November 1999 arXiv papers — page 22

John Bahcall, Plamen Krastev, Alexei Smirnov

The ratio of the measured to the predicted standard model CC event rates in SNO will be 0.47 if no oscillations occur. The best-fit active oscillation predictions for the CC ratio are: 0.35-39 (MSW) and 0.38-42 (vacuum) (all for a 5 MeV energy threshold), typically about 20% less than the no-oscillation expectation. We calculate the predicted ratios for six

J. Hamilton, C. J. Isham, J. Butterfield

We extend the topos-theoretic treatment given in previous papers of assigning values to quantities in quantum theory, and of related issues such as the Kochen-Specker theorem. This extension has two main parts: the use of von Neumann algebras as a base category (Section 2); and the relation of our generalized valuations to (i) the assignment to quantities of

Volodymyr Krasnoholovets, Dmytro Ivanovsky

We propose the deterministic dynamics of a free particle in a physical vacuum, which is considered as a discrete (quantum) medium. The motion of the particle is studied taking into account its interactions with the medium. It is assumed that this interaction results in the appearance of special virtual excitations, called "inertons," in the vacuum me

Volodymyr Krasnoholovets

A vacuum medium model is advanced. The motion of a relativistic particle in relation to its interaction with the medium is discussed. It is predicted that elementary excitations of the vacuum, called "inertons," should exist. The equations of the particle path in Euclidean space are derived. The motion is marked by the relations basic for quantum mec

A. G. Zagorodny, P. P. J. M. Schram, S. A. Trigger

Within the kinetic approach velocity and charge distributions of grains in stationary dusty plasmas are calculated and the relations between the effective temperatures of such distributions and plasma parameters are established. It is found that the effective temperature which determines the velocity grain distribution could be anomalously large due to the a

C. Hanhart

The production of mesons in nucleon-nucleon collisions is reviewed from the viewpoint of the meson-exchange picture. In the first part various possible production mechanisms and their relative importance are discussed. In addition, general features of meson production are described. In the second part special emphasis is put on pion production. Implications

A. Echeverrí a-Enrí quez, M. C. Muñoz-Lecanda, N. Román-Roy

Actions of Lie groups on presymplectic manifolds are analyzed, introducing the suitable comomentum and momentum maps. The subsequent theory of reduction of presymplectic dynamical systems with symmetry is studied. In this way, we give a method of reduction which enables us to remove gauge symmetries as well as non-gauge ``rigid'' symmetries at once.

Kefeng LIU, Xiaonan MA

In LM, we proved a family version of the famous Witten rigidity theorems and several family vanishing theorems for elliptic genera. In this paper, we gerenalize our theorems LM in two directions. First we establish a family rigidity theorem for the Dirac operator on loop space twisted by general positive energy loop group representations. Second we prove a f

Suemi Rodriguez-Romo

We analize the role of GL_2, a quantum group constructed by Dipper-Donkin, as a global symmetry for quantum chains, and show the way to construct all possible Hamiltonians for four states quantum chains with GL_2 global symmetry. In doing this, we search all inner actions of GL_2 on the Clifford algebra C(1,3) and show them. We also introduce the correspondi

Zhiqin Lu

In this paper, we give some estimates of the sum of the square norm of the sections of the pluricanonical bundles over a Riemann surface with genus greater than 2 and Gauss curvature (-1). Using these estimate, we give a uniform estimate of the corona problem on Riemann surfaces.

Yi Ouyang

For any odd squarefree integer r, we get complete description of the G_r=Gal(Q(mu_r)/Q) group cohomology of the universal ordinary distribution U_r in this paper. Moreover, if M is a fixed integer which divides l-1 for all prime factors l of r, we study the cohomology group H^{*}(G_r, U_r/MU_r). In particular, we explain the mysterious construction of the el

Yi Ouyang

We prove an abstract index formula about Sinnott's symbol between two different lattices. We also develop the theory of the universal distribution and predistribution in a double complex point of view. The theory of spectral sequence is used to interpret the index formula and to analyze the cohomology of the universal distribution. Combing these results,

Harald G. Svendsen

This is a thesis submitted for the cand.scient. degree at the University of Oslo. It is meant to give a thorough presentation of two methods for deriving tensionless limits of strings, and the analogue in other models. Also, the applicability of these methods are investigated by explicitly going through the calculations for a variety of models. An important

A. Gorsky

We discuss dualities of the integrable dynamics behind the exact solution to the N=2 SUSY YM theory. It is shown that T duality in the string theory is related to the separation of variables procedure in dynamical system. We argue that there are analogues of S duality as well as 3d mirror symmetry in the many-body systems of Hitchin type governing low-energy

A. Bassetto, L. Griguolo, F. Vian

In these notes Yang-Mills theories in 1+1 dimensions are reviewed. Instantons on a sphere prove to be -in the decompactification limit- the key issue to clarify an old controversy between equal-time and light-front quantization.

V. E. Rochev

A new approach proposed recently by author for the calculation of Green functions in quantum field theory and quantum mechanics is briefly reviewed. The method is applied to nonperturbative calculations for anharmonic oscillator, $ϕ^4$-theory, quantum electrodynamics and other models.

N. Mankoc Borstnik, H. B. Nielsen

We compare the way one of us got spinors out of fields, which are a priori antisymmetric tensor fields, to the Dirac-Kähler rewriting. Since using our Grassmann formulation is simple it may be useful in describing the Dirac-Kähler formulation of spinors and in generalizing it to vector internal degrees of freedom and to charges. The ``cheat'' concern

Alfred D. Shapere, Cumrun Vafa

We study geometric engineering of Argyres-Douglas superconformal theories realized by type IIB strings propagating in singular Calabi-Yau threefolds. We use this construction to count the degeneracy of light BPS states under small perturbations away from the conformal point, by computing the degeneracy of D3-branes wrapped around supersymmetric 3-cycles in t

Harry J. Lipkin

We consider all hyperon data relevant to spin and flavor structure of hyperons. In addition to masses and magnetic moments considered as static properties in Hyperon99 we include also relevant data from hyperon decays and spin structure determined from deep inelastic scattering. Any theoretical model for the hyperons with parameters to be determined from exp

J. Gasser, V. E. Lyubovitskij, A. Rusetsky

Using non relativistic effective Lagrangian techniques, we analyze the hadronic decay of the pi+pi- atom and the strong energy-level shift of pionic hydrogen in the ground state. We derive general formulae for the width and level shift, valid at next-to-leading order in isospin breaking. The result is expressed in terms of hadronic threshold amplitudes that

Harry J. Lipkin

The new SELEX measurement $σ_{tot}(Σp) = 36.96 \pm 0.65$ at P = 609 GeV/c and the new 1998 Particle-Data-Group Regge (PDG) analysis of hadron total cross sections with an additional even-signature-exchange contribution recall the 1975 two-component-Pomeron model (TCP), which introduced such an additional term and predicted $σ_{tot}(Σp) = 37.07$ mb. in 1975 a

Masafumi Koike, Joe Sato

We consider possibilities of observing T-violation effects in neutrino oscillation experiments with very long baseline (~ 10000 km) using low energy neutrino (~ several hundreds MeV). We show that the matter effect effectively changes only the first-second generation mixing angle, respecting solar neutrino deficits and atmospheric neutrino anomalies. The eff

M. L. Mangano

I review the recent results in the field of QCD at high energy presented to this Conference. In particular, I will concentrate on measurements of $\as$ from studies of event structures and jet rates, jet production in hadronic collisions, and heavy quark production.

Jonathan A. Bagger, Jonathan L. Feng, Nir Polonsky, Ren-Jie Zhang

In supersymmetric models, the well-known tension between naturalness and experimental constraints is relieved if the squarks and sleptons of the first two generations are superheavy, with masses of order 10 TeV, and all other superpartners are light, with masses of order 1 TeV. We show that even if all scalar masses and trilinear A parameters are of order 10

A. Delgado, A. Pomarol, M. Quiros

We study the implications of extra dimensions of size $R\sim 1/TeV$ on electroweak and flavor physics due to the presence of Kaluza-Klein excitations of the SM gauge-bosons. We consider several scenarios with the SM fermions either living in the bulk or being localized at different points of an extra dimension. Global fits to electroweak observables provide

A. Brandenburg, M. Flesch, P. Uwer

We discuss the polarization and spin correlations of top quarks produced above threshold at a future linear collider, including QCD radiative corrections.

D. Palle

We show that a Majorana heavy neutrino with a mass O(100TeV) is a good candidate particle for cold dark matter. It can be responsible for the majority of the cosmological diffuse photon background owing to lifetime of the order of O(10^(25)s), dominantly fixed by the radiative two-body decay. The lifetime is suppressed by two mechanisms: the leptonic GIM can

M. Faber, J. Greensite, S. Olejnik

The dominance of center degrees of freedom is observed in SU(3) lattice gauge theory in maximal center gauge. The full asymptotic string tension is reproduced, after center projection, by the center elements alone. When center vortices are removed from lattice configurations, the string tension tends to zero. This provides further evidence for the role playe

Y. A. Kulchitsky, M. V. Kuzmin

The e/$π$ ratio for the Barrel Combined Calorimeter Prototype, composed from electromagnetic LAr calorimeter and hadronic Tile calorimter was investigated. Response of Combined Calorimeter on pions and electrons in the energy region 20 - 300 GeV was studied. Found $e/h = 1.37\pm0.01\pm0.02$ is in good agreement with results from previous Combined Calorimeter

M. Abe, T. Emura, S. Odaka

The trailing edge of tube drift-chamber signals for charged particles is expected to provide information concerning the particle passage time. This information may be useful for separating meaningful signals from overlapping garbage at high-rate experiments, such as the future LHC experiments. We carried out a cosmic-ray test using a small tube chamber in or

Ulrich H. Gerlach

We exhibit a purely quantum mechanical carrier of the imprints of gravitation by identifying for a relativistic system a property which (i) is independent of its mass and (ii) expresses the Poincare invariance of spacetime in the absence of gravitation. This carrier consists of the phase and amplitude correlations of waves in oppositely accelerating frames.

Bin Wang, Elcio Abdalla, Ru-Keng Su

Different geometrical and topological properties have been shown for two kinds of extreme Reissner-Nordstr$\ddot{o}$m-anti-de Sitter black holes. The relationship between the geometrical properties and the intrinsic thermodynamical properties has been made explicit.

J Baker, S Brandt, M Campanelli, C O Lousto

We compare the fully nonlinear and perturbative evolution of nonrotating black holes with odd-parity distortions utilizing the perturbative results to interpret the nonlinear results. This introduction of the second polarization (odd-parity) mode of the system, and the systematic use of combined techniques brings us closer to the goal of studying more compli

Dietrich Stauffer, Robert M. Ziff

Monte Carlo simulations alone could not clarify the corrections to scaling for the size-dependent p_c(L) above the upper critical dimension. Including the previous series estimate for the bulk threshold $p_c(\infty)$ gives preference for the complicated corrections predicted by renormalization group and against the simple 1/L extrapolation. Additional Monte-

A. Gammal, T. Frederico, Lauro Tomio, Ph. Chomaz

The stability of a Bose-Einstein condensed state of trapped ultra-cold atoms is investigated under the assumption of an attractive two-body and a repulsive three-body interaction. The Ginzburg-Pitaevskii-Gross (GPG) nonlinear Schrödinger equation is extended to include an effective potential dependent on the square of the density and solved numerically for t

Sviatoslav S. Sokolov, Antonio Carlos A. Ramos, Nelson Studart

The energetics and transport properties of the polaron in the anisotropic surface over liquid helium are investigated. The localization radii and the energy of the ground and excited states are calculated using the variational method within the hydrodynamic model of the polaron. In particular, we have considered maximal anisotropy which corresponds to the sy

O. G. Balev, Nelson Studart, P. Vasilopoulos

We present a microscopic treatment of edge magnetoplasmons (EMP's) within the random-phase approximation for strong magnetic fields, low temperatures, and filling factor $ν=1(2)$, when a weak short-period superlattice potential is imposed along the Hall bar. The modulation potential modifies both the spatial structure and the dispersion relation of the f

Leticia F. Cugliandolo, Jorge Kurchan

We present a scenario for the nonequilibrium dynamics in the limit of small entropy production. We discuss (i) the appearence of different time-scales, (ii) the modification of the fluctuation-dissipation theorem and its relation to effective temperatures and partial equilibrations and (iii) the validity of Onsager reciprocity relations. We distinguish these

Jacek Dziarmaga, Mariusz Sadzikowski

Formation of domain walls during a rapid phase transition in a quasi one dimensional Cahn-Hiliard equation describing binary fluids in a thin tube is studied. Density of kinks scales like a sixth root of quench rate for equal concentrations and like a square root of quench rate for unequal concentrations of fluids. For a slow inhomogeneous transition the den

Tom Davis, John Cardy

The two-dimensional random-bond Q-state Potts model is studied for Q near 2 via the perturbative renormalisation group to one loop. It is shown that weak disorder induces cross-correlations between the quenched-averages of moments of the two-point spin/spin and energy/energy correlation functions, which should be observable numerically in specific linear com

Joachim Buschle, Philipp Maass, Wolfgang Dieterich

We propose a general formalism to study the static properties of a system composed of particles with nearest neighbor interactions that are located on the sites of a one-dimensional lattice confined by walls (``confined Takahashi lattice gas''). Linear recursion relations for generalized partition functions are derived, from which thermodynamic quant

I. Campillo, J. M. Pitarke

We report a first-principles description of the induced wake potential and density in real solids. The linear-response formalism is used to obtain the potential and density induced by an external charge penetrating through an inhomogeneous periodic system. The linear dynamical response of the system is evaluated in the random-phase approximation, by includin

A. Lipowski

In an attempt to explain the uniqueness of the coding mechanism of living cells as contrasted with multi-species structure of ecosystems we examine two models of individuals with some replicative properties. In the first model the system generically remains in a multi-species state. Even though for some of these species the replicative probability is very hi

Raphael Exartier, Luca Peliti

We study the stationary nonequilibrium regime which settles in when two single-spin paramagnets each in contact with its own thermal bath are coupled. The response vs. correlation plot exhibits some features of aging systems, in particular the existence, in some regimes, of effective temperatures.

Andrew M. Martin, Thomas Gramespacher, Markus Buttiker

In this work we show how to calculate the equilibrium and non-equilibrium charge fluctuations in a gated normal mesoscopic conductor which is attached to one normal lead and one superconducting lead. We then consider an example where the structure is placed in a high magnetic field, such that the transport is dominated by edge states. We calculate the equili

J. Tworzydlo, C. W. J. Beenakker

Elastic waves of short wavelength propagating through the upper layer of the Earth appear to move faster at large separations of source and receiver than at short separations. This scale dependent velocity is a manifestation of Fermat's principle of least time in a medium with random velocity fluctuations. Existing perturbation theories predict a linear

J. de Gier, M. T. Batchelor, M. Maslen

We calculate the phase diagram of an integrable anisotropic 3-leg quantum spin tube connected to the su(8) algebra. We find several quantum phase transitions for antiferromagnetic rung couplings. Their locations are calculated exactly from the Bethe Ansatz solution and we discuss the nature of each of the different phases.

Plamen Ch. Ivanov, Armin Bunde, Luís A. N. Amaral, Shlomo Havlin

We compare scaling properties of the cardiac dynamics during sleep and wake periods for healthy individuals, cosmonauts during orbital flight, and subjects with severe heart disease. For all three groups, we find a greater degree of anticorrelation in the heartbeat fluctuations during sleep compared to wake periods. The sleep-wake difference in the scaling e

M. Pustilnik, K. Flensberg, Q. Niu

Quantized single-electron transport driven by surface acoustic waves (SAW) through a pinched-off narrow constriction is studied theoretically. Long-range Coulomb interaction causes the tunneling coupling between the two-dimensional electron gas (2DEG) and the moving minimum of the SAW-induced potential to decay rapidly with time. The energy scale, associated

D. Branch, D. J. Jeffery, M. Blaylock, K. Hatano

We discuss a simple model for the formation of a supernova spectral line by resonance scattering in the presence of external illumination of the line-forming region by light from circumstellar interaction (toplighting). The simple model provides a clear understanding of the most conspicuous toplighting effect: a rescaling or, as we prefer, a ``muting'&#3

H. Bluhm, O. Marggraf, K. S. de Boer, P. Richter

In ORFEUS II spectra of the sdO star BD +39 3226 interstellar hydrogen and deuterium is detected. From Ly alpha profile fitting and a curve of growth analysis of the Lyman series of H I and D I we derive the column densities N(H)=1.20(+0.28/-0.22)*10^20 cm^(-2) and N(D)=1.45(+0.50/-0.38)*10^(15) cm^(-2). From the analysis of metal absorption lines in ORFEUS

F. Reale, G. Peres

In a recent letter (ApJ 517, L155) Lenz et al. have shown the evidence of uniform temperature along steady long coronal loops observed by TRACE in two different passbands (171 A and 195 A filters). We propose that such an evidence can be explained by the sub-arcsecond structuring of the loops across the magnetic field lines. In this perspective, we present a

M. J. Lewis, Katherine Freese, Gregory Tarle

We extend the Parker bound on the galactic flux $\cal F$ of magnetic monopoles. By requiring that a small initial seed field must survive the collapse of the protogalaxy, before any regenerative dynamo effects become significant, we develop a stronger bound. The survival and continued growth of an initial galactic seed field $\leq 10^{-9}$G demand that ${\ca

J. N. Abdurashitov, V. E. Yants, C. V. Parfenov

Ultracompact primordial black hole binaries with masses > 10^{16} g are considered. If PBHB's contribute significant part of the dark matter of the Galaxy one can expect an existence of high-frequent non-thermal diffuse gravitational radiation with flux of ~1 erg cm^{-2} s^{-1}. The possibility of coalescence of the PBHB's in Galaxy's halo to be

G. Cusumano, M. C. Maccarone, L. Nicastro, B. Sacco

We revisited the BeppoSAX observation of SAX J0635+0533, suggested as a possible counterpart to the gamma-ray source 2EG J0635+0521. We have discovered a 33.8 ms pulsation from the source and derived an improved position, consistent with the location of the Be star proposed as a binary companion. We interpret the periodicity as the spin period of a neutron s

M. Ostrowski

A plasma velocity shear layer and/or a tangential flow discontinuity provide conditions allowing for energetic particle acceleration. We review such acceleration processes acting both in non-relativistic and in relativistic flows. In heliospheric conditions shear layers can provide particles with energies compatible with the observed values (from several keV

W. J. Maciel

In this work, a review is given of some recent results and problems involved in the determination of chemical abundances of galactic planetary nebulae, particularly regarding disk and bulge objects.

Andrea Possenti, Monica Colpi, Ulrich Geppert, Luciano Burderi

We investigate the statistical evolution of magnetic neutron stars recycled in Low Mass Binary (LMB) systems, simulating synthetic populations. Irrespective to the details of the physical models, we find to be significant the fraction of neutron stars spinning close to their mass shedding limit relative to the millisecond pulsar population. The simulated neu

L. Morales-Rueda, T. R. Marsh, I. Billington

We present spectroscopy of the dwarf nova IP Pegasi taken during two consecutive nights, 5 and 6 days after the start of an outburst. Even this late in the outburst, Doppler maps show marked spiral structure in the accretion disc, at least as strongly as seen earlier in other outbursts of IP Peg. The spiral shocks are present on both nights with no diminutio

Paola Marigo, Cesare Chiosi, Leo Girardi, Tiziana Sarrubbi

We present new evolutionary models for zero-metallicity stars, covering a large range of initial masses (from 0.8 to 100 M_sun). Models are computed with overshooting from stellar cores and convective envelopes, and assuming mass-loss from the most massive stars. We discuss the main evolutionary features of these stars, and provide estimates of the amount of

E. Viard, F. Delplancke, N. Hubin, N. Ageorges

This paper describes the qualitative effects of LGS spot elongation and Rayleigh scattering on ALFA wavefront sensor images. An analytical model of Rayleigh scattering and a numerical model of laser plume generation at the altitude of the Na-layer were developed. These models, integrated into a general AO simulation, provide the sensor sub-aperture images. I

D. Mitra, S. Konar, D. Bhattacharya, A. V. Hoensbroech

The evolution of the multipolar structure of the magnetic field of isolated neutron stars is studied assuming the currents to be confined to the crust. Lower orders ($\le 25$) of multipole are seen to evolve in a manner similar to the dipole suggesting little or no evolution of the expected pulse shape. We also study the multifrequency polarization position

L. Lara, A. Alberdi, J. M. Marcaide, T. W. B. Muxlow

We present Space-VLBI observations of the quasar 3C395 which show evidence of the existence of a large bend in the inner parts of its jet, close to the core. This bend would explain why previous Earth-based cm-VLBI observations could not detect the ejection of new moving components, as expected from flux density variability in this source. In general, the ob

R. Ramachandran

Observations of proper motions and their statistical analyses show that the predominant number of pulsars have velocities of the order of 200-250 km/sec. The pulsar population exhibits "asymmetric drift" in the Galaxy. Though there are compelling evidences to show that pulsars receive a significant fraction of their velocities due to asymmetric super

I. Yamamura, K. Kawaguchi, S. T. Ridgway

We report the identification of SH $Δv=1$ ro-vibrational lines in the published high-resolution infrared spectrum of the S-type star, R And. This is the first astronomical detection of this molecule. The lines show inverse P-Cygni profiles, indicating infall motion of the molecular layer due to stellar pulsation. A simple spherical shell model with a constan

A. de la Macorra

We show that the evolution of the quintessence energy density $Ω_Q$ is model independent in an accelerating universe. The accelerating behaviour has lasted at most 0.5 e-folds of expansion assuming a present day value of $Ω_Q=2/3$. The generic evolution differs from the exact solution by a percentage given by $r=2\gm_Q$, with $\gm_Q=(ρ_Q+p_Q)/ρ_Q$. For a sma

L. Ciotti, G. Bertin

In this paper we describe some analytical properties of the R^{1/m} law proposed by Sersic (1968) to categorize the photometric profiles of elliptical galaxies. In particular, we present the full asymptotic expansion for the dimensionless scale factor b(m) that is introduced when referring the profile to the standard effective radius. Surprisingly, our asymp

A. P. Jacob, T. R. Bedding, J. G. Robertson, M. Scholz

We discuss the wavelength dependence of angular diameters of M giants from an observational perspective. Observers cannot directly measure an optical-depth radius for a star, despite this being a common theoretical definition. Instead, they can use an interferometer to measure the square of the fringe visibility. We present new plots of the wavelength-depend

Vinod Krishan

This book is a valuable introduction to astrophyscial plasmas and fluids for graduate students of astronomy preparing either for a research career in the field or just aspiring to achieve a decent degree of familiarity with 99% of the cosmos. The contents provide a true representation of the phenomenal diversity of dominant roles that plasmas and fluids play

Simon J. O'Toole, Teresa C. Teixeira, Timothy R. Bedding, Hans Kjeldsen

We have obtained time-series spectra for the pulsating hot subdwarf (sdB) PG1605+072. Previous time-series photometry of this star has shown maximum amplitude variations of about 0.1 mag and at least 50 periods. The pulsator has the largest amplitude and longest periods of all the pulsating sdBs (or EC14026 stars) discovered so far, and appears to be unusual

Scott M. Ransom

I describe a computationally simple, efficient, and sensitive method to search long observations for pulsars in binary systems. The technique looks for orbitally induced sidebands in the power spectrum around a nominal spin frequency, enabling it to detect pulsars in high- or low-mass binaries with short orbital periods (P_orb <~ 5 h).

T. R. Bedding, B. C. Conn, A. A. Zijlstra

We use wavelets to investigate period and amplitude changes in Mira and semiregular variables and found a variety of behaviours. Period and amplitude changes often go together, perhaps because changes in amplitude are causing period changes via non-linear effects.

Rob Ivison, Ian Smail, Amy Barger, Jean-Paul Kneib

We present extensive observations of a sample of distant, submm galaxies detected in the field of the massive cluster lens, A1835, using SCUBA. Taken in conjunction with earlier observations of other submm-selected sources (Ivison et al. 1998; Smail et al. 1999; Soucail et al. 1999) we now have detailed, multi-wavelength observations of 7 examples of the sub

A. G. Agnese, R. Festa

Starting from a previously stated hypothesis concerning the discretization of the orbits for periodic celestial motions, the mass of ups-Andromedae and the periods of its b- and d- companions are estimated using the accurately known period of the massive c-companion. Moreover, the periods and the orbital major semiaxes of other hypotetically existing and not

Ralf S. Klessen, Fabian Heitsch, Mordecai-Mark Mac Low

Observed molecular clouds often appear to have very low star formation efficiencies and lifetimes an order of magnitude longer than their free-fall times. Their support is attributed to the random supersonic motions observed in them. We study the support of molecular clouds against gravitational collapse by supersonic, gas dynamical turbulence using direct n

Ivan Kostov

We solve exactly the 6-vertex model on a dynamical random lattice, using its representation as a large N matrix model. The model describes a gas of dense nonintersecting oriented loops coupled to the local curvature defects on the lattice. The model can be mapped to the c=1 string theory, compactified at some length depending on the vertex coupling. We give

Michael N. Leuenberger, Daniel Loss

We generalize the Landau-Zener theory of coherent tunneling transitions by taking thermal relaxation into account. The evaluation of a new generalized master equation containing a dynamic tunneling rate that includes the interaction between the relevant system and its environment leads to an incoherent Zener transition probability with an exponent that is tw

M. Kaplinghat, G. Steigman, T. P. Walker

We have recently considered cosmologies in which the Universal scale factor varies as a power of the age of the Universe and concluded that they cannot satisfy the observational constraints on the present age, the magnitude-redshift relation for SN Ia, and the primordial element (D, He3, He4, and Li7) abundances. This claim has been challenged in a proposal

F. Borzumati, C. Greub, T. Hurth, D. Wyler

The gluino-induced contributions to the decay b-> s gamma are investigated in supersymmetric frameworks with generic sources of flavour violation. It is shown that, when QCD corrections are taken into account, the relevant operator basis of the Standard Model effective Hamiltonian gets enlarged to contain: i) magnetic and chromomagnetic operators with a fact

Jonathan Bagger, Takeo Moroi, Erich Poppitz

We consider the effects of anomalies on the supersymmetry-breaking parameters in supergravity theories. We construct a supersymmetric expression for the anomaly-induced terms in the 1PI effective action; we use this result to compute the complete one-loop formula for the anomaly-induced gaugino mass. The mass receives contributions from the super-Weyl, Kahle

Joel E. Moore, Xiao-Gang Wen

The splitting of the Kondo resonance in the density of states of an Anderson impurity in finite magnetic field is calculated from the exact Bethe-ansatz solution. The result gives an estimate of the electron spectral function for nonzero magnetic field and Kondo temperature, with consequences for transport experiments on quantum dots in the Kondo regime. The

H. Neuberger

New exact upper and lower bounds are derived on the spectrum of the square of the hermitian Wilson Dirac operator. It is hoped that the derivations and the results will be of help in the search for ways to reduce the cost of simulations using the overlap Dirac operator. The bounds also apply to the Wilson Dirac operator in odd dimensions and are therefore re

Gautam Rupak

An effective field theory calculation of the n+p->d+gamma cross section accurate to 1% for center of mass energy E up to ~1 MeV is presented. At these energies, which are relevant for big-bang nucleosynthesis, isovector magnetic transitions M1 and isovector electric transitions E1 give the dominant contributions. The M1 amplitude is calculated up to next-to-

F. Delduc, A. Sorin

Three inequivalent real forms of the complex N=4 supersymmetric Toda chain hierarchy (Nucl. Phys. B558 (1999) 545, solv-int/9907004) in the real N=2 superspace with one even and two odd real coordinates are presented. It is demonstrated that the first of them possesses a global N=4 supersymmetry, while the other two admit a twisted N=4 supersymmetry. A new s

Sergio De Filippo

Only craziness I am ashamed about.

A. G. Abanov, P. B. Wiegmann

We trace the origin of theta-terms in non-linear sigma-models as a nonperturbative anomaly of current algebras. The non-linear sigma-models emerge as a low energy limit of fermionic sigma-models. The latter describe Dirac fermions coupled to chiral bosonic fields. We discuss the geometric phases in three hierarchies of fermionic sigma-models in spacetime dim

Matthew G. Baring

The observation by the CANGAROO experiment of TeV emission from SN 1006, in conjunction with several instances of non-thermal X-ray emission from supernova remnants, has led to inferences of super-TeV electrons in these extended sources. While this is sufficient to propel the theoretical community in their modelling of particle acceleration and associated ra

M. R. Adams

We report results of the first measurements of Lambda and Antilambda polarization produced in deep inelastic polarized muon scattering on the nucleon. The results are consistent with an expected trend towards positive polarization with increasing x_F. The polarizations of Lambda and Antilambda appear to have opposite signs. A large negative polarization for

Z. Gamba, B. M. Powell

There is ample experimental evidence on the existence of several crystalline phases of C4F8, although they still have been not clearly identified. In this paper we perform a series of molecular dynamics (MD) simulations using a partially flexible molecular model, which takes into account the mixing of the low frequency intramolecular modes and lattice modes.

Somshubhro Bandyopadhyay

We present two method for optimal entanglement concentration from pure entangled states by local actions only. However a prior knowledge of the Schmidt coefficients is required. The first method is optimally efficient only when a finite ensemble of pure entangled states are available whereas the second method realizes the single pair optimal concentration pr

R. J. Furnstahl, Brian D. Serot

Power counting is applied to relativistic mean-field energy functionals to estimate contributions to the energy from individual terms. New estimates for isovector, tensor, and gradient terms in finite nuclei are shown to be consistent with direct, high-quality fits. The estimates establish a hierarchy of model parameters and identify how many parameters are

M. Abud, F. Buccella, D. Falcone, G. Ricciardi

Assuming a Zee-like matrix for the right-handed neutrino Majorana masses in the see-saw mechanism, one gets maximal mixing for vacuum solar oscillations, a very small value for $U_{e3}$ and an approximate degeneracy for the two lower neutrino masses. The scale of right-handed neutrino Majorana masses is in good agreement with the value expected in a SO(10) m

Elisabetta Pallante, Antonio Pich

We quantify the important effect of strong final state interactions in the weak $K\to2π$ amplitudes, using the measured $π$--$π$ phase shifts with J=0 and $I=0,2$. The final rescattering of the two pions provides a strong enhancement of the $ΔI =1/2$ amplitude, which so far has been neglected in the theoretical predictions of $ε&#39;/ε$. This correction incr

Synge Todo, Kiyoshi Kato

We present a general strategy to extend quantum cluster algorithms for S=1/2 spin systems, such as the loop algorithm, to systems with arbitrary size of spins. In general, the partition function of a high-S spin system is represented in terms of the path integral of a S=1/2 model with special boundary conditions. We introduce additional graphs to be assigned

B. F. Liu, W. Yuan, F. Meyer, E. Meyer-Hofmeister

We apply the disk-corona evaporation model (Meyer & Meyer-Hofmeister) originally derived for dwarf novae to black hole systems. This model describes the transition of a thin cool outer disk to a hot coronal flow. The mass accretion rate determines the location of this transition. For a number of well studied black hole binaries we take the mass flow rates de

Yoon-Ho Kim, Maria V. Chekhova, Sergei P. Kulik, Yanhua Shih

We study first-order interference in spontaneous parametric down-conversion generated by two pump pulses that do not overlap in time. The observed modulation in the angular distribution of the signal detector counting rate can only be explained in terms of a quantum mechanical description based on biphoton states. The condition for observing interference in

Anjana Sinha, Rajkumar Roychoudhury

In a recent paper by Gomes and Adhikari (J.Phys B30 5987(1997)) a matrix formulation of the Bohr-Sommerfield quantization rule has been applied to the study of bound states in one dimension quantum wells. Here we study these potentials in the frame work of supersymmetric WKB (SWKB) quantization approximation and find that SWKB quantization rule is superior t

S. Khlebnikov

We describe macroscopic quantum memory devices based on type-II toroidal superconductors and estimate in one case and compute in another the rates at which quantum information stored in these devices ``degrades&#39;&#39; because of thermal fluctuations. In the case when the entire solid torus is superconducting, the Boltzmann factor in the rate corresponds t

Somshubhro Bandyopadhyay

We present an optimal method for teleporting an unknown qubit using any pure entangled state.

Ernst Karl Kunst

As has been shown before (a brief comment will be given in the text), relativistic mass and relativistic time dilation of moving bodies are equivalent as well as time and mass in the rest frame. This implies that the time dilation due to the gravitational field is combined with inertial and gravitational mass as well and permits the computation of the gravit