September 1999 arXiv papers — page 22

Yoshitaka Okumura

Noncommutative geometry(NCG) on the discrete space successfully reproduces the Higgs mechanism of the spontaneously broken gauge theory, in which the Higgs boson field is regarded as a kind of gauge field on the discrete space. We could construct the generalized differential geometry(GDG) on the discrete space $M_4\times Z_N$ which is very close to NCG in ca

Heiyoung Shin

We consider typeIIA supergravity solution of D2-branes and D3-branes localized within D6-branes in the near-core region of D6-branes. With these solutions we can calculate the spectrum of the glueball mass in QCD3 and QCD4. The equation of motion describing the dilaton has the same eigenvalues and the same glueball masses in QCD3 and QCD4. Glueball mass spec

D. V. Shirkov

We start with a simple introduction into the renormalization group (RG) in quantum field theory and give an overview of the renormalization group method. The third section is devoted to essential topics of the renorm-group use in the QFT. Here, some fresh results are included. Then we turn to the remarkable proliferation of the RG ideas into various fields o

S. A. Bulgadaev

The 3D vector van der Waals (or conformal) nonlinear sigma-model is proposed. It is shown that it has the "hedgehog"-like topological excitations with logarithmic energy. Their "neutral" configurations have nontrivial topological structures described by Hopf invariant. A possible influence of these excitations on the properties of the model a

D. Minic

We discuss deformation quantization of the covariant, light-cone and conformal gauge-fixed p-brane actions (p>1) which are closely related to the structure of the classical and quantum Nambu brackets. It is known that deformation quantization of the Nambu bracket is not of the usual Moyal type. Yet the Nambu bracket can be quantized using the Zariski deforma

Amand Faessler, Fedor Simkovic

The modern theories of Grand Unification (GUT) and supersymmetric (SUSY) extensions of standard model (SM) suppose that the conservation laws of the SM may be violated to some small degree. The nuclei are well-suited as a laboratory to test fundamental symmetries and fundamental interactions like lepton flavor (LF) and lepton number (LN) conservation. A prom

M. Garcia Perez, O. Philipsen, I. -O. Stamatescu

We present a cooling method controlled by a physical cooling radius that defines a scale below which fluctuations are smoothed out while leaving physics unchanged at all larger scales. This method can be generally used as a gauge invariant low pass filter to extract the physics from noisy MC configurations. Here we apply this method to study topological prop

S. Basak, Asit K. De

We investigate a U(1) lattice chiral gauge theory with the waveguide formulation of the domain wall fermions and with compact gauge fixing. In the reduced model limit, there seems to be no mirror chiral modes at the waveguide boundary.

F. Berruto, E. Coletti, G. Grignani, P. Sodano

A lattice strong coupling calculation of the spectrum and chiral condensate of the 't Hooft model is presented. The agreement with the results of the continuum theory is strikingly good even at the fourth order in the strong coupling expansion.

L3 Collaboration

We report on measurements of the mass and total decay width of the W boson with the L3 detector at LEP. W-pair events produced in $\mathrm{e^+e^-}$ interactions between 161 GeV and 183 GeV centre-of-mass energy are selected in a data sample corresponding to a total luminosity of 76.7 pb$^{-1}$. Combining all final states in W-pair production, the mass and to

L3 Collaboration

We measure Bose-Einstein correlations between like-sign charged pion pairs in hadronic Z decays with the L3 detector at LEP. The analysis is performed in three dimensions in the longitudinal center-of-mass system. The pion source is found to be elongated along the thrust axis with a ratio of transverse to longitudinal radius of $0.81\pm 0.02 ^{+0.03}_{-0.19}

L3 Collaboration

The two-photon width $Γ_{γγ}$ of the $η_c$ meson has been measured with the L3 detector at LEP. The $η_c$ is studied in the decay modes $π^+π^-π^+π^-$, $π^+π^-$K$^+$K$^-$, K$_s^0$K$^\pmπ^\mp$, K$^+$K$^-π^{0}$, $π^+π^-η$, $π^+π^-η'$, and $ρ^+ρ^-$ using an integrated luminosity of 140 pb$^{-1}$ at $\sqrt{s} \simeq 91$ GeV and of 52 pb$^{-1}$ at $\sqrt{s} \

Alain Verberkmoes, Bernard Nienhuis

Details are presented of a recently announced exact solution of a model consisting of triangular trimers covering the triangular lattice. The solution involves a coordinate Bethe Ansatz with two kinds of particles. It is similar to that of the square-triangle random tiling model, due to M. Widom and P. A. Kalugin. The connection of the trimer model with rela

S. S. Manna, A. D. Chakrabarti, R. Cafiero

A directed dissipative sandpile model is studied in the two-dimension. Numerical results indicate that the long time steady states of this model are critical when grains are dropped only at the top or, everywhere. The critical behaviour is mean-field like. We discuss the role of infinite avalanches of dissipative models in periodic systems in determining the

C. C. Abilio, L. Amico, Rosario Fazio, B. Pannetier

The transition line of superconducting arrays of holes exhibits a rich field structure due to the interference of superconducting states nucleated at the holes edges. We studied by means of resistance measurements their effect on the T*c(H) line as a function of transverse magnetic field using regular arrays of nanofabricated micron size holes. The arrays tr

You-Hua Chu, C. -H. Rosie Chen, Shih-Ping Lai

Some extragalactic SNRs are more than two orders of magnitude more luminous than the young Galactic SNR Cas A. These SNRs are called super-luminous or ultra-luminous SNRs. Their high luminosities can be caused by chance superpositions of multiple objects, interactions with a very dense environment, or unusually powerful supernova explosions. Four super-lumin

R. Atkins

The Milagrito water Cherenkov detector near Los Alamos, New Mexico, operated as a sky monitor at energies of a few TeV between February 1997 and May 1998 including the period of the strong, long-lasting 1997 flare of Markarian 501. Milagrito served as a test run for the full Milagro detector. An event excess with a significance of 3.7 sigma from Markarian 50

K. F. Gunn, T. Shanks

Models invoking large populations of obscured AGN are known to provide good fits to the spectrum of the X-ray background and the observed soft and hard X-ray number counts. An important consequence of these models is that significant quantities of dust are required in order to provide the obscuring medium, which will be heated by the nuclear radiation from t

Robert A. Schommer, N. B. Suntzeff, R. C. Smith

We summarize the current status of cosmological measurements using SNe Ia. Searches to an average depth of z~0.5 have found approximately 100 SNe Ia to date, and measurements of their light curves and peak magnitudes find these objects to be about 0.25mag fainter than predictions for an empty universe. These measurements imply low values for Omega_M and a po

Subhabrata Majumdar, Ravi Subrahmanyan

In the context of cold dark matter (CDM) cosmological models, we have simulated images of the brightness temperature fluctuations in the cosmic microwave background (CMB)sky owing to the Sunyaev Zel$^{\prime}$dovich (S-Z) effect in a cosmological distribution of clusters. We compare the image statistics with recent ATCA limits on arcmin-scale CMB anisotropy.

C. D. Koresko, G. A. Blake, M. E. Brown, A. I. Sargent

We present an infrared imaging study of the low-mass pre-main sequence binary system Haro 6-10. This system is one of a handful in which the optically-visible primary has the characteristics of a normal T Tauri star, while the secondary is a so-called "infrared companion" (IRC), a strongly extincted object which emits most of its luminosity in the in

J. A. Surace, D. B. Sanders, A. S. Evans

We present high spatial resolution (FWHM 0.3-0.8&#34;) BIHK&#39;-band imaging of a sample of ultraluminous infrared galaxies with &#34;cool&#34; mid-infrared colors (f25/f60 < 0.2) which select against AGN-like systems and which form a complementary sample to the &#34;warm&#34; ULIGs of Surace et al. (1998). We find that all of the cool ULIGs are either adva

K. Tomita

To explain the puzzling situation in the observed bulk flows on scales $\sim 150 h^{-1}$ Mpc ($H_0 = 100 h^{-1}$ km sec$^{-1}$ Mpc$^{-1}$), we consider the observational behavior of spherically symmetric inhomogeneous cosmological models, which consist of inner and outer homogeneous regions connected by a shell or an intermediate self-similar region. It is a

N. Benitez, J. L. Sanz

A correlation between the surface density of foreground galaxies tracing the Large Scale Structure and the position of distant galaxies and quasars is expected from the magnification bias effect (Canizares 1981). We show that this foreground--background correlation function w_{fb} can be used as a straightforward and almost model-free method to measure the c

A. M. Gago, H. Nunokawa, R. Zukanovich Funchal

We have reexamined the possibility of explaining the solar neutrino problem through long-wavelength neutrino oscillations induced by a tiny breakdown of the weak equivalence principle of general relativity. We found that such gravitationally induce oscillations can provide a viable solution to the solar neutrino problem.

Martin Plihal, David C. Langreth, Peter Nordlander

The response of a quantum dot in the Kondo regime to rectangular pulsed bias potentials of various strengths and durations is studied theoretically. It is found that the rise time is faster than the fall time, and also faster than time scales normally associated with the Kondo problem. For larger values of the pulsed bias, one can induce dramatic oscillation

J. Lehar, E. Falco, C. Kochanek, B. McLeod

We report on a program to obtain HST observations of galaxy-mass gravitational lens systems at optical and infrared wavelengths. Here we discuss the properties of 10 two-image gravitational lens systems (Q0142-100=UM673, B0218+357, SBS0909+532, BRI0952-0115, LBQS1009-0252, Q1017-207=J03.13, B1030+074, HE1104-1805, Q1208+1011, and PKS1830-211). We grouped the

A. G. Souza Filho, K. C. V. Lima, A. P. Ayala, I. Guedes

This work reports on the first Raman detection of the tetragonal to monoclinic phase transition in PZT ceramics near morphotropic phase boundary at low temperatures. The transition is characterized by changes in the frequency of lattice modes with the temperature. The results presented here confirm the previous one recently reported by Noheda et al. using hi

Pilar Hernandez, Karl Jansen, Laurent Lellouch

We calculate the large-volume and small-mass dependences of the quark condensate in quenched QCD using Neuberger&#39;s operator. We find good agreement with the predictions of quenched chiral perturbation theory, enabling a determination of the chiral lagrangian parameter Σ, up to a multiplicative renormalization.

Yungui Gong

We apply the holographic principle to the Brans-Dicke cosmology. We analyze the holographic bound in both the Jordan and Einstein frames. The holographic bound is satisfied for both the k=0 and k=-1 universe, but it is violated for the k=1 matter dominated universe.

Z. Chacko, Markus A. Luty, Eduardo Ponton

We consider theories with one or more compact dimensions with size r > 1/M, where M is the fundamental Planck scale, with the visible and hidden sectors localized on spatially separated &#34;3-branes.&#34; We show that a bulk U(1) gauge field spontaneously broken on the hidden-sector 3-brane is an attractive candidate for the messenger of supersymmetry break

Christof Gattringer, Ivan Hip, C. B. Lang

We study the 2-flavor lattice Schwinger model with Wilson fermions in the chiral limit. The quark mass is determined using the PCAC definition. We numerically compute the masses of the iso-triplet (pi) and iso-singlet particles (eta) for different quark masses and compare our results with analytical formulas.

G. Papp, B. -J. Schaefer, H. -J. Pirner, J. Wambach

We compare and discuss the dependence of a polynomial truncation of the effective potential used to solve exact renormalization group flow equation for a model with fermionic interaction (linear sigma model) with a grid solution. The sensitivity of the results on the underlying cutoff function is discussed. We explore the validity of the expansion method for

Joaquim Prades

We report on recent advances at understanding the $ΔI= 1/2$ rule for kaons. We get reasonable matching between short-- and long--distances for scales between between 0.6 and 1.0 GeV and reproduce the $ΔI=1/2$ rule huge enhancement in the chiral limit. A detailed analysis of the different contributions to the relevant octet and 27-plet couplings is done. For

Arvind Rajaraman, Moshe Rozali

We construct a Dirichlet boundary state for linear dilaton backgrounds. The state is conformally invariant and satisfies Cardy&#39;s conditions. We apply this construction to two dimensional string theory.

A. Gorsky, M. Shifman

We study the central extensions of the N=1 superalgebras relevant to the soliton solutions with the axial geometry - strings, wall junctions, etc. A general expression valid in any four-dimensional gauge theory is obtained. We prove that the only gauge theory admitting BPS strings at weak coupling is supersymmetric electrodynamics with the Fayet-Iliopoulos t

J. L. Jacquot

In the framework of a gauge invariant continuous and non-perturbative regularization scheme based on the smearing of point like interactions by means of cutoff functions, we show that the axial anomaly, though cutoff independent, depends on the shape of the cutoff functions. The standard value for the strength of the axial anomaly is recovered if we assume t

Toru Aonishi, Masato Okada

The role of the Onsager reaction term (ORT) is not yet well understood in frustrated coupled oscillator systems, since the Thouless-Anderson-Palmer (TAP) and replica methods cannot be directly applied to these non-equilibrium systems. In this paper, we consider two oscillator associative memory models, one with symmetric and one with asymmetric dilution of c

G. J. Gounaris, J. Layssac, P. I. Porfyriadis, F. M. Renard

We study the helicity amplitudes of the process gamma gamma to ZZ in the Standard Model at high energy. These amplitudes receive contributions from the W and charged quark and lepton loops, analogous to those encountered in the gamma gamma to gamma gamma, gamma Z cases studied before. But gamma gamma to ZZ also receives contributions from the Higgs s-channel

Holger F. Hofmann

The continuous transition from a low resolution quantum nondemolition measurement of light field intensity to a precise measurement of photon number is described using a generalized measurement postulate. In the intermediate regime, quantization appears as a weak modulation of measurement probability. In this regime, the measurement result is strongly correl

Piero Madau, Christopher Thompson

We consider the radiative acceleration to relativistic bulk velocities of a cold, optically thin plasma which is exposed to an external source of gamma-rays. The flow is driven by radiative momentum input to the gas, the accelerating force being due to Compton scattering in the relativistic Klein-Nishina limit. The bulk Lorentz factor of the plasma, Gamma, d

Rob Clifton, Hans Halvorson, Adrian Kent

It was recently shown that the nonseparable density operators for a bipartite system are trace norm dense if either factor space has infinite dimension. We show here that non-local states -- i.e., states whose correlations cannot be reproduced by any local hidden variable model -- are also dense. Our constructions distinguish between the cases where both fac

P. Narayana Swamy

The theory of Fermion oscillators has two essential ingredients: zero-point energy and Pauli exclusion principle. We devlop the theory of the statistical mechanics of generalized q-deformed Fermion oscillator algebra with inclusion principle (i.e., without the exclusion principle), which corresponds to ordinary fermions with Pauli exclusion principle in the

Andreas Klappenecker

We show how periodized wavelet packet transforms and periodized wavelet transforms can be implemented on a quantum computer. Surprisingly, we find that the implementation of wavelet packet transforms is less costly than the implementation of wavelet transforms on a quantum computer.

Lawrence R. Pratt, Susan B. Rempe

A statistical thermodynamic development is given of a new implicit solvent model that avoids the traditional system size limitations of computer simulation of macromolecular solutions with periodic boundary conditions. This implicit solvent model is based upon the quasi-chemical approach, distinct from the common integral equation trunk of the theory of liqu

M. V. Stoitsov, J. Dobaczewski, P. Ring, S. Pittel

We introduce a local-scaling point transformation to allow for modifying the asymptotic properties of the deformed three-dimensional Cartesian harmonic oscillator wave functions. The resulting single-particle bases are very well suited for solving the Hartree-Fock-Bogoliubov equations for deformed drip-line nuclei. We then present results of self-consistent

R. Ganz

A systematic study of two particle correlations measured by the NA49 experiment is summarized. Radii from Bose Einstein interferometry have been determined separately in different parts of phase space, for different collision systems and at different incident beam energies. Moreover, first results of a new method of accessing space-time asymmetries in the em

R. Ganz

The possible transition of nuclear matter to a deconfined phase in relativistic nucleus-nucleus collisions is explored by a systematic variation of the collision system by means of system size, beam energy and centrality of the collision all measured within the same experiment NA49 at the CERN SPS. The investigation takes advantage of the large number of had

Mark Hovey

In this paper, we try to realize the unbounded derived category of an abelian category as the homotopy category of a Quillen model structure on the category of unbounded chain complexes. We construct such a model structure based on injective resolutions for an arbitrary Grothendieck category, as has apparently also been done by Morel. In particular, this wor

Anton Deitmar

Let $G$ be the semidirect product $\A^1\ltimes \A$ of the adeles and the norm 1 ideles. Let $\Ga$ be the discrete subgroup $\Q^\times\ltimes\Q$. In this paper the trace formula for this setting is established and used to give the complete decomposition of the $G$-representation on $L^2(\Ga\bs G)$. It turns out that every character of the norm-1 idele class g

Anton Deitmar

We show that the zeta function of a regular graph admits a representation as a quotient of a determinant over a $L^2$-determinant of the combinatorial Laplacian.

Tahl Nowik

Let F be a closed orientable surface. If i,i&#39;:F \to R^3 are two regularly homotopic generic immersions, then it has been shown in [N] that all generic regular homotopies between i and i&#39; have the same number mod 2 of quadruple points. We denote this number by Q(i,i&#39;) \in Z/2. We show that for any generic immersion i:F\to R^3 and any diffeomorphis

Michael Dine, Josh Gray

We generalize the proof of the non-renormalization of the four derivative operators in ${\cal N}=4$ Yang Mills theory with gauge group SU(2) to show that certain terms with 2N derivatives are not renormalized in the theory with gauge group SU(N). These terms may be determined exactly by a simple perturbative computation. Similar results hold for finite ${\ca

H. Saleur

I discuss and extend the recent proposal of Leclair and Mussardo for finite temperature correlation functions in integrable QFTs. I give further justification for its validity in the case of one point functions of conserved quantities. I also argue that the proposal is not correct for two (and higher) point functions, and give some counterexamples to justify

Nick E. Mavromatos, Elizabeth Winstanley

We formulate the field equations for $SU(\infty)$ Einstein-Yang-Mills theory, and find spherically symmetric black-hole solutions. This model may be motivated by string theory considerations, given the enormous gauge symmetries which characterize string theory. The solutions simplify considerably in the presence of a negative cosmological constant, particula

M. Shifman

The Yuri Golfand Memorial Volume commemorates Thirty Years of Supersymmetry. It will be published soon by World Scientific. The participants of the project are: D. Brace, L. Brink, S. Deser, G. Dvali, B. Feng, D. Freedman, G.-L. Gervais, G. Gabadadze, M. Grisaru, A. Hanany, Y.-H. He, S. Hellerman, E. D&#39;Hoker, P. Fayet, V. Kac, I. Klebanov, N. Koretz-Golf

Ernest Ma

The permutation symmetry $S_3$ is appplied to obtain two equal Majorana neutrino masses, while maintaining three different charged-lepton masses and suppressing neutrinoless double beta decay. The resulting radiative splitting of the two neutrinos is shown to be suitable for solar neutrino vacuum oscillations.

Keith A. Olive

Progress in early Universe cosmology, including strings, extra dimensions, inflation, phase transitions, and baryogenesis, is reviewed.

Antonio Pich, Joaquim Prades

We present a general analysis of SU(3) breaking effects in the semi-inclusive tau hadronic width. The recent ALEPH measurements of the inclusive Cabibbo--suppressed decay width of the tau and several moments of its invariant mass distribution are used to determine the value of the strange quark mass. We obtain, in the MS scheme, m_s(M_\tau^2) = (119\pm 24) M

M. Czakon, J. Gluza, F. Jegerlehner, M. Zralek

Precision experiments, such as those performed at LEP and SLC, offer us an excellent opportunity to constrain extended gauge model parameters. To this end, it is often assumed, that in order to obtain more reliable estimates, one should include the sizable one--loop Standard Model (SM) corrections, which modify the $Z^0$ couplings as well as other observable

Wolfgang Ochs

Recent results concerning the evidence and classification of the J^{PC}=0^{++} states, obtained with P. Minkowski, are presented: The isoscalars f_0(980) and f_0(1500) are classified as members of the 0^{++} nonet, while the broad state called f_0(400-1200) and the state f_0(1370) are considered as different components of a single broad resonance, the lowest

Sanghyeon Chang, Shiro Tazawa, Masahiro Yamaguchi

We examine the axion model in the large extra dimensions scenario with TeV scale gravity. To obtain an intermediate-scale decay constant of the axion, the axion is assumed to live in a sub-spacetime (brane) of the whole bulk. In this model there appear Kaluza-Klein modes of the axion which have stronger interaction than those of the graviton. The axion brane

Bijoy Kundu, Pankaj Jain, John P. Ralston, Jim Samuelsson

We review the current status of electromagnetic form factor calculations in perturbative QCD. There is growing evidence that factorization prescriptions involving a transverse coordinate integration, such as that of Li and Sterman, are more appropriate than the prescription of LePage and Brodsky. Color transparency is naturally described within the formalism

Qaisar Shafi, Zurab Tavartkiladze

We propose a new mechanism in which the generation of the supersymmetric $μ$-term as well charged lepton masses is closely tied to R-parity violation involving heavy vector-like families . A realistic example based on $SU(3)_c\times SU(2)_L\times U(1)_Y$, supplemented by the symmetry ${\cal R}\times {\cal U}(1)$, is presented, where ${\cal R}$ (${\cal U}(1)$

Spencer R. Klein, Joakim Nystrand

Photons emitted from the electromagnetic fields of relativistic heavy ions can fluctuate into quark anti-quark pairs and scatter from a target nucleus, emerging as vector mesons. These coherent interactions are identifiable by final states consisting of the two nuclei and a vector meson with a small transverse momentum. The emitters and targets can switch ro

Robert G. Edwards, Urs M. Heller, Joe Kiskis, Rajamani Narayanan

The properties of the spectrum of the overlap Dirac operator and their relation to random matrix theory are studied. In particular, the predictions from chiral random matrix theory in topologically non-trivial gauge field sectors are tested.

Ch. Hoelbling, C. Rebbi, V. A. Rubakov

We present the results of a study of the free energy of a monopole pair in pure SU(2) theory at finite temperature, both below and above the deconfinement tran sition. We find a Yukawa potential between monopoles in both phases. At low temp erature, the screening mass is compatible with the lightest glueball mass. At hi gh temperature, we observe an increase

P. W. Stephenson

We report two probes of centre vortices in pure SU(2). First, we attempt to generate plaquette-size Z(2) vortices in a quasi-random way to compare the structure with those of projected centre vortices from the full theory; our prescription is, however, not completely random. Second, we test the effect of centre vortices on Wilson loops as a function of posit

A. Rajantie

In Abelian theories, one can write for the hard thermal loop equations of motions a local formulation that is more economical than the traditional Vlasov formulation and is in explicitly canonical form. I show how this formulation can be used for simulating non-equilibrium dynamics in the Abelian Higgs model.

I. Montvay

In QCD one can change the representation of the gauge group for quarks and/or the gauge group itself. Examples of such generalizations are: (a) supersymmetric Yang-Mills theory with gauge group SU(2) or SU(3); (b) QCD with SU(2) colour and quarks in the adjoint representation; (c) QCD with three equal-mass quarks. Experience and perspectives in simulations o

B. Alles, M. Pepe

We present complete three loop results and preliminary four loop results for the 2D O(n) nonlinear sigma model with 0-loop and 1-loop Symanzik improved actions. This calculation aims to test the improvement in the numerical precision that the combination of Symanzik actions and effective couplings can give in Monte Carlo simulations.

B. Alles, M. D&#39;Elia, A. Di Giacomo

We investigate the topological susceptibility of the QCD vacuum with two flavours of dynamical staggered fermions on the lattice both at zero and finite temperature. At zero temperature we study the dependence of the signal on the fermion mass and at finite temperature we analyze the behaviour across the phase transition.

P. H. Damgaard, U. M. Heller, R. Niclasen, K. Rummukainen

We classify SU(3) gauge field configurations in different topological sectors by the smearing technique. In each sector we compute the distribution of low lying eigenvalues of the staggered Dirac operator. In all sectors we find perfect agreement with the predictions for the sector of topological charge zero. The smallest Dirac operator eigenvalues of stagge

L3 Collaboration

A search for unstable neutral and charged heavy leptons as well as for stable charged heavy leptons is performed at center-of-mass energies $\sqrt{s}$ = 183 and 189 GeV with the L3 detector at LEP. No evidence for their existence is found. We exclude neutral heavy leptons which couple to the electron, muon or tau family, of the Dirac type for masses below 92

L3 Collaboration

A search for heavy neutrinos that are isosinglets under the standard $SU(2)_L$ gauge group is made at center-of-mass energies 130 $< \sqrt{s} <$ 189 GeV with the L3 detector at LEP. Such heavy neutrinos are expected in many extensions of the Standard Model. The search is performed for the first generation heavy singlet neutrino, $\mathrm{N}_e$, through the d

L3 Collaboration

Inclusive production of $\mathrm{D^{*\pm}}$ mesons in two-photon collisions was measured by the L3 experiment at LEP. The data were collected at a centre-of-mass energy $\sqrt{s} = 189$ GeV with an integrated luminosity of $176.4 \mathrm{pb^{-1}}$. Differential cross sections of the process $\mathrm{e^+e^- \to D^{*\pm} X}$ are determined as functions of the

L3 Collaboration

A search for the Standard Model Higgs boson is carried out on 176.4pb$^{-1}$ of data collected by the L3 detector at a center-of-mass energy of 189 GeV. The data are consistent with the expectations of Standard Model processes and no evidence of a Higgs signal is observed. Combining the results of this search with those at lower center-of-mass energies, a lo

S. Carlip

According to the general theory of relativity, kinetic energy contributes to gravitational mass. Surprisingly, the observational evidence for this prediction does not seem to be discussed in the literature. I reanalyze existing experimental data to test the equivalence principle for the kinetic energy of atomic electrons, and show that fairly strong limits o

J. Podolsky, K. Vesely

Recent results demonstrating the chaotic behavior of geodesics in non-homogeneous vacuum pp-wave solutions are generalized. Here we concentrate on motion in non-homogeneous sandwich pp-waves and show that chaos smears as the duration of these gravitational waves is reduced. As the number of radial bounces of any geodesic decreases, the outcome channels to in

Sunggeun Lee, Chanyong Park, Sang-Jin Sin

We study the cosmology of the Brans-Dicke(BD) theory coupled to perfect fluid type matter. In our previous works, the case where matter is coming from the Ramond-Ramond sector of the string theory was studied. Here, we study the case where matter is coming from the NS-NS sector. Exact solutions are found and the cosmology is classified according to the value

Yungui Gong

We studied the Einstein-Brans-Dicke cosmology in detail. The difference of the evolution of the universe is significant between Einstein-Brans-Dicke cosmology and standard big-bang model during the radiation-dominated era. The power-law evolution of the scale factor is fast enough to solve the cosmological puzzles and slow enough to avoid the graceful exit p

Jean-Daniel Boissonnat, Jurek Czyzowicz, Olivier Devillers, Mariette Yvinec

Two planar sets are circularly separable if there exists a circle enclosing one of the sets and whose open interior disk does not intersect the other set. This paper studies two problems related to circular separability. A linear-time algorithm is proposed to decide if two polygons are circularly separable. The algorithm outputs the smallest separating circl

Jean-Daniel Boissonnat, Olivier Devillers, Sylvain Lazard

We study the problem of computing the free space F of a simple legged robot called the spider robot. The body of this robot is a single point and the legs are attached to the body. The robot is subject to two constraints: each leg has a maximal extension R (accessibility constraint) and the body of the robot must lie above the convex hull of its feet (stabil

Jean-Daniel Boissonnat, Jurek Czyzowicz, Olivier Devillers, Jorge Urrutia

A circle $C$ separates two planar sets if it encloses one of the sets and its open interior disk does not meet the other set. A separating circle is a largest one if it cannot be locally increased while still separating the two given sets. An Theta(n log n) optimal algorithm is proposed to find all largest circles separating two given sets of line segments w

Jean-Daniel Boissonnat, Jurek Czyzowicz, Olivier Devillers, Jean-Marc Robert

We consider the motion planning problem for a point constrained to move along a smooth closed convex path of bounded curvature. The workspace of the moving point is bounded by a convex polygon with m vertices, containing an obstacle in a form of a simple polygon with $n$ vertices. We present an O(m+n) time algorithm finding the path, going around the obstacl

S. Mohanty, R. N. Behera

In tree search problem the best-first search algorithm needs too much of space . To remove such drawbacks of these algorithms the IDA* was developed which is both space and time cost efficient. But again IDA* can give an optimal solution for real valued problems like Flow shop scheduling, Travelling Salesman and 0/1 Knapsack due to their real valued cost est

Victor Kurasov

The final (third) part of the theory gives the results of numerical calculations according to the formulas derived in the previous two parts. Also the comparison with the already published theories is given. Some conclusions connected with the qualitative picture of the nucleation process are presented.

Victor Kurasov

The second part of the theory for the multicomponent nonisothermal nucleation is presented. The solution of the kinetic equation already derived in the first part is given with the help of the Chapman-Enskog procedure. At first the relaxation stage is considered. The special choice of the relaxation operator allows to refuse from the special small parameter

S. Rosenkranz, R. Osborn, L. Vasiliu-Doloc, J. W. Lynn

The spin correlations of the bilayer manganite $La_{1.2}Sr_{1.8}Mn_{2}O_{7}$ have been studied using neutron scattering. On cooling within the paramagnetic state, we observe purely two-dimensional behavior with a crossover to three-dimensional scaling close to the ferromagnetic transition. Below $T_C$, an effective finite size behavior is observed. The quant

Victor Kurasov

The first part of the theory for the multicomponent nonisothermal nucleation is presented. On the base of analysis of the elementary acts of interation between an embryo and environment the kinetic equation is derived. This equation will be solved later and gives the nucleation rate for nonisothermal nucleation in the system with many condensating components

Yogesh N. Joglekar, Allan H. MacDonald

Double-layer quantum Hall systems at Landau level filling factor $ν=1$ have a broken symmetry ground state with spontaneous interlayer phase coherence and a gap between symmetric and antisymmetric subbands in the absence of interlayer tunneling. We examine the influence of quantum fluctuations on the spectral function of the symmetric Green&#39;s function, p

M. W. C. Dharma-wardana, F. Perrot

We use the now well known spin-unpolarized exchange-correlation energy E_{xc} of the uniform electron gas as the basic ``many-body&#39;&#39; input to determine the temperature T_q of a classical Coulomb fluid having the same correlation energy as the quantum system. It is shown that the spin-polarized pair distribution functions (SPDFs) of the classical flui

Ingve Simonsen, Alex Hansen

We introduce a fast algorithm for generating long self-affine profiles. The algorithm, which is based on the fast wavelet transform, is faster than the conventional Fourier filtering algorithm. In addition to increased performance for large systems, the algorithm, named the wavelet filtering algorithm, a priori gives rise to profiles for which the long-range

Horacio E. Castillo, Paul M. Goldbart

Randomly crosslinked macromolecules undergo a liquid-to-amorphous solid phase transition at a critical crosslink concentration. This transition has two main signatures: the random localization of a fraction of the monomers and the emergence of a nonzero static shear modulus. In this article, a semi-microscopic statistical mechanical theory of the elastic pro

P. Dubos, P. Charlat, Th. Crozes, P. Paniez

We have developped a novel lift-off process for fabrication of high quality superconducting submicron niobium structures. The process makes use of a thermostable polymer with a high transition temperature T_{g}= 235 C and an excellent chemical stability. The superconducting critical temperature of 100 nm wide niobium lines is above 7 K. An example of shadow

J. Quintanilla, B. L. Gyorffy

We study a simple BCS-like model which describes unconventional superconductivity on the basis of an electron-electron attraction corresponding to the delta-shell potential: $U(r) = -g δ(r-r_0)$. It predicts a $T_c$ vs. doping behavior similar to that characteristic of the High-$T_c$ cuprates.

C. W. J. Beenakker, K. J. H. van Bemmel, P. W. Brouwer

We study the effect of localisation on the propagation of a pulse through a multi-mode disordered waveguide. The correlator <u(omega1)u*(omega2)> of the transmitted wave amplitude u at two frequencies differing by delta_omega has for large delta_omega the stretched exponential tail ~exp(-sqrt{tau_D delta_omega/2}). The time constant tau_D=L^2/D is given by t

A. V. Mahajan, H. Alloul, G. Collin, J. F. Marucco

We present detailed data and analysis of the effects of Zn substitution on the planar Cu site in YBa$_2$Cu$_3$O$_{6+x}$ (YBCO$_{6+x}$) as evidenced from our $^{89}$Y NMR measurements on oriented powders. For $x<<1$ we find additional NMR lines which are associated with the Zn substitution. From our data on the intensities and temperature dependence of the sh

Jose A. Miranda

Isolated domains in lipid monolayers exhibit shape transitions as a consequence of the competing effects of line tension and long-range dipolar interactions. Nontrivial integrals ultimately arise in instability analysis calculations of these domains. In this work we present a closed form evaluation of such integrals in terms of associated Legendre functions.

V. A. Ivanov, Z. V. Popovic, P. Khuong, V. V. Moshchalkov

The AV_nO_{2n+1} mixed valence compounds (n=1, A=Na) are classified as dimerized layered system with strongly interacting d-electrons of vanadium ions. The derived band gaps, energy dispersion relations and density of electronic states are in a good agreement with available experimental and theoretical data. The correlated band gap provides the insulating st