August 1999 arXiv papers — page 9

A. Schaefer, O. V. Teryaev

The conservation of the intrinsic transverse momentum during parton fragmentation imposes non-trivial constraints on T-odd fragmentation functions. These significantly enhance the differences between the favoured and unfavoured fragmentation functions, which could be relevant to understand the azimuthal asymmetries of charged pion production observed recentl

Masayuki Yamagami, Kenichi Matsuyanagi

High-spin yrast structure of 32S is investigated by means of the cranked Skyrme-Hartree-Fock method in the three-dimensional Cartesian-mesh representation without imposing restrictions on spatial symmetries. The result suggests that 1) a crossover from the superdeformed to the hyperdeformed-like configurations takes place on the yrast line at angular momentu

Oren Bergman, Matthias R Gaberdiel

A brief introduction to the boundary state approach to Dirichlet branes is given. The example of the non-BPS D-string of Type IIA on K3 is analysed in some detail, and its dual heterotic state is identified.

Daniel A. Lidar, Dave Bacon, Julia Kempe, K. B. Whaley

Coherence in an open quantum system is degraded through its interaction with a bath. This decoherence can be avoided by restricting the dynamics of the system to special decoherence-free subspaces. These subspaces are usually constructed under the assumption of spatially symmetric system-bath coupling. Here we show that decoherence-free subspaces may appear

E. Gava, K. S. Narain, M. H. Sarmadi

We study, using ADHM construction, instanton effects in an ${\CN}=2$ superconformal $Sp(N)$ gauge theory, arising as effective field theory on a system of $N$ D-3-branes near an orientifold 7-plane and 8 D-7-branes in type I' string theory. We work out the measure for the collective coordinates of multi-instantons in the gauge theory and compare with the

Emanuel Knill, Raymond Laflamme, Lorenza Viola

Quantum error correction protects quantum information against environmental noise. When using qubits, a measure of quality of a code is the maximum number of errors that it is able to correct. We show that a suitable notion of ``number of errors'' e makes sense for any system in the presence of arbitrary environmental interactions. In fact, the notio

M. Drndic, G. Zabow, C. S. Lee, J. H. Thywissen

Cryogenically cooled microelectromagnet mirrors were used to reflect a cloud of free-falling laser-cooled 85Rb atoms at normal incidence. The mirrors consisted of microfabricated current-carrying Au wires in a periodic serpentine pattern on a sapphire substrate. The fluorescence from the atomic cloud was imaged after it had bounced off a mirror. The transver

Dmitry V. Skryabin

General asymptotic approach to the stability problem of multi-parameter solitons in Hamiltonian systems $i\partial E_n/\partial z=δH/δE_n^*$ has been developed. It has been shown that asymptotic study of the soliton stability can be reduced to the calculation of a certain sequence of the determinants, where the famous determinant of the matrix consisting fro

R. Higa, M. R. Robilotta

The exchange of a single pion does not contribute to $Nα$ scattering, due to the isoscalar nature of the target. Therefore peripheral $Nα$ scattering may be used to probe existing models for the two-pion exchange component of the $NN$ potential. In a recent work we have considered this possibility using an effective $Nα$ interaction based on two-body forces

F. C. Khanna, A. M. Rakhimov, U. T. Yakhshiev

In this paper the dependence of meson-nucleon-nucleon vertex form factors is studied as a function of termperature. The results are obtained starting from a zero temperature Bonn potential. The temperature dependence of the vertex form factors and radii is studied in the thermofield dynamics, a real-time operator formalism of finite temperature field theory.

Yu. E. Titarenko, O. V. Shvedov, V. F. Batyaev, E. I. Karpikhin

The results of measurements and computer simulations are presented for the yields of residual product nuclei in thin targets: U-nat irradiated by 0.1, 0.8, 1.2, and 1.6 GeV and Tc-99 irradiated by 0.2, 0.8, 1.0, 1.4, and 1.6 GeV protons. The yields were measured at ITEP by direct high-precision gamma spectrometry. About 820 cross sections are presented and u

Silviu Olariu, Agata Olariu

We have calculated the incident photon power density P_2 for which the two-step induced emission rate from an isomeric nucleus becomes equal to the natural isomeric decay rate. We have analyzed two-step transitions for isomeric nuclei with a half-life greater than 10 min, for which there is an intermediate state of known energy, spin and half-life, for which

I. V. Popescu, T. Badica, Agata Olariu, Olga Guguianu

Aerosols deposits on filters from ten Romanian towns with different kinds and levels of industrial development have been studied. The concentration of elements with Z~16 have been measured by particle - induced X-ray emission (PIXE) analysis. It has been determined 15 elements: S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Hg and Pb.

Silviu Olariu, Agata Olariu

We study the possibility to influence the lifetime of nuclear isomeric states with the aid of incident fluxes of photons. We assume that a nucleus initially in an isomeric state |i> first absorbs an incident photon of energy E_{ni} to reach a higher intermediate state |n>, then the state |n> decays to a lower state |l>. In favorable cases the two-step induce

Agata Olariu, Mioara Constantinescu, O. Constantinescu, T. Badica

Radiochemical neutron activation analysis has been applied to investigate the microelements in gold samples with archaeological importance. Chemical separation has allowed the determination of traces of Ir, Os, Sb, Zn, Co, Fe, Ni. Instrumental neutron activation analysis has been used for the determination of Cu.

Oscar Bolina, Pierluigi Contucci, Bruno Nachtergaele, Shannon Starr

We show that the ground states of the three-dimensional XXZ Heisenberg ferromagnet with a 111 interface have excitations localized in a subvolume of linear size R with energies bounded by O(1/R^2). As part of the proof we show the equivalence of ensembles for the 111 interface states in the following sense: In the thermodynamic limit the states with fixed ma

Haisheng Li

In this paper, given a module $W$ for a vertex operator algebra $V$ and a nonzero complex number $z$ we construct a canonical (weak) $V\otimes V$-module ${\cal{D}}_{P(z)}(W)$ (a subspace of $W^{*}$ depending on $z$). We prove that for $V$-modules $W, W_{1}$ and $W_{2}$, a $P(z)$-intertwining map of type ${W'\choose W_{1}W_{2}}$ ([H3], [HL0-3]) exactly am

David B. Massey

Throughout our work on the Lê cycles of an affine hypersurface singularity, our primary algebraic tool consisted of a method for taking the Jacobian ideal of a complex analytic function and decomposing it into pure-dimensional "pieces". These pieces were obtained by considering the relative polar varieties of Lê and Teissier as gap sheaves. A gap she

Alexander Brudnyi

We prove local inequalities for analytic functions defined on a convex body in $\Re^{n}$ which generalize well-known classical inequalities for polynomials.

David B. Massey

We compare and contrast various notions of the "critical locus" of a complex analytic function on a singular space. After choosing a topological variant as our primary notion of the critical locus, we justify our choice by generalizing Lê and Saito's result that constant Milnor number implies that Thom's a_f condition is satisfied.

J. E. Marsden, T. S. Ratiu, S. Shkoller

We present a geometric analysis of the incompressible averaged Euler equations for an ideal inviscid fluid. We show that solutions of these equations are geodesics on the volume-preserving diffeomorphism group of a new weak right invariant pseudo metric. We prove that for precompact open subsets of ${\mathbb R}^n$, this system of PDEs with Dirichlet boundary

David B. Massey

We prove a derived category version of the Sebastiani-Thom Theorem, which describes the vanishing cycles of the sum of two functions of disjoint variables.

Marc A. A. van Leeuwen

An introduction is given to the Littlewood-Richardson rule, and various combinatorial constructions related to it. We present a proof based on tableau switching, dual equivalence, and coplactic operations. We conclude with a section relating these fairly modern techniques to earlier work on the Littlewood-Richardson rule.

Chiang-Mei Chen, Dmitri V. Gal'tsov, Sergei A. Sharakin

A non-local classical duality between the three-block truncated 11D supergravity and the 8D vacuum gravity with two commuting Killing symmetries is established. The supergravity four-form field is generated via an inverse dualisation of the corresponding Killing two-forms in six dimensions. 11D supersymmetry condition is shown to be equivalent to existence o

Chiang-Mei Chen, Dmitri V. Gal'tsov, Sergei A. Sharakin

New solution to the six-dimensional vacuum Einstein's equations is constructed as a non-linear superposition of two five-dimensional solutions representing the Melvin-Gibbons-Maeda Universe and its S-dual. Then using duality between D=8 vacuum and a certain class of D=11 supergravity configurations we generate M2 and M5 fluxbranes as well as some of thei

N. D. Lambert, P. C. West

We discuss the possibility that the electro-weak and strong interactions arise as the low energy effective description of branes in M-theory. As a step towards constructing such a model we show how one can naturally obtain SU(N_1)\times SU(N_2)\times U(1) gauge theories from branes, including matter in the bi-fundamental representation of SU(N_1)\times SU(N_

A. Chakrabarti, D. H. Tchrakian

Starting with the curvature 2-form a recursive construction of totally antisymmetrised 2p-forms is introduced, to which we refer as p-Riemann tensors. Contraction of indices permits a corresponding generalisation of the Ricci tensor. Static, spherically symmetric ``$p$-Ricci flat'' Schwarzschild like metrics are constructed in this context for d>2p+1

Brent H. Allen, Robert J. Perry

We calculate a renormalized Hamiltonian for pure-glue QCD and diagonalize it. The renormalization procedure is designed to produce a Hamiltonian that will yield physical states that rapidly converge in an expansion in free-particle Fock-space sectors. To make this possible, we use light-front field theory to isolate vacuum effects, and we place a smooth cuto

Mihir P. Worah

CP violation is a crucial component in the creation of the matter - anti matter asymmetry of the universe. An important open question is whether the CP violating phenomena observeable in terrestrial experiments have any relation with those responsible for baryogenesis. We discuss two mechanisms of baryogenesis where this question can be meaningfully posed: `

Mario E. Gomez

We discuss proton decay induced by dimension--5 operators in supersymmetric models containing extra hypercharge-1/3 color-triplets. We derive a general formula relating dimension-5 operator to the color-triplet mass matrix. We show that certain zeros in the triplet mass-matrix together with some triplet coupling selection rules can lead to elimination of dim

Hilmar Forkel

We discuss how hadronic bag models can be generalized in the framework of fuzzy set theory to implement effects of a smooth and extended phase boundary.

Martin Groves, Warren B. Perkins

We present a systematic determination of the order hbar fermionic energy shift when an electroweak string is perturbed. We show that the combined effect of zero modes, bound states and continuum states is to lower the total fermionic ground state energy of the string when the Higgs instability of the string is excited. The effect of the Dirac sea is thus to

A. Donnachie, H. G. Dosch, M. Rueter

The total hadronic gamma*gamma* cross sections at high energy are calculated as a function of energy and photon virtuality in a model combining Regge exchange, the quark box diagram (a fixed pole in Regge language) and soft and hard pomeron exchanges evaluated in the context of dipole-dipole scattering. Good agreement is obtained with the data for the real g

Jochen Bartels, Claas Bontus, Hubert Spiesberger

We consider diagrams with up to four t-channel gluons in order to specify gluonic twist-four contributions to deep inelastic structure functions. This enables us to extend the method developed by R.K.Ellis, W.Furmanski, and R.Petronzio (EFP) to the gluonic case. The method is based on low-order Feynman diagrams in combination with a dimensional analysis. It

S. I. Kruglov

We investigate the theory of particles with arbitrary spin and anomalous magnetic moment in the Lorentz representation (0,s)X(s,0), in an external constant and uniform electromagnetic field. We obtain the density matrix of free particles in pure spin states. The differential probability of pair producing particles with arbitrary spin by an external constant

E. Boos, H. -J. He, W. Kilian, A. Pukhov

Extending earlier investigations, we analyze the quasi-elastic scattering of strongly interacting electroweak bosons at high-energy e+-e- colliders. The three processes e+e- -> bar-nu nu W+W-, bar-nu nu ZZ, and e-e- -> W-W- are examined at a c.m. energy of 1 TeV for high-luminosity runs. The expected experimental error on the scattering amplitude, parameter-

Torbjörn Sjöstrand, Valery A. Khoze

Heavy objects like the W, Z and t are short-lived compared with typical hadronization times. When pairs of such particles are produced, the subsequent hadronic decay systems may therefore become interconnected. We study such potential effects at Linear Collider energies.

M. B. Gay Ducati, C. B. Mariotto

Our goal is the study of color effects on the $J/ψ$ and $D$ mesons production, as well as the study of their elastic production. We use the Color Evaporation Model (CEM), where a single factor takes into account the probability that the $c\bar{c}$ produced in a color octet state turns into a physical (colorless) quarkonium or continues as a color octet, prod

K. Langfeld, M. Engelhardt, H. Reinhardt, O. Tennert

We introduce quantum gauge fixing (QGF) as a new class of gauge fixings. While the maximal center gauge might not show vortex dominance, the confining properties of the vortices observed in past lattice calculations are argued to have been obtained in a gauge more akin to QGF than to the strict maximal center gauge.

G. Bauer

A sample of 400 $B^0_d/\bar{B}{^0_d} \to J/ψK^0_s$ decays collected in $\bar{p}p$ collisions by the CDF detector is used to directly measure the CP-violation parameter $\sin(2β)$. We find $\sin(2β) = 0.79 ^{+0.41}_{-0.44}$,favoring the standard model expectation of a large $CP$ violation in this $B^0$ decay mode.

Bernhard Haisch, Alfonso Rueda

A brief overview is presented of the basis of the electromagnetic zero-point field in quantum physics and its representation in stochastic electrodynamics. Two approaches have led to the proposal that the inertia of matter may be explained as an electromagnetic reaction force. The first is based on the modeling of quarks and electrons as Planck oscillators a

Viqar Husain, Sebastian Jaimungal

A fundamental problem with attempting to quantize general relativity is its perturbative non-renormalizability. However, this fact does not rule out the possibility that non-perturbative effects can be computed, at least in some approximation. We outline a quantum field theory calculation, based on general relativity as the classical theory, which implies a

Massimo Giovannini

We discuss the production of multi-photons squeezed states induced by the time variation of the (Abelian) gauge coupling constant in a string cosmological context. Within a fully quantum mechanical approach we solve the time evolution of the mean number of produced photons in terms of the squeezing parameters and in terms of the gauge coupling. We compute th

Manasse Mbonye

Spherically symmetric Black Holes of the Vaidya type are examined in an asymptotically de Sitter, higher dimensional spacetime. The various horizons are located. The structure and dynamics of such horizons are studied.

H. N. Núñez-Yépez

The dynamical effects on the scale factors due to the scalar $ϕ$-field at the early stages of a supposedly anisotropic Universe expansion in the scalar-tensor cosmology of Jordan-Brans and Dicke is studied. This universe shows an {\sl isotropic} evolution and, depending on the value of the theorie's coupling parameter $ω$, it can begin from a singularity

Marshall Bern, David Eppstein

We use circle-packing methods to generate quadrilateral meshes for polygonal domains, with guaranteed bounds both on the quality and the number of elements. We show that these methods can generate meshes of several types: (1) the elements form the cells of a Voronoi diagram, (2) all elements have two opposite right angles, (3) all elements are kites, or (4)

Simon Buckingham Shum, Enrico Motta, John Domingue

This paper is concerned with tracking and interpreting scholarly documents in distributed research communities. We argue that current approaches to document description, and current technological infrastructures particularly over the World Wide Web, provide poor support for these tasks. We describe the design of a digital library server which will enable aut

C. Jarzynski

We analyze the microscopic evolution of a system undergoing a far-from-equilibrium thermodynamic process. Explicitly accounting for the degrees of freedom of participating heat reservoirs, we derive a hybrid result, similar in form to both the fluctuation theorem, and a statement of detailed balance. We relate this result to the steady-state fluctuation theo

E. Ardonne, P. Bouwknegt, S. Guruswamy, K. Schoutens

Two fundamental aspects of so-called non-abelian quantum Hall states (the q-pfaffian states and more general) are a (generalized) pairing of the participating electrons and the non-abelian statistics of the quasi-hole excitations. In this paper, we show that these two aspects are linked by a duality relation, which can be made manifest by considering the K-m

O. E. Raichev, P. Vasilopoulos, F. T. Vasko

We study theoretically the effect of an electric field on the electron states and far-infrared optical properties in narrow-gap lead salt quantum wells. The electron states are described by a two-band Hamiltonian. An application of a strong electric field across the well allows the control of the energy gap between the two-dimensional (2D) states in a wide r

V. I. Yukalov, E. P. Yukalova

The peculiarities of electric current are studied occurring in semiconductors with strongly nonuniform distribution of charge carriers. The formation of such nonuniformities and the regulation of carrier mobilities can be realized by means of external irradiation, for instance, charge-particle beams and laser irradiation. The transient effect of negative ele

R. Jin, Y. Liu, F. Lichtenberg

The transverse and longitudinal in-plane magnetoresistances in the normal state of superconducting Sr2RuO4 single crystals have been measured. At low temperatures, both of them were found to be positive with a linear magnetic-field dependence above a threshold field, a result not expected from electronic band theory. We argue that such behavior is a manifest

U. Schneider, P. Lunkenheimer, A. Pimenov, R. Brand

Dielectric spectroscopy is one of the most commonly used techniques for the investigation of the dynamic response of glass-forming materials. The tremendous slow-down of the particle motions when approaching the glass transition and especially the fast processes in glass-forming materials, which have come into the focus of scientific interest recently, make

D. V. Khveshchenko, P. W. Anderson

We discuss the problem of the X-ray absorption in a system of interacting fermions and, in particular, those features in the X-ray spectra that can be used to discriminate between conventional Fermi-liquids and novel "strange metals". Focusing on the case of purely forward scattering off the core-hole potential, we account for the relevant interactio

Randall D. Kamien

The chiral structure of liquid crystalline phases arises due to the intrinsic chirality of the constituent mesogens. While it is seemingly straightforward to quantify the macroscopic chirality by using, for instance, the cholesteric pitch or the optical rotatory power, it is not as simple to quantify the chirality of a single molecule. I will discuss a syste

Yadin Y. Goldschmidt

In this paper we revisit the problem of a (non self-avoiding) polymer chain in a random medium which was previously investigated by Edwards and Muthukumar (EM). As noticed by Cates and Ball (CB) there is a discrepancy between the predictions of the replica calculation of EM and the expectation that in an infinite medium the quenched and annealed results shou

G. Aichmayr, M. Jetter, L. Vina, J. Dickerson

We have shown experimentally that an electric field decreases the energy separation between the two components of a dense spin-polarized exciton gas in a coupled double quantum well, from a maximum splitting of $\sim 4$ meV to zero, at a field of $\sim $35 kV/cm. This decrease, due to the field-induced deformation of the exciton wavefunction, is explained by

S. Ostertun, J. Kiltz, T. Wolf, A. Bock

We investigate the electronic background as well as the O2-O3 mode at 330 cm^-1 of highly doped YbBa2Cu3O7-delta in B1g symmetry. Above the critical temperature Tc the spectra consist of an almost constant electronic background and superimposed phononic excitations. Below Tc the superconducting gap opens and the electronic background redistributes exhibiting

M. Opel, R. Nemetschek, C. Hoffmann, R. Philipp

We describe results of electronic Raman-scattering experiments in differently doped single crystals of Y-123 and Bi-2212. The comparison of AF insulating and metallic samples suggests that at least the low-energy part of the spectra originates predominantly from excitations of free carriers. We therefore propose an analysis of the data in terms of a memory f

N. Lingg, D. Maurer, V. Müller, K. A. McEwen

For a high-quality single crystal of UPd_3 we present the relevant elastic constants and ultrasonic attenuation data. In addition to the magnetic phase transition at T_2=4.4 +/- 0.1K and the quadrupolar transition at T_1~6.8K, we find orbital ordering at T_0=7.6 +/- 0.1K concomitant with a symmetry change from hexagonal to orthorhombic. A striking feature is

Kurt Binder, Erik Luijten, Marcus Müller, Nigel B. Wilding

Using the concept of finite-size scaling, Monte Carlo calculations of various models have become a very useful tool for the study of critical phenomena, with the system linear dimension as a variable. As an example, several recent studies of Ising models are discussed, as well as the extension to models of polymer mixtures and solutions. It is shown that usi

Girish S. Setlur

In this short write-up we argue that self-consistent diagrammatic perturbation theory(i.e. Feynman diagrams) for the one-particle Green function is unable to capture some important qualitative features no matter how self-consistently the Green functions are obtained. This write-up is intended to highlight the short-comings of perturbation theory and also tou

M. R. Zapatero Osorio, V. J. S. Bejar, R. Rebolo, E. L. Martin

We present J-band photometry and low-resolution optical spectroscopy (600-1000 nm) for one of the faintest substellar member candidates in the young sigma Ori cluster, SOri 47 (I=20.53, Bejar et al. 1999). Its very red (I-J)=3.3+/-0.1 color and its optical spectrum allow us to classify SOri 47 as an L1.5-type object which fits the low-luminosity end of the c

Z. M. Leinhardt, D. C. Richardson, T. Quinn

There is increasing evidence that many km-sized bodies in the Solar System are piles of rubble bound together by gravity. We present results from a project to map the parameter space of collisions between km-sized spherical rubble piles. The results will assist in parameterization of collision outcomes for Solar System formation models and give insight into

Maxim Lyutikov, Anuj Parikh

We apply a theory of wave propagation through a turbulent medium to the scattering of radio waves in pulsar magnetospheres. We find that under conditions of strong density modulation the effects of magnetospheric scintillations in diffractive and refractive regimes may be observable. The most distinctive feature of the magnetospheric scintillations is their

C. J. Horowitz, Gang Li

The well known charge conjugation violating interactions in the Standard Model increase neutrino- and decrease anti-neutrino- nucleon cross sections. This impacts neutrino transport in core collapse supernovae through "recoil" corrections of order the neutrino energy $k$ over the nucleon mass $M$. All $k/M$ corrections to neutrino transport deep insi

Merav Opher, Reuven Opher

It has recently been argued that there are no dynamic screening corrections to Salpeter's enhancement factor in thermonuclear reactions, in the weak-screening limit. The arguments used were: 1) The Gibbs probability distribution is factorable into two parts, one of which, $exp(-β\sum e_{i}e_{j}/r_{ij})$ ($β=1/k_{B}T$), is independent of velocity space; a

J. I. Katz

When gamma-rays emerge from a central source they may undergo Compton scattering in surrounding matter. The resulting Compton-scattered electrons radiate. Coherent radiation by such Compton electrons follows nuclear explosions above the Earth's atmosphere. Particle acceleration in instabilities produced by Compton electron currents may explain the radio

Miriani G. Pastoriza, Claudia Winge, Fabricio Ferrari, F. Duccio Macchetto

HST images of NGC 3379 show that the V and I luminosity profiles in the inner 13 arcsec of this E1 galaxy are represented by two different components: a stellar bulge following a Sersic Law with exponent n = 2.36, and a central core (r < 0.7 arcsec) with a characteristic &#34;cuspy&#34; profile. Subtraction of the underlying stellar component represented by

Candace Oaxaca Wright, Tereasa G. Brainerd

We investigate the gravitational lensing properties of dark matter halos with Navarro, Frenk & White (NFW) density profiles and derive an analytic expression for the radial dependence of the shear, $γ(x)$, due to these objects. In addition, we derive an expression for the mean shear interior to a given radius, $\barγ(x)$, and use this to quantify systematic

S. B. Popov, M. E. Prokhorov

In this paper we semianalyticaly evaluate influence of the exponential decay of magnetic field on the fate of isolated neutron stars. The fact of ROSAT observations of several X-ray sources, which can be accreting old isolated neutron stars gives us an opportunity to put some limits on the parameters of the exponential decay. We argue, that, if most part of

P. N. Best, H. J. A. R&#34;ottgering, M. S. Longair

An analysis of the kinematics and ionisation state of the emission line gas of a sample of 14 3CR radio galaxies with redshifts z~1 is carried out. The data used for these studies, deep long--slit spectroscopic exposures from the WHT, are presented in an accompanying paper. It is found that radio sources with small linear sizes (<150 kpc) have lower ionisati

P. N. Best, H. J. A. R&#34;ottgering, M. S. Longair

Deep long-slit spectroscopic data are presented for a sample of 14 3CR radio galaxies at redshift z ~ 1, previously studied in detail using the Hubble Space Telescope, the Very Large Array, and UKIRT. Analysis of the [OII] 3727 emission line structures at 5 Ang spectral resolution is carried out to derive the kinematic properties of the emission line gas. In

Andreas A. Berlind, Vijay K. Narayanan, David H. Weinberg

Measurements of the cosmological density parameter (Omega) using techniques that exploit the gravity-induced motions of galaxies yield, in linear perturbation theory, the degenerate parameter combination beta=Omega^{0.6}/b, where the linear bias parameter b is the ratio of the fluctuation amplitudes of the galaxy and mass distributions. However, the relation

Kingman Cheung

CDF recently measured the quantity $\frac{σ(B_c^+)}{σ(B^+)} \frac{{\rm BR}(B_c^+ \to J/ψ\ell^+ ν)}{{\rm BR}(B^+ \to J/ψK^+)}$, {}from which we determine the ratio $\frac{σ(B_c^+)}{σ(\bar b)}$ to be $(2.08\err{1.06}{0.95})\times 10^{-3}$. In this note, we show that the ratio $\frac{σ(B_c^+)}{σ(\bar b)}$ obtained by dividing the $σ(B_c^+)$ by the leading order

G. L. Payne, W. Gloeckle, J. L. Friar

The asymptotic behavior of three-body scattering wave functions in configuration space is studied by considering a model equation that has the same asymptotic form as the Faddeev equations. Boundary conditions for the wave function are derived, and their validity is verified by numerical calculations. It is shown that these boundary conditions for the partia

Maya Paczuski, Dante R. Chialvo, Per Bak

This paper has been withdrawn by the authors.

J. L. Friar, D. Hüber, H. Witala, G. L. Payne

Quartet n-d scattering lengths are calculated using second-generation nucleon-nucleon potential models. These results are compared to the corresponding quantity recently calculated using chiral perturbation theory.

A. Lorke, R. J. Luyken, A. O. Govorov, J. P. Kotthaus

Making use of self-assembly techniques, we demonstrate the realization of nanoscopic semiconductor quantum rings in which the electronic states are in the true quantum limit. We employ two complementary spectroscopic techniques to investigate both the ground states and the excitations of these rings. Applying a magnetic field perpendicular to the plane of th

S. M. H. Wong

The effects of color screening on the hadronization of a parton plasma into a hadron gas are examined at the energies of the relativistic heavy ion collider. It is found to have the tendency to prevent hadronization and therefore delaying the conversion of the partons into a hadron gas. Because of the continual expansion, the resulting hadron gas number dens

Eduardo Eyras

We consider non-BPS D8 (and D7) branes in type 0 open string theory and describe under which circumstances these branes are stable. We find stable non-BPS D7 and D8 in type 0 with and without D9-branes in the background. By extending the descent relations between D-branes to type 0 theories, the non-BPS D8-brane is considered as the result of a tachyon conde

Mario Franz, Hyun-Chul Kim, Klaus Goeke

We study the effective weak chiral Lagrangian within the framework of the instanton vacuum. We incorporate the $ΔS=1,2$ effective weak Hamiltonian into the effective low-energy QCD partition function defining the chiral symmetric quark-Goldstone boson interactions with the momentum-dependent dynamical quark mass. Employing the derivative expansion, we derive

Alan Horwitz

Let M(f) denote the Midpoint Rule and T(f) the Trapezoidal Rule for estimating integral_a^b f(x) dx. Then Simpson's Rule = tM(f) + (1-t)T(f), where t = 2/3. We generalize Simpson's Rule to multiple integrals as follows. Let D be some polygonal region in R^n, let P_0,...,P_m denote the vertices of D, and let P_(m+1) = center of mass of D. Define the linear fu

R. A. Roemer, M. Leadbeater, M. Schreiber

Much evidence has been collected to date which shows that repulsive electron-electron interaction can lead to the formation of particle pairs in a one-dimensional random energy landscape. The localization length \lambda_2 of these pair states is finite, but larger than the localization length \lambda_1 of the individual particles. After a short review of pre

Kazutoshi Ohta

We investigate the supersymmetric index of N=2,3 SU(n) supersymmetric Yang-Mills Chern Simons theories at level k by using the brane configuration with a (p,q)5-brane. We can explain that the supersymmetry breaking occurs when k<n in terms of the s-rule for Type IIB branes. The supersymmetric index coincides with the number of the possible supersymmetric bra

Anne-Christine Davis, Matthew Lilley

In cosmological first-order phase transitions, the progress of true-vacuum bubbles is expected to be significantly retarded by the interaction between the bubble wall and the hot plasma. We examine the evolution and collision of slow-moving true-vacuum bubbles. Our lattice simulations indicate that phase oscillations, predicted and observed in systems with a

Philip Yock

The new astronomical technique of gravitational microlensing enables measurements of high precision to be made in certain circumstances. Useful advances have been made in the fields of galactic astronomy, stellar astronomy and planetary science. The technique is best suited to the southern sky, and several observations have been made from Australasia. A samp

A. Del Popolo

I study the evolution of haloes density profiles as a function of time in the SCDM and LCDM cosmologies. Following Del Popolo et al. (1999), I calculate the concentration parameter c=r_v/a and study its time evolution. For a given halo mass, I find that c(z) ~1/(1+z) both in the LCDM and SCDM cosmology, in agreement with Bullock et al. (1999) analytic model

J. N. Abdurashitov, V. N. Gavrin, A. V. Kalikhov, A. A. Shikhin

The principle of operation, design, registration system and main characteristics of a fast neutrons spectrometer are described. The spectrometer is intended for direct measurements of ultra low fluxes of fast neutrons. It is sensitive to neutron fluxes of 10^-7 neutrons/(cm^2 s^1) and lower with the neutron energy above 700 keV. The detection efficiency of f

L. Hannelius, D. O. Riska, L. Ya. Glozman

The strangeness magnetic moment of the proton is shown to be small in the chiral quark model. The dominant loop contribution is due to kaons. The K^* loop contributions are proportional to the difference between the strange and light constituent quark masses or $m_{K^*}^{-2}$ and therefore small. The loop fluctuations that involve radiative transitions betwe

J. Gegelia

Next to leading order effective field theory calculations are performed for $ {}^1S_0$ NN scattering using subtractive renormalization procedure. One pion exchange and contact interaction potentials are iterated using Lippman-Schwinger equation. Satisfactory fit to the Nijmegen data is obtained for the momenta up to 300 MeV in the centre of mass frame. Phase

L. Hlavaty

The equations that define the Lax pairs for generalized principal chiral models can be solved for any constant nondegenerate bilinear form on SU(2). Necessary conditions for the nonconstant metric on SU(2) that define the integrable models are given.

Kenji Kajiwara, Tetsu Masuda, Masatoshi Noumi, Yasuhiro Ohta

Determinant formulas for the general solutions of the Toda and discrete Toda equations are presented. Application to the $τ$ functions for the Painlevé equations is also discussed.

Michael B. Mensky

Under certain assumptions it is shown that the decay of level 2 of a three-level system onto level 1 is slowed down because of the further decay of level 1 onto level 0. It is argued that this phenomenon may be interpreted as a consequence of the quantum Zeno effect. The reason why this may be possible is that the second decay (or accompanying photon radiati

S. M. Roy

We present a simple proof of quantum contextuality for a spinless particle with a one dimensional configuration space. We then discuss how the maximally realistic deterministic quantum mechanics recently constructed by this author and V. Singh can be applied to different contexts.

Horia Scutaru

We obtain a general formula for the transition probabilities between any state of the algebra of the canonical commutation relations (CCR-algebra) and a squeezed quasifree state. Applications of this formula are made for the case of multimode thermal squeezed states of quantum optics using a general canonical decomposition of the correlation matrix valid for

Raymond Y. Chiao

We discuss the possibility that photons, which are bosons, can form a 2D superfluid due to Bose-Einstein condensation inside a nonlinear Fabry-Perot cavity filled with atoms in their ground states. A &#34;photon fluid&#34; forms inside the cavity as a result of multiple photon-photon collisions mediated by the atoms during a cavity ring-down time. The effect

Kevin A. Mitchell, Robert G. Littlejohn

For a three-body system, a quantum wave function $Ψ^\ell_m$ with definite $\ell$ and $m$ quantum numbers may be expressed in terms of an internal wave function $χ^\ell_k$ which is a function of three internal coordinates. This article provides necessary and sufficient constraints on $χ^\ell_k$ to ensure that the external wave function $Ψ^\ell_m$ is analytic.

Agata Olariu

A statistical study on 565 works of art of different great painters was done and it was calculated the ratio of the 2 sides of a paintings. Assuming that all the painters under discussion enter in a statistics with equal weights it is shown that the average value obtained for the ratio of the sides is 1.34. This value, determined experimentally is significan

Jijun Zhao

Tight-binding molecular dynamics (TBMD) is used to study the structural and electronic properties of silver clusters. The ground state structures of Ag clusters up to 21 atoms are optimized via TBMD combined with genetic algorithm (GA). The detailed comparison with {\em ab initio} results on small Ag$_n$ clusters (n=3-9) proves the validity of the tight-bind