arXiv papers from March 2000

I. Chemakin, V. Cianciolo, B. A. Cole, R. Fernow

The first detailed measurements of the centrality dependence of strangeness production in p-A collisions are presented. Lambda and Kshort dn/dy distributions from 17.5 GeV/c p-Au collisions are shown as a function of "grey" track multiplicity and the estimated number of collisions, nu, made by the proton. The nu dependence of the Lambda yield deviates from a

Alejandro Mariano, Jorge G. Hirsch

The Quasiparticle Random Phase Approximation equations are solved taking into account the Pauli Principle at the expectation value level, and allowing changes in the mean field occupation numbers to minimize the energy while having the correct number of particles in the correlated vacuum. The study of Fermi pn excitations in $^{76}$Ge using a realistic Hilbe

Joel S. Rozowsky, Charles B. Thorn

The nonrelativistic interpretation of quantum field theory achieved by quantization in an infinite momentum frame is spoiled by the inclusion of a mode of the field carrying p+=0. We therefore explore the viability of doing without such a mode in the context of spontaneous symmetry breaking (SSB), where its presence would seem to be most needed. We show that

S. K. Dutta, D. Feldbaum, G. Raithel

Cold, dense Rydberg gases produced in a cold-atom trap are investigated using spectroscopic methods and time-resolved electron counting. On the discrete Rydberg resonances we observe large trap losses and long lasting electron emission from the Rydberg gas (>30ms). Our observations are explained by quasi-elastic l-mixing collisions between Rydberg atoms and

A. Mariano, G. López Castro

A dynamical model based on effective Lagrangians is proposed to describe the bremsstrahlung reaction $ \pi N \to \pi N \gamma$ at low energies. The $\Delta(1232)$ degrees of freedom are incorporated in a way consistent with both, electromagnetic gauge invariance and invariance under contact transformations. The model also includes the initial and final state

C. -R. Ji, C. Mitchell

While the particle-number-conserving convolution formalism established in the Drell-Yan-West reference frame is frequently used to compute exclusive amplitudes in the light-front quantization, this formalism is limited to only those frames where the light-front helicities are not changed and the good (plus) component of the current remains unmixed. For an ex

Seth Lloyd

This paper investigates a variety of unconventional quantum computation devices, including fermionic quantum computers and computers that exploit nonlinear quantum mechanics. It is shown that unconventional quantum computing devices can in principle compute some quantities more rapidly than `conventional' quantum computers.

Paul D. Feldman, Melissa A. McGrath, Darrell F. Strobel, H. Warren Moos

We report new observations of the spectrum of Ganymede in the spectral range 1160 - 1720 A made with the Space Telescope Imaging Spectrograph (STIS) on HST on 1998 October 30. The observations were undertaken to locate the regions of the atomic oxygen emissions at 1304 and 1356 A, previously observed with the GHRS on HST, that Hall et al. (1998) claimed indi

Dallas C. Kennedy

Cosmic ray antiprotons have been detected for over 20 years and are now measured reliably. Standard particle and astrophysics predict a conventional spectrum and abundance of secondary antiprotons consistent with all current measurements. These measurements place limits on exotic Galactic antiproton sources and non-standard antiproton properties. Complicatio

D. P. Rideout, R. D. Sorkin

We find evidence for a continuum limit of a particular causal set dynamics which depends on only a single ``coupling constant'' $p$ and is easy to simulate on a computer. The model in question is a stochastic process that can also be interpreted as 1-dimensional directed percolation, or in terms of random graphs.

Victor Kurasov

The theoretical description of the heterogeneous nucleation kinetics is presented. This description takes into account the perturbation of the vapor phase initiated by the growing droplets. The form of the density profile around the growing droplet is analyzed which leads to some special approximations. Then the process of nucleation in the whole system is d

Itsaso Olasagasti, Alexander Vilenkin

Solutions of Einstein's equations are found for global defects in a higher-dimensional spacetime with a nonzero cosmological constant Lambda. The defect has a (p-1)-dimensional core (brane) and a `hedgehog' scalar field configuration in the n extra dimensions. For Lambda = 0 and n > 2, the solutions are characterized by a flat brane worldsheet and a solid an

V. A. Miransky, I. A. Shovkovy, L. C. R. Wijewardhana

We study the Bethe-Salpeter equations for spin zero diquark composites in the color superconducting phase of N_f=2 cold dense QCD. The explicit form of the spectrum of the diquarks, containing an infinite tower of narrow (at high density) resonances, is derived. It is argued that there are five pseudo-Nambu-Goldstone bosons (pseudoscalars) that remain almost

Conall Kennedy, Emil M. Prodanov

We investigate (4+1)- and (5+0)-dimensional gravity coupled to a non-compact scalar field sigma-model and a perfect fluid within the context of the Randall-Sundrum scenario. We find cosmological solutions with a rolling fifth radius and a family of warp factors. Included in this family are both the original Randall-Sundrum solution and the self-tuning soluti

Todor Stanev, Ralph Engel, Anita Muecke, Raymond J. Protheroe

We present a new calculation of the propagation of protons with energies above $10^{19}$ eV over distances of up to several hundred Mpc. The calculation is based on a Monte Carlo approach using the event generator SOPHIA for the simulation of hadronic nucleon-photon interactions and a realistic integration of the particle trajectories in a random extragalact

Alexander Moroz

It is shown that simple face-centered-cubic (fcc) structures of both metallic and coated metallic spheres are ideal candidates to achieve a tunable complete photonic bandgap (CPBG) for optical wavelengths using currently available experimental techniques. For coated microspheres with the coating width to plasma wavelength ratio $l_c/\lambda_p \leq 10%$ and t

J. Fuchs, C. Schweigert, J. Walcher

In string theory various projections have to be imposed to ensure supersymmetry. We study the consequences of these projections in the presence of world sheet boundaries. A-type boundary conditions come in several classes; only boundary fields that do not change the class preserve supersymmetry. Our analysis takes in particular properly into account the reso

U. Al Khawaja, H. T. C. Stoof

We calculate the frequencies and damping rates of the low-lying collective modes of a Bose-Einstein condensed gas at nonzero temperature. We use a complex nonlinear Schr\"odinger equation to determine the dynamics of the condensate atoms, and couple it to a Boltzmann equation for the noncondensate atoms. In this manner we take into account both collisions be

John R. Klauder

The present article is primarily a review of the projection-operator approach to quantize systems with constraints. We study the quantization of systems with general first- and second-class constraints from the point of view of coherent-state, phase-space path integration, and show that all such cases may be treated, within the original classical phase space

R. N. Mohapatra, A. Pérez-Lorenzana, C. A. de S. Pires

We study the cosmology of models with four space and one time dimension where our universe is a 3-brane and report a few results which extend existing work in several directions. Assuming a stable fifth dimension, we obtain a solution for the metric, which does not depend on any arbitrary parameters. We discuss some implications of this result.

The E864 Collaboration

We report on measurements by the E864 experiment at the BNL-AGS of the yields of light nuclei in collisions of Au(197) with beam momentum of 11.5 A GeV/c on targets of Pb(208) and Pt(197). The yields are reported for nuclei with baryon number A=1 up to A=7, and typically cover a rapidity range from y(cm) to y(cm)+1 and a transverse momentum range of approxim

W. Stoll, P. M. Wong

Chern number formulas for holomorphic jet bundles are computed for projective curves and for projective surfaces. These formulas are used to show that certain minimal surfaces of general type (generic hypersurfaces of degree at least 5 in projective 3-spaces in particular) are hyperbolic in the sense of complex hyperbolic geometry.

C. S. Kochanek, Martin White

We study the evolution of Hernquist profile ``galaxies'' in the presence of self-interacting dark matter (SIDM), where the properties of the dark matter can be parameterized by one number, sigma-hat = sigma M/a^2 for a halo of mass M and break radius a. While the halos form constant density cores of size a/2 on the core radius relaxation time scale core coll

J. Betancort-Rijo, M. Lopez-Corredoira

We have developed a generalization of the Zeldovich approximation (ZA) that is exact in a wide variety of situations, including plannar, spherical and cilyndrical symmetries. We have shown that this generalization, that we call complete Zeldovich approximation (CZA), is exact to second order at an arbitrary point within any field. For gaussian fields, the th

Rongfeng Sun, Harvey Gould, Jon Machta, Lincoln Chayes

Phase transitions of fluid mixtures of the type introduced by Stillinger and Helfand are studied using a continuum version of the invaded cluster algorithm. Particles of the same species do not interact, but particles of different types interact with each other via a repulsive potential. Examples of interactions include the Gaussian molecule potential and a

Dean Lee

We review recent developments in non-perturbative field theory using modal field methods. We discuss Monte Carlo results as well as a new diagonalization technique known as the quasi-sparse eigenvector method.

Philippe Droz-Vincent

In order to reduce the Klein-Gordon equation (with minimal coupling), we introduce a generalization of the so-called "mode solutions" that are well-known in the special case of a Robertson-Walker universe. After separation of the variables, we end up with a partial differential equation in lower dimension. A reduced version of the Gordon current arises and i

Bin Wang, Chi-Yong Lin, Elcio Abdalla

Complex frequencies associated with quasinormal modes for large Reissner-Nordstr$\ddot{o}$m Anti-de Sitter black holes have been computed. These frequencies have close relation to the black hole charge and do not linearly scale with the black hole temperature as in Schwarzschild Anti-de Sitter case. In terms of AdS/CFT correspondence, we found that the bigge

jason howald

In this note we calculate the multiplier ideal associated to an arbitrary monomial ideal in C^n. We discuss applications to the calculation of log canonical thresholds.

P. Aurenche, F. Gelis, H. Zaraket

In recent studies, the production rate of photons or lepton pairs by a quark gluon plasma has been found to be enhanced due to collinear singularities. This enhancement pattern is very dependent on rather strict collinearity conditions between the photon and the quark momenta. It was estimated by neglecting the collisional width of quasi-particles. In this p

Dipak Munshi, Peter Coles

In the very near future, weak lensing surveys will map the projected density of the universe in an unbiased way over large regions of the sky. In order to interpret the results of studies it is helpful to develop an understanding of the errors associated with quantities extracted from the observations. In a generalization of one of our earlier works, we pres

Simon J. Clark, Robin W. Tucker

A tensor description of perturbative Einsteinian gravity about an arbitrary background spacetime is developed. By analogy with the covariant laws of electromagnetism in spacetime, gravito-electromagnetic potentials and fields are defined to emulate electromagnetic gauge transformations under substitutions belonging to the gauge symmetry group of perturbative

U. Sperhake, K. R. P. Sjodin, J. A. Vickers

An implicit, fully characteristic, numerical scheme for solving the field equations of a cosmic string coupled to gravity is described. The inclusion of null infinity as part of the numerical grid allows us to apply suitable boundary conditions on the metric and matter fields to suppress unphysical divergent solutions. The code is tested by comparing the res

James Binney, Walter Dehnen, Gianpaolo Bertelli

High-quality Hipparcos data for a complete sample of nearly 12000 main-sequence and subgiant stars, together with Padua isochrones, are used to constrain the star-formation history of the solar neigbourhood and the processes that stochastically accelerate disk stars. The velocity dispersion of a coeval group of stars is found to increase with time from ~8 km

S. O. Kepler, Anjum Mukadam, D. E. Winget, R. E. Nather

We observe G117-B15A, the most precise optical clock known, to measure the rate of change of the main pulsation period of this blue-edge DAV white dwarf. Even though the obtained value is only within 1 sigma, Pdot = (2.3 +/- 1.4) x 10^{-15} s/s, it is already constraining the evolutionary timescale of this cooling white dwarf star.

L. Siess, E. Dufour, M. Forestini

We present new grids of pre-main sequence (PMS) tracks for stars in the mass range 0.1 to 7.0 Msun. The computations were performed for four different metallicities (Z=0.01, 0.02, 0.03 and 0.04). A fifth table has been computed for the solar composition (Z=0.02), including a moderate overshooting. We describe the update in the physics of the Grenoble stellar

Michael Dennin

I report on the direct observation of a uniform twist mode of the director field in electroconvection in I52. Recent theoretical work suggests that such a uniform twist mode of the director field is responsible for a number of secondary bifurcations in both electroconvection and thermal convection in nematics. I show here evidence that the proposed mechanism

P. Yu. Kulikov, I. M. Narodetskii, A. I. Onischenko

The enhancement of the Lambda_b decay width relative to B decay one due to the difference of Fermi motion effects in Lambda_b and B is calculated in the light--front quark model with the simplifying assumption that Lambda_b consists of the heavy quark and light scalar diquark. In order to explain the large deviation from unity in the experimental result for

M. Batista, R. J. M. Covolan, A. N. Pontes

A phenomenological analysis of diffractive dissociation of nuclei in proton-nucleus and meson-nucleus collisions is presented. The theoretical approach employed here is able to take into account at once data of the HELIOS and EHS/NA22 collaborations that exhibit quite different atomic mass dependences. Possible extensions of this approach to hard diffraction

S. O. Kepler, E. L. Robinson, D. Koester, J. C. Clemens

We have obtained time-resolved ultraviolet spectroscopy for the pulsating DAV stars G226-29 and G185-32, and for the pulsating DBV star PG1351+489 with the Hubble Space Telescope Faint Object Spectrograph, to compare the ultraviolet to the optical pulsation amplitude and determine the pulsation indices. We find that for essentially all observed pulsation mod

James S. Ulvestad

Archival VLA data has been used to produce arcsecond-resolution 6- and 20-cm images of the region surrounding the nuclear 200-pc (~15") starburst in NGC 253. Twenty-two discrete sources stronger than 0.4 mJy have been detected within ~2 kpc (~3') of the galaxy nucleus; almost all these sources must be associated with the galaxy. None of the radio sources coi

Jiannis Pachos

A geometrical approach to quantum computation is presented, where a non-abelian connection is introduced in order to rewrite the evolution operator of an energy degenerate system as a holonomic unitary. For a simple geometrical model we present an explicit construction of a universal set of gates, represented by holonomies acting on degenerate states.

P Boyle, C Davies

We present the results of a perturbative calculation to match the axial and vector currents for semileptonic $B\to D^{(\ast)}$ decays in lattice NRQCD to the continuum \MSb scheme. The matching is performed to $O(\alpha_s\frac{\vec{p}}{M})$ in Feynman gauge and in the on-shell renormalisation scheme. The spatial and temporal components of the currents renorm

Z. Dogic, D. Frenkel, S. Fraden

There is increasing evidence that entropy can induce microphase separation in binary fluid mixtures interacting through hard particle potentials. One such phase consists of alternating two dimensional liquid-like layers of rods and spheres. We study the transition from a uniform miscible state to this ordered state using computer simulations and compare resu

K. Goeke, P. V. Pobylitsa, M. V. Polyakov, D. Urbano

In these short notes we present a parametrization of the results obtained in the chiral quark-soliton model for polarized antiquark distributions $\Delta\bar u$, $\Delta\bar d$ and $\Delta\bar s$ at a low normalization point around mu=0.6 GeV.

Alexander V. Khaetskii, Yuli V. Nazarov

We have studied spin-flip transitions between Zeeman sublevels in GaAs electron quantum dots. Several different mechanisms which originate from spin-orbit coupling are shown to be responsible for such processes. It is shown that spin-lattice relaxation for the electron localized in a quantum dot is much less effective than for the free electron. The spin-fli

Andrzej J. Buras, Robert Fleischer

As we pointed out recently, the neutral decays $B_d\to\pi^\mp K^\pm$ and $B_d\to\pi^0K$ may provide non-trivial bounds on the CKM angle $\gamma$. In this paper, we reconsider this approach in the light of recent CLEO data, which look very interesting. In particular, the results for the corresponding CP-averaged branching ratios are in favour of strong constr

K. R. S. Balaji, W. Grimus

We show that, for Majorana neutrinos propagating in a constant magnetic field, the flavour survival probabilities for left-handed neutrinos is the same as for right-handed neutrinos, i.e., $P^M (\nu_{\alpha L}\to\nu_{\alpha L}) = P^M (\nu_{\alpha R}\to\nu_{\alpha R})$, where $\alpha = e, \mu, \tau$, whereas in the Dirac case the corresponding probabilities $

Adam F. Falk, Alexey A. Petrov

We propose a new method for measuring the CKM phase gamma using the partial rates for CP-tagged Bs decays. Such an experiment could be performed at a very high luminosity symmetric e+e- collider operating at the Upsilon(5S) resonance, where the Bs-Bsbar state is produced in a state of definite CP. We also discuss CP-tagging in the Bd system at the Upsilon(4S

GianCarlo Ghirardi

In this paper we reconsider the constraints which are imposed by relativistic requirements to any model of dynamical reduction. We review the debate on the subject and we call attention on the fundamental contributions by Aharonov and Albert. Having done this we present a new formulation, which is much simpler and more apt for our analysis, of the proposal p

Andrei Zelevinsky

Double Bruhat cells in a semisimple group are intersections of cells in two Bruhat decompositions corresponding to two opposite Borel subgroups. They form a geometric framework for the study of total positivity in semisimple groups; they are also closely related to symplectic leaves in the corresponding Poisson-Lie groups. The term "cells" might be misleadin

Haijun Zhou, Yang Zhang, Zhong-can Ou-Yang

This paper aims at a comprehensive understanding on the novel elastic property of double-stranded DNA (dsDNA) discovered very recently through single-molecule manipulation techniques. A general elastic model for double-stranded biopolymers is proposed and a new structural parameter called the folding angle $\phi$ is introduced to characterize their deformati

D. Gomez Dumm, A. Pich, J. Portoles

Within the resonance chiral effective theory we study the dressed propagators of the spin-1 fields, as arise from a Dyson-Schwinger resummation perturbatively constructed from loop diagrams with absorptive contributions in the s-channel. We apply the procedure to the vector pion form factor and the elastic pion-pion scattering to obtain the off-shell width o

J. van der Heide, E. Laenen, L. Phaf, S. Weinzierl

Single top quark production at hadron colliders allows a direct measurement of the top quark charged current coupling. We present the complete tree-level helicity amplitudes for four processes involving the production and semileptonic decay of a single top quark: W-gluon fusion, flavor excitation, s-channel production and W-associated production. For the fir

Yasuyuki Kachi, János Kollár

We prove that a smooth projective variety of dimension n is isomorphic to projective n-space iff the canonical class is -(n+1)-times an ample divisor. In characteristic zero this was proved by Kobayashi-Ochiai. We also extend the second adjunction theorem of Ionescu and Fujita to arbitrary characteristic.

M. Gazdzicki, M. I. Gorenstein

A validity of a recent estimate of an upper limit of charm production in central Pb+Pb collisions at 158 AGeV is critically discussed. Within a simple model we study properties of the background subtraction procedure used for an extraction of the charm signal from the analysis of dilepton spectra. We demonstrate that a production asymmetry between positively

Stefan Schroeer

Using Maruyama's theory of elementary transformations, I show that the Brauer group surjects onto the cohomological Brauer group for separated geometrically normal algebraic surfaces. As an application, I infer the existence of nonfree vector bundles on proper normal algebraic surfaces.

J. Baacke, K. Heitmann

We consider the large-N $\Phi^4$ theory with spontaneously broken symmetry at finite temperature. We study, in the large-N limit, quantum states which are characterized by a time dependent, spatially homogenous expectation value of one of the field components, $\phi_N(t)$, and by quantum fluctuations of the other $N-1$ components, that evolve in the backgrou

Keizo Matsubara

We show that the gauge groups SU(N), SO(N) and Sp(N) cannot be realized on a flat noncommutative manifold, while it is possible for U(N).

D. Bonamy, L. Laurent, Ph. Claudin, J. -Ph Bouchaud

Electrical conductivity measurements on a 2D packing of metallic beads have been performed to study internal rearrangements in weakly pertubed granular materials. Small thermal perturbations lead to large non gaussian conductance fluctuations. These fluctuations are found to be intermittent and gathered in bursts. The distributions of the waiting time betwee

Alex Kaivarainen

New models of Turbulence, Superfluidity and Superconductivity, based on new Hierarchic theory, general for liquids and solids (physics/0102086), have been proposed. CONTENTS: 1 Turbulence. General description; 2 Mesoscopic mechanism of turbulence; 3 Superfluidity. General description; 4 Mesoscopic scenario of fluidity; 5 Superfluidity as a hierarchic self-or

K. S. Novoselov, Yu. V. Dubrovskii, V. A. Sablikov, D. Yu. Ivanov

Nonlinear electron transport in normally pinched-off quantum wires was studied. The wires were fabricated from AlGaAs/GaAs heterostructures with high-mobility two-dimensional electron gas by electron beam lithography and following wet etching. At certain critical source-drain voltage the samples exhibited a step rise of the conductance. The differential cond

Alex Kaivarainen

1. Theoretical background for macroscopic oscillations in condensed matter; 2. The hypothesis of [entropy - mass - time] interrelation; 3. The entropy - information content of matter as a hierarchic system; 4. Experimentally revealed macroscopic oscillations; 5. Phenomena in water and aqueous systems, induced by magnetic field: Coherent radio-frequency oscil

Gerd Rudolph, Matthias Schmidt, Igor P. Volobuev

A method for determining the orbit types of the action of the group of gauge transformations on the space of connections for gauge theories with gauge group SU(n) in space-time dimension d<=4 is presented. The method is based on the 1:1-correspondence between orbit types and holonomy-induced Howe subbundles of the underlying principal SU(n)-bundle. It is sho

Robert Weston

We give a construction of impurity operators in the `algebraic analysis' picture of RSOS models. Physically, these operators are half-infinite insertions of certain fusion-RSOS Boltzmann weights. They are the face analogue of insertions of higher spin lines in vertex models. Mathematically, they are given in terms of intertwiners of $U(\hat{sl}_2)_q$ modules

Pietro Slavich

It was recently claimed that single stop production at the Tevatron, occurring via R-parity (and baryon number) violating couplings, could lead to observable signals. In this talk I present some results of a work in progress, showing that rare B decays and K0-K0bar mixing strongly constrain such a possibility.

T. Bloecker, K. -H. Hofmann, F. Przygodda, G. Weigelt

We present computer simulations of interferometric imaging with the VLT interferometer and the AMBER instrument. These simulations include both the astrophysical modelling of a stellar object by radiative transfer calculations and the simulation of light propagation from the object to the detector (through atmosphere, telescopes, and the AMBER instrument), s

Evarist Giné, Rafał Latała, Joel Zinn

A Bernstein-type exponential inequality for (generalized) canonical U-statistics of order 2 is obtained and the Rosenthal and Hoffmann-J{\o}rgensen inequalities for sums of independent random variables are extended to (generalized) U-statistics of any order whose kernels are either nonnegative or canonical

Ernst Joachim Weniger

Sequence transformations accomplish an acceleration of convergence or a summation in the case of divergence by detecting and utilizing regularities of the elements of the sequence to be transformed. For sufficiently large indices, certain asymptotic regularities normally do exist, but the leading elements of a sequence may behave quite irregularly. The Gauss

M. Maltoni

Though LEP II direct searches still cannot exclude a chargino nearly degenerate with the lightest neutralino if its mass is only slightly above half of the Z boson mass and the sneutrino is light, it can be excluded indirectly analyzing precision data. In this particular limit simple analytical formulas for oblique electroweak radiative corrections are prese

M. Maltoni

The existence of extra chiral generations is strongly disfavored by the precision electroweak data if all the extra fermions are heavier than m_Z. However fits as good as the SM can be obtained if one allows the new neutral leptons to have masses close to 50 GeV. In the framework of SUSY models precision measurements cannot exclude one additional generation

H. H. Wen, X. H. Chen, W. L. Yang, Z. X. Zhao

By measuring the superconducting diamagnetic moments for an underdoped and an overdoped La_{2-x}Sr_xCuO_4 single crystal with equal qualities and roughly equal transition temperatures, it is found that the underdoped sample has only one transition which corresponds to H_{c2}, but the overdoped sample has two transitions with the higher one at H_{c2}. Further

P. Ilg, I. V. Karlin, H. C. Öttinger

We present a self-consistent method for deriving moment equations for kinetic models of polymer dynamics. The Doi model [M. Doi, J.Polymer. Sci., Polym. Phys. Ed. 19, 229 (1981)] of liquid-crystalline polymers with the Onsager excluded-volume potential is considered as an example. To lowest order, this method amounts to a simple effective potential different

V. A. Khoze, M. I. Konchatnij, N. P. Merenkov, G. Pancheri

The hadronic invariant mass distribution for the process of electron-positron annihilation into a pair of charged pions accompanied by a photon radiated from the initial state has been studied for the region of DA$\Phi$NE energies. The Born cross-section and the electromagnetic radiative corrections to it are calculated for realistic conditions of the KLOE d

B. I. S. van der Ventel, G. C. Hillhouse, P. R. De Kock

Within the framework of the relativistic plane wave impulse approximation (RPWIA), complete sets of quasielastic $(\vec{p}, \vec{p}^{'})$ and $(\vec{p}, \vec{n})$ spin observables are calculated employing a general Lorentz invariant representation of the NN scattering matrix (referred to as the IA2 representation). The use of a complete representation elimin

G. Yusa, H. Shtrikman, I. Bar-Joseph

We study the evolution of the absorption spectrum of a modulation doped GaAs/AlGaAs semiconductor quantum well with decreasing the carrier density. We find that there is a critical density which marks the transition from a Fermi edge singularity to a hydrogen-like behavior. At this density both the lineshape and the transitions energies of the excitons chang

Prabhakar Pradhan, S. Sridhar

Non-universal correlations due to localization are observed in statistical properties of experimental eigenfunctions of quantum chaotic and disordered microwave cavities. Varying energy {E} and mean free path {l} enable us to experimentally tune from localized to delocalized states. Large level-to-level Inverse Participation Ratio (IPR I_{2}) fluctuations ar

A. Masiero, M. Peloso, L. Sorbo, R. Tabbash

We propose a new scenario of baryogenesis in the context of theories with large extra dimensions. The baryon number is almost conserved at zero temperature by means of a localization mechanism recently analyzed by Arkani-Hamed and Schmaltz: leptons and quarks are located at two slightly displaced positions in the extra space, and this naturally suppresses th

David Garfinkle, Carsten Gundlach, James Isenberg, Niall OMurchadha

Brady, Creighton and Thorne have proposed a choice of the lapse and shift for numerical evolutions in general relativity that extremizes a measure of the rate of change of the three-metric (BCT gauge). We investigate existence and uniqueness of this gauge, and comment on its use in numerical time evolutions.

Y. N. Srivastava, A. Widom

If the Einstein field equations are employed at the tree level, then the decay of the standard model Higgs particle into two gravitons is shown to be independent of the gravitational coupling strength G. The result follows from the physical equivalence between the Higgs induced ``inertial mass'' and the ``gravitational mass'' of general relativity. If the Hi

F. Caputo, V. Castellani, M. Marconi, V. Ripepi

We use the results from recent computations of updated non-linear convective pulsating models to constrain the distance modulus of Galactic globular clusters through the observed periods of first overtone RRc pulsators. The resulting relation between the mean absolute magnitude of RR Lyrae stars <M_V(RR)> and the heavy element content [Fe/H] appears well in

A. Smailagic, E. Spallucci

We construct explicit form of the anomalous effective action, in arbitrary even dimension, for Abelian vector and axial gauge fields coupled to Dirac fermions. It turns out to be a surprisingly simple extension of 2D Schwinger model effective action.

Chuansheng Xiong

We give an explicit realization of quantum Nambu bracket via matrix of multi-index, which reduces in the continunm limit to the classical Nambu bracket.

S. Ray, J. Dey, M. Dey, K. Ray

Compactness of some stars is explained if they are strange stars (SS) as shown by Dey et al. (1998) (D98) and Li et al. (1999a). One of these compact star candidates is the SAX J1808.4-3658 (SAX in short) believed to be an important link in the genesis of radio pulsars. SS have also been suggested for bursting X-ray pulsars (GRO J1744-28, Cheng et al. 1998),

Xiao-Gang He

Three different methods, using $B_d\to J/\psi K_S$, $J/\psi K_S \pi^0$, $B_d\to K^-\pi^+, \pi^+\pi^-$ and $B_u\to K^- \pi^0, \bar K^0 \pi^-, \pi^-\pi^0$, to extract hadronic model independent information about new physics are discussed in this talk.

Izumi Hachisu, Mariko Kato

A theoretical light curve for the 1987 outburst of V394 Coronae Austrinae (V394 CrA) is modeled to obtain various physical parameters of this recurrent nova. We then apply the same set of parametersto a quiescent phase and confirm that these parameters give a unified picture of the binary. The early visual light curve (1-10 days after the optical maximum) is

Brett McInnes

In its Euclidean formulation, the AdS/CFT correspondence begins as a study of Yang-Mills conformal field theories on the sphere, S^4. It has been successfully extended, however, to S^1 X S^3 and to the torus T^4. It is natural to hope that it can be made to work for any manifold on which it is possible to define a stable Yang-Mills conformal field theory. We

Saebyok Bae

The author considers the effects of the CP-violating phases, e. g. arg(A_t) and arg(mu) on the e^+ e^- --> {tilde t}_1 {tilde t}_1^* (H_1) processes. The third generation squark trilinear terms give significant contributions to the Higgs potential at the one-loop level. This results in the changes of the stop masses and the lighter stop - the lighter anti-st

T. I. Belova, V. A. Gani, A. E. Kudryavtsev

The time evolution of initially formed large amplitude bubble of disoriented chiral condensate (DCC) is studied. It is found that the evolution of this object may have a relatively long pre-decay stage. Simple explanation of such delay of the DCC bubble decay is given. This delay is related to the existence of the approximate solutions of multi-soliton type

Keita Kishigi, Yasumasa Hasegawa

The coexistent state of the spin density wave (SDW) and the charge density wave (CDW) in the one-dimensional quarter-filled system and with the Coulomb interaction up to the next-nearest sites under magnetic fields is studied. It is found that, in the coexistent state of $2k_{\rm F}$-SDW and $2k_{\rm F}$-CDW, the charge order is suppressed and $2k_{\rm F}$-S

Fabrizio Brighenti, William G. Mathews

If mass and angular momentum were conserved in cooling flows associated with luminous, slowly rotating elliptical galaxies, the inflowing hot gas would spin up, resulting in disks of cold gas and X-ray images that are highly flattened along the equatorial plane out to several effective radii. Such X-ray flattening is not observed at the spatial resolution cu

Xinzhong Chen, Edward A. Spiegel

We use the transfer equation in relativistic form to develop an expansion of the one-photon distribution for a medium with constant photon mean free path, $\epsilon$. The resulting radiative viscosity tensor may be expressed either as a simple integral operator acting on the Thomas stress tensor or as the solution of an inhomogenous, linear partial different

M. K. Hassan

We consider the fragmentation process with mass loss and discuss self-similar properties of the arising structure both in time and space focusing on dimensional analysis. This exhibits a spectrum of mass exponents $\theta$, whose exact numerical values are given for which $x^{-\theta}$ or $t^{\theta z}$ has the dimension of particle size distribution functio

M. Casas, N. J. Davidson, M. de Llano, T. A. Mamedov

A two-dimensional (2D) assembly of noninteracting, temperature-dependent, composite-boson Cooper pairs (CPs) in chemical and thermal equilibrium with unpaired fermions is examined in a binary boson-fermion statistical model as the superconducting singularity temperature is approached from above. The model is derived from {\it first principles} for the BCS mo

P. Sutton

In D-dimensional spacetimes which can be foliated by n-dimensional homogeneous subspaces, a quantum field can be decomposed in terms of modes on the subspaces, reducing the system to a collection of (D-n)-dimensional fields. This allows one to write bare D-dimensional field quantities like the Green function and the effective action as sums of their (D-n)-di

Miguel S. Costa

We consider the N=4 SU(N) Super Yang Mills theory on the Coulomb branch with gauge symmetry broken to S(U(N_1) x U(N_2)). By integrating the W particles, the effective action near the IR SU(N_i) conformal fixed points is seen to be a deformation of the Super Yang Mills theory by a non-renormalized, irrelevant, dimension 8 operator. The correction to the two-

Graciela Gelmini, Paolo Gondolo, Gabriele Varieschi

We analyze the possibility that neutrino telescopes may provide an experimental determination of the slope lambda of the gluon distribution in the proton at momentum fractions x smaller than the accelerator reach. The method is based on a linear relation between lambda and the spectral index (slope) of the down-going atmospheric muon flux above 100 TeV, for

Antun Milas

We study fusion rings for degenerate minimal models ($p=q$ case) for N=0 and N=1 (super)conformal algebras. We consider a distinguished family of modules at the level $c=1$ and $c=3/2$ and show that the corresponding fusion rings are isomorphic to the representation rings for ${\mathfrak sl}(2, {\bf C})$ and ${\mathfrak osp}(1|2)$ respectively.

Saurabh Jha, Guillermo Torres, Robert P. Stefanik, David W. Latham

The triple-lined spectroscopic triple system HD 109648 has one of the shortest periods known for the outer orbit in a late-type triple, 120.5 days, and the ratio between the periods of the outer and inner orbits is small, 22:1. With such extreme values, this system should show orbital element variations over a timescale of about a decade. We have monitored t

Kingman Cheung

In this talk, I briefly review collider signatures for two models of extra dimensions. The first one was proposed by Arkani-Hamed {\it et al.} that gravity is free to propagate in extra dimensions of very large size ($\alt 1$ mm). Collider signatures for this model can be divided into two types: (i) emission of real gravitons into extra dimensions, and (ii)