June 2000 arXiv papers — page 3

Filippo Castiglione

We describe a new model to simulate the dynamic interactions between market price and the decisions of two different kind of traders. They possess spatial mobility allowing to group together to form coalitions. Each coalition follows a strategy chosen from a proportional voting ``dominated'' by a leader's decision. The interplay of both kind of a

B. Sandow, K. Gloos, R. Rentzsch, A. N. Ionov

We have investigated the effect of the long-range Coulomb interaction on the one-particle excitation spectrum of n-type Germanium, using tunneling spectroscopy on mechanically controllable break junctions. The tunnel conductance was measured as a function of energy and temperature. At low temperatures, the spectra reveal a minimum at zero bias voltage due to

Nick N. Gorkavyi, Leonid M. Ozernoy, Tanya Taidakova, John C. Mather

(Abridged) Using an efficient computational approach, we have reconstructed the structure of the dust cloud in the Solar system between 0.5 and 100 AU produced by the Kuiper belt objects. Our simulations offer a 3-D physical model of the `kuiperoidal' dust cloud based on the distribution of 280 dust particle trajectories produced by 100 known Kuiper belt

Patrick B. Hall, H. K. C. Yee, Huan Lin, Simon L. Morris

We present five candidate gravitational lenses discovered spectroscopically in the Canadian Network for Observational Cosmology Field Galaxy Redshift Survey (CNOC2), along with one found in followup observations. Each has a secure redshift based on several features, plus a discrepant emission line which does not match any known or plausible feature and is vi

Piercarlo Bonifacio, Elisabetta Caffau, Paolo Molaro

We derive an intrinsic colour calibration for F--K stars using broad band Johnson colours and line indices KP and HP2. Through this calibration we can determine E(B-V) of an individual star within 0.03 mag. The E(B-V) values thus derived are in excellent agreement with those derived from Stromgren photometry through the Schuster & Nissen (1989) calibration.

Prasenjit Saha

This paper shows that the mass-sheet degeneracy and other degeneracies in lensing have simple geometrical interpretations: they are mostly rescalings of the arrival-time surface. Different degeneracies appear in Local Group lensing and in cosmological lensing, because in the former the absolute magnification is measured but the image structure is not resolve

C. Lobo, A. Iovino, D. Lazzati, G. Chincarini

We present a new algorithm to search for distant clusters of galaxies on catalogues deriving from imaging data, as those of the ESO Imaging Survey. Our algorithm is a matched filter one, similar to that adopted by Postman et al. (1996), aiming at identifying cluster candidates by using positional and photometric data simultaneously. The main novelty of our a

Simon F. Portegies Zwart

We study the evolution and observability of young and compact star clusters near the Galactic center, such as the Arches cluster and the Quintuplet. The star clusters are modeled with a combination of techniques; using direct N-body, integration to calculate the motions of all stars and detailed stellar and binary evolution to follow the evolution of the sta

K. Iwasawa, A. C. Fabian, O. Almaini, P. Lira

We report the detection of an absorbed central X-ray source and its strong, rapid variability in NGC4395, the least luminous Seyfert nucleus known. The X-ray source exhibits a number of flares with factors of 3-4 flux changes during a half day ASCA observation. Such X-ray variability is in constrast to the behaviour of other low luminosity active galaxies. I

Jozef Klacka

Comments to the statements of Srikanth (1999) are presented. As for the standard definition of the Poynting-Robertson drag, the results of Srikanth (1999) are incorrect. Srikanth's statements about the isothermality condition and ``red-shift'' are also discussed. Srikanth's results are generalized for the most general case of the equation of

Norbert Straumann

A pedagogical description of a simple ungeometrical approach to General Relativity is given, which follows the pattern of well understood field theories, such as electrodynamics. This leads quickly to most of the important weak field predictions, as well as to the radiation damping of binary pulsars. Moreover, certain consistency arguments imply that the the

Halton Arp

The brightest apparent magnitude examples of ultra luminous infrared galaxies (ULIRG's) are studied here in X-ray, optical, infrared and radio wavelengths. It is is found that they have associated material reaching out to apparent diameters of the order of a degree on the sky. Gas, dust, X-ray material and quasars appear to be ejected from the active nuc

D. Greusard, D. Friedli, H. Wozniak, L. Martinet

Surface photometry in the J and K' bands of 15 southern Seyfert or starburst galaxies is presented. The detailed central morphology and structural properties of these objects were analyzed by fitting ellipses to isophotes. New central peculiar structures have been identified like, for instance, three double-barred systems (ESO 215-G031; ESO 320-G030; ESO

Jean-Christophe Hamilton

Observations of the Cosmic Microwave Background (CMB) temperature fluctuations are a powerful tool for testing theories of the early Universe and for measuring cosmological parameters. We present basics of CMB physics, review some of the most recent results and discuss their implications for cosmology. The Archeops balloon-borne experiment is designed to map

F. J. Sevilla, M. Grether, M. Fortes, M. de Llano

The Bose-Einstein condensation (BEC) temperature $T_{c}$ of Cooper pairs (CPs) created from a very general interfermion interaction is determined for a {\it linear}, as well as the usual quadratic, energy {\it vs}% center-of-mass momentum dispersion relation. This $T_{c}$ is then compared to that of Wen & Kan (1988) in $d=2+ε$ dimensions, for small $ε$, in a

Matthias Liebendoerfer, Anthony Mezzacappa, Friederich-Karl Thielemann, O. E. Bronson Messer

We report on the stellar core collapse, bounce, and postbounce evolution of a 13 solar mass star in a self-consistent general relativistic spherically symmetric simulation based on Boltzmann neutrino transport. We conclude that approximations to exact neutrino transport and omission of general relativistic effects were not alone responsible for the failure o

Gerald B. Cleaver, Alon E. Faraggi, Christopher Savage

Recently it was demonstrated that free fermionic heterotic-strings can produce models with solely the Minimal Supersymmetric Standard Model states in the low energy spectrum. This unprecedented result provides further strong evidence for the possibility that the true string vacuum shares some of the properties of the free fermionic models. Past free fermioni

M. B. Johnson, B. Z. Kopeliovich, A. V. Tarasov

Broadening of the transverse momentum of a parton propagating through a medium is treated using the color dipole formalism, which has the advantage of being a well developed phenomenology in deep-inelastic scattering and soft processes. Within this approach, nuclear broadening should be treated as color filtering, i.e. absorption of large-size dipoles leadin

L. Canton, W. Schadow

We consider a new three-nucleon force generated by the exchange of one pion in the presence of a 2N correlation. The underlying irreducible diagram has been recently suggested by the authors as a possible candidate to explain the puzzle of the vector analyzing powers $A_y$ and $iT_{11}$ for nucleon-deuteron scattering. Herein, we have calculated the elastic

L. Di Lella, A. Pilaftsis, G. Raffelt, K. Zioutas

We explore the physics potential of a terrestrial detector for observing axionic Kaluza-Klein excitations coming from the Sun within the context of higher-dimensional theories of low-scale quantum gravity. In these theories, the heavier Kaluza-Klein axions are relatively short-lived and may be detected by a coincidental triggering of their two-photon decay m

Francesco Mainardi, Marco Raberto, Rudolf Gorenflo, Enrico Scalas

We complement the theory of tick-by-tick dynamics of financial markets based on a Continuous-Time Random Walk (CTRW) model recently proposed by Scalas et al., and we point out its consistency with the behaviour observed in the waiting-time distribution for BUND future prices traded at LIFFE, London.

Luc Blanchet, Guillaume Faye

The two purposes of the paper are (1) to present a regularization of the self-field of point-like particles, based on Hadamard's concept of ``partie finie'', that permits in principle to maintain the Lorentz covariance of a relativistic field theory, (2) to use this regularization for defining a model of stress-energy tensor that describes point-

S. S. Kamalov, S. N. Yang, D. Drechsel, O. Hanstein

Recent JLab data of the differential cross section for the reaction p(e,e&#39;p)pi0 in the invariant mass region of 1.1 < W < 1.4 GeV at four-momentum transfer squared Q^2= 2.8 and 4.0 (GeV/c)$^2$ are analyzed with two models, both of which give an excellent description of most of the existing pion electroproduction data below W < 1.5 GeV. We find that at up

I. Bakas, A. Bilal, J. -P. Derendinger, K. Sfetsos

All high-temperature phases of the known N=4 superstrings in five dimensions can be described by the universal thermal potential of an effective four-dimensional supergravity. This theory, in addition to three moduli s, t, u, contains non-trivial winding modes that become massless in certain regions of the thermal moduli space, triggering the instabilities a

Luis Alvarez-Gaume, Spenta R. Wadia

In this note we present a operator formulation of gauge theories in a quantum phase space which is specified by a operator algebra. For simplicity we work with the Heisenberg algebra. We introduce the notion of the derivative (transport) and Wilson line (parallel transport) which enables us to construct a gauge theory in a simple way. We illustrate the formu

M. Penttinen, M. V. Polyakov, A. G. Shuvaev, M. Strikman

We compute amplitude of deeply virtual Compton scattering in the parton model. We found that the amplitude up to the accuracy O(1/Q) depends on new skewed parton distributions (SPD&#39;s). These additional contributions make the DVCS amplitude explicitly transverse.

S. Bourque, P. Mathieu

The Painlevé analysis of a generic multiparameter N=2 extension of the Korteweg-de Vries equation is presented. Unusual aspects of the analysis, pertaining to the presence of two fermionic fields, are emphasized. For the general class of models considered, we find that the only ones which manifestly pass the test are precisely the four known integrable super

Jose F. Nieves, Palash B. Pal

When neutrinos travel through a normal matter medium, the electron neutrinos couple differently to gravity compared to the other neutrinos, due to the presence of electrons in the medium and the absence of the other charged leptons. We calculate the momentum-dependent part of the matter-induced gravitational couplings of the neutrinos under such conditions,

Roberto Franzosi, Vittorio Penna

We investigate the energy spectrum structure of a system of two (identical) interacting bosonic wells occupied by N bosons within the Schwinger realization of the angular momentum. This picture enables us to recognize the symmetry properties of the system Hamiltonian H and to use them for characterizing the energy eigenstates. Also, it allows for the derivat

Dumitru M. Ghilencea, Graham G. Ross

We apply the standard approach of RG flow for the gauge couplings in N=1 D=4 Supergravity to show how to match its results with the heterotic $Z_3$ orbifold and Type IIB ${Z_3}$ orientifold-based models. Using only supergravity, anomaly cancellation and the requirement of unification we determine the part of the Kähler potential of the model invariant under

H. A. Carteret, A. Higuchi, A. Sudbery

We find a canonical form for pure states of a general multipartite system, in which the constraints on the coordinates (with respect to a factorisable orthonormal basis) are simply that certain ones vanish and certain others are real. For identical particles they are invariant under permutations of the particles. As an application, we find the dimension of t

C. -L. Chou, H. -L. Lai, C. -P. Yuan

Motived by the neutrino oscillation data, we consider the lightest tau sneutrino $\tilde ν_{τ_1}$ (which is mostly the right tau sneutrino) to be the lightest supersymmetric particle (LSP) in the framework of the minimal supersymmetric Standard Model. Both the standard and the non-standard trilinear scalar coupling terms are included for the right tau sneutr

Oded Agam, Avraham Schiller

A microscopic theory is developed for the projection (quantum mirage) of the Kondo resonance from one focus of an elliptic quantum corral to the other focus. The quantum mirage is shown to be independent of the size and the shape of the ellipse, and experiences λ_F/4 oscillations (λ_F is the surface-band Fermi wavelength) with an increasing semimajor axis le

Sayan Kar, Parthasarathi Majumdar, Soumitra Sengupta, Aninda Sinha

A spacetime with torsion produced by a Kalb-Ramond field coupled gravitationally to the Maxwell field, in accordance with a recent proposal by two of us (PM and SS), is argued to lead to an optical activity in synchrotron radiation from cosmologically distant radio sources. We suggest that this could qualitatively explain observational data from a large numb

Yuri G. Prokhorov

We study Mori&#39;s three-dimensional contractions $f\colon X\to Z$. It is proved that on the ``good&#39;&#39; model $(\bar X,\bar S)$ the exceptional divisor has no elliptic components of $Diff_{\bar S}$ with coefficients $\ge 6/7$.

Jerome Martin, Nelson Pinto-Neto, Ivano Damiao Soares

We explicitly calculate the Green functions describing quantum changes of topology in Friedman-Lemaitre-Robertson-Walker Universes whose spacelike sections are compact but endowed with distinct topologies. The calculations are performed using the long wavelength approximation at second order in the gradient expansion. We argue that complex metrics are necess

Hiroo Azuma, Masashi Ban

In this paper, we propose a method of enciphering quantum states of two-state systems (qubits) for sending them in secrecy without entangled qubits shared by two legitimate users (Alice and Bob). This method has the following two properties. First, even if an eavesdropper (Eve) steals qubits, she can extract information from them with certain probability at

Avinash Khare, Bhabani Prasad Mandal

We show that the quasi-exactly solvable eigenvalues of the Schrödinger equation for the PT-invariant potential $V(x) = -(ζ\cosh 2x -iM)^2$ are complex conjugate pairs in case the parameter M is an even integer while they are real in case M is an odd integer. We also show that whereas the PT symmetry is spontaneously broken in the former case, it is unbroken

S. A. Trigger

A kinetic equation for dust particles with a new kinetic variable - the mass of grains - is suggested for the description of processes with changing mass in dusty plasmas and neutral systems.

Francesco di Liberto

The expansions or the compressions of the ideal gas in the quasi-static Carnot cycle, can be performed (on adiabatic or isothermal way) by slowly increasing or decreasing the external pressure by means of small weights acting on the piston of the vessel containing the gas. We call them shortly the ``driving weights&#39;&#39; (dw). Let N be their number, a la

A. M. Ignatov, S. A. Trigger

It is shown that absorption of ions by the dust grain may reduce the effective translational temperature of the dust component below the ambient gas temperature.

Zu-Guo Yu, Vo Anh

A time series model based on the global structure of the complete genome is proposed. Three kinds of length sequences of the complete genome are considered. The correlation dimensions and Hurst exponents of the length sequences are calculated. Using these two exponents, some interesting results related to the problem of classification and evolution relations

Gregory M. Smith

A solution to the problem of unifying the General Relativistic and Quantum Theoretical formalisms is given which introduces a new non-axiomatic symbolic method and an algebraic generalization of the Calculus to non-finite symbolisms without reference to the concept of a limit. An essential feature of the non-axiomatic method is the inadequacy of any (finite)

D. Blaschke, G. Burau, Yu. L. Kalinovsky

We investigate the in-medium modification of the charmonium breakup processes due to the Mott-effect for D-mesons at the chiral phase transition. A model calculation for the process J/Psi+pi --> D+D^*+ h.c. is presented which demonstrates that threshold effects in the thermal averaged breakup cross section can be explained as a Mott transition where final st

W. Schadow, O. Nohadani, W. Sandhas

We discuss the available data for the differential and the total cross section for the photodisintegration of $^3$He and $^3$H and the corresponding inverse reactions below $E_γ= 100$ MeV by comparing with our calculations using realistic $NN$ interactions. The theoretical results agree within the errorbars with the data for the total cross sections. Excelle

Yoshikazu Fujiwara, Michio Kohno, Choki Nakamoto, Yasuyuki Suzuki

The G-matrix equation is most straightforwardly formulated in the resonating-group method if the quark-exchange kernel is directly used as the driving term for the infinite sum of all the ladder diagrams. The inherent energy-dependence involved in the exchange term of the normalization kernel plays the essential role to define the off-shell T-matrix uniquely

B. Desplanques

The parity-non-conserving (pnc) asymmetry in \vec{n} + p \to d+γat thermal energies has recently been calculated using effective field-theory methods. A comparison of this calculation with much more elaborate calculations performed in the 70&#39;s is made. This allows one to assess the validity of this new approach as presently used. It is found to overshoot

A. Marinov, S. Gelberg, D. Kolb, J. L. Weil

Relatively low energy and very enhanced alpha-particle groups have been observed in various actinide fractions produced via secondary reactions in a CERN W target which had been irradiated with 24-GeV protons. In particular, 5.14, 5.27 and 5.53 MeV alpha-particle groups with corresponding half-lives of 3.8(+ -)1.0 y, 625(+ -)84 d and 26(+ -)7 d, have been se

Henk van Beijeren, J. R. Dorfman

The connection between the rate of entropy production and the rate of phase space contraction for thermostatted systems in nonequilibrium steady states is discussed for a simple model of heat flow in a Lorentz gas, previously described by Spohn and Lebowitz. It is easy to show that for the model discussed here the two rates are not connected, since the rate

Sergey B. Karavashkin

Exact analytic solutions for one-dimensional elastic lumped line under affection of external force inclined to the axe of line is analyzed. It is shown that in this case an inclined wave being described by implicit function propagates along the line. The conclusions were extended both to unforced vibrations in the line and to distributed-parameters line vibr

Eric Babson, Paul E. Gunnells, Richard Scott

We construct a smooth symmetric compactification of the space of all labeled tetrahedra in P^3.

Andrzej Roslanowski, Saharon Shelah

We show that, consistently, for some regular cardinals theta<lambda, there exists a Boolean algebra B such that B=lambda^+ and for every subalgebra B&#39; of B of size lambda^+ we have Depth(B&#39;)=theta.

B. M. Brown, M. Marletta

We consider the effect of regularization by interval truncation on the spectrum of a singular non-selfadjoint Sturm-Liouville operator. We present results on spectral inclusion and spectral exactness for the cases where the singularity is in Sims Case II or Sims Case III. For Sims Case I we present a test for spectral inexactness, which can be used to detect

J. Donin

Let M be a coadjoint semisimple orbit of a simple Lie group G. Let $U_h(\g)$ be a quantum group corresponding to G. We construct a universal family of $U_h(\g)$ invariant quantizations of the sheaf of functions on M and describe all such quantizations. We also describe all two parameter $U_h(\g)$ invariant quantizations on M, which can be considered as $U_h(

Martina Brück, Xi Du, Joonsang Park, Chuu-Lian Terng

There is a hierarchy of commuting soliton equations associated to each symmetric space U/K. When U/K has rank n, the first n flows in the hierarchy give rise to a natural first order non-linear system of partial diffferential equations in n variables, the so called U/K-system. Let G_{m,n} denote the Grassmannian of n-dimensional linear subspaces in R^{m+n},

M. R. Razvan

This paper is concerned with some well-known Ljusternik-Schnirelmann categories. We desire to find some links and relations among them. This has been done by using the concepts of precategoty, T-collection and closure of a category.

Ludmil Katzarkov, Tony Pantev, Carlos Simpson

We propose a definition of ``nonabelian mixed Hodge structure&#39;&#39; together with a construction associating to a smooth projective variety $X$ and to a nonabelian mixed Hodge structure $V$, the ``nonabelian cohomology of $X$ with coefficients in $V$&#39;&#39; which is a (pre-)nonabelian mixed Hodge structure denoted $H=Hom(X_M, V)$. We describe the basi

M. Cahen, S. Gutt, J. Horowitz, J. Rawnsley

We consider invariant symplectic connections $\nabla$ on homogeneous symplectic manifolds $(M,ω)$ with curvature of Ricci type. Such connections are solutions of a variational problem studied by Bourgeois and Cahen, and provide an integrable almost complex structure on the bundle of almost complex structures compatible with the symplectic structure. If $M$ i

I. Heckenberger

For transcendental values of q the quantum tangent spaces of all left-covariant first order differential calculi of dimension less than four on the quantum group $\SLq 2$ are given. All such differential calculi $Γ$ are determined and investigated for which the left-invariant differential one-forms $ω(u^1_2)$, $ω(u^2_1)$ and $ω(u^1_1-u^2_2)$ generate $Γ$ as

Yasushi Homma

We study the higher spin Dirac operators on 3-dimensional manifolds and show that there exist two Laplace type operators for each associated bundle. Furthermore, we give lower bound estimations for the first eigenvalues of these Laplace type operators.

Atsushi Kamita

We show that there exists a natural q-analogue of the b-function for the prehomogeneous vector space of commutative parabolic type, and calculate them explicitly in each case. Our method of calculating the b-functions seems to be new even for the original case q=1.

Adrian Muller

In this work quantum electrodynamics at T > 0 is considered. For this purpose we use thermo field dynamics and the causal approach to quantum field theory according to Epstein and Glaser, the latter being a rigorous method to avoid the well-known ultraviolet divergencies of quantum field theory. It will be shown that the theory is infrared divergent if the u

Duiliu-Emanuel Diaconescu, Michael R. Douglas

We argue that D-branes corresponding to rational B boundary states in a Gepner model can be understood as fractional branes in the Landau-Ginzburg orbifold phase of the linear sigma model description. Combining this idea with the generalized McKay correspondence allows us to identify these states with coherent sheaves, and to calculate their K-theory classes

Vipul Periwal

It is argued that D-brane charge takes values in K-homology. For smooth manifolds with spin structure, this could explain why the phase factor $Ω(x)$ calculated with a D-brane state x in IIB theory appears in Diaconescu, Moore and Witten&#39;s computation of the partition function of IIA string theory.

Giampiero Esposito, Alexander Yu. Kamenshchik, Klaus Kirsten

The zero-point energy of a conducting spherical shell is studied by imposing the axial gauge via path-integral methods, with boundary conditions on the electromagnetic potential and ghost fields. The coupled modes are then found to be the temporal and longitudinal modes for the Maxwell field. The resulting system can be decoupled by studying a fourth-order d

Giampiero Esposito, Alexander Yu. Kamenshchik, Klaus Kirsten

The zero-point energy of a conducting spherical shell is studied by imposing the axial gauge via path-integral methods, with boundary conditions on the electromagnetic potential and ghost fields. The coupled modes are then found to be the temporal and longitudinal modes for the Maxwell field. The resulting system can be decoupled by studying a fourth-order d

C. Bizdadea

Topological Yang-Mills theory is derived in the framework of Lagrangian BRST cohomology.

D. V. Fursaev

Quantum fields on a stationary space-time in a rotating Killing reference frame are considered. Finding solutions of wave equations in this frame is reduced to a fiducial problem on a static background. The rotation results in a gauge connection in a way similar to appearance of gauge fields in Kaluza-Klein models. Such a Kaluza-Klein method in theory of rot

A. P. Balachandran, T. R. Govindarajan, B. Ydri

In our previous paper (hep-th/9911087), we proposed a resolution for the fermion doubling problem in discrete field theories based on the fuzzy sphere and its cartesian products. In this paper after a review of that work, we bring out its relationship to the Ginsparg-Wilson approach.

Seungjoon Hyun, Hyeonjoon Shin

This paper has been withdrawn by the authors because the action has already been given in hep-th/9907202.

Edward Witten

I briefly review the arguments which in the 1970&#39;s convinced many theoretical physicists to anticipate lepton number violation, and to guess a range of neutrino masses.

Dimiter Hadjimichef

The general meson-baryon potential obtained in the context of the Fock-Tani formalism is applied in the $K^{+}N$ system. A simple spin-dependent interaction on quark level is used in order to compare with known results. The short range nature of the equivalent local potential is shown.

K. S. Babu, B. Dutta, R. N. Mohapatra

The electric dipole moment of the muon (d_mu) is evaluated in supersymmetric models with nonzero neutrino masses and large neutrino mixing arising from the seesaw mechanism. It is found that if the seesaw mechanism is embedded in the framework of a left-right symmetric gauge structure, the interactions responsible for the right-handed neutrino Majorana masse

G. Domokos, S. Kovesi-Domokos, Paul T. Mikulski

It has been suggested that the characteristic energy of string models may be considerably lower than the observed Planck mass. In such schemes, the unification of interactions takes place around the string scale, perhaps as low as a few tens of TeV. Consequently, at energies above the string scale, neutrinos acquire interactions comparable in strength to str

V. A. Ilyin, M. Maltoni, V. A. Novikov, L. B. Okun

Using the computer code CompHEP we estimate the number of events and the background, at LEP II and TESLA, for the reaction $e^+ e^- \to N\bar{N}γ$, where $N$ is a hypothetical Dirac neutrino with mass of the order of 50 GeV.

Sidi Cherkawi Benzahra

I consider the behavior of the quark-antiquark potential, called the Cornell Potential, in a quark-gluon plasma. Since mesons are no longer bound in the quark-gluon plasma, there might be a relationship between the string tension of the quark-antiquark potential, the mass of the quark, and the coupling constant.

K. K. Jeong, C. S. Kim, Yeong Gyun Kim

We discuss the implications of charged lepton energy cut to the hadronic invariant mass spectrum in charmless semileptonic B decays. Charged-lepton energy cut is inevitable in order to remove secondary leptonic events such as b -> c, tau -> l, and to identify the chaged leptons at detectors experimentally. We consider three possible lepton energy cuts, E_l^{

Antoni Szczurek

Based on the world DIS data we extract $F_2^p - F_2^n$ as a function of Bjorken $x$ and photon virtuality $Q^2$. The standard PDFs fail to describe the experimental data below $Q^2 <$ 7 GeV$^2$. The trend of the data is approximately explained by our recent model.

Osamu Yasuda

Superkamiokande atmospheric neutrino data (contained and upward going through $μ$ events) for 990 days are analyzed in the framework of four neutrinos (three active and one sterile neutrinos) without imposing constraints of Big Bang Nucleosynthesis. It is shown that the wide range of the oscillation parameters is allowed at 90% confidence level ($0.1\lesssim

Tetsuo Sawada

In order to confirm the strong Van der Waals force in the nucleon-nucleon interaction, it is proposed to measure precisely the angular distribution of the cross section of the low energy ($T_{lab}=20 \sim 30MeV.$) proton-proton scattering. By using the spectrum of the long range interaction obtained from the analysis of the phase shift data of the S-wave of

Dan Pirjol

We present a bound on the weak phase $α$ from isospin-breaking effects in weak radiative decays, which requires the CP-averaged branching ratios for the weak radiative decays $B^\pm\to ρ^\pm γ$, $B^0\to ρ^0/ωγ$, $B\to K^* γ$ and the photon energy spectrum in $B\toγ\ellν_\ell$. We carefully identify all sources of isospin breaking, which could possibly mask i

A. Ghinculov, Y. -P. Yao

We describe a general analytic-numerical reduction scheme for evaluating any 2-loop diagrams with general kinematics and general renormalizable interactions, whereby ten special functions form a complete set after tensor reduction. We discuss the symmetrical analytic structure of these special functions in their integral representation, which allows for opti

David Dooling, Kyungsik Kang

Using the resolution of the gauge hierarchy problem recently proposed by Randall and Sundrum, we find a natural explanation for the observed fermion masses and mixings of the three Standard Model (SM) generations. Localizing massless SM matter generations on neighboring 3-branes in an extra dimensional world leads to effective four dimensional masses and mix

A. V. Berezhnoy, A. K. Likhoded

In the framework of the vector dominance model (VDM) new contribution into the cross-section of $D^*$-meson photoproduction at HERA has been estimated. This contribution is due to the interaction of the virtual vector $c\bar c$-mesons from photon with the proton. It has been shown that the mechanism under discussion plays the essential role for all values of

L Del Debbio, A Di Giacomo, B Lucini

We construct the creation operator of a vortex using the methods developed for monopoles. The vacuum expectation value of this operator is interpreted as a disorder parameter describing vortex condensation and is studied numerically on a lattice in SU(2) gauge theory. The result is that vortices behave in the vacuum in a similar way to monopoles. The disorde

B. Linet

We determine the expression of the electrostatic self-energy for a point charge in the static black holes with spherical symmetry having suitable properties

W. R. Esposito Miguel, J. G. Pereira

By exploring the relationship between the propagation of electromagnetic waves in a gravitational field and the light propagation in a refractive medium, it is shown that, in the presence of a positive cosmological constant, the velocity of light will be smaller than its special relativity value. Then, restricting again to the domain of validity of geometric

Giampiero Esposito, Giuseppe Pollifrone

In a path-integral approach to quantum cosmology, the Lorenz gauge-averaging term is studied for Euclidean Maxwell theory on a portion of flat four-space bounded by two concentric three-spheres, but with arbitrary values of the gauge parameter. The resulting set of eigenvalue equations for normal and longitudinal modes of the electromagnetic potential cannot

Luciano da Fontoura Costa

A novel non-linear approach to fast and effective comparison of sequences is presented, compared to the traditional cross-correlation operator, and illustrated with respect to DNA sequences.

Carlo Drioli, Davide Rocchesso

Radial Basis Function Networks (RBFNs) are used primarily to solve curve-fitting problems and for non-linear system modeling. Several algorithms are known for the approximation of a non-linear curve from a sparse data set by means of RBFNs. However, there are no procedures that permit to define constrains on the derivatives of the curve. In this paper, the O

Dale Gerdemann, Gertjan van Noord

Previous work (Frank and Satta 1998; Karttunen, 1998) has shown that Optimality Theory with gradient constraints generally is not finite state. A new finite-state treatment of gradient constraints is presented which improves upon the approximation of Karttunen (1998). The method turns out to be exact, and very compact, for the syllabification analysis of Pri

Ady Stern, S. M. Girvin, A. H. MacDonald, Ning Ma

Spielman et al. have recently observed a large zero-bias peak in the tunnel conductance of a bi-layer system in a quantum Hall ferromagnet state. We argue that disorder-induced topological defects in the pseudospin order parameter limit the peak size and destroy the predicted Josephson effect. We predict that the peak would be split and shifted by an in-plan

E. Ben-Naim, P. L. Krapivsky

We investigate fragmentation processes with a steady input of fragments. We find that the size distribution approaches a stationary form which exhibits a power law divergence in the small size limit, P(x) ~ x^{-3}. This algebraic behavior is robust as it is independent of the details of the input as well as the spatial dimension. The full time dependent beha

S. Inouye, R. F. Loew, S. Gupta, T. Pfau

A Bose-Einstein condensate illuminated by a single off-resonant laser beam (``dressed condensate&#39;&#39;) shows a high gain for matter waves and light. We have characterized the optical and atom-optical properties of the dressed condensate by injecting light or atoms, illuminating the key role of long-lived matter wave gratings produced by the condensate a

U. Leonhardt, T. Kiss, P. Piwnicki

In our paper we estimated the quantum backaction of dispersive imaging with off-resonant light on Bose-Einstein condensates. We have calculated the rates of the two processes involved, phase diffusion and depletion of the condensate. We compare here the depletion rate obtained within our model limitations to the Rayleigh scattering rate, both having the same

Subhadip Raychaudhuri, Yonathan Shapir, Vladimir Chernyak, Shaul Mukamel

The mean first passage time (MFPT) for photoexcitations diffusion in a funneling potential of artificial tree-like light-harvesting antennae (phenylacetylene dendrimers with generation-dependent segment lengths) is computed. Effects of the non-linearity of the realistic funneling potential and slow random solvent fluctuations considerably slow down the cente

Giuliano Benenti, Giulio Casati

We study the time dependence of the ionization probability of Rydberg atoms driven by a microwave field. The quantum survival probability follows the classical one up to the Heisenberg time and then decays inversely proportional to time, due to tunneling and localization effects. We provide parameter values which should allow one to observe such decay in lab

Leon Balents, Leo Radzihovsky

We show that the interlayer tunneling I--V in double-layer quantum Hall states displays a rich behavior which depends on the relative magnitude of sample size, voltage length scale, current screening, disorder and thermal lengths. For weak tunneling, we predict a negative differential conductance of a power-law shape crossing over to a sharp zero-bias peak.

A. Gendiar, A. Surda

The classical two-dimensional anisotropic triangular nearest-neighbor Ising (ATNNI) model is studied by the density matrix renormalization group (DMRG) technique when periodic boundary conditions are imposed. Applying the finite-size scaling to the DMRG results a commensurate-disordered (C-D) phase transition line as well as temperature and magnetic critical

M. Krech

The surface scaling behavior of classical isotropic Heisenberg magnets is investigated by Monte - Carlo methods in d=3 dimensions for various values of the surface - to - bulk coupling ratio J_1/J. For J_1/J <= 1.0 critical behavior according to the ordinary surface universality class is found. New estimates for magnetic surface exponents are presented and c