December 1997 arXiv papers — page 8

Giorgio Parisi, Frantisek Slanina

We present a variational approach for directed polymers in $D$ transversal dimensions which is used to compute the corrections to the mean field theory predictions with broken replica symmetry. The trial function is taken to be a symmetrized version of the mean-field solution, which is known to be exact for $D=\infty$. We compute the free energy correspondin

Paolo Politi

Domain structures appear in ultrathin magnetic films, if an easy-axis anisotropy, favouring the direction perpendicular to the film, overcomes the shape anisotropy. We will study the nature of the magnetic ground state and how the different parameters influence the domain structure. Both Ising and Heisenberg spins will be considered: in the latter case, a re

G. Brunthaler, T. Dietl, A. Prinz, M. Sawicki

A metal-insulator transition was induced by in-plane magnetic fields up to 27 T in homogeneously Sb-doped Si/SiGe superlattice structures. The localisation is not observed for perpendicular magnetic fields. A comparison with magnetoconductivity investigations in the weakly localised regime shows that the delocalising effect originates from the interaction-in

Stavros Theodorakis, Epameinondas Leontidis

We present a description of very dense vortex lattices in highly anisotropic multilayers, for high fields parallel to the layers. We show that a magnetic field inversion can occur away from the center of a vortex, provided the layers are sufficiently far apart.

Dmitrii S. Golubev, Andrei D. Zaikin

We develope a theory of a fundamental effect of the interaction-induced decoherence of the electron wave function in a disordered metal. With the aid of the Keldysh technique and the path integral formalism we derive a formally exact equation of motion for the electron density matrix in the presence of interaction. We demonstrate that the effect of interacti

Albert Diaz-Guilera, Conrad J. Perez, Alex Arenas

We analyze the physical mechanisms leading either to synchronization or to the formation of spatio-temporal patterns in a lattice model of pulse-coupled oscillators. In order to make the system tractable from a mathematical point of view we study a one-dimensional ring with unidirectional coupling. In such a situation, exact results concerning the stability

R. Grosser, A. Martin, M. Niemetz, E. V. Pechen

The damping of the oscillations of a small permanent magnet (spherical shape, radius 0.1 mm) levitating between two parallel epitaxial YBCO films is measured as a function of oscillation amplitude and temperature. At small amplitudes the dissipation is found to be orders of magnitude lower than in bulk YBCO, Q-factors exceeding one million at low temperature

Jian-Sheng Wang, Chee Kwan Gan

We study the critical relaxation of the two-dimensional Ising model from a fully ordered configuration by series expansion in time t and by Monte Carlo simulation. Both the magnetization (m) and energy series are obtained up to 12-th order. An accurate estimate from series analysis for the dynamical critical exponent z is difficult but compatible with 2.2. W

Yigal Meir

Using a mapping of a layered three-dimensional system with significant inter-layer tunneling onto a spin-Hamiltonian, the phase diagram in the strong magnetic field limit is obtained in the semi-classical approximation. This phase diagram, which exhibit a metallic phase for a finite range of energies and magnetic fields, and the calculated associated critica

R. Osborn, S. Rosenkranz, D. N. Argyriou, L. Vasiliu-Doloc

Neutron scattering investigations of the paramagnetic correlations in the layered manganite La$_{1.2}$Sr$_{1.8}$Mn$_{2}$O$_{7}$, which exhibits colossal magnetoresistance above the Curie transition at T$_C$ = 112 K, show that spins in neighboring layers within each bilayer are strongly canted at an average angle that is dependent on both the magnetic field a

Andreas Wirzba

The scattering problems of a scalar point particle from a finite assembly of n>1 non-overlapping and disconnected hard disks, fixed in the two-dimensional plane, belong to the simplest realizations of classically hyperbolic scattering systems. Here, we investigate the connection between the spectral properties of the quantum-mechanical scattering matrix and

Una Hwang, John P. Hughes, Robert Petre

We present the results of broadband fits to the X-ray spectrum of Tycho's supernova remnant obtained by the Solid-State Imaging Spectrometers on the ASCA Observatory. We use single-temperature, single-ionization-age, nonequilibrium ionization models to characterize the ejecta and the blast-shocked interstellar medium. Based on the Fe K emission at 6.5 ke

Hyong C. Lee, Guy S. Miller

We develop a simple, time-dependent Comptonization model to probe the origins of spectral variability in accreting neutron star systems. In the model, soft ``seed photons'' are injected into a corona of hot electrons, where they are Compton upscattered before escaping as hard X-rays. The model describes how the hard X-ray spectrum varies when the pro

Xin-Min Hua, Demosthenes Kazanas, Wei Cui

The Fourier frequency dependent hard X-ray lag, first discovered from the analysis of aperiodic variability of the light curves of the black hole candidate Cygnus X-1, turns out to be a property shared by several other accreting compact sources. We show that the lag can be explained in terms of Comptonization process in coronae of hot electrons with inhomoge

Ojars J. Sovers, John L. Fanselow, Christopher S. Jacobs

Summarizes current status of radio interferometry at radio frequencies between Earth-based receivers, for astrometric and geodetic applications. Emphasizes theoretical models of VLBI observables that are required to extract results at the present accuracy levels of 1 cm and 1 nanoradian. Highlights the achievements of VLBI during the past two decades in refe

Daniel Proga, Scott J. Kenyon, John C. Raymond

We describe a non-LTE photoionization code to calculate the wind structure and emergent spectrum of a red giant wind illuminated by the hot component of a symbiotic binary system. We consider spherically symmetric winds with several different velocity and temperature laws and derive predicted line fluxes as a function of the red giant mass loss rate, \mdot.

Jane C. Charlton, Christopher W. Churchill

The study of galaxy evolution using quasar absorption lines requires an understanding of what components of galaxies and their surroundings are contributing to the absorption in various transitions. This paper considers the kinematic composition of the class of 0.4 < z < 1.0 MgII absorbers, particularly addressing the question of what fraction of this absorp

Francesco Haardt

We present preliminary results of BeppoSAX AO1 observations of 3C 273 performed in January 1997. We also present a close comparison with data obtained during the satellite SVP, in July 1996. On average, the AO1 flux is about a factor 2 higher than the flux detected during the SVP, and roughly on the middle of the historical X-ray flux range. Power law fits w

Charles F. Gammie

I review recent numerical studies of accretion disks, focusing on measurements of the turbulent shear stress, or $α$, in the shearing box model. I conclude with a list of astronomically relevant open questions that can be settled via future numerical experiments.

T. Belloni, M. Mendez, A. R. King, M. van der Klis

GRS 1915+105, one of the two known galactic microquasars, shows an extremely complex variability in the X-ray band, comparable to no other X-ray source in the sky. Making use of RXTE/PCA data, we have analyzed the X-ray spectral distribution throughout the variability. We find that all variations can be attributed to the rapid appearance and disappearance of

T. Belloni, G. Matt, D. De Martino, L. Chiappetti

RE 0751+14 is a member of the class of Soft Intermediate Polars. Unlike classical Intermediate Polars, they are characterized by the presence of a soft component in their X-ray spectra, in addition to the hard component typical of these systems. The broad-band coverage of the Narrow-Field instruments on board BeppoSAX is ideal for the study of such objects.

John K. Cannizzo

We examine in detail several aspects of the physics of accretion disks of possible relevance to the outburst mechanism of the black hole X-ray transients. We adopt the one dimensional, time dependent model described in detail by Cannizzo, Chen, & Livio with parameters appropriate for a system such as A0620-00. We investigate (1) the effect of the grid spacin

S. Paltani, T. J. -L. Courvoisier, M. Turler, R. Walter

In 3C 273, ultraviolet flux and X-ray flux measured by BATSE are not well correlated, contrarily to predictions of several models, unless the X-ray flux lags the UV emission by 1.75 yr. The absence of observed correlation at small lag cannot be due to spectral variability. A Comptonizing corona model is however compatible with all UV and X-ray observations c

P. Bonifacio, P. Molaro, T. C. Beers, G. Vladilo

We present a high-resolution spectroscopic analysis of the extremely-metal-poor star CS 22957-027, which Beers et al (1992) noted to exhibit a rather strong G-band. For Teff = 4839 K, derived from broadband photometry, our analysis obtains log g = 2.25, and a very low metallicity of [Fe/H]=-3.43 +/- 0.12. The carbon-to-iron ratio is found to be enhanced by a

C. Done, P. Magdziarz

We re-analyse the ASCA and GINGA X-ray data from BY Cam, a slightly asynchronous magnetic accreting white dwarf. The spectra are strongly affected by complex absorption, which we model as a continuous (power law) distribution of covering fraction and column of neutral material. This absorption causes a smooth hardening of the spectrum below 3 keV, and is pro

C. Done, P. T. Zycki, D. A. Smith

We identify the reflected component in the GINGA spectra of Nova Muscae, a Black Hole transient system which has been used as the prototype for the recent advection dominated disk models. We see that the reflected spectrum is generally significantly relativistically smeared, and use this and the amount of reflection to track the innermost extent of the accre

Cecilia Kozma, Claes Fransson

Using the temperature and ionization calculated in our previous paper, we model the spectral evolution of SN 1987A. The IR-catastrophe is seen in the metal lines as a transition from thermal to non-thermal excitation, most clearly in the [O I] 6300, 6364 lines. The distribution of the different zones, and therefore the gamma-ray deposition, is determined fro

Cecilia Kozma, Claes Fransson

The temperature and ionization of SN 1987A is modeled between 200 and 2000 days in its nebular phase, using a time-dependent model. We include all important elements, as well as the primary composition zones in the supernova. The energy input is provided by radioactive decay of Co-56, Co-57, and Ti-44. The thermalization of the resulting gamma-rays and posit

Giuseppe Tormen, Antonaldo Diaferio, David Syer

Using high resolution cosmological N-body simulations, we investigate the survival of dark matter satellites falling into larger haloes. Satellites preserve their identity for some time after merging. We compute their loss of mass, energy and angular momentum as dynamical friction, tidal forces and collisions with other satellites dissolve them. We also anal

C. Done, P. Magdziarz

ASCA and GINGA X-ray data from the magnetic Cataclysmic Variable BY Cam show that the spectrum is strongly affected by complex absorption, probably from the pre-shock accretion column. The intrinsic emission from the shock is significantly better described by the theoretically expected multi-temperature structure rather than a single temperature plasma, but

R. Carballo, S. F. Sanchez, J. I. Gonzalez-Serrano, C. R. Benn

We present K-band imaging and photometry of a sample of 52 radio loud quasars (RQs) selected from the B3 survey with flux densities above 0.5 Jy at 408 MHz. The optical completeness of the sample is 90% and the quasars cover the redshift range 0.4 - 2.3. For ~57% of the sources for which the quality of the images allowed a detailed morphological study (16/28

R. Nartallo, W. K. Gear, A. G. Murray, E. I Robson

We present the results of the first survey and monitoring study of the linear polarisation properties of compact, flat-spectrum radio sources at millimetre/submillimetre wavelengths and discuss the implications of the inferred magnetic field structure for the emission models involving shock waves in relativistic jets on sub-parsec scales. We find significant

S. Bardelli, E. Zucca, G. Zamorani, G. Vettolani

The Shapley Concentration is the richest supercluster of clusters in the nearby universe and its core is a remarkable complex formed by the ACO clusters A3558, A3562 and A3556, and by the two minor groups SC 1327-312 and SC 1329-314. This structure has been studied in various wavelength bands, revealing that it is probably dynamically very active. In this pa

Anatoly Klypin, Jon Holtzman

Particle-Mesh (PM) codes are still very useful tools for testing predictions of cosmological models in cases when extra high resolution is not very important. We release for public use a cosmological PM N-body code. We provide a complete package of routines needed to set initial conditions, to run the code, and to analyze the results. The package allows you

Marcin Sawicki, H. K. C. Yee

Broadband optical and IR spectral energy distributions are determined for spectroscopically confirmed z>2 Lyman break objects in the Hubble Deep Field (HDF). These photometric data are compared to spectral synthesis models which take into account the effects of metallicity and of internal reddening due to dust. It is found that, on average, Lyman break objec

Nelson Caldwell, James Rose

We present spectra of nine low-luminosity early-type galaxies (M_B > -17.5) in the Coma cluster. The spectra, which were obtained with the Multiple Mirror Telescope and cover the spectral region 3300-5350 A, exhibit a large variation in Balmer line strengths. In fact the line strength variation among the Coma low-luminosity galaxies is as large as that found

Thomas Bauer

Let $X$ be a smooth projective variety over the complex numbers. One knows by the Cone Theorem that the closed cone of curves of $X$ is rational polyhedral whenever $c_1(X)$ is ample. For varieties $X$ such that $c_1(X)$ is not ample, however, it is in general difficult to determine the structure of $\bar NE(X)$. The purpose of this paper is to study the con

Victor V. Batyrev, Yu. Tschinkel

Let ${\cal L} = (L, \| \cdot \|_v)$ be an ample metrized invertible sheaf on a smooth quasi-projective algebraic variety $V$ defined over a number field. Denote by $N(V,{\cal L},B)$ the number of rational points in $V$ having ${\cal L}$-height $\leq B$. We consider the problem of a geometric and arithmetic interpretation of the asymptotic for $N(V,{\cal L},B

Robert G. Leigh, Moshe Rozali

We study the new ``gauge&#39;&#39; theories in 5+1 dimensions, and their non-commutative generalizations. We argue that the $θ$-term and the non-commutative torus parameters appear on an equal footing in the non-critical string theories which define the gauge theories. The use of these theories as a Matrix description of M-theory on $T^5$, as well as a close

Fernando Abadie

We extend the theory of tensor products of C*-algebras to the larger category of Fell bundles over locally compact groups. We prove that, like in the case of C*-algebras, there exist maximal and minimal tensor products. Given two Fell bundles, we compare the tensor products of their cross-sectional algebras with the cross-sectional algebras of their tensor p

Alexandros Kehagias, Herve Partouche

We discuss higher derivative interactions in the type IIB superstring in ten dimensions. From the fundamental string point of view, the non-perturbative corrections are due to D-instantons. We argue that they can alternatively be understood as arising from $(p,q)$-strings. We derive a non-renormalization theorem for eight-derivative bosonic interactions, whi

G. Papadopoulos

We show that the fluxes of the various six-dimensional &#34;gauge&#34; theories are associated to below threshold bound states of D-branes with the NS-5-branes and KK-monopoles which preserve half of bulk supersymmetry. We then present the supergravity solutions that correspond to these bound states. In addition using the worldvolume solitons of IIA and IIB

Miguel S. Costa, Malcolm J. Perry

We consider a supersymmetric system of D-5-branes compactified on a 5-torus with a self-dual background field strength on a 4-torus and carrying left-moving momentum along a circle. The corresponding supergravity solution describes a 5-dimensional black hole with a regular horizon. The entropy of this black hole may be explained in terms of the Landau degene

Washington Taylor, Mark Van Raamsdonk

We consider subleading terms in the one-loop Matrix theory potential between a classical membrane state and a supergraviton. Nontrivial terms arise at order v/r^8 and v^3/r^8 which are proportional to the angular momentum of the membrane state. The effective potential for a graviton moving in a boosted Kerr-type metric is computed and shown to agree precisel

A. J. Buras, A. Romanino, L. Silvestrini

We present a model independent analysis of new-physics contributions to the decays K^+ \to π^+ ν\bar νand K_L \to π^0 ν\bar ν. We parameterize the effects of new physics in these decays by two parameters: r_K and θ_K, with r_K=1 and θ_K=0 in the Standard Model (SM). We show how these parameters can be extracted from future data. This analysis offers some ins

S. L. Dubovsky, D. S. Gorbunov, S. V. Troitsky

We present a toy model which has the following properties: i) it is strongly coupled at a certain scale and breaks supersymmetry at this scale; ii) matter superfields of (one generation of) the Standard Model are effective low energy degrees of freedom of this strongly coupled theory; iii) direct gauge mediation of supersymmetry breaking occurs due to messen

Beth A. Brown, Joel N. Bregman

To test the cooling flow model of early-type galaxies, we obtained a complete magnitude-limited sample of 34 early-type galaxies, observed with the PSPC and HRI on ROSAT. The X-ray to optical distribution of galaxies implies a lower envelope that is consistent with the stellar emission inferred from Cen A. When this stellar component is removed, the gaseous

Dmitri Orlov

We study derived categories of coherent sheaves on abelian varieties. We give a criterion for the equivalence of the derived categories on two abelian varieties. We describe the autoequivalence group for the derived category of coherent sheaves of an abelian variety.

M. I. Forcada-Miro

I use a 1-D Lagrangian code which follows both a gaseous and a dark component to study the effects of a metagalactic UV background on the formation of dwarf galaxies. In the case of an ionising background consistent with the existing observational constraints no effect has been found in halos with circular velocity above 60 km/s. The effect is very mild in h

M. I. Forcada-Miro, S. D. M. White

We use a 1-D Lagrangian code which follows both a gaseous and a dark component to study the radiative shocks that appear in the evolution of spherical scale-free perturbations in an Einstein-de Sitter Universe. The detailed behaviour of the shock depends on whether the radiative cooling is dominated by bremsstrahlung or line cooling. Bremsstrahlung is the ma

Jiro Kodaira, Takashi Nasuno, Hiroshi Tochimura, Kazuhiro Tanaka

We investigate the nucleon&#39;s transverse spin-dependent structure function g_2(x, Q^{2}) in the framework of the operator product expansion and the renormalization group. We construct the complete set of the twist-3 operators for the flavor singlet channel, and give the relations among them. We develop an efficient, covariant approach to derive the anomal

Koji Uryu, Yoshiharu Eriguchi

We have succeeded in obtaining exact configurations of irrotational binary systems for compressible (polytropic) equations of state. Our models correspond to binaries of equal mass neutron star systems in the viscosity free limit. By using the obtained sequences of stationary states, the evolution of binary systems of irrotational neutron stars due to gravit

A. Chakrabarti

An iterative map of the unit disc in the complex plane (Appendix) is used to explore certain aspects of selfdual, four dimensional gauge fields (quasi)periodic in the Euclidean time. These fields are characterized by two topological numbers and contain standard instantons and monopoles as different limits. The iterations do not correspond directly to a discr

Sinisa Karnas, Sergei V. Ketov

The N-extended self-dual supergravity in the ultra-hyperbolic four-dimensional spacetime of kleinian signature (2+2) is given in the N-extended harmonic superspace. We reformulate the on-shell N-extended self-dual supergravity constraints of Siegel to a `zero-curvature&#39; representation, and solve all of them but one in terms of a single superfield prepote

V. F. Obraztsov, S. R. Slabospitsky, O. P. Yushchenko

We show that a search for $e^+ e^- \to t \bar q$ $(\bar q = \bar c, \bar u)$ events at LEP--2 collider provide a possibility to improve significantly the modern constraints on coupling constants of anomalous $t$--quark interaction via flavor--changing neutral currents.

Ashoke Sen

We compare the logarithm of the degeneracy of BPS saturated elementary string states and the string modified Bekenstein-Hawking entropy of the corresponding black holes in N=2 supersymmetric heterotic string compactification to four dimensions. As in the case of N=4 supersymmetric theory, the two results match up to an overall undetermined numerical factor.

Fotini Markopoulou, Lee Smolin

We describe abstract (p,q) string networks which are the string networks of Sen without the information about their embedding in a background spacetime. The non-perturbative dynamical formulation invented for spin networks, in terms of causal evolution of dual triangulations, is applied to them. The formal transition amplitudes are sums over discrete causal

Guo-xing Ju, Shi-kun Wang, Ke Wu, Chi Xiong

We analysis the symmetries of the reflection equation for open $XYZ$ model and find their solutions $K^{\pm}$ case by case. In the general open boundary conditions, the Lax pair for open one-dimensional $XYZ$ spin-chain is given.

Nickolay Y. Gnedin, Oleg Y. Gnedin

We solve the Boltzmann equation for cosmological neutrinos around the epoch of the electron-positron annihilation in order to verify the freeze-out approximation and to compute accurately the cosmological neutrino distribution function. We find the radiation energy density to be about 0.3% higher than the one predicted by the freeze-out approximation. As a r

Nima Arkani-Hamed, Markus A. Luty, John Terning

We present new theories of dynamical SUSY breaking in which the strong interactions that break SUSY also give rise to composite quarks and leptons with naturally small Yukawa couplings. In these models, SUSY breaking is communicated directly to the composite fields without ``messenger&#39;&#39; interactions. The compositeness scale can be anywhere between 10

Jinwu Ye, Subir Sachdev

We study the consequences of long-range Coulomb interactions at the critical points between integer/fractional quantum Hall states and an insulator. We use low energy theories for such transitions in anyon gases in the presence of an external periodic potential. We find that Coulomb interactions are marginally irrelevant for the integer quantum Hall case. Fo

Spencer R. Klein

Most calculations of air shower development have been based on the Bethe-Heitler cross sections for bremsstrahlung and pair production. However, for energetic enough particles, a number of different external factors can reduce these cross sections drastically, slowing shower development and lengthening the showers. Four mechanisms that can suppress bremsstra

S. Deser, L. Griguolo, D. Seminara

We present two compact derivations of the correct definition of the Chern-Simons term in the topologically non trivial context of thermal $QED_3$. One is based on a transgression descent from a D=4 background connection, the other on embedding the abelian model in SU(2). The results agree with earlier cohomology conclusions and can be also used to justify a

Marcia T. Fontenelle, Samuel L. Braunstein, Wolfgang P. Schleich, Mark Hillery

Recently, Torgerson and Mandel [Phys. Rev. Lett. 76, 3939 (1996)] have reported a disagreement between two schemes for measuring the phase difference of a pair of optical fields. We analyze these schemes and derive their associated phase-difference probability distributions, including both their strong and weak field limits. Our calculation confirms the main

Alexander V. Bogdanov, Ashot S. Gevorkyan

The system of oscillator interacting with vacuum is considered as a problem of random motion of quantum reactive harmonic oscillator (QRHO). It is formulated in terms of a wave functional regarded as complex probability process in the extended space. This wave functional obeys some stochastic differential equation (SDE). Based on the nonlinear Langevin type

A. A. Davydov

The obstructions for an arbitrary fusion algebra to be a fusion algebra of some semisimple monoidal category are constructed. Those obstructions lie in groups which are closely related to the Hochschild cohomology of fusion algebras with coefficients in the K-theory of the ground (algebraically closed) field.

R. Gaehler, J. Felber, F. Mezei, R. Golub

We present scattering from many body systems in a new light. In place of the usual van Hove treatment, (applicable to a wide range of scattering processes using both photons and massive particles) based on plane waves, we calculate the scattering amplitude as a space-time integral over the scattering sample for an incident wave characterized by its correlati

J. Shertzer, J. Ackermann, P. Schmelcher

It was earlier reported [PRL 78 199, (1997)] that long-lived excited states of positronium can be formed in crossed electric and magnetic fields at laboratory field strengths. Unlike the lower-lying states that are localized in the magnetically distorted Coulomb well, these long-lived states which can possess a lifetime up to many years are localized in an o

A. Nersessian, V. M. Ter-Antonyan

The monopole systems with hidden symmetry of the two-dimensional Coulomb problem are considered. One of them, the &#34;charge-charged magnetic vortex&#34; with a half-spin, is constructed by reducing the quantum circular oscillator with respect to the action of the parity operator. The other two systems are constructed by reduction from the two-dimensional c

R. Aldrovandi, L. P. Freitas

A precise meaning is given to the notion of continuous iteration of a mapping. Usual discrete iterations are extended into a dynamical flow which is a homotopy of them all. The continuous iterate reveals that a dynamical map is formend by independent component modes envolving without interference with each other.

Anne C. Skeldon, Mary Silber

We consider the transition from a spatially uniform state to a steady, spatially-periodic pattern in a partial differential equation describing long-wavelength convection. This both extends existing work on the study of rolls, squares and hexagons and demonstrates how recent generic results for the stability of spatially-periodic patterns may be applied in p

S. Nickerson, T. Csorgo, D. Kiang

Having first performed a Monte Carlo simulation to justify the analysis technique to be used, we then analyze the Bose-Einstein correlation functions from CERN experiment NA44 in the context of the core-halo model. Although experimental resolution and error bar distribution prevents a direct observation of the halo structure, the values for the core radius a

L. Alvarez-Ruso, S. K. Singh, M. J. Vicente Vacas

We study the weak production of $Δ$ (i.e. $e^{-} + p \to Δ^{0}+ ν_{e}$ and $e^{+} + p \to Δ^{++} + \barν_{e}$) in the intermediate energy range corresponding to the Mainz and TJNAF electron accelerators. The differential cross sections $σ(θ)$ are found to be of the order of $ 10^{-39}$ cm$^2$/sr, over a range of angles which increases with energy. The possib

H. Schmieden

The recoil proton polarization in the $π^0$ production off the proton with longitudinally polarized electron beam has been studied as a means to measure quadrupole components in the N to $Δ$ transition. On top of the $Δ$ resonance a high sensitivity to a possible Coulomb quadrupole excitation is found in parallel kinematics. The ratio of $S_{1+}/M_{1+}$ mult

M. Warda, B. Nerlo-Pomorska, K. Pomorski

The binding energies, shapes and sizes of even-even beta-stable nuclei with A >= 40 and a few chains of isotopes with Z=50, 56, 82, 94 protons and isotones with N=50, 82, 126 neutrons are analyzed. The average isospin dependence of the radii of protons and neutrons evaluated within the relativistic mean field theory is studied. A simple, phenomenological for

A. Polls, H. Müther, R. Machleidt, M. Hjorth-Jensen

Different modern phase shift equivalent NN potentials are tested by evaluating the partial wave decomposition of the kinetic and potential energy of the deuteron. Significant differences are found, which are traced back to the matrix elements of the potentials at medium and large momenta. The influence of the localisation of the one-pion-exchange contributio

S. B. Carr, I. R. Afnan, B. F. Gibson

The reaction $Ξ^-d\to nΛΛ$ is studied within the framework of the Faddeev equations as a possible tool to gain insight into the final state $Λ$--$Λ$ interaction. The neutron differential energy spectrum gives a final state interaction that is sensitive to both the $Λ$--$Λ$ amplitude at threshold, and the coupling between the $Λ$--$Λ$ and $Ξ$--$N$ channels. T

John Terning

I consider N=1 supersymmetric SU(N_c) gauge theories with matter fields consisting of one antisymmetric representation, five flavors, and enough anti-fundamental representations to cancel the gauge anomaly. Previous analyses are extended to the case of even N_c with no superpotential. Using holomorphy I show that the theory has an interacting infrared fixed

Dariusz Chruscinski

We show that the nonlinear Born-Infeld field equations supplemented by the &#34;dynamical condition&#34; (certain boundary condition for the field along the particle&#39;s trajectory) define perfectly deterministic theory, i.e. particle&#39;s trajectory is determined without any equations of motion. It is a first step towards constructing the consistent theo

Jim Stasheff

This is a survey of `Cohomological Physics&#39;, a phrase that first appeared in the context of anomalies in gauge theory. Differential forms were implicit in physics at least as far back as Gauss (1833) (cf. his electro-magnetic definition of the linking number), and more visibly in Dirac&#39;s magnetic monopole (1931). The magnetic charge was given by the

Michael Gutperle

An overview over effects of D-instantons in ten dimensional IIB superstring theory is given, including the supergravity instanton solution, instanton induced effective interaction vertices, the conjectured $SL(2,Z)$ invariant completion of such terms and the connection of such terms to a one loop calculation in eleven dimensional supergravity.

B. Pioline

We review exact results obtained for R^4 couplings in maximally supersymmetric type II string theories. These couplings offer a privileged scene to understand the rules of semiclassical calculus in string theory. Upon expansion in weak string coupling, they reveal an infinite sum of non-perturbative e^{-1/g} effects that can be imputed to euclidean D-branes

Francois Gieres

The goal of this introduction to symmetries is to present some general ideas, to outline the fundamental concepts and results of the subject and to situate a bit the following lectures of this school. [These notes represent the write-up of a lecture presented at the fifth ``Seminaire Rhodanien de Physique: Sur les Symetries en Physique&#34; held at Dolomieu

Sergei V. Ketov

Some exact solutions to the hypermultiplet low-energy effective action in N=2 supersymmetric four-dimensional gauge field theories with massive `quark&#39; hypermultiplets are discussed. The need for a spontaneous N=2 supersymmetry breaking is emphasized, because of its possible relevance in the search for an ultimate theoretical solution to the confinement

Changhyun Ahn

The moduli space of vacua for the confining phase of N=1 $Sp(N_c)$ supersymmetric gauge theories in four dimensions is studied by M theory fivebrane. We construct M theory fivebrane configuration corresponding to the perturbation of superpotential in which the power of adjoint field is related to the number of NS&#39;5 branes in type IIA brane configuration.

Anastasia Volovich

It was conjectured by Witten that a BPS-saturated domain wall exists in the M-theory fivebrane version of QCD (MQCD) and can be represented as a supersymmetric three-cycle in the sense of Becker et al with an appropriate asymptotic behavior. We derive the differential equation which defines an associative cycle in $G_2$ holonomy seven-manifold corresponding

Frank E. Paige

Methods to make precision measurements of SUSY masses and parameters at the CERN Large Hadron Collider are described.

Isard Dunietz

It has been known for many years that the Bd(t) -> D(*)+/- {pi-/+, rho-/+, a1-/+} modes may involve observable CP violating effects. This note describes how to determine cleanly the Cabibbo-Kobayashi-Maskawa (CKM) phase phi = -2 beta - gamma = -pi + alpha - beta, even in the presence of possible final state interactions. A discrete ambiguity remains.

S. Dawson, L. Reina

We compute QCD corrections to the processes $e^+e^-\to t \bar t h^0$ and $pp\to t \bar t h^0$ by treating the Higgs boson as a parton which radiates off a heavy quark. This approximatiion is valid in the limits $M_h<<M_t$ and $M_h, M_t<<\sqrt{s}$. The corrections increase the rate for $pp\to t \bar t h^0$ at the LHC by a factor of 1.2 to 1.5 over the lowest

S. Weinzierl, O. Yakovlev

We report on recent improvements for the $B\toπ$ form factor. The updated value of $|V_{ub}|$ is presented.

Valery A. Khoze

I survey some recent advances in the applications of the analytical perturbative approach to the description of particle distributions in multi-jet processes. New tests of the perturbatively based picture in the (semi) soft region are discussed.

I. Iashvili, A. Kharchilava

We study the inclusive production of the next-to-lightest neutralino chi2, decaying directly, or via slepton, into two leptons and the lightest neutralino. The dilepton invariant mass spectrum in these decays has a characteristic sharp edge near the kinematical upper limit. We propose to exploit this feature as a search strategy for the chi2, and thereby for

M. Drees, S. Pakvasa, X. Tata, T. ter Veldhuis

Renormalizable lepton number violating interactions that break R-parity can induce a Majorana mass for neutrinos. Based on this, we show that it is possible to obtain a phenomenologically viable neutrino mass matrix that can accommodate atmospheric neutrino data via $\nu_{\mu}$--$\nu_{\tau}$ mixing and the solar neutrino data via either the large or small an

R Delbourgo, Dongsheng Liu

We provide succinct covariant amplitude decompositions of 2-body weak hadronic decays, with which to compare data, including exclusive rates, helicity amplitudes and polarizations. For weak decays, the systematic dependence of these amplitudes on masses and quantum numbers of participating particles are determined within a factor of about two by the CKM angl

T. Reisz

Quantum chromodynamics has a rather complicated phase structure. The finite temperature, chiral phase structure depends on the number of flavours and to a large extent on the particular values of the fermion masses. For two massless flavours there is a true second order transition. It has been argued that this transition belongs to the universality class of

Daniel M. Kaplan

The first experimental limit on CP violation in pi -> mu -> e decay is extracted from published results of the CERN g-2 experiment.

ZEUS Collaboration

Elastic and proton-dissociative rho0 photoproduction (gamma p-->rho0 p,gamma p -->rho0 N,with rho0-->pi+pi-) has been studied in ep interactions at HERA for gamma-p centre-of-mass energies in the range 50<W<100 GeV and for |t|<0.5 GeV2; the results on the p-dissociative reaction are presented for masses of the dissociated proton system in the range MN^2<0.1W

M. J. Reboucas, A. F. F. Teixeira

The five-dimensional (5D) Riemannian Gödel-type manifolds are examined in light of the equivalence problem techniques, as formulated by Cartan. The necessary and sufficient conditions for local homogeneity of these 5D manifolds are derived. The local equivalence of these homogeneous Riemannian manifolds is studied. It is found that they are characterized by

John F. Donoghue

The quantum theory of General Relativity at low energy exists and is of the form called &#34;effective field theory&#34;. In this talk I describe the ideas of effective field theory and its application to General Relativity.

Masayuki Tanimoto, Tatsuhiko Koike, Akio Hosoya

We briefly show how we can obtain Hamiltonians for spatially compact locally homogeneous vacuum spacetimes. The dynamical variables are categorized into the curvature parameters and the Teichmüller parameters. While the Teichmüller parameters usually parameterise the covering group of the spatial sections, we utilise another suitable parameterization where t