April 1999 arXiv papers — page 11

S. Bar-Shalom, J. Wudka

We consider the inclusive reaction \ell^+ \ell^- -> nb +X (n = number of b-jets) in lepton colliders for which we propose a useful approximately conserved quantum number b_P=(-1)^n that we call b-Parity (b_P). We make the observation that the Standard Model (SM) is essentially b_P-even since SM b_P-violating signals are necessarily CKM suppressed. In contras

P. Colangelo, F. De Fazio

We analyze the radiative leptonic $B_c$ decay mode: $B_c \to \ell νγ$ ($\ell=e, μ$) using a QCD-inspired constituent quark model. The prediction: ${\cal B}(B_c \to \ell νγ)\simeq 3 \times 10^{-5}$ makes this channel experimentally promising in view of the large number of $B_c$ mesons which are expected to be produced at the future hadron facilities.

Peter D. Olmsted, C. -Y. David Lu

We analyze the behavior of a suspension of rigid rod-like particles in shear flow using a modified version of the Doi model, and construct diagrams for phase coexistence under conditions of constant imposed stress and constant imposed strain rate, among paranematic, flow-aligning nematic, and log-rolling nematic states. We calculate the effective constitutiv

V. D. Toneev, J. Cleymans, E. G. Nikonov, K. Redlich

It is shown that the condition for chemical freeze-out, average energy per hadron approximately 1 GeV, selects the softest point of the equation of state, namely the point where the pressure divided by the energy density has a minimum. The sensitivity to the equation of state used is discussed. The previously proposed mixed phase model, which is consistent w

Arti Tandon, Ziqiang Wang, Gabriel Kotliar

We study the interactions between the coherent quasiparticles and the incoherent Mott-Hubbard excitations and their effects on the low energy properties in the $U=\infty$ Hubbard model. Within the framework of a systematic large-N expansion, these effects first occur in the next to leading order in 1/N. We calculate the scattering phase shift and the free en

R. N. Faustov, A. P. Martynenko

The proton structure and proton polarizability corrections to the Lamb shift of electronic hydrogen and muonic hydrogen were evaluated on the basis of modern experimental data on deep inelastic structure functions. Numerical value of proton polarizability contribution to (2P-2S) Lamb shift is equal to 4.4 GHz.

Dieter Joseph

Self-organized critical models are used to describe the 1/f-spectra of rather different physical situations like snow avalanches, noise of electric currents, luminosities of stars or topologies of landscapes. The prototype of the SOC-models is the sandpile model of Bak, Tang and Wiesenfeld (Phys. Rev. Lett. 59, (1987) 351). We implement this model on non-per

Xuan-Yem Pham, Zhi-zhong Xing

Determination of the CP-violating parameters \sin 2βand \sin 2β' is shown to be possible from B^0_d vs \bar{B}^0_d \to D^{*+}D^{*-} and B^0_s vs \bar{B}^0_s \to D^{*+}_sD^{*-}_s decays {\it without} doing the angular analysis. The P-wave dilution factors of these two asymmetries are found to be 0.89 and 0.90, respectively, using the factorization approxi

G. Baur, K. Hencken, D. Trautmann, S. Sadovsky

Due to coherence, there are strong electromagnetic fields of short duration in very peripheral collisions. They give rise to photon-photon and photon-nucleus collisions with high flux up to an invariant mass region hitherto unexplored experimentally. After a general survey photon-photon luminosities in relativistic heavy ion collisions are discussed. Special

N. F. Nasrallah

The Golberger- Treiman discrepancy is related to the asymptotic behaviour of the pionic form factor of the nucleon obtained from baryonic QCD sum rules. The result is .015<=Delta_{GT}<=.022

H. Heiselberg, M. Hjorth-Jensen

Using the most recent realistic effective interactions for nuclear matter with a smooth extrapolation to high densities including causality, we constrain the equation of state and calculate maximum masses of rotating neutron stars. First and second order phase transitions to, e.g., quark matter at high densities are included. If neutron star masses of $\sim

Alessandro Strumia, Nikolaos Tetradis

We estimate bubble-nucleation rates for cosmological phase transitions. We concentrate on the evaluation of the pre-exponential factor, for which we give approximate analytical expressions. Our approach relies on the use of a real coarse-grained potential. We show how the coarse-graining scale can be determined in the studies of high-temperature phase transi

Paolo Sibani, Andreas Pedersen

We study populations of agents evolving in fitness landscapes constructed according to the rules of a modified NK model with a tunable amount of neutral paths. In the `punctuated equilibrium&#39; regime evolutionary events are identified as jumps in the mean population fitness, and the statistics of these jumps in an ensemble of independently evolving popula

Anders Westerberg, Niclas Wyllard

We explore the possibility of constructing p-brane world-volume actions with the requirements of kappa-symmetry and gauge invariance as the only input. In the process, we develop a general framework which leads to actions interpolating between Poincare-dual descriptions of the world-volume theories. The method does not require any restrictions on the on-shel

T. Tohyama, Y. Shibata, S. Maekawa, Z. -X. Shen

The numerically exact diagonalization study on small clusters of the t-J model with the second- and third- neighbor hopping terms shows that a novel spin liquid state is realized around a doped hole with momentum k=(pi,0) and energy \sim 2J compared with that with (pi/2,pi/2) in insulating cuprates, where the spin and charge degrees of freedom are approximat

Pil Hun Song, Dima L. Shepelyansky

We study the level spacing statistics $P(s)$ and eigenstate properties of spinless fermions with Coulomb interaction on a two dimensional lattice at constant filling factor and various disorder strength. In the limit of large lattice size, $P(s)$ undergoes a transition from the Poisson to the Wigner-Dyson distribution at a critical total energy independent o

Kang Young Lee, H. S. Song, JeongHyeon Song

We study large extra dimension effects on the polarizations of the $W$ pair and electron beam at the $e^+ e^-\to W^+ W^-$ process. It is shown that the measurements of the cross section for transversely polarized $W$ pair with the right-handed electron beam remarkably enhance the possibilities to see the low scale quantum gravity effects. Higher Linear Colli

Kazutoshi Ohta

We study the correspondence between the moduli space of vacua of three-dimensional supersymmetric Yang-Mills (Maxwell) Chern-Simons theories and brane configurations with (p,q)5-brane. For Coulomb branches, the number of the massless adjoint scalar fields in various supersymmetric theories exactly coincides with the number of the freely moving directions of

P. L. Christiansen, J. C. Eilbeck, V. Z. Enolskii, N. A. Kostov

We consider travelling periodic and quasiperiodic wave solutions of a set of coupled nonlinear Schrödimger equations. In fibre optics these equations can be used to model single mode fibers with strong birefringence and two-mode optical fibres. Recently these equations appear as modes, which describe pulse-pulse interaction in wavelength-division-multiplexed

N. A. Kostov

We consider complementary dynamical systems related to stationary Korteweg-de Vries hierarchy of equations. A general approach for finding elliptic solutions is given. The solutions are expressed in terms of Novikov polynomials in general quais-periodic case. For periodic case these polynomials coincide with Hermite and Lamé polynomials. As byproduct we deri

N. A. Kostov, Z. T. Kostova

The hierarchy of integrable equations are considered. The dynamical approach to the theory of nonlinear waves is proposed. The special solutions(nonlinear waves) of considered equations are derived. We use powerful methods of computer algebra such differential resultant and others.

D. Jonathan, A. Vidiella-Barranco, K. Furuya

The phenomenon of atomic population trapping in the Jaynes-Cummings Model is analysed from a dressed-state point of view. A general condition for the occurrence of partial or total trapping from an arbitrary, pure initial atom-field state is obtained in the form of a bound to the variation of the atomic inversion. More generally, it is found that in the pres

Andris Ambainis, Richard Bonner, Rusins Freivalds, Arnolds Kikusts

We construct a hierarchy of regular languages such that the current language in the hierarchy can be accepted by 1-way quantum finite automata with a probability smaller than the corresponding probability for the preceding language in the hierarchy. These probabilities converge to 1/2.

Alberto Barchielli, Giancarlo Lupieri

Quantum stochastic differential equations have been used to describe the dynamics of an atom interacting with the electromagnetic field via absorption/emission processes. Here, by using the full quantum stochastic Schroedinger equation proposed by Hudson and Parthasarathy fifteen years ago, we show that such models can be generalized to include other process

A. V. Taichenachev, A. M. Tumaikin, V. I. Yudin

A simple theoretical model describing the positive sign of subnatural-width absorption resonances in the recent experiment of Akulshin and co-workers (Phys. Rev. A, {\bf 57}, 2996 (1998)) is proposed. An analytical expression for the linear response to the weak probe field is found in the low-saturation limit with respect to the control field. It is shown th

Jan M Rost, Thomas Pattard

It is shown that recently measured cross sections for double ionization of negative ions ($H^-, O^-$, and $C^-$) possess a universal shape when plotted in suitable dimensionless units. The shape can be represented with a simple analytical function, following the same principles as it has been done in establishing a universal shape function for single ionizat

G. Quznetsov

The tracelike probability is expressed by the leptons and quarks Hamiltonians.

Jan-e Alam, Sourav Sarkar, Pradip Roy, Bikash Sinha

The formalism of photon and dilepton productions in a thermal bath are discussed in the frame work of finite temperature field theory. The emission rate has been expressed in terms of the discontinuities or imaginary part of the photon self energy in the thermal bath. The photon and dilepton emissions have been computed by taking into account the in-medium m

Peter Kuchment, Boris Vainberg

The problem of absence of eigenvalues imbedded into the continuous spectrum is considered for a Schrödinger operator with a periodic potential perturbed by a sufficiently fast decaying ``impurity&#39;&#39; potential. Results of this type have previously been known for the one-dimensional case only. Absence of embedded eigenvalues is shown in dimensions two a

K. Araki, K. Suzuki, K. Kishida, S. Kishiba

Multiresolution approximation (MRA) of the vector fields on T^3 is studied. We introduced in the Fourier space a triad of vector fields called helical vectors which derived from the spherical coordinate system basis. Utilizing the helical vectors, we proved the orthogonal decomposition of L^2(T^3) which is a synthesis of the Hodge decomposition of the differ

Anthony Bahri, Martin Bendersky

We use the Adams spectral sequence to compute the KO-theory of all toric manifolds and certain singular toric varieties.

J. Biswas, V. Srinivas

We prove an analogue of the Lefschetz (1,1) Theorem characterizing cohomology classes of Cartier divisors (or equivalently first Chern classes of line bundles) in the second integral cohomology. Let $X$ be a normal complex projective variety. We show that the classes of Cartier divisors in $H^2(X,Z)$ are precisely the classes $x$ such that (i) the image of $

M. S. Baouendi, P. Ebenfelt, L. P. Rothschild

It is shown that a formal mapping between two real-analytic hypersurfaces in complex space is convergent provided that neither hypersurface contains a nontrivial holomorphic variety. For higher codimensional generic submanifolds, convergence is proved e.g. under the assumption that the source is of finite type, the target does not contain a nontrivial holomo

Mike Zabrocki

We present a formulas to add a row or a column to the power, monomial, forgotten, Schur, homogeneous and elementary symmetric functions. As an application of these operators we show that the operator that adds a column to the Schur functions can be used to calculate a formula for the number of pairs of standard tableaux the same shape and height less than or

S. Kudla, M. Rapoport

We define special cycles on arithmetic models of twisted Hilbert-Blumenthal surfaces at primes of good reduction. These are arithmetic versions of these cycles. In particular, we characterize the non-degenerate intersections and partially determine the generating series formed from the intersection numbers of them relating it to the value at the center of sy

Takahiro Hayashi

Using face algebras (i.e. algebras of L-operators of IRF models), we construct modular tensor categories with positive definite inner product, whose fusion rules and S-matrices are the same as (or slightly different from) those obtained by $U_q (\frak{sl}_{N})$ at roots of unity. Also we obtain state-sums of ABF models on framed links which give quantum SU(2

Takahiro Hayashi

By studying ``points of the underlying quantum groups&#39;&#39;of coquasitriangular Hopf (face) algebras, we construct ribbon categories for each lattice models without spectral parameter of both vertex and face type. Also, we give a classification of the braiding and the ribbon structure on quantized classical groups and modular tensor categories closely re

Alexander Sergeev

Let V be a finite dimensional complex superspace and G a simple (or a ``close&#39;&#39; to simple) Lie superalgebra of matrix type, i.e., a Lie subsuperalgebra in GL(V). Under the classical invariant theory for G we mean the description of G-invariant elements of the tensor algebra of V. In math.RT/9810113 the invariants are described up to polarization oper

Takahiro Hayashi

For each finite semisimple tensor category, we associate a quantum group (face algebra) whose comodule category is equivalent to the original one, in a simple natural manner. To do this, we also give a generalization of the Tannaka-Krein duality, which assigns a face algebra for each tensor category equipped with an embedding into a certain kind of bimodule

Brian P. Dolan, Alex Lewis

A family of connections on the space of couplings for a renormalizable field theory is defined. The connections are obtained from a Levi-Civita connection, for a metric which is a generalisation of the Zamolodchikov metric in two dimensions, by adding a family of tensors which are solutions of the renormalization group equation for the operator product expan

G. Delfino

This paper has been withdrawn by the author

Carl R. Schmidt

I discuss the calculation of the next-to-leading logarithmic (NLL) corrections to the BFKL resummation, as well as some of the issues that arise in this formalism at NLL. In particular I consider the large size and apparent instability of the corrections, and I address some of the attempts to understand and tame them.

Yu. F. Pirogov, O. V. Zenin

The extension of the standard model with pairs of the vector-like families is studied. The quark mixing matrices for the left- and right-handed charged currents, as well as those for the flavour changing neutral currents, the Z and Higgs mediated, are found. Both the model independent parametrization for an arbitrary case and an explicit realization for the

A. Kirk, the WA102 Collaboration

A partial wave analysis of the centrally produced KK and pipi systems shows that the fJ(1710) has J = 0. In addition, a study of central meson production as a function of the difference in transverse momentum (dPT) of the exchanged particles shows that undisputed qqbar mesons are suppressed at small dPT whereas the glueball candidates are enhanced and that t

A. V. Borisov, P. E. Sizin

The polarization operator of an axion in a degenerate gas of electrons occupying the ground-state Landau level in a superstrong magnetic field $H\gg H_0=m_e^2c^3/e\hbar =4.41\cdot 10^{13}$ G is investigated in a model with a tree-level axion-electron coupling. It is shown that a dynamic axion mass, which can fall within the allowed range of values $(10^{-5}

Adrian Mirea, Elemer Nagy

Simulating pp collisions at LHC energies in the framework of the SUGRA model and the detection of the produced leptons and jets by ATLAS we demonstrate that a clean signature of SUSY can be obtained over a large domain of the parameter space in the case of L-violating R parity breaking ($λ$ couplings). The obtained signal allows the reconstruction of the SUS

S. Bonazzola, E. Gourgoulhon, J. -A. Marck

We present results of numerical computations of quasiequilibrium sequences of binary neutron stars with zero vorticity, in the general relativistic framework. The Einstein equations are solved under the assumption of a conformally flat spatial 3-metric (Wilson-Mathews approximation). The evolution of the central density of each star is monitored as the orbit

Albert Roura, Enric Verdaguer

The two-point function characterizing the stress tensor fluctuations of a massless minimally coupled field for an invariant vacuum state in de Sitter spacetime is discussed. This two-point function is explicitly computed for spacelike separated points which are geodesically connected. We show that these fluctuations are as important as the expectation value

S. Chaudhuri, P. F. Bagwell, D. McInturff, J. C. P. Chang

We correlate transmission electron microscope (TEM) pictures of superconducting In contacts to an AlGaAs/GaAs heterojunction with differential conductance spectroscopy performed on the same heterojunction. Metals deposited onto a (100) AlGaAs/GaAs heterostructure do not form planar contacts but, during thermal annealing, grow down into the heterostructure al

S. Martins, W. A. M. Morgado, M. S. O. Massunaga, M. Bahiana

Thin films of diblock copolymer subject to gravitational field are simulated by means of a cell dynamical system model. The difference in density of the two sides of the molecule and the presence of the field causes the formation of lamellar patterns with orientation parallel to the confining walls even when they are neutral. The concentration profile of tho

N S Branco, Cristiano J Silva

We study the $m=3$ bootstrap percolation model on a cubic lattice, using Monte Carlo simulation and finite-size scaling techniques. In bootstrap percolation, sites on a lattice are considered occupied (present) or vacant (absent) with probability $p$ or $1-p$, respectively. Occupied sites with less than $m$ occupied first-neighbours are then rendered unoccup

M. Switkes, C. M. Marcus, K. Campman, A. C. Gossard

A quantum pumping mechanism which produces dc current or voltage in response to a cyclic deformation of the confining potential in an open quantum dot is reported. The voltage produced at zero current bias is sinusoidal in the phase difference between the two ac voltages deforming the potential and shows random fluctuations in amplitude and direction with sm

P. Sunthar, V. Kumaran

The leading order &#34;temperature&#34; of a dense two dimensional granular material fluidised by external vibrations is determined. An asymptotic solution is obtained where the particles are considered to be elastic in the leading approximation. The velocity distribution is a Maxwell-Boltzmann distribution in the leading approximation. The density profile i

V. M. Pudalov, G. Brunthaler, A. Prinz, G. Bauer

We studied the weak field Hall voltage in 2D electron layers in Si-MOS structures with different mobilities, through the metal-insulator transition. In the vicinity of the critical density on the metallic side of the transition, we have found weak deviations (about 6-20 %) of the Hall voltage from its classical value. The deviations do not correlate with the

L. Ghivelder, I. Abrego Castillo, M. A. Gusmao, J. A. Alonso

Magnetic and specific-heat measurements are performed in three different samples of LaMnO_{3+δ}, with δ=0.11, 0.15 and 0.26, presenting important disorder effects, such as carrier localization, due to high amounts of La and Mn vacancies. For the samples with δ=0.11 and 0.15, magnetic measurements show signatures of a two-step transition: as the temperature i

Jean-Pierre Gazeau, Jacek Miekisz

We present a method of coding general self-similar structures. In particular, we construct a symmetry group of a one-dimensional Thue-Morse quasicrystal, i.e., of a nonperiodic ground state of a certain translation-invariant, exponentially decaying interaction.

J. Bergenholtz, M. Fuchs

The colloidal gel and glass transitions are investigated using the idealized mode coupling theory (MCT) for model systems characterized by short-range attractive interactions. Results are presented for the adhesive hard sphere and hard core attractive Yukawa systems. According to MCT, the former system shows a critical glass transition concentration that inc

M. C. Bergère

We improve Haldane&#39;s formula which gives the number of configurations for $N$ particles on $d$ states in a fractional statistic defined by the coupling $g=l/m$. Although nothing is changed in the thermodynamic limit, the new formula makes sense for finite $N=pm+r$ with $p$ integer and $0<r\leq m.$ A geometrical interpretation of fractional statistic is g

Janusz Jedrzejewski, Jacek Miekisz

We study ground-state orderings of particles in classical lattice-gas models of adsorption on crystal surfaces. In the considered models, the energy of adsorbed particles is a sum of two components, each one representing the energy of a one-dimensional lattice gas with two-body interactions in one of the two orthogonal lattice directions. This feature reduce

Kikuo Harigaya

Disorder effects on the density of states in carbon nanotubes are analyzed by a tight binding model with Gaussian bond or site disorder. Metallic armchair and semiconducting zigzag nanotubes are investigated. In the strong disorder limit, the conduction and valence band states merge, and a finite density of states appears at the Fermi energy in both of metal

Richard Jordan, Bruce Turkington, Craig Zirbel

A statistical model of self-organization in a generic class of one-dimensional nonlinear Schrodinger (NLS) equations on a bounded interval is developed. The main prediction of this model is that the statistically preferred state for such equations consists of a deterministic coherent structure coupled with fine-scale, random fluctuations, or radiation. The m

L. Biferale, M. Cencini, D. Vergni, A. Vulpiani

The exit time statistics of experimental turbulent data is analyzed. By looking at the exit-time moments (Inverse Structure Functions) it is possible to have a direct measurement of scaling properties of the laminar statistics. It turns out that the Inverse Structure Functions show a much more extended Intermediate Dissipative Range than the Structure Functi

Gilbert P. Holder, John E. Carlstrom

The Sunyaev-Zel&#39;dovich (SZ) effect from clusters of galaxies should yield a significant signal in cosmic microwave background(CMB) experiments at small angular scales ($\ell \ga 1000$). Experiments with sufficient frequency coverage should be able to remove much of this signal in order to recover the primary anisotropy. The SZ signal is interesting in it

A. Aloisi, M. Tosi, L. Greggio

The star formation history in IZw18 has been inferred from HST/WFPC2 archival data. This is done by comparing the derived V, B-V and V, V-I color-magnitude diagrams and luminosity functions with synthetic ones, based on various sets of stellar evolutionary tracks. At a distance of 10 Mpc, the stars resolved in the field of IZw18 allow for a lookback time up

A. Gauger, Y. Y. Balega, P. Irrgang, R. Osterbart

We present the first diffraction-limited speckle masking observations of the oxygen-rich AGB star AFGL 2290. The data was obtained with the Russian 6m SAO telescope. At the wavelength of 2.11um a resolution of 75mas was achieved. The reconstructed image reveals that the CDS of AFGL 2290 is slightly non-spherical. The stellar contribution to the total 2.11um

Maureen van den Berg, Frank Verbunt, Robert D. Mathieu

We have obtained optical spectra of seven stars in the old galactic cluster M67 that are unusual sources of X-rays, and investigate whether the X-ray emission is due to magnetic activity or to mass transfer. The two binaries below the giant branch S1063 and S1113, the giant with the white dwarf companion S1040 and the eccentric binary on the subgiant branch

F. Halzen

Although high energy neutrino astronomy is a multidisciplinary science, gamma ray bursts have become the theoretical focus since recent astronomical observations revealed their potential as cosmic particle accelerators. This spotlight is shared with investigations of the potential of high energy telescopes to observe oscillating atmospheric neutrinos. The Su

Ramon Khanna

The generation and evolution of magnetic fields in the plasma accreting into a rotating black hole is studied in the 3+1 split of the Kerr metric. Attention is focused on effects of the gravitomagnetic potential. The gravitomagnetic force appears as battery term in the generalized Ohm&#39;s law. The gravitomagnetic battery is likely to saturate at higher fie

S. Basa

Neutrinos may offer a unique opportunity to explore the far Universe at high energy. The ANTARES collaboration aims at building a large undersea neutrino detector able to observe astrophysical sources (AGNs, X-ray binary systems, ...) and to study particle physics topics (neutrino oscillation, ...). After a description of the research opportunities of such a

GianLuca Israel, Stefano Covino, Luigi Stella, Sergio Campana

We report the results of two ROSAT HRI observations of the recently discovered 11s X-ray pulsar 1RXS J170849.0-400910. A refined position with a smaller error radius (10&#34; uncertainty) and a new spin period measurement were obtained. These results allowed to derive a period derivative of about 7 times 10^-4 s yr^-1 and to perform a photometric and spectro

Christoph Schaab, Manfred K. Weigel

Recently discovered quasi periodic oscillations in the X-ray brightness of low mass X-ray binaries are used to derive constraints on the mass of the neutron star component and the equation of state of neutron star matter. The observations are compared with models of rapidly rotating neutron stars which are calculated by means of an exact numerical method in

G. Giovannini, M. Tordi, L. Feretti

We present the first results of the search of new halo and relic candidates in the NRAO VLA Sky Survey. We have inspected a sample of 205 clusters from the X-ray-brightest Abell-type clusters presented by Ebeling et al (1996), and found 29 candidates. Out of them, 11 clusters are already known from the literature to contain a diffuse cluster-wide source, whi

Daniel Huber, Daniel Pfenniger

The interstellar medium (ISM) reveals strongly inhomogeneous structures at every scale. These structures do not seem completely random since they obey certain power laws. Larson's law (\citeyear{Larson81}) $\sigma \propto R^{\delta}$ and the plausible assumption of virial equilibrium justify to consider fractals as a possible description of the ISM. In the f

U. Fritze-v. Alvensleben, U. Lindner, C. S. Möller, K. J. Fricke

We extend our spiral galaxy models that successfully describe nearby template spectra as well as the redshift evolution of CFRS and HDF spirals to include - in a chemically consistent way - the redshift evolution of a series of individual elements. Comparison with observed DLA abundances shows that DLAs might well be the progenitors of present-day spiral typ

E. Athanassoula, M. Bureau

We develop diagnostics based on gas kinematics to identify the presence of a bar in an edge-on spiral galaxy and determine its orientation. We use position-velocity diagrams (PVDs) obtained by projecting edge-on two-dimensional hydrodynamical simulations of the gas flow in a barred galaxy potential. We show that when a nuclear spiral is formed, the presence

F. Bauer

We present the Period-Luminosity relations from 290 Cepheids towards the LMC and 590 Cepheids towards the SMC. The two data sets were obtained using the two wide field CCD cameras of the EROS 2 microlensing survey. We observe a significant slope change of the period-luminosity relation for the SMC fundamental mode Cepheids with periods shorter than 2 days. M

R. Rapp, T. Schaefer, E. V. Shuryak, M. Velkovsky

Instantons generate strong non-perturbative interactions between quarks. In the vacuum, these interactions lead to chiral symmetry breaking and generate constituent quark masses on the order of 300-400 MeV. The observation that the same forces also provide attraction in the scalar diquark channel leads to the prediction that cold quark matter is a color supe

T. J. Hollowood, V. V. Khoze, W. Lee, M. P. Mattis

A longstanding puzzle concerns the calculation of the gluino condensate <{trλ^2\over 16π^2}> = cΛ^3 in N=1 supersymmetric SU(N) gauge theory: so-called weak-coupling instanton (WCI) calculations give c=1, whereas strong-coupling instanton (SCI) calculations give, instead, c=2[(N-1)!(3N-1)]^{-1/N}. By examining correlators of this condensate in arbitrary mult

Charanjit S. Aulakh, Borut Bajc, Alejandra Melfo, Andrija Rasin

We show that intermediate scales in supersymmetric grand unified theories may exist naturally. Their origin is traced to the violation of the survival principle: in supersymmetry internal symmetries often forbid cubic couplings in the superpotential. This leads to a plethora of light supermultiplets whose masses are generated only by higher dimensional opera

Tatiana G. Rappoport, M. S. Figueira, M. A. Continentino

We study the influence of short range antiferromagnetic correlations between local $f$-electrons on the transport and thermodynamic properties of Kondo insulators, as first proposed by Coqblin et al. for metallic heavy fermions. The inter-site magnetic correlations produce an effective bandwidth for the $f$-electrons. They are treated on the same footing as

Anders W. Sandvik

A multi-chain mean-field theory is developed and applied to a two-dimensional system of weakly coupled S=1/2 Heisenberg chains. The environment of a chain C_0 is modeled by a number of neighbor chains C_d, d = +/-1,...,+/-n, with the edge chains (d=+/-n) coupled to a staggered field. Using a quantum Monte Carlo method, the effective (2n+1)-chain Hamiltonian

David Hochberg, Carmen Molina-Paris, Juan Perez-Mercader, Matt Visser

Stochastic partial differential equations (SPDEs) are the basic tool for modeling systems where noise is important. In this paper we set up a functional integral formalism and demonstrate how to extract all the one-loop physics for an arbitrary SPDE subject to arbitrary Gaussian noise. It is extremely important to realize that Gaussian noise does not imply t

J. X. Lu, Shibaji Roy

An (m, n)-string bound state (with m, n relatively prime integers) in type IIB string theory can be interpreted from the D-string worldsheet point of view as n D-strings carrying m units of quantized electric flux or quantized electric field. We argue, from the D-brane worldvolume point of view, that similar Dp-brane bound states should also exist for $2 \le

K. Scharnhorst

The article reviews some of the (fairly scattered) information available in the mathematical literature on the subject of angles in complex vector spaces. The following angles and their relations are considered: Euclidean, complex, and Hermitian angles, (Kasner&#39;s) pseudo-angle, the Kaehler angle (synonyms for the latter used in the literature are: angle

W. Chen, Tingxiu Zhong

This paper points out that the differential quadrature (DQ) and differential cubature (DC) methods due to their global domain property are more efficient for nonlinear problems than the traditional numerical techniques such as finite element and finite difference methods. By introducing the Hadamard product of matrices, we obtain an explicit matrix formulati

K. S. Virbhadra, George F. R. Ellis

We study strong gravitational lensing due to a Schwarzschild black hole. Apart from the primary and the secondary images we find a sequence of images on both sides of the optic axis; we call them {\em relativistic images}. These images are formed due to large bending of light near r = 3M (the closest distance of approach r_o is greater than 3M). The sources

W. Chen

By using the Hadamard matrix product concept, this paper introduces two generalized matrix formulation forms of numerical analogue of nonlinear differential operators. The SJT matrix-vector product approach is found to be a simple, efficient and accurate technique in the calculation of the Jacobian matrix of the nonlinear discretization by finite difference,

Semyon Pol&#39;shin

The solutions of the arbitrary-spin massless wave equations over ${\bf R}^1 \times H^3$ space are obtained using the generalized coherent states for the Lorentz group. The use of these solutions for the construction of invariant propagators of quantized massless fields with an arbitrary spin over the ${\bf R}^1 \times H^3$ space is considered. The expression

Jaroslaw Wlodarczyk

The main goal of the present paper is two-fold. First we extend the theory of toroidal embeddings introduced by Kempf, Knudsen, Mumford and Saint-Donat to the class of toroidal varieties with stratifications (which is the main body of the paper). Second we give a proof of the following weak factorization theorem as an application and illustration of the theo

J. Santiago, F. J. Yndurain

We use the known values of the two loop Wilson coefficients and the three loop anomalous dimension matrix $γ(n)$ to perform a next-to-next-to leading order (NNLO) calculation of $ep$ deep inelastic scattering. Because $γ(n)$ is only known for a few values of $n$, the method of average reconstruction has to be used, which leaves 102 effective experimental poi

Masakazu Murakami

Possible ordered states in the 2D extended Hubbard model with on-site (U>0) and nearest-neighbor (V) interaction are examined near half filling, with emphasis on the effect of finite V. First, the phase diagram at absolute zero is determined in the mean field approximation. For $V<0$, a state where d_{x^{2}-y^{2}}-wave superconductivity (dSC), commensurate s

M. Tanimoto, T. Watari, T. Yanagida

We impose $O(3)_L\times O(3)_R$ flavor symmetry in the supersymmetric standard model. Three lepton doublets $\ell_i$ transform as an $O(3)_L$ triplet and three charged leptons $\bar e_i$ as an $O(3)_R$ triplet, while Higgs doublets $H$ and $\bar H$ are $O(3)_L\times O(3)_R$ singlets. We discuss a flavor $O(3)_L\times O(3)_R$ breaking mechanism that leads to

Satish. D. Joglekar, A. Misra

We use the earlier results on the correlations of axial gauge Green&#39;s functions and the Lorentz gauge Green&#39;s functions obtained via finite field-dependent BRS transformations to study the question of the correct treatment of 1/(eta\cdot k)^p- type singularities in the axial gauge boson propagator. We show how the known treatment of the 1/(k^2)^n-typ

J. Evslin, M. B. Halpern, J. E. Wang

We obtain the orbifold Virasoro master equation (OVME) at integer order lambda, which summarizes the general Virasoro construction on orbifold affine algebra. The OVME includes the Virasoro master equation when lambda=1 and contains large classes of stress tensors of twisted sectors of conventional orbifolds at higher lambda. The generic construction is like

S. Nojiri, O. Obregon, S. D. Odintsov, K. E. Osetrin

Using large N, 4d anomaly induced one-loop effective action for conformally invariant matter (typical GUT multiplet) we study the possibility to induce the primordial spherically symmetric wormholes at the early Universe. The corresponding effective equations are obtained in two different coordinate frames. The numerical investigation of these equations is d

Philip R. Page

We construct (hybrid) baryons in the flux-tube model of Isgur and Paton. In the limit of adiabatic quark motion, we build proper eigenstates of orbital angular momentum and construct the flavour, spin and J^P of hybrid baryons from the symmetries of the system. The lowest mass hybrid baryon is estimated at approximately 2 GeV.

Niky Kamran, Robert Milson, Peter Olver

We completely characterize all nonlinear partial differential equations leaving a given finite-dimensional vector space of analytic functions invariant. Existence of an invariant subspace leads to a re duction of the associated dynamical partial differential equations to a system of ordinary differential equations, and provide a nonlinear counterpart to quas

V. V. Ulyanov, O. B. Zaslavskii

Considered is quantum tunnelling in anisotropic spin systems in a magnetic field perpendicular to the anisotropy axis. In the domain of small field the problem of calculating tunnelling splitting of energy levels is reduced to constructing the perturbatio n series with degeneracy, the order of degeneracy being proportional to a spin value. Partial summation

Konrad Banaszek

Optical homodyne tomography is discussed in the context of classical image processing. Analogies between these two fields are traced and used to formulate an iterative numerical algorithm for reconstructing the Wigner function from homodyne statistics.

A. S. Parkins, H. J. Kimble

We describe schemes for transferring quantum states between light fields and the motion of a trapped atom. Coupling between the motion and the light is achieved via Raman transitions driven by a laser field and the quantized field of a high-finesse microscopic cavity mode. By cascading two such systems and tailoring laser field pulses, we show that it is pos