April 1999 arXiv papers — page 3

A. Denner, S. Dittmaier, M. Roth, D. Wackeroth

The complete matrix elements for e^+ e^- -> 4f and e^+ e^- -> 4f + gamma are calculated in the Electroweak Standard Model for polarized massless fermions. The matrix elements for all final states are reduced to a few compact generic functions. Monte Carlo generators for e^+ e^- -> 4f and e^+ e^- -> 4f + gamma are constructed. We compare different treatments

A. Ashtekar, D. Marolf, J. Mourão, T. Thiemann

Osterwalder and Schrader introduced a procedure to obtain a (Lorentzian) Hamiltonian quantum theory starting from a measure on the space of (Euclidean) histories of a scalar quantum field. In this paper, we extend that construction to more general theories which do not refer to any background, space-time metric (and in which the space of histories does not a

Tomohiro Harada, Ken-ichi Nakao, Hideo Iguchi

It was recently shown that the metric functions which describe a spherically symmetric space-time with vanishing radial pressure can be explicitly integrated. We investigate the nakedness and curvature strength of the shell-focusing singularity in that space-time. If the singularity is naked, the relation between the circumferential radius and the Misner-Sha

C. S. Kim, Jake Lee, W. Namgung

Direct CP violations in $B_{l4}$ decays ($B^\pm \to π^+π^- l^\pm ν_l$) are investigated within the Standard Model (SM) and also in its extensions. In the decay processes, we include various excited states as intermediate states decaying to the final hadrons, $π^+ + π^-$. The CP violation within the SM is induced by the interferences between intermediate reso

S. E. Konstein

The superalgebra of observables of the rational Calogero model based on the root system R is the associative superalgebra generated by polynomials in N indeterminates, the differential-difference Dunkl's operators and the group algebra of the Coxeter group G generated by the root system R. It is shown that this superalgebra possesses Q_R supertraces, whe

Jens Schmalzing, Thomas Buchert, Adrian L. Melott, Varun Sahni

We apply Minkowski functionals and various derived measures to decipher the morphological properties of large-scale structure seen in simulations of gravitational evolution. Minkowski functionals of isodensity contours serve as tools to test global properties of the density field. Furthermore, we identify coherent objects at various threshold levels and calc

Debbie W. Leung, Isaac L. Chuang, Fumiko Yamaguchi, Yoshihisa Yamamoto

We present an efficient scheme which couples any designated pair of spins in heteronuclear spin systems. The scheme is based on the existence of Hadamard matrices. For a system of $n$ spins with pairwise coupling, the scheme concatenates $cn$ intervals of system evolution and uses at most $c n^2$ pulses where $c \approx 1$. Our results demonstrate that, in m

M. J. Werner

For the first time a method for realizing macroscopic quantum optical solitons is presented. Simultaneous photon-number and momentum squeezing is predicted using soliton propagation in an interferometer. Extraction of soliton pulses closer to true quantum solitons than their coherent counterparts from mode-locked lasers is possible. Moreover, it is a general

A. M. Steinberg

We are in the process of building an experiment to study the tunneling of laser-cooled Rubidium atoms through an optical barrier. A particularly thorny set of questions arises when one considers the possibility of observing a tunneling particle while it is in the ``forbidden'' region. In earlier work, we have discussed how one might probe a tunneling

C. Brif, A. Mann

We propose a feasible experimental scheme, employing methods of population spectroscopy with two-level atoms, for a test of Bell's inequality for massive particles. The correlation function measured in this scheme is the joint atomic $Q$ function. An inequality imposed by local realism is violated by any entangled state of a pair of atoms.

Stefan Weigert

To reconstruct a mixed or pure quantum state of a spin s is possible through coherent states: its density matrix is fixed by the probabilities to measure the value s along 4s(s+1) appropriately chosen directions in space. Thus, after inverting the experimental data, the statistical operator is parametrized entirely by expectation values. On this basis, a sym

Sameen Ahmed Khan, Modesto Pusterla

An interpretation of the ``halo puzzle'' in accelerators based on quantum-like diffraction is given. Comparison between this approach and the others based on classical mechanics equations is exhibited.

Sameen Ahmed Khan

Present understanding of accelerator optics is based mainly on classical mechanics and electrodynamics. In recent years quantum theory of charged-particle beam optics has been under development. In this paper the newly developed formalism is outlined.

I. V. Schweigert, V. A. Schweigert, F. M. Peeters

The melting transition of the five different lattices of a bilayer crystal is studied using the Monte-Carlo technique. We found the surprising result that the square lattice has a substantial larger melting temperature as compared to the other lattice structures, which is a consequence of the specific topology of the temperature induced defects. A new meltin

Chi-Keung Chow, Thomas D. Cohen

The probability distribution in $R$, the proportion of neutral pions to all pions emitted in heavy ion collisions in certain kinematic regions, has been suggested as a signal of a disoriented chiral condensate (D$χ$C). Here we note that the signature can be greatly enhanced by making suitable cuts in the data. In particular, we consider reducing the data set

W. D. Heiss, R. G. Nazmitdinov, R. A. Lynch

Manifestations of pronounced shell effects are discovered when adding nonaxial octupole deformations to a harmonic oscillator model. The degeneracies of the quantum spectra are in a good agreement with the corresponding main periodic orbits and winding number ratios which are found by classical analysis.

S. S. Kamalov, Shin Nan Yang

Recent experiment indicates that the behavior exhibited by the ratios $E_{1^+}/M_{1^+}$ and $S_{1^+}/M_{1^+}$ of the $γ^* N \leftrightarrow Δ$ transition remain small and negative for $Q^2 \le 4.0 GeV^2$. It implies that the perturbative QCD is still not applicable at these momentum transfers. We show that these data can be explained in a dynamical model for

T. C. Dorlas, N. Macris, J. V. Pulé

We consider a random Schrodinger operator in an external magnetic field. The random potential consists of delta functions of random strengths situated on the sites of a regular two-dimensional lattice. We characterize the spectrum in the lowest N Landau bands of this random Hamiltonian when the magnetic field is sufficiently strong, depending on N. We show t

Ralph L. Cohen, John D. S. Jones, Graeme B. Segal

In this paper we study the question of when does a closed, simply connected, integral symplectic manifold (W,omega) have the stability property for its spaces of based holomorphic spheres? This property states that in a stable limit under certain gluing operators, the space of based holomorphic maps from a sphere to X, becomes homotopy equivalent to the spac

Piotr Minc

By a Knaster continuum we understand the inverse limit of copies of [0,1] with open bonding maps. We prove that for any two Knaster continua K_1 and K_2, there are 2^\aleph_0 distinct homotopy types of maps of K_1 onto K_2 that map the endpoint of K_1 to the endpoint of K_2.

János Kollár

Let H be the supremum of finitely many real polynomials of degree d and assume that H has a strict local minimum at 0. We prove a Łojasiewicz-type inequality $H(x_1,...,x_n) > ||(x_1,...,x_n)||^s$ where s depends only on d and n. This implies a similar inequality where $(x_1,...,x_n)$ runs through the points of a semi-algebraic set.

Philip Boyland

This paper investigates dynamics that persist under isotopy in classes of orientation-preserving homeomorphisms of orientable surfaces. The persistence of periodic points with respect to periodic and strong Nielsen equivalence is studied. The existence of a dynamically minimal representative with respect to these relations is proved and necessary and suffici

Gottfried Barthel, Jean-Paul Brasselet, Karl-Heinz Fieseler, Ludger Kaup

We investigate the equivariant intersection cohomology of a toric variety. Considering the defining fan of the variety as a finite topological space with the subfans being the open sets (that corresponds to the "toric" topology given by the invariant open subsets), equivariant intersection cohomology provides a sheaf (of graded modules over a sheaf o

S. Gustafson, I. M. Sigal

We study the linearized stability of n-vortex solutions of the magnetic Ginzburg-Landau (or Abelian-Higgs) equations. We prove that the fundamental vortices (n=1,-1) are stable for all values of the coupling constant, k, and we prove that the higher-degree vortices (|n| > 1) are stable for k < 1 and unstable for k > 1. This resolves a long-standing conjectur

Andreas Defant, Carsten Michels

We prove an abstract interpolation theorem which interpolates the (r,2)-summing and (s,2)-mixing norm of a fixed operator in the image and the range space. Combined with interpolation formulas for spaces of operators we obtain as an application the original Bennett-Carl inequalities for identities acting between Minkowski spaces l_u as well as their analogue

A. Panov

The article is devoted to the problem of classification of Manin triples up to weak and gauge equivalence. The case of complex simple Lie algebras can be obtained by the papers of A.Belavin, V.Drinfel&#39;d, M.Semenov-Tian-Shanskii. Studing the action of conjugation on complex Manin triples, we get the list of real doubles. We classify all $ad$-invariant for

N. Askitas

A formula for the difference of Vassiliev invariants of degree k+1 of two knots all of whose Vassiliev invariants of degree k agree is proven. The proof uses K. Habiro&#39;s C-moves and his theorem which relates them to Vassiliev invariants.

Andrew Chamblin, Roberto Emparan, Clifford V. Johnson, Robert C. Myers

The physical properties of Reissner-Nordstrom black holes in (n+1)-dimensional anti-de Sitter spacetime are related, by a holographic map, to the physics of a class of n-dimensional field theories coupled to a background global current. Motivated by that fact, and the recent observations of the striking similarity between the thermodynamic phase structure of

A. T. Suzuki, A. G. M. Schmidt

The well-known $D$-dimensional Feynman integrals were shown, by Halliday and Ricotta, to be capable of undergoing analytic continuation into the domain of negative values for the dimension of space-time. Furthermore, this could be identified with Grassmannian integration in positive dimensions. From this possibility follows the concept of negative dimensiona

Neil Russell

Possibilities for observing signals of CPT and Lorentz violation in the spectroscopy of hydrogen and antihydrogen are considered. We show that transitions between the c and d hyperfine sublevels in the 1S state can exhibit theoretically detectable effects that would be unsuppressed by powers of the fine-structure constant. This transition may therefore offer

F. Donato, N. Fornengo, P. Salati

Once the energy spectrum of the secondary component is well understood, measurements of the antiproton cosmic-ray flux at the Earth will be a powerful way to indirectly probe for the existence of supersymmetric relics in the galactic halo. Unfortunately, it is still spoilt by considerable theoretical uncertainties. As shown in this work, searches for low-ene

Robert N. Cahn, Mihir P. Worah

We discuss the usefulness of the CP violating semi-leptonic asymmetry a_{SL} not only as a signal of new physics, but also as a tool in constraining the CKM parameters. We show that this technique could yield useful results in the first years of running at the B factories. We present the analysis graphically in terms of M_{12}, the dispersive part of the B-B

Andrzej Czarnecki, Kirill Melnikov, Alexander Yelkhovsky

Recent results on second order quantum corrections to semileptonic decays of b quarks and positronium spectroscopy are reviewed. Similarities between calculations in these seemingly different problems are demonstrated. Technical aspects of solving systems of recurrence relations, and application of dimensional regularization to bound states are explained.

S. P. Klevansky, R. H. Lemmer, C. Wilmot

The Das-Mathur-Okubo (DMO) sum rule for the polarizability of charged pions is evaluated for the Nambu-Jona-Lasinio model Lagrangian in both its minimal and extended forms. A comparison is made with the results obtained using the same sum rule from chiral perturbation theory (CHPT), approximate QCD sum rule calculations, explicit calculations on the lattice

J. Bernabeu

The manifestation of CP, T violation in the leptonic sector is studied for flavour neutrino oscillations, both in vacuum and in matter. Different conditions of short-base-line versus long-base-line experiments are discussed.

Galit Eyal, Yosef Nir

We investigate supersymmetric models where neither R-parity nor lepton number nor baryon number is imposed. The full high energy theory has an exact horizontal U(1) symmetry that is spontaneously broken. Quarks and Higgs fields carry integer horizontal charges but leptons carry half integer charges. Consequently, the effective low energy theory has two speci

Chao-hsi Chang, Cai-Dian Lu, Guo-Li Wang, Hong-Shi Zong

The radiative corrections to the pure leptonic decay $B_c \to \ellν_{\ell}$ up-to one-loop order is presented. How to cancel the infrared divergences appearing in the loop calculations, and the radiative decay $B_c \to \ellν_{\ell}γ$ is shown precisely. It is emphasized that the radiative decay may be separated properly and may compare with measurements dire

H. Arodź, H. -J. Pirner

Small momenta limit of the lattice color dielectric model in the SU(3)_c case is considered. We show that in that limit the model involves a coarse-grained gluon field, a color singlet &#34;bleached gluon&#34; field, and both color singlet and octet rank two symmetric tensor fields constructed from the first order derivatives of a vector field. In contradist

Craig McNeile

I review the results from lattice gauge theory for the masses of exotic hybrid mesons.

MACRO Collaboration

In this paper we present the results of a search for nuclearites in the penetrating cosmic radiation using the scintillator and track-etch subdetectors of the MACRO apparatus. The analyses cover the beta =v/c range at the detector depth (3700 hg/cm^2) 10^-5 < beta < 1; for beta = 2 x 10^-3 the flux limit is 2.7 x 10^-16 cm^-2 s^-1 sr^-1 for an isotropic flux

V. A. Maisheev

Problems of the experimental observation of the birefringence of high-energy gamma-quanta propagating in single crystals are discussed.

Jeongwon Ho, Sungjoon Kim, Bum-Hoon Lee

We make analytic derivation for maximum masses of stable boson stars formed by scalar fields with any higher order self-interactions and show that those are equivalent to numerical results. It is shown that the contribution of the higher order self-interaction terms to the maximum mass decreases as $(m/M_p)^2$ power.

Chun-Chung Chen, Hyunggyu Park, Marcel den Nijs

The width W of the active region around an active moving wall in a directed percolation process diverges at the percolation threshold p_c as W \simeq A ε^{-ν_\parallel} \ln(ε_0/ε), with ε=p_c-p, ε_0 a constant, and ν_\parallel=1.734 the critical exponent of the characteristic time needed to reach the stationary state ξ_\parallel \sim ε^{-ν_\parallel}. The lo

C. S. O&#39;Hern, T. C. Lubensky, J. Toner

We predict the existence of a totally new class of phases in weakly coupled, three-dimensional stacks of two-dimensional (2D) XY-models. These ``sliding phases&#39;&#39; behave essentially like decoupled, independent 2D XY-models with precisely zero free energy cost associated with rotating spins in one layer relative to those in neighboring layers. As a res

E. Overbeck, Ch. Sinn, M. Watzlawek

Theoretical calculations for colloidal charge-stabilized and hard sphere suspensions show that hydrodynamic interactions yield a qualitatively different particle concentration dependence of the short-time self-diffusion coefficient. The effect, however, is numerically small and hardly accessible by conventional light scattering experiments. Applying multiple

Alain Rochefort, Phaedon Avouris

We have evaluated the energies required to twist carbon nanotubes (NTs), and investigated the effects of these distortions on their electronic structure and electrical properties. The computed distortion energies are high, indicating that it is unlikely that extensive twisting is the result of thermal excitation. Twisting strongly affects the electronic stru

D. Guery-Odelin, F. Zambelli, J. Dalibard, S. Stringari

Starting from the Boltzmann equation we calculate the frequency and the damping of the monopole and quadrupole oscillations of a classical gas confined in an harmonic potential. The collisional term is treated in the relaxation time approximation and a gaussian ansatz is used for its evaluation. Our approach provides an explicit description of the transition

M. Hasenbusch, T. Toeroek

We present a Monte Carlo study of the two-component $ϕ^4$ model on the simple cubic lattice in three dimensions. By suitable tuning of the coupling constant $λ$ we eliminate leading order corrections to scaling. High statistics simulations using finite size scaling techniques yield $ν=0.6723(3)[8]$ and $η=0.0381(2)[2]$, where the statistical and systematical

M. L. Kulić, O. V. Dolgov

Physical properties of anisotropic superconductors like the critical temperature and others depend sensitively on the electron mean free path. The sensitivity to impurity scattering and the resulting anomalies are considered a characteristic feature of strongly anisotropic pairing. These anomalies are usually analyzed in terms of s-wave impurity scattering w

D. A. Gorokhov, G. Blatter

We study the elastic (1+1)-dimensional string subject to a random gaussian potential on scales smaller than the correlation radius of the disorder potential (Larkin problem). We present an exact calculation of the probability function ${\cal P} [F(u,L)]$ for the free energy $F$ of a string starting at $(0,0)$ and ending at $(u,L)$. The function ${\cal P}(F)$

X. H. Chen, Z. S. Liu, S. Y. Li, H. C. Dam

A novel fulleride Sm6C60 has been synthesized using high temperature solid state reaction. The Rietveld refinement on high resolution synchrotron X-ray powder diffraction data shows that Sm6C60 is isostructural with body-centered cubic A6C60 (A=K, Ba). Raman spectrum of Sm6C60 is similar to that of Ba6C60, and the frequencies of two Ag modes in Sm6C60 are ne

X. H. Chen, T. Takenobu, T. Muro, H. Fudo

Raman shift dependence of charge transfer is studied in the two fulleride families of AxBa3C60 (x=0,3; A=K,Rb) and KxSm2.75C60 (x=0,3.25). It is found that the Raman spectra are essentially identical to each other for all ternary fullerides, The results show a crossover point at the boundary of t1u and t1g bands for the Raman shift dependence of charge trans

X. H. Chen, S. Taga, Y. Iwasa

Raman spectra are reported for Ba doped fullerides, BaxC60(x=3,4,and 6). The lowest frequency Hg modes split into five components for Ba4C60 and Ba6C60 even at room temperature, allowing us a quantitative analysis based on the electron-phonon couping theory. For the superconducting Ba4C60, the density of states at the Fermi energy was derived as 7 eV-1, whil

Mai Suan Li

A three-dimensional lattice of the Josephson junctions with a finite self-conductance is employed to model the ceramic superconductors. The nonlinear ac susceptibility and the compensation effect are studied by Monte Carlo simulations in this model. The compensation effect is shown to be due to the existence of the chiral glass phase. We demonstrate, in agre

Yoshihiro Asai, Hideki Katagiri

We have studied electron correlations in the doped two-dimensional (2D) Hubbard model by using the coupled-cluster method (CCM) to investigate whether or not the method can be applied to correct the independent particle approximations actually used in ab-initio band calculations. The double excitation version of the CCM, implemented using the approximate cou

Bruno Eckhardt, Alois Mersmann

We analyze the properties of a 19 dimensional Galerkin approximation to a parallel shear flow. The laminar flow with a sinusoidal shape is stable for all Reynolds numbers Re. For sufficiently large Re additional stationary flows occur; they are all unstable. The lifetimes of finite amplitude perturbations show a fractal dependence on amplitude and Reynolds n

Katherine Freese, Brian Fields, David Graff

The nature of the dark matter in the Halo of our Galaxy remains a mystery. Arguments are presented that the dark matter does not consist of ordinary stellar or substellar objects, i.e., the dark matter is not made of faint stars, brown dwarfs, white dwarfs, or neutron stars. In fact, faint stars and brown dwarfs constitute no more than a few percent of the m

Luis A. Anchordoqui, G. E. Romero, Diego F. Torres, I. Andruchow

We have investigated 631 time profiles of gamma ray bursts from the BATSE database searching for observable signatures produced by microlensing events related to natural wormholes. The results of this first search of topologically nontrivial objects in the Universe can be used to constrain their number and mass.

P. J. E. Peebles, A. Vilenkin

Since an acceptable dark matter candidate may interact only weakly with ordinary matter and radiation, it is of interest to consider the limiting case where the dark matter interacts only with gravity and itself, the matter originating by the gravitational particle production at the end of inflation. We use the bounds on the present dark mass density and the

Reza Tavakol, Eurico Covas

We briefly discuss the status of the intermittency hypothesis, according to which the grand minima type variability in solar-type stars may be understood in terms of dynamical intermittency. We review concrete examples which establish this hypothesis in the mean-field setting. We discuss some difficulties and open problems regarding the establishment of this

L. Sidoli, S. Mereghetti, G. L. Israel, L. Chiappetti

We report the results of a survey of the Galactic Center region (|l| < 2deg, |b| < 0.5deg) performed with the BeppoSAX satellite. The flux from the center of our Galaxy corresponds to a luminosity of ~3 10^{35} erg/s in the 2-10 keV range. Due to the limited angular resolution ($\gsim 1&#39;$) only part of it is supposed to come from Sagittarius A*, the non-

Eric C. Ford

Numerous X-ray bursts show strong oscillations in their flux at several hundred Hz as revealed by RXTE. Analyzing one such oscillation from the X-ray binary Aql X-1, I find that low energy photons (3.5-5.7 keV) lag high energy photons (>5.7 keV) by approximately 1 radian. The oscillations are thought to be produced by hot spots on the spinning neutron star.

A. Saha, A. Sandage, G. A. Tammann, L. Labhardt

(Abridged) Repeated imaging observations have been made of NGC 3627 with the HST in 1997/98, over an interval of 58 days. Images were obtained on 12 epochs in the F555W band and on five epochs in the F814W band. The galaxy hosted the prototypical, `Branch normal&#39;, type Ia supernova SN 1989B. A total of 83 variables have been found, of which 68 are defini

Alistair R. Walker

We present a deep color magnitude diagram for the galactic globular cluster NGC 2808 (C0911-646), reaching 3 magnitudes below the main sequence turnoff. A set of local photometric standards are provided, and the mean cluster reddening and metallicity are constrained using several photometric techniques. The unusual horizontal branch morphology discovered by

Yutaka Fujita, Motokazu Takizawa, Masahiro Nagashima, Motohiro Enoki

We have investigated the effect of pressure from intracluster medium (ICM) on disk galaxies in merging clusters. The ram-pressure on the galaxies rapidly increases when two clusters collide. This leads to stripping of the interstellar medium (ISM) and decrease of star formation rate (SFR) of the galaxies. On the other hand, the increase of SFR caused by comp

D. Martinez-Delgado, A. Aparicio

Ursa Minor (UMi) is one of the closest satellites of the Milky Way (d=69 kpc). It is possibly a disrupted dSph interacting with the external Galactic halo. This makes its study quite necessary in the forementioned context. In this paper we present preliminary results of a wide field photometry survey of UMi and discuss the presence of an intermediate-age pop

E. C. Moran, A. V. Filippenko, L. C. Ho, J. C. Shields

We present X-ray (ROSAT), infrared, and radio observations of NGC 4395, which harbors the optically least luminous type 1 Seyfert nucleus discovered thus far. In combination with published optical and ultraviolet spectra, we have used these data to assemble the broadband spectral energy distribution (SED) of the galaxy&#39;s nucleus. Interestingly, the SED o

J. Williams, R. Walser, J. Cooper, E. A. Cornell

Two internal hyperfine states of a Bose-Einstein condensate in a dilute magnetically trapped gas of ${}^{87}$Rb atoms are strongly coupled by an external field that drives Rabi oscillations between the internal states. Due to their different magnetic moments and the force of gravity, the trapping potentials for the two states are offset along the vertical ax

D. E. Gonzalez Trotter, F. Salinas, Q. Chen, A. S. Crowell

The present paper reports high-accuracy cross-section data for the 2H(n,nnp) reaction in the neutron-proton (np) and neutron-neutron (nn) final-state-interaction (FSI) regions at an incident mean neutron energy of 13.0 MeV. These data were analyzed with rigorous three-nucleon calculations to determine the 1S0 np and nn scattering lengths, a_np and a_nn. Our

Abrecht Karle

A first analysis of the AMANDA-B 10-string array data is presented. A total of 113 days of data from its first year of operation in 1997 have been analyzed. High energy neutrinos generate upward moving muons. Cosmic ray muons penetrating the ice sheet to a depth of 2000 m are the major source of background. We discuss the method used to reject the background

Dirk Kreimer, Eckehard W. Mielke

In Riemann-Cartan spacetimes with torsion only its axial covector piece $A$ couples to massive Dirac fields. Using renormalization group arguments, we show that besides the familiar Riemannian term only the Pontrjagin type four-form $dA\wedge dA$ does arise additionally in the chiral anomaly, but not the Nieh-Yan term $d^\star A$, as has been claimed in a re

W. C. Chang

Strangeness production in Au+Au collisions has been measured via the yields of K+ and K- at 6, 8 AGeV and of anti-Lambda at 10.8 AGeV beam kinetic energy in experiment E917. By varying the collision centrality and beam energy, a systematic search for indications of new phenomena and in-medium effects under high baryon density is undertaken.

James Propp

This document is built around a list of thirty-two problems in enumeration of matchings, the first twenty of which were presented in a lecture at MSRI in the fall of 1996. I begin with a capsule history of the topic of enumeration of matchings. The twenty original problems, with commentary, comprise the bulk of the article. I give an account of the progress

A. H. Hoang, T. Teubner

The complete NNLO QCD corrections to the total cross section $σ(e^+e^- \to Z*,γ*\to t\bar t)$ in the kinematic region close to the top-antitop threshold are calculated by solving the corresponding Schroedinger equations exactly in momentum space in a consistent momentum cutoff regularization scheme. The corrections coming from the same NNLO QCD effects to th

J. V. Pulé, M. Scrowston

We consider a single band approximation to the random Schroedinger operator in an external magnetic field. The spectrum of such an operator has been characterized in the case where delta impurities are located on the sites of a lattice. In this paper we generalize these results by letting the delta impurites have random positions as well as strengths; they a

D. Challet, M. Marsili, R. Zecchina

We study analytically a simple game theoretical model of heterogeneous interacting agents. We show that the stationary state of the system is described by the ground state of a disordered spin model which is exactly solvable within the simple replica symmetric ansatz. Such a stationary state differs from the Nash equilibrium where each agent maximizes her ow

A. Kaminski, J. Mesot, H. Fretwell, J. C. Campuzano

Recent improvements in momentum resolution by a factor of 32 lead to qualitatively new ARPES results on the spectra of Bi2Sr2CaCu2O8 (Bi2212) along the (pi,pi) direction, where there is a node in the superconducting gap. With improved resolution, we now see the intrinsic lineshape, which indicates the presence of true quasiparticles at the Fermi momentum in

Konstadinos Sfetsos

We construct a new class of two-dimensional field theories with target spaces that are finite multiparameter deformations of the usual coset G/H-spaces. They arise naturally, when certain models, related by Poisson-Lie T-duality, develop a local gauge invariance at specific points of their classical moduli space. We show that canonical equivalences in this c

V. Latora, A. Rapisarda, S. Ruffo

We study the link between relaxation to the equilibrium and anomalous superdiffusive motion in a classical N-body hamiltonian system with long-range interaction showing a second-order phase-transition in the canonical ensemble. Anomalous diffusion is observed only in a transient out-of-equilibrium regime and for a small range of energy, below the critical on

Dileep P. Jatkar, S. Randjbar-Daemi

We study \kk spectrum of type IIB string theory compactified on $AdS_5 \times T^{nn&#39;}$ in the context of $AdS/CFT$ correspondence. We examine some of the modes of the complexified 2 form potential as an example and show that for the states at the bottom of the \kk tower the corresponding $d=4$ boundary field operators have rational conformal dimensions.

Bum-Hoon Lee, Hyuk-jae Lee, Nobuyoshi Ohta, Hyun Seok Yang

We study various three-dimensional supersymmetric Maxwell Chern-Simons solitons by using type IIB brane configurations. We give a systematic classification of soliton spectra such as topological BPS vortices and nontopological vortices in $\mathcal{N}=2,3$ supersymmetric Maxwell Chern-Simons system via the branes of type IIB string theory. We identify the br

V. Yu. Irkhin, M. I. Katsnelson

The longitudinal and transverse nuclear magnetic relaxation rates $1/T_1(T)$ and $1/T_2(T)$ are calculated for three- and two-dimensional (3D and 2D) metallic ferro- and antiferromagnets (FM and AFM) with localized magnetic moments in the spin-wave temperature region. The contribution of the one-magnon decay processes is strongly enhanced in comparison with

S. J. Childs

In this work the issue of whether key energetic properties (nonlinear, exponential-type dissipation in the abscence of forcing and long-term stability under conditions of time dependent loading) are automatically inherited by deforming reference descriptions is resolved. These properties are intrinsic to real flows and the conventional Navier-Stokes equation

H. Hofmann, F. A. Ivanyuk

Numerical computations of transport coefficients at low temperatures are presented for shapes typically encountered in nuclear fission. The influence of quantum effects of the nucleonic degrees of freedom is examined, with pair correlations included. Consequences for global collective motion are studied for the case of the decay rate. The range of temperatur

Chao-Hsi Chang, Yi-Bing Ding, Xue-Qian Li, Sheng Ping Tong

To further investigate the applicability of the projection scheme for eliminating the unphysical divergence $s/m_e^2$ due to U(1) gauge invariance violation, we study the process $e^-+W^+\to e^-+\bar t+b$ which possesses advantages of simplicity and clearness. Our study indicates that the projection scheme can indeed eliminate the unphysical divergence $s/m_

Amri Wandel

The masses of the central black holes in Active Galactic Nuclei (AGNs) can be estimated using the broad emission-lines as a probe of the virial mass. Using reverberation mapping to determine the size of the Broad Line Region (BLR) and the width of the variable component of the line profile H$β$ line it is possible to find quite accurate virial mass estimates

E. Harikumar, M. Sivakumar

We start with a new first order gauge non-invariant formulation of massive spin-one theory and map it to a reducible gauge theory viz; abelian $B{\wedge}F$ theory by the Hamiltonian embedding procedure of Batalin, Fradkin and Tyutin(BFT). This equivalence is shown from the equations of motion of the embedded Hamiltonian. We also demonstrate that the original

L. Ya. Glozman

It is shown that the principal pattern in baryon spectroscopy, which is associated with the flavor-spin dependent hyperfine interaction, is due to the spontaneous breaking of chiral symmetry in QCD and persists in the chiral limit. All corrections, which are associated with a finite quark (Goldstone boson) mass are suppressed by the factor $(μ/Λ_χ$)^2 and hi

J. Froehlich, G. M. Graf, D. Hasler, J. Hoppe

We derive the power law decay, and asymptotic form, of SU(2) x Spin(d) invariant wave-functions which are zero-modes of all s_d=2(d-1) supercharges of reduced (d+1)-dimensional supersymmetric SU(2) Yang Mills theory, resp. of the SU(2)-matrix model related to supermembranes in d+2 dimensions.

M. Frank, H. Hamidian, K. Puolamaki

We investigate a large class of supersymmetric SO(10) grand unified theories within the framework of gauge-mediated supersymmetry breaking. We start with the most general messenger sector and imbedd the standard model gauge group into either SU(2)_L X SU(2)_R X U(1)_{B-L} or SU(2)_L X U(1)_{I_{3R}} X U(1)_{B-L}. We find that the conditions of the perturbativ

M. Adler, E. Horozov, P. van Moerbeke

Consider a semi-infinite skew-symmetric moment matrix, $m_{\iy}$ evolving according to the vector fields $\pl m / \pl t_k=\Lb^k m+m \Lb^{\top k} ,$ where $\Lb$ is the shift matrix. Then the skew-Borel decomposition $ m_{\iy}:= Q^{-1} J Q^{\top -1} $ leads to the so-called Pfaff Lattice, which is integrable, by virtue of the AKS theorem, for a splitting invol

Pawel Horodecki, Michal Horodecki, Ryszard Horodecki

We define the binding entanglement channel as the quantum channel through which quantum information cannot be reliably transmitted, but which can be used to share bound entanglement. We provide a characterization of such class of channels. We also show that any bound entangled state can be used to construction of the map corresponding the binding entanglemen

Hoi-Kwong Lo

Quantum key distribution is the most well-known application of quantum cryptography. Previous proposed proofs of security of quantum key distribution contain various technical subtleties. Here, a conceptually simpler proof of security of quantum key distribution is presented. The new insight is the invariance of the error rate of a teleportation channel: We

Boris F. Samsonov

Darboux transformation operators that produce multisoliton potentials are analyzed as operators acting in a Hilbert space. Isometric correspondence between Hilbert spaces of states of a free particle and a particle moving in a soliton potential is established. It is shown that the Darboux transformation operator is unbounded but closed and can not realize an

K. Banaszek, C. Radzewicz, K. Wodkiewicz, J. S. Krasinski

We present an experimental realisation of the direct scheme for measuring the Wigner function of a single quantized light mode. In this method, the Wigner function is determined as the expectation value of the photon number parity operator for the phase space displaced quantum state.

B. G. Sidharth

It is shown in this paper that recent results that below the Fermi temperature, Fermions obey anomalous semionic statistics, could explain such apparently diverse phenomena as the magnetism of Pulsars and White Dwarfs on the one hand and earth like planets, on the other.

Valery P. Dmitriyev

An exact analogy of electromagnetic fields and particles can be found in mechanics of a turbulent ideal fluid with voids. The system is supposed to form a fine dispersion of voids in the fluid. This microscopically discontinuous medium is treated as a continuum. The turbulence is described in terms of the Reynolds stresses. Perturbations of the homogeneous i

S. S. Dimitrova, D. N. Kadrev, A. N. Antonov, M. V. Stoitsov

The two-body density matrix for $^{4}He,^{16}O$ and $^{40}Ca$ within the Low-order approximation of the Jastrow correlation method is considered. Closed analytical expressions for the two-body density matrix, the center of mass and relative local densities and momentum distributions are presented. The effects of the short-range correlations on the two-body n

J. Delorme, M. Ericson, P. A. M. Guichon, A. W. Thomas

Chiral symmetry restoration in a dense medium is to some extent a consequence of the nuclear pion cloud. These pions induce a mixing of the axial and vector current contributions in the axial and vector correlators. We discuss their influence on hadron masses and investigate the signal produced by the remaining contribution associated with chiral symmetry re

Raja Ramanna

In an earlier work, several properties of fundamental particles were brought together by a simple equation based on continuity and discreteness. It is shown here, that the maximum modes of decay of all fundamental particles can also be predicted without any arbitrary parameters. The method used is to break up the mean lifetimes of particles to obtain the max