

The lifting of the two-fold degeneracy of the conduction valleys in a strained silicon quantum well is critical for spin quantum computing. Here, we obtain an accurate measurement of the splitting of the valley states in the low-field region of interest, using the microwave spectroscopy technique of electron valley resonance (EVR). We compare our results wit

Giacomo Mauro D'Ariano, Lorenzo Maccone, Paoloplacido Lo Presti

By quantum calibration we name an experimental procedure apt to completely characterize an unknown measurement apparatus by comparing it with other calibrated apparatuses. Here we show how to achieve the calibration of an arbitrary measuring apparatus, by using it in conjunction with a ``tomographer'' in a correlation setup with an input bipartite sy

Roderich Tumulka

This paper is an introduction to the ideas of Bohmian mechanics, an interpretation of quantum mechanics in which the observer plays no fundamental role. Bohmian mechanics describes, instead of probabilities of measurement results, objective microscopic events. In recent years, Bohmian mechanics has attracted increasing attention by researchers. The form of a

Chien-Yuan Chen, Chih-Cheng Hsueh

In this paper, we first define the quantum discrete logarithm problem (QDLP)which is similar to classical discrete logarithm problem. But, this problem cannot be solved by Shor's quantum algorithm. Based on quantum discrete logarithm problem, we present a novel quantum secret key encryption algorithm. The receiver constructs his quantum channel using the

U. Harbola, S. Mukamel

The electric conductance of a molecular junction is calculated by recasting the Keldysh formalism in Liouville space. Dyson equations for nonequilibrium many body Green's functions (NEGF) are derived directly in real (physical) time. The various NEGFs appear naturally in the theory as time ordered products of superoperators, while the Keldysh forward/bac

Volker Hannstein, Gerhard C. Hegerfeldt

We investigate the effect of the dipole-dipole interaction on the quantum jump statistics of three atoms. This is done for three-level systems in a V configuration and in what may be called a D configuration. The transition rates between the four different intensity periods are calculated in closed form. Cooperative effects are shown to increase by a factor

Daniel A. Lidar

It is shown that the canonical problem of classical statistical thermodynamics, the computation of the partition function, is in the case of +/-J Ising spin glasses a particular instance of certain simple sums known as quadratically signed weight enumerators (QWGTs). On the other hand it is known that quantum computing is polynomially equivalent to classical

Chopin Soo, Cyrus C. Y. Lin

We compute, for massive particles, the explicit Wigner rotations of one-particle states for arbitrary Lorentz transformations; and the explicit Hermitian generators of the infinite-dimensional unitary representation. For a pair of spin 1/2 particles, Einstein-Podolsky-Rosen-Bell entangled states and their behaviour under the Lorentz group are analysed in the

Ayako Yamada, Koji Kubo, Tonau Nakai, Kanta Tsumoto

Recently, it has been confirmed that long duplex DNA molecules with sizes larger than several tens of kilo-base pairs (kbp), exhibit a discrete conformational transition from an elongated coil state to a compact globule state upon the addition of various kinds of chemical species that usually induce DNA condensation. In this study, we performed a single-mole

J. C. Nacher, N. Ueda, T. Yamada, M. Kanehisa

Many real networks can be understood as two complementary networks with two kind of nodes. This is the case of metabolic networks where the first network has chemical compounds as nodes and the second one has nodes as reactions. The second network can be related to the first one by a technique called line graph transformation (i.e., edges in an initial netwo

Paul Indelicato, V. M. Shabaev, A. V. Volotka

The interelectronic-interaction effect on the transition probabilities in high-Z He-like ions is investigated within a systematic quantum electrodynamic approach. The calculation formulas for the interelectronic-interaction corrections of first order in 1/Z are derived using the two-time Green function method. These formulas are employed for numerical evalua

Marisa Roberto, Elton C. Da Silva, Ibere L. Caldas, Ricardo L. Viana

In this work we study the ergodic magnetic limiters (EML) action on field lines from the point of view of a chaotic scattering process, considering the so-called exit basins, or sets of points in the chaotic region which originate field lines hitting the wall in some specified region. We divide the tokamak wall into three areas of equal poloidal angular leng

Timo A. Nieminen, Norman R. Heckenberg, Halina Rubinsztein-Dunlop

A circularly polarized rotationally symmetric paraxial laser beams carries hbar angular momentum per photon as spin. Focussing the beam with a rotationally symmetric lens cannot change this angular momentum flux, yet the focussed beam must have spin less than hbar per photon. The remainder of the original spin is converted to orbital angular momentum, manife

Mayeul Arminjon

Euler's interpretation of Newton's gravity (NG) as Archimedes' thrust in a fluid ether is presented in some detail. Then a semi-heuristic mechanism for gravity, close to Euler's, is recalled and compared with the latter. None of these two "gravitational ethers" can obey classical mechanics. This is logical since the ether defines the

Jiunn-Wei Chen, Dean Lee, Thomas Schaefer

Using effective field theory we derive inequalities for light nuclei in the Wigner symmetry limit. This is the limit where isospin and spin degrees of freedom can be interchanged. We prove that the energy of any three-nucleon state is bounded below by the average energy of the lowest two-nucleon and four-nucleon states. We show how this is modified by lowest

J. Arrington, V. F. Dmitriev, R. J. Holt, D. M. Nikolenko

It has been suggested that two-photon exchange corrections could explain the discrepancy between Rosenbluth extractions of the proton form factors and recent polarization transfer measurements. We propose a precise comparison of electron-proton and positron-proton scattering at Q^2=1.6 GeV^2 to determine if two-photon exchange at moderate Q^2 values is in fa

Alberto Vancheri, Paolo Giordano, Denise Andrey, Sergio Albeverio

A new kind of cellular automaton (CA) for the study of the dynamics of urban systems is proposed. The state of a cell is not described using a finite set, but by means of continuum variables. A population sector is included, taking into account migration processes from and towards the external world. The transport network is considered through an integration

Guido Boffetta, Jahanshah Davoudi, Bruno Eckhardt, Joerg Schumacher

Finite time correlations of the velocity in a surface flow are found to be important for the formation of clusters of Lagrangian tracers. The degree of clustering characterized by the Lyapunov spectrum of the flow is numerically shown to be in qualitative agreement with the predictions for the white-in-time compressible Kraichnan flow, but to deviate quantit

Kanehisa Takasaki

Recent results on the Grassmannian perspective of soliton equations with an elliptic spectral parameter are presented along with a detailed review of the classical case with a rational spectral parameter. The nonlinear Schrödinger hierarchy is picked out for illustration of the classical case. This system is formulated as a dynamical system on a Lie group of

D. Tieudjo, D. I. Moldavanskii

The description of the automorphism group of group $<a, b; [a^m,b^n]=1>$ ($m,n>1$) in terms of generators and defining relations is given. This result is applied to prove that any normal automorphism of every such group is inner.

D. Tieudjo, D. I. Moldavanskii

Conjugacy separability of any group of the class of one-relator groups given by the presentation $<a, b; [a^m,b^n]=1>$ ($m,n>1$) is proven.

R. F. Goldin, S. Martin

Let M be the product of two compact Hamiltonian T-spaces X and Y. We present a formula for evaluating integrals on the symplectic reduction of M by the diagonal T action. At every regular value of the moment map for X x Y, the integral is the convolution of two distributions associated to the symplectic reductions of X by T and of Y by T. Several examples il

Ines Kath, Martin Olbrich

Following our approach to metric Lie algebras developed in math.DG/0312243 we propose a way of understanding pseudo-Riemannian symmetric spaces which are not semi-simple. We introduce cohomology sets (called quadratic cohomology) associated with orthogonal modules of Lie algebras with involution. Then we construct a functorial assignment which sends a pseudo

I. Cahit

Acceptable but due to extensive usage of a computer rather unpleasant proof of the famous four color map problem of Francis Guthrie were settled eventually by W. Appel and K. Haken in 1976. Using the same method but shortening the proof twenty years later by another team, namely N. Robertson, D.P. Sanders, P.D. Seymour and R. Thomas would not improve conside

Susumu Tanabe

One studies a system of differential equations defined by Abel integrals associated to a real cycle defined for the versal deformation of an isolated simple singularity. As application, one obtains an estimation on the multiplicity of zeros of the Abel integral in terms of quasihomogeneous weights associated to the Hamiltonian and the integrand function.

Lars Kadison

We study quasi-Hopf algebras and their subobjects over certain commutative rings from the point of view of Frobenius algebras. We introduce a type of Radford formula involving an anti-automorphism and the Nakayama automorphism of a Frobenius algebra, then view several results in quantum algebras from this vantage-point. In addition, separability and strong s

Yong-Cheol Kim

We survey the classical results of the Dirichlet Approximation Theorem.

Michael Blank, Leonid Bunimovich

We study a class of dynamical systems which generalizes and unifies some models arising in the analysis of switched flow systems in manufacturing. General properties of these dynamical systems, called pseudo billiards, as well as some their perturbations are discussed.

Helge Glockner

We describe finite-dimensional smooth Lie groups over local fields of positive characteristic which do not admit an analytic Lie group structure compatible with the given topological group structure, and C^n-Lie groups without a compatible C^{n+1}-Lie group structure, for each positive integer n. We also present examples of non-analytic, smooth automorphisms

Mohamed Ben Ayed, Khalil El Mehdi, Mokhless Hammami, Mohameden Ould Ahmedou

We consider a Yamabe type problem on a family $A_ε$ of annulus shaped domains of $\R^3$ which becomes &#34;thin&#34; as $ε$ goes to zero. We show that, for any given positive constant $C$, there exists $ε_0$ such that for any $ε< ε_0$, the problem has no solution $u_ε$ whose energy is less than $C$. Such a result extends to dimension three a result previousl

Ville Kolehmainen, Matti Lassas, Petri Ola

We show how to eliminate the error caused by an incorrectly modeled boundary in electrical impedance tomography (EIT). In practical measurements, one usually lacks the exact knowledge of the boundary. Because of this the numerical reconstruction from the measured EIT data is done using a model domain that represents the best guess for the true domain. Howeve

F. Peherstorfer, P. Yuditskii

We present a point of view on results of the paper of Geronimo and Johnson [Comm. Math, Phys. 193 (1998)] that allow infinitely dimensional generalization up to the case when spectrum is supported on a Cantor set of positive Lebesgue measure.

Soichi Okada

An alternating sign matrix is a square matrix with entries 1, 0 and -1 such that the sum of the entries in each row and each column is equal to 1 and the nonzero entries alternate in sign along each row and each column. To some of the symmetry classes of alternating sign matrices and their variations, G. Kuperberg associate square ice models with appropriate

Stefan Berceanu

For simple Lie groups, the only homogeneous manifolds $G/K$, where $K$ is maximal compact subgroup,for which the phase of the scalar product of two coherent state vectors is twice the symplectic area of a geodesic triangle are the hermitian symmetric spaces. An explicit calculation of the multiplicative factor on the complex Grassmann manifold and its noncom

Laszlo Lovasz

Connection matrices were introduced by Freedman, Lovasz and Schrijver [1], who used them to characterize graph homomorphism functions. The goal of this note is to determine the exact rank of these matrices. The result can be rephrased in terms of graph algebras (also introduced in [1]. Yet another version proves that if two k-tuples of nodes behave the same

Alexandr Prishlyak

We construct a topological invariant for a Morse-Smale flow on a 3-manifold and prove that the flows are topologically equivalent iff their invariants are same.

Meng Chen

1) We give a 3-dimensional analogue of M. Noether&#39;s inequality for canonically polarized threefolds: $K^3\ge 2(2p_g-5)/3$. This inequality is sharp by known examples of M. Kobayashi. 2) Given a minimal 3-fold $X$ of general type with canonical singularities, if $K^3< (3p_g-5)/2$, we show that $X$ must be birationally fibred by curves of genus 2.

Mathias Schulze

This paper has been withdrawn by the author since the proof of Lemma 8 is not correct.

Cristina Antonescu, Erik Christensen

An AF C*-algebra has a natural filtration as an increasing sequence of finite dimensional C*-algebras. We show that it is possible to construct a Dirac operator which relates to this filtration in a natural way and which will induce a metric for the weak*-topology on the state space of the algebra. In the particular case of a UHF C*-algebra, the construction

S. K. Roushon

In this note we point out an error in the above paper and refer to some papers where this error is corrected and a more general theorem is proved.

Mohamed Ben Ayed, Khalil El Mehdi, Mokhless Hammami

In this paper a fourth order equation involving critical growth is considered under Navier boundary condition. We give some topological conditions on a given function to ensure the existence of solutions. Our methods involve the study of the critical points at infinity and their contribution to the topology of the level sets of the associated Euler Lagrange

Yang-Hui He

These lectures, given at the Chinese Academy of Sciences for the BeiJing/HangZhou International Summer School in Mathematical Physics, are intended to introduce, to the beginning student in string theory and mathematical physics, aspects of the rich and beautiful subject of D-brane gauge theories constructed from local Calabi-Yau spaces. Topics such as orbif

Stephen C. Davis

The effective four-dimensional, linearised gravity of a Randall-Sundrum-like brane world model is analysed. The model includes higher order curvature terms (such as the Gauss-Bonnet term) and a scalar field. The resulting brane worlds can have better agreement with observations than the equivalent Einstein gravity models.

Peter van Nieuwenhuizen

We give a simple introduction to ordinary and conformal supergravity, and write their actions as squares of curvatures.

A. Bashir, A. Raya

We study the gauge dependence of the fermion propagator in quenched QED3 with and without dynamical symmetry breaking in the light of its Landau-Khalatnikov-Fradkin Transformation (LKFT). In the former case, starting with the massive bare propagator in the Landau gauge, we obtain non perturbative propagator in an arbitrary covariant gauge. At the one-loop le

A. T. Suzuki, J. H. O. Sales

At the classical level, the inverse differential operator for the quadratic term in the gauge field Lagrangian density fixed in the light front through the multiplier (nA)^2 yields the standard two term propagator with single unphysical pole of the type (kn)^-1. Upon canonical quantization on the light-front, there emerges a third term of the form (kn^(mu)n^

F. A. Schaposnik

Classical and quantum aspects of noncommutative field theories are discussed. In particular, noncommutative solitons and instantons are constructed and also d=2,3 noncommutative fermion and bosonic (Wess-Zumino-Witten and Chern-Simons)theories are analyzed.

P. Narayana Swamy

We present a theory of quantized radiation fields described in terms of q-deformed harmonic oscillators. The creation and annihilation operators satisfy deformed commutation relations and the Fock space of states is constructed in this formalism in terms of basic numbers familiar from the theory of quantum groups. Expressions for the Hamiltonian and momentum

E. G. S. Luna, M. J. Menon, J. Montanha

We investigate some aspects and consequences of the extrema bounds for the soft Pomeron intercept, recently determined by means of global fits to $pp$ and $\bar{p}p$ total cross section data at both accelerator and cosmic-ray energy regions (scattering data). We also examine the effects of the secondary Reggeons by introducing fitted trajectories from Chew-F

Matthias Neubert

Using results on soft-collinear factorization for inclusive B-meson decay distributions, a systematic study of the partial B->Xs+gamma decay rate with a cut E_gamma<E_0 on photon energy is performed. For values E_0<1.9 GeV the rate can be calculated without reference to shape functions. The result depends on three large scales: m_b, \sqrt{m_b Delta}, and Del

M. Awramik, M. Czakon, A. Freitas, G. Weiglein

We give some details of the recently completed calculation of the full two-loop fermionic corrections to the effective leptonic weak mixing angle. Among others, we describe the C++ library DiaGen/IdSolver, which was used to reduce the two-loop light fermion vertex diagrams to linear combinations of master integrals with rational function coefficients.

T. Stockamp

Recently, Mueller and Son discussed the time evolution of a dense system towards equilibrium in a scalar field theory. They show the equivalence of the classical field approximation and the Boltzmann equation in all but linear terms in the occupation number. Here we present the generalization to high energy QCD.

Oleg A. Teplov

The calculations and analysis of a variance have shown, that masses of mesons up to 1000 MeV strongly correlate with a model spectrum of potential wells at mass of harmonic up-quark 105.6 MeV. It is shown, that probability of casual correspondence of the meson and model spectrums is less than 1 ppm. The harmonic quark model is applied to L=0 hadrons for the

C. Hanhart

In a recent paper by the TAPS collaboration \cite{exp} a first measurement of a bound system of an $η$ meson and a ${^3}$He nucleus was reported. In this comment we critically reexamine the interpretation of the data and show that the data prefers a solution where there is no bound state present. Given the low statistics of the measurement, however, it does

M. Klasen, G. Kramer

We have calculated the diffractive dijet cross section in low-Q^2 ep scattering in the HERA regime. The results of the calculation in LO and NLO are compared to recent experimental data of the H1 collaboration. We find that in LO the calculated cross sections are in reasonable agreement with the experimental results. In NLO, however, some of the cross sectio

Antonio Pineda

Here we would like to review recent progress on the resummation on logarithms of $α_s$ in heavy quarkonium. We will mainly focus on the phenomenological relevance of these achievements. Determinations of the $η_b(1S)$ mass, $B_c(1S)$ hyperfine splitting, inclusive electromagnetic decays and implications for $t$-$\bar t$ production near threshold.

D. L. Borisyuk, A. P. Kobushkin, Yu. V. Kutafin

We calculate total cross section for production of the $Ξ_{3/2}(1862)$ exotic baryon in $\bar{K}N \to KΞ_{3/2}$ reaction assuming the following spin-parity values of the $Ξ_{3/2}$ baryon 1/2+, 1/2-, 3/2+, 3/2-. We demonstrate that the reaction total cross section strongly depends on the spin of the $Ξ_{3/2}$ baryon.

Kingman Cheung

In this talk, I describe a few interesting physics beyond the standard model that are quite unique for $γγ$ collisions, including large extra dimension model (ADD), warped extra dimension model (Randall-Sundrum) model, universal extra dimension model, as well as techni-pions of technicolor models.

Antonio Pineda

The resummation of logarithms in Quantum Field Theories is a long tale plenty of successes, yet the resummation of logarithms in non-relativistic theories has remained elusive. This was the most frustrating, since the first quantum field theory log ever computed was the Lamb shift one. We briefly review recent progress on the resummation of logarithms of $α$

Nikodem J. Poplawski, Adam P. Szczepaniak, J. T. Londergan

This work analyses hadronic decays of exotic mesons, with a focus on the lightest one, the $J^{PC}=1^{-+}$ $π_{1}$, in a fully relativistic formalism, and makes comparisons with non-relativistic results. We also discuss Coulomb gauge decays of normal mesons that proceed through their hybrid components. The relativistic spin wave functions of mesons and hybri

K. Huebner, O. Kaczmarek, F. Karsch, O. Vogt

We study the behaviour of free energies of baryonic systems composed of three heavy quarks on the lattice in SU(3) pure gauge theory at finite temperature. For all temperatures above $T_c$ we find that the connected part of the singlet (decuplet) free energy of the three quark system is given by the sum of the connected parts of the free energies of $qq$-tri

N. Ishii, T. Doi, H. Iida, M. Oka

The penta-quark(5Q) baryon is studied in anisotropic quenched lattice QCD with renormalized anisotropy a_s/a_t=4 for a high-precision mass measurement. The standard Wilson action at beta=5.75 and the O(a) improved Wilson quark action with kappa=0.1210(0.0010)0.1240 are employed on a 12^3 \times 96 lattice. Contribution of excited states is suppressed by usin

Howard D. Trottier, Kit Yan Wong

String breaking by dynamical quarks in three-dimensional lattice QCD is analyzed through measurements of the potential and the local color-electric field strength generated by a static quark-antiquark pair. Simulations were done for unquenched SU(2) color with two flavors of staggered light quarks. An improved gluon action was used, which allows simulations

B. Aubert, BABAR Collaboration

We present preliminary measurements of the CP-violating asymmetries in the decay $B^0\to f_0(980)(\toπ^+π^{-}) K_s^0$. The results are obtained from a data sample of $209\times10^6$ $Υ(4S) \to B\bar{B}$ decays collected with the BaBar detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. From a time-dependent maximum-likelihood fit we measure the mix

The BABAR Collaboration, B. Aubert

The (Delta I = 1) decay D_s^* --> Ds pi0 and (ΔI = 0) decay D_s^* --> Ds gamma have been reconstructed using 90.4 fb^-1 of data recorded by the BaBar detector at the PEP-II asymmetric-energy e^+e^- collider. The relative branching fraction of isospin violating decay to isospin conserving decay has been measured. Our preliminary result for this ratio is Gamma

B. Aubert, BABAR Collaboration

With a sample of 88.8 BBbar pairs produced at PEP-II in e+e- annihilation through the Upsilon(4S) resonance and recorded with the BABAR detector, we search for the B+ --> K*0 Rho+ decay mode. A signal is observed for the first time with a significance of more than 5 sigma. We measure a preliminary branching fraction of BR(B+ --> K*0 Rho+)=[17.0 +-2.9 (stat)

Wesley H. Smith, U. Wisconsin

A summary of recent results from ZEUS is presented. New ZEUS results from HERA-1 data include Structure Functions, QCD fits, analysis of hadronic final states, precision measurements of alpha_s, production of heavy flavor mesons and baryons and studies of diffraction. Results from the new HERA-II running include the measurement of the cross section for polar

B. Aubert, BABAR Collaboration

We present a search for the decay $B^{+} \to τ^{+} ν_τ$ in $124.1 \times 10^{6}$ $Υ(4S)$ decays recorded with the $BABAR$ detector at the SLAC PEP-II $B$-Factory. A sample of events with one reconstructed exclusive semi-leptonic B decay ($B^- \to D^{*0} \ell^- \barν_{\ell}$) is selected, and in the recoil a search for $B^{+} \to τ^{+} ν_τ$ signal is performe

David Garfinkle

A numerical and analytic treatment is presented here of the evolution of initial data of the kind that was conjectured by Hertog, Horowitz and Maeda to lead to a violation of cosmic censorship. That initial data is essentially a thick domain wall connecting two regions of anti de Sitter space. The evolution results in no violation of cosmic censorship, but r

V. Pelykh

Expression for the Witten-Nester 4-spinor 3-form of the Hamiltonian density of gravitational field in the asymptotically flat space-time in terms of the Sommers-Sen spinors, direct with a certain orthonormal three-frame connect, is obtained. A direct connection between the one and the ADM Hamiltonian density in the Sen-Witten frame is established on this bas

V. Pelykh

The elliptic system of equations, which is general-covariant and locally SU(2)-covariant, is investigated. The new condition of the Dirichlet problem solvability and the condition of zeros absence for solutions are obtained for this system, which contains in particular case the Sen-Witten equation. On this basis it is proved the existence of the wide class o

O. I. Streltsova, E. E. Donets, E. A. Hayryan, D. A. Georgieva

In this paper we obtain unstable even-parity eigenmodes to the static regular spherically symmetric solutions of the SU(2) Yang-Mills-dilaton coupled system of equations in 3+1 Minkowski space-time. The corresponding matrix Sturm-Liouville problem is solved numerically by means of the continuous analogue of Newton&#39;s method. The method, being the powerful

Jan Metzger

This paper presents a method for computing two-dimensional constant mean curvature surfaces. The method in question uses the variational aspect of the problem to implement an efficient algorithm. In principle it is a flow like method in that it is linked to the gradient flow for the area functional, which gives reliable convergence properties. In the backgro

Peng Wang, Gilberto M. Kremer, Daniele S. M. Alves, Xin-He Meng

By establishing that Palatini formulation of $L(R)$ gravity is equivalent to $ω=-3/2$ Brans-Dicke theory, we show that energy-momentum tensor is covariantly conserved in this type of modified gravity theory.

F. L. Williams, P. G. Kevrekidis, T. Christodoulakis, C. Helias

In this communication, we analyze the case of 3+1 dimensional scalar field cosmologies in the presence, as well as in the absence of spatial curvature, in isotropic, as well as in anisotropic settings. Our results extend those of Hawkins and Lidsey [Phys. Rev. D {\bf 66}, 023523 (2002)], by including the non-flat case. The Ermakov-Pinney methodology is devel

Julien Sylvestre

We present detailed numerical simulations of a laser phase stabilization scheme for LISA, where both lasers emitting along one arm are locked to each other. Including the standard secondary noises and spacecraft motions that approximately mimic LISA&#39;s orbit, we verify that very stable laser phases can be obtained, and that time delay interferometry can b

Mayeul Arminjon

We investigate the point-particle limit of the equations of motion valid for a system of extended bodies in a scalar alternative theory of gravitation: the size of one of the bodies being a small parameter xi, we calculate the limit, as xi tends towards 0, of the post-Newtonian (PN) acceleration of this small body. We use the asymptotic scheme of PN approxim

John M. Hitchcock, Jack H. Lutz, Sebastiaan A. Terwijn

Constructive dimension and constructive strong dimension are effectivizations of the Hausdorff and packing dimensions, respectively. Each infinite binary sequence A is assigned a dimension dim(A) in [0,1] and a strong dimension Dim(A) in [0,1]. Let DIM^alpha and DIMstr^alpha be the classes of all sequences of dimension alpha and of strong dimension alpha, re

Sameer Tilak, Vinay Kolar, Nael B. Abu-Ghazaleh, Kyoung-Don Kang

The ability of a sensor node to determine its physical location within a network (Localization) is of fundamental importance in sensor networks. Interpretating data from sensors will not be possible unless the context of the data is known; this is most often accomplished by tracking its physical location. Existing research has focused on localization in stat

Holger Schaefers, Walter T. Strunz

We investigate the dynamics of electron spin qubits in quantum dots. Measurement of the qubit state is realized by a charge current through the dot. The dynamics is described in the framework of the quantum trajectory approach, widely used in quantum optics, and we show that it can be applied successfully to problems in condensed matter physics. The relevant

K. -W. Lee, J. Kunes, P. Novak, W. E. Pickett

Charge disproportionation (CD) and spin differentiation in Na$_{1/2}$CoO$_2$ are studied using the correlated band theory approach. The simultaneous CD and gap opening seen previously is followed through a first order charge disproportionation transition 2Co$^{3.5+} \to$ Co$^{3+}$+Co$^{4+}$, whose ionic identities are connected more closely to spin (S=0, S=1

J. -E. Wegrowe, H. -J. Drouhin

In the context of spin electronics, the two spin-channel model assumes that the spin carriers are composed of two distinct populations: the conduction electrons of spin up, and the conduction electrons of spin down. In order to distinguish the paramagnetic and ferromagnetic contributions in spin injection, we describe the current injection with four channels

R. D. McDonald, N. Harrison, P. Goddard, J. Singleton

Graf {\it et al.} [Phys. Rev. Lett. {\bf 93} 076406 (2004)] recently attributed features in the magnetic-field-dependent longitudinal resistance of (Per)$_2$Pt(mnt)$_2$ to a cascade of field-induced charge-density waves (FICDWs). Here we show that a quantitative magnetotransport analysis reveals orbital quantization to be absent, disproving the presence of F