September 1997 arXiv papers — page 13

Paolo M. Gensini, Rafael Hurtado, Galileo Violini

The dispersive determination of $π{Y}Σ$ coupling constants ($Y = Λ, Σ$) and the implications for low-energy $\bar{K}N$ analysis are discussed. (Presented by G. Violini at the "7th Int. Symp. on Meson-Nucleon Physics and the Structure of the Nucleon, MENU '97", Vancouver, B.C., July 28th - August 1st, 1977).

V. T. Dolgopolov, G. E. Tsydynzhapov, A. A. Shashkin, E. V. Deviatov

We employ a magnetocapacitance technique to study the spectrum of the soft two-subband (or double-layer) electron system in a parabolic quantum well with a narrow tunnel barrier in the centre. In this system unbalanced by gate depletion, at temperatures $T\agt 30$ mK we observe two sets of quantum oscillations: one originates from the upper electron subband

Mark D. Gould, Yao-Zhong Zhang, Huan-Qiang Zhou

An integrable eight state supersymmtric $U$ model is proposed, which is a fermion model with correlated single-particle and pair hoppings as well as uncorrelated triple-particle hopping. It has an $gl(3|1)$ supersymmetry and contains one symmetry-preserving free parameter. The model is solved and the Bethe ansatz equations are obtained.

Wolfgang Mueck

The method of geodesic expansions is systematically explained. Based on the Haar measures of the group of geodesic expansions the semiclassical sum over immersed manifolds is constructed. Gauge fixing is performed via the Faddeev Popov method.

John Dubinski

Most clusters and groups of galaxies contain a giant elliptical galaxy in their centres which far outshines and outweighs normal ellipticals. The origin of these brightest cluster galaxies is intimately related to the collapse and formation of the cluster. Using an N-body simulation of a cluster of galaxies in a hierarchical cosmological model, we show that

H. Aratyn, L. A. Ferreira, J. F. Gomes, A. H. Zimerman

The algebraic matrix hierarchy approach based on affine Lie $sl (n)$ algebras leads to a variety of 1+1 soliton equations. By varying the rank of the underlying $sl (n)$ algebra as well as its gradation in the affine setting, one encompasses the set of the soliton equations of the constrained KP hierarchy. The soliton solutions are then obtained as elements

Francisco Delgado C., Bogdan Mielnik

The Zeldovich hypothesis is revised and the meaning of quasi energy spectra is discussed. The observation of Floquet resonance for microobjects in quickly oscillating external fields might bring a new information about the time scale of hypothetical quantum jumps.

R. Laflamme, E. Knill, W. H. Zurek, P. Catasti

We describe the creation of a Greenberger-Horne-Zeilinger (GHZ) state of the form |000>+|111> (three maximally entangled quantum bits) using Nuclear Magnetic Resonance (NMR). We have successfully carried out the experiment using the proton and carbon spins of trichloroethylene, and confirmed the result using state tomography. We have thus extended the space

L. Lanz, B. Vacchini

Coherent and incoherent neutron-matter interaction is studied inside a recently introduced approach to subdynamics of a macrosystem. The equation describing the interaction is of the Lindblad type and using the Fermi pseudopotential we show that the commutator term is an optical potential leading to well-known relations in neutron optics. The other terms, us

Zbigniew Oziewicz

We consider a pair of independent scalar products, one scalar product on vectors, and another independent scalar product on dual space of co-vectors. The Clifford co-product of multivectors is calculated from the dual Clifford algebra. With respect to this co-product unit is not group-like and vectors are not primitive. The Clifford product and the Clifford

R. Haering-Oldenburg

We introduce a reduced form of a Birman-Murakami-Wenzl Algebra associated to the braid group of Coxeter type B and investigate its semisimplicity, Bratteli diagram and Markov trace. Applications in knot theory and physics are outlined.

B. Enriquez

We review the construction by G. Felder and the author of the realization of the elliptic quantum groups of sl(2)-type by quantum currents.

Paolo M. Gensini, Rafael Hurtado, Galileo Violini

We delineate a ``theoretical'' $χ^2$--functional technique to implement fixed--$t$ analyticity on the invariant amplitudes for the $\bar{K}N$, $πΛ$, $πΣ$ coupled channels in a fast and straightforward way.

Beata Randrianantoanina

We show that Rudin-Plotkin isometry extension theorem in $L_p$ implies that when $X$ and $Y$ are isometric subspaces of $L_p$ and $p$ is not an even integer, $1 \leq p < \infty$, then $X$ is complemented in $L_p$ if and only if $Y$ is; moreover the constants of complementation of $X$ and $Y$ are equal. We provide examples demonstrating that this fact fails w

Alvaro Arias, Gelu Popescu

General results of interpolation (eg. Nevanlinna-Pick) by elements in the noncommutative analytic Toeplitz algebra $F^\infty$ (resp. noncommutative disc algebra $A_n$) with consequences to the interpolation by bounded operator-valued analytic functions in the unit ball of ${\bf C}^n$ are obtained. Non-commutative Poisson transforms are used to provide new vo

Tamara Hummel, Carl Jockusch

We study some generalized notions of cohesiveness which arise naturally in connection with effective versions of Ramsey&#39;s Theorem. An infinite set $A$ of natural numbers is $n$--cohesive (respectively, $n$--r--cohesive) if $A$ is almost homogeneous for every computably enumerable (respectively, computable) $2$--coloring of the $n$--element sets of natura

G. S. Danilov

For a calculation of divergent fermion string amplitudes a regularization procedure invariant under the supermodular group is constructed. By this procedure superstring amplitudes of an arbitrary genus are calculated using both partition functions and superfield vacuum correlators computed early. A finiteness of superstring amplitudes and related topics are

Matthew J. Strassler

Four-dimensional N=1 supersymmetric Spin(N) gauge theories with matter in the vector and spinor representations are considered. Dual descriptions are known for some of these theories. It is noted that when masses are given to all fields in the spinor representation, the dual gauge group G breaks to a group H such that \pi_2(G/H)=Z_2. The quantum numbers of t

P. S. Montague

By considering constraints on the dimensions of the Lie algebra corresponding to the weight one states of Z_2 and Z_3 orbifold models arising from imposing the appropriate modular properties on the graded characters of the automorphisms on the underlying conformal field theory, we propose a set of constructions of all but one of the 71 self-dual meromorphic

Michael Joyce

Radiation domination at the electroweak epoch is a simplifying assumption, but one for which there is no observational basis. Treating the expansion rate as a variable, I re-examine electroweak baryogenesis in various scenarios. At a first order phase transition the main effect is on the sphaleron bound, which becomes a lower bound on the expansion rate in a

O. J. P. Eboli, R. Z. Funchal, T. L. Lungov

We study the potentiality of the CERN Large Hadron Collider (LHC) to unravel the existence of first generation scalar leptoquarks. Working with the most general $SU(2)_L \otimes U(1)_Y$ invariant leptoquark interactions, we analyze in detail the signals and backgrounds that lead to a final state containing a pair $e^+e^-$ and jets. Our results indicate that

Gordon L. Kane

In this talk, as requested, I begin with a overview and with some basic reminders about how evidence for supersymmetry in nature might appear -- in particular, how SUSY signatures are never clear so it is difficult to search for them without major theoretical input. Models can be usefully categorized phenomenologically by naming their LSP -- that is, once th

Levon Pogosian, Tanmay Vachaspati

In studying the formation of topological defects, it is conventional to assume the ``geodesic rule&#39;&#39; which is equivalent to minimizing gradients of the order parameter. This assumption has been called into question in field-theoretic studies of first order phase transitions and in the case of local defects. We present a scheme for numerically investi

F. Larios, Tim Tait, C. --P. Yuan

We study production of t {\bar t} via W^+ W^- fusion, including the relevant backgrounds at the proposed Linear Collider (an e^+ e^- collider with \sqrt{S} = 1.5 TeV) in the context of a Higssless Standard Model (SM), i.e. a nonlinear SU(2)_L \times U(1)_Y chiral Lagrangian, including dimension five W^+ W^- t {\bar t} interactions. Deviation from the SM tota

R. Rueckl, R. Settles, H. Spiesberger

We study pair production of leptoquarks in e+e- annihilation at linear colliders. A detailed simulation including beamstrahlung and initial state radiation, leptoquark decay and hadronization, as well as detector smearing, is performed. Discovery limits are estimated for center-of-mass energies of 500 and 800 GeV. The prospects for determining masses and cou

Giancarlo D&#39;Ambrosio

We review some new developments in the theoretical description of the processes K ->pi gamma gamma, K_L ->gamma l^+ l^-, K_L ->pi^0 e^+ e^- and K_L ->mu^+ mu^-.

German Rodrigo, Arcadi Santamaria, Mikhail Bilenky

Next-to-leading order QCD corrections to three jet heavy quark production in $e^+ e^-$ collisions, including quark mass effects, are presented. The extraction of the b-quark mass form LEP data is considered and the first experimental evidence for the running of a quark mass is discussed.

M. Grazzini

One particle inclusive cross sections in the target fragmentation region are considered and an explicit calculation is performed in (ϕ^3)_6 model field theory. The collinear divergences can be correctly absorbed into a parton density and a fragmentation function but the renormalized cross section gets a large logarithmic correction as expected in a two scale

Jun Cao, Tao Huang, Hui-fang Wu

The widths of a glueball decay to two pions or kaons are analyzed in the pQCD framework. Our results show that the glueball ground state has small branching ratio for two-meson decay mode, which is around $10^{-2}$. The predicted values are consistent with the data of $ξ\toππ, KK$ if $ξ$ particle is a $2^{++}$ glueball. Applicability of pQCD to the glueball

H. Hoeber

We determine the masses of the light and the strange quarks in the MS-bar-scheme using our high-statistics lattice simulation of QCD with dynamical Wilson fermions. For each of our three sea quarks we have analyzed our data at five different values of the valence quark mass, enabling us to parameterize our fit results in the (sea-quark mass, valence quark ma

Kenichiro Aoki

We show that the dimensionful scalar cubic coupling in 3+1 dimensions gives rise to non-decoupling effects and analyze the behavior of these effects. In the process, we clarify how it is perturbatively consistent to construct theories in which the cubic coupling is dominant. We use the scalar sector of the Supersymmetric Standard Model as an example. We disc

Alexander Tabachenko

The neutral pion electroproduction on the proton is considered in the framework phenomenological model based on the PCAC, current algebra with hard pions and chiral symmetry breaking interaction. The s- wave differential cross-section of the electroproduction of neutral pions off protons near the threshold is predicted as function photon momentum transfer sq

L. Del Debbio, M. Faber, J. Greensite, S. Olejnik

We present a method for locating center vortices (``fluxons&#39;&#39;) in thermalized lattice gauge field configurations. We find evidence, in lattice Monte Carlo simulations, that the asymptotic string tension of fundamental-representation Wilson loops is due to fluctuations in the number of center vortices linking those loops.

Massimo D&#39;Elia, Adriano Di Giacomo, Enrico Meggiolaro

We determine, by numerical simulations on a lattice, the gauge-invariant two-point correlation functions of the gauge field strengths in the QCD vacuum with four flavours of dynamical staggered fermions.

I. Hip, C. B. Lang, R. Teppner

We study the 2-flavour lattice Schwinger model: QED in D=2 with two fermion species of identical mass. In the simulation we are using Wilson fermions where chiral symmetry is explicitly broken. Since there is no known simple order parameter it is non-trivial to identify the critical line of the chiral phase transition. We therefore need to find observables w

J. Peisa, C. Michael

We measure the ground and excited states for B mesons in the static limit using maximally variance reduced estimators for light quark propagators. Because of the large number of propagators we are able to measure accurately also orbitally excited P, D and F states. We also present some results for Lambda_b.

UKQCD Collaboration, K. C. Bowler, R. D. Kenway, L. Lellouch

We present the results of the first lattice study of semileptonic decays of baryons containing a b-quark. Predictions for the decay distributions are given and the Isgur-Wise functions for heavy baryons are computed, for values of the velocity transfer up to about omega=1.2. The computations are performed on a 24^3 x 48 lattice at beta=6.2 using the Sheikhol

She-Sheng Xue

We present a preliminary study of a chiral-gauge-invariant Wilson term for the Standard Model on a lattice. In the strong coupling limit for doublers, this Wilson term shows that the doublers of leptons (quarks) are anti-baryons (anti-leptoquarks), and they are decoupled by getting gauge invariant masses. We discuss that the possibility of achieving the low-

C. R. Gattringer, I. Hip, C. B. Lang

We discuss the interplay between topologically non-trivial gauge field configurations and the spectrum of the Wilson-Dirac operator in lattice gauge theory. Our analysis is based on analytic arguments and numerical results from a lattice simulation of QED_2.

T. W. Baumgarte, G. B. Cook, M. A. Scheel, S. L. Shapiro

We perform fully relativistic calculations of binary neutron stars in corotating, circular orbit. While Newtonian gravity allows for a strict equilibrium, a relativistic binary system emits gravitational radiation, causing the system to lose energy and slowly spiral inwards. However, since inspiral occurs on a time scale much longer than the orbital period,

Chris M. Chambers

The last seven years has produced a growing body of evidence which concludes that the Cauchy horizon in black hole-de Sitter spacetimes is classically stable when the surface gravity at the cosmological event horizon is greater than that at the Cauchy horizon. That stability persists for a finite, but non-zero, region of the black hole&#39;s parameter space,

Chi-Keung Ng

In this paper, we will prove that if $A$ is a $C^*$-algebra with an effective coaction $ε$ by a compact quantum group, then the fixed point algebra and the reduced crossed product are Morita equivalent. As an application, we prove an imprimitivity type theorem for crossed products of coactions by discrete Kac $C^*$-algebras.

I. Vattulainen, J. Merikoski, T. Ala-Nissila, S. C. Ying

We study the non-Arrhenius behavior of surface diffusion near the second-order phase transition boundary of an adsorbate layer. In contrast to expectations based on macroscopic thermodynamic effects, we show that this behavior can be related to the average microscopic jump rate which in turn is determined by the waiting-time distribution W(t) of single-parti

Reinhold Egger, Andrei Komnik

A quantum Monte Carlo simulation method has been developed and applied to study the critical behavior of a single Kondo impurity in a Luttinger liquid. This numerically exact method has no finite-size limitations and allows to simulate the whole temperature range. Focusing on the impurity magnetic susceptibility, we determine the scaling functions, in partic

I. I. Mazin, D. J. Singh

The known and usable truly nonlocal functionals for exchange-correlation energy of the inhomogeneous electron gas are the ADA (average density approximation) and the WDA (weighted density approximation). ADA, by design, yields the correct linear response function of the uniform electron gas. WDA is constructed so that it is exact in the limit of one-electron

R. S. Markiewicz, M. T. Vaughn

We briefly summarize two related calculations. First, we demonstrate that the instabilities (either nesting or pairing) associated with the high-T_c cuprates can be described by an SO(6) transformation group. There are two independent 6-dimensional representations (`superspins&#39;). One superspin combines Zhang&#39;s 5-component superspin with a flux phase

E. N. M. Cirillo, G. Gonnella, S. Stramaglia

We analyze the dynamical scaling behavior in a two-dimensional spin model with competing interactions after a quench to a striped phase. We measure the growth exponents studying the scaling of the interfaces and the scaling of the shrinking time of a ball of one phase plunged into the sea of another phase. Our results confirm the predictions found in previou

A. F. Volkov, K. E. Nagaev, R. Seviour

The fluctuation conduction of NSN and SNS contacts above T_c are analyzed. For NSN contacts, both Aslamazov-Larkin and Maki- Thompson corrections to the conduction are found to be of the same order and diverge for T_c^* < T_c according to the law (T - T_c^*)^-1. For SNS contacts, the Aslamazov - Larkin correction vanishes,while the Maki - Thompson correction

Jonathan Doye, Richard Sear, Daan Frenkel

We have studied the thermodynamics of isolated homopolymer chains of varying stiffness using a lattice model. A complex phase behaviour is found; phases include chain-folded `crystalline&#39; structures, the disordered globule and the coil. It is found, in agreement with recent theoretical calculations, that the temperature at which the solid-globule transit

Marcus Mueller, Andreas Werner

We investigate interfacial properties between two highly incompatible polymers of different stiffness. The extensive Monte Carlo simulations of the binary polymer melt yield detailed interfacial profiles and the interfacial tension via an analysis of capillary fluctuations. We extract an effective Flory-Huggins parameter from the simulations, which is used i

Andreas Schadschneider, Michael Schreckenberg

We investigate two models for traffic flow with modified acceleration (&#39;slow-to-start&#39;) rules. Even in the simplest case $v_{max}=1$ these rules break the &#39;particle-hole` symmetry of the model. We determine the fundamental diagram (flow-density relationship) using the so-called car-oriented mean-field approach (COMF) which yields the exact soluti

S. Drewes, S. R. Renn

We present the results of a series of Quantum Monte Carlo calculations of the temperature dependent conductance of dissipative non-superconducting tunnel junctions. Finite size scaling methods are used to demonstrate the absence of coherent transport in Ohmic tunnel junctions. However, a quantum phase transition between coherent and incoherent behavior is fo

G. Boffetta, A. Crisanti, F. Paparella, A. Provenzale

We study the dynamics of systems with different time scales, when access only to the slow variables is allowed. We use the concept of Finite Size Lyapunov Exponent (FSLE) and consider both the case when the equations of motion for the slow components are known, and the situation when a scalar time series of one of the slow variables has been measured. A disc

A. Venkatesan, M. Lakshmanan

The behaviour of a driven double well Duffing-van der Pol (DVP) oscillator for a specific parametric choice ($\mid α\mid =β$) is studied. The existence of different attractors in the system parameters ($f-ω$) domain is examined and a detailed account of various steady states for fixed damping is presented. Transition from quasiperiodic to periodic motion thr

John T. Stocke, Travis A. Rector

Two new Mg II absorbers are presented (z=1.340 in S5 0454+844 and z=1.117 in PKS 2029+121), bringing the total number of Mg II systems in the 1 Jy radio-selected BL Lac sample to 10. Five of the ten absorption systems are at W > 1A; this is a factor of four to five greater than the number expected based upon quasar sightlines, and is 2.5 to 3 sigma greater t

J. Michael Shull

Wasn&#39;t this a fun meeting? Yes, except for the rain. This summary highlights scientific themes of the 13th IAP conference: (1) The History of Baryons; (2) The History of Metals; (3) Reionization of the IGM; (4) The Assembly of Galaxies, plus a &#34;wish list&#34; of future projects for observers and theorists.

J. Michael Shull

I discuss recent HST observations and interpretation of low-z Ly-alpha clouds toward nearby Seyferts and QSOs, including their frequency, space density, estimated mass, association with galaxies, and contribution to Omega_b. Our HST/GHRS detections of 73 Lya absorbers with N_HI > 10^12.6 cm^(-2) along 11 sightlines covering pathlength Delta(cz) = 86,000 km/s

Renyue Cen, Steven Phelps, Jordi Miralda-Escudé, Jeremiah P. Ostriker

We examine the correlational property of $\lya$ clouds in detail and compare it to that of mass and galaxies. We show that the correlation strength of $\lya$ clouds is somewhat weaker than that of the underlying matter, which in turn is weaker than that of galaxies (biased galaxy formation). On the scales probed, $10-300$km/s, for $\lya$ clouds, we find that

A. C. Quillen, Gary Bower

In M84 dust features are not aligned with the galaxy isophotes but are perpendicular to the radio jets. We estimate the timescale that the gas disk should precess in the galaxy. Since this timescale is short ($\sim 2\times 10^7$ years at 100 pc) we consider mechanisms that could cause the gas disk to be misaligned with the galaxy. One possibility is that a c

F. Pedichini, A. Di Paola, L. Stella, R. Buonanno

Until recently the positions of gamma ray bursts were not sufficiently well known within a short timescale to localize and identify them with known celestial sources. Following the historical detection of the X-ray afterglow of the burst GRB970228, extending from 30 s to 3 days after the main peak, by the Beppo-SAX satellite and that of an optical transient

U. Heber, S. Moehler, I. N. Reid

Previous spectroscopic analyses of Blue Horizontal Branch (BHB) stars in six globular clusters revealed too low masses in four clusters when compared to canonical evolutionary theory, while the masses of the BHB stars in NGC 6752 and M 5 are found to be consistent with theory. We recalculated BHB star masses using new cluster distances derived by Reid (1997a

S. Faïsse, B. Milliard

The spectral indexes distribution of a quasar sample is derived from a far-UV survey. A red average spectrum is found which comes in support of significant evolution of the QSO spectral energy distribution (SED) since $z\approx2.5$.

Christopher W. Mauche

Recent results are presented and discussed regarding the EUV and X-ray emission of nonmagnetic cataclysmic variables. Emphasis is given to high accretion rate systems (novalike variables and dwarf novae in outburst), and to a number of apparent discrepancies between observations and the theory of the boundary layer between the accretion disk and the surface

Brandon Carter, David Langlois, Denis Priou

Irrotational relativistic vortex configurations in uniform subsonic motion with respect to a surrounding perfect fluid are analysed for the purpose of application to superfluid layers in neutron stars. Asymptotic solutions are found by asymptotically expanding the flow equation at large distances from the vortex core and then by solving it order by order. Th

Lawrence Ein

The purpose of this note is to give a survey of the algebraic properties of multiplier ideals, and illustrate some of their applications to classical projective geometry.

Jean-Marc Drézet

The structure of the generic prioritary sheaf on the projective plane is given, when it cannot be semi-stable

D. R. Stewart, D. Sprinzak, C. M. Marcus, C. I. Duruoz

We have studied the ground and excited state spectra of a semiconductor quantum dot for successive numbers of electron occupancy using linear and nonlinear magnetoconductance measurements. We present the first observation of direct correlation between the mth excited state of the N electron system and the ground state of the N+m electron system for m up to 4

Markus A. Luty, John Terning

We construct supersymmetric gauge theories with new mechanisms of dynamical supersymmetry breaking. The models have flat directions at the classical level, and different mechanisms lift these flat directions in different regions of the classical moduli space. In one branch of the moduli space, supersymmetry is broken by confinement in a novel manner. The mod

Victor T. Kim, Grigorii B. Pivovarov

Current issues on jet production in hadron collisions for Regge-limit of QCD are briefly discussed.

Victor T. Kim, Grigorii B. Pivovarov, James P. Vary

Inclusive single jet production in hadron collisions is considered. It is shown that the QCD parton model predicts a nonmonotonic dependence of the inclusive cross section on the fraction of the energy deposited in the jet registered, if it is normalized on the same cross section measured at another collision energy. Specifically, if the cross section is nor

Tetsufumi Tanamoto, Masahito Ueda

A theory of tunneling through a quantum dot is presented which enables us to study combined effects of Coulomb blockade and discrete energy spectrum of the dot. The expression of tunneling current is derived from the Keldysh Green&#39;s function method, and is shown to automatically satisfy the conservation at DC current of both junctions.

R. Maiolino, A. Krabbe, N. Thatte, R. Genzel

We present high angular resolution (0&#34;.15-0&#34;.5) near infrared images and spectroscopy of the Circinus galaxy, the closest Seyfert 2 galaxy known. The data reveal a non-stellar nuclear source at 2.2 microns. The coronal line region and the hot molecular gas emission extend for 20-50 pc in the ionization cone. The data do not show evidence for a point-

R. Gonzalez Felipe

The parity-violating topological term in the effective action for 2+1 massive fermions is computed at finite temperature in the presence of a constant background field strength tensor. Gauge invariance of the finite-temperature effective action is also discussed.

Jonathan Fine

This paper defines new intersection homology groups. The basic idea is this. Ordinary homology is locally trivial. Intersection homology is not. It may have significant local cycles. A local-global cycle is defined to be a family of such local cycles that is, at the same time, a global cycle. The motivating problem is the numerical characterisation of the fl

Gabriela C. Surpi, Diego D. Harari

We estimate the effects of weak lensing by large-scale density inhomogeneities and long-wavelength gravitational waves upon the polarization properties of electromagnetic radiation as it propagates from cosmologically distant sources. Scalar (density) fluctuations do not rotate neither the plane of polarization of the electromagnetic radiation nor the source

Georg Junker, Pinaki Roy

Using algebraic tools of supersymmetric quantum mechanics we construct classes of conditionally exactly solvable potentials being the supersymmetric partners of the linear or radial harmonic oscillator. With the help of the raising and lowering operators of these harmonic oscillators and the SUSY operators we construct ladder operators for these new conditio

Harald Fritzsch

The observed hierarchy of the quark masses is interpreted as a signal for an underlying ``subnuclear democracy&#39;&#39; as the relevant symmetry of the quark mass terms. A simple breaking of the symmetry leads to a mixing between the second and the third family, in agreement with observation. Introducing the mixing between the first and the second family, o

H. Chamati, D. M. Danchev, N. S. Tonchev

A d-dimensional finite quantum model system confined to a general hypercubical geometry with linear spatial size L and ``temporal size&#39;&#39; 1/T (T - temperature of the system) is considered in the spherical approximation under periodic boundary conditions. Because of its close relation with the system of quantum rotors it represents an effective model f

Jerzy Kijowski, Giulio Magli

A new formulation of the Hamiltonian dynamics of the gravitational field interacting with(non-dissipative) thermo-elastic matter is discussed. It is based on a gauge condition which allows us to encode the six degrees of freedom of the ``gravity + matter&#39;&#39;-system (two gravitational and four thermo-mechanical ones), together with their conjugate momen

A. Bressan, G. L. Granato, L. Silva

We have investigated the spectro-photometric properties of the Asymptotic Giant Branch (AGB) stars and their contribution to the integrated infrared emission in simple stellar populations (SSP). Adopting analytical relations describing the evolution of these stars in the HR diagram and empirical relations for the mass-loss rate and the wind terminal velocity

Seiji Mukaigawa, Taizo Muta, Sergei D. Odintsov

A class of finite GUTs in curved spacetime is considered in connection with the cosmological inflation scenario. It is confirmed that the use of the running scalar-gravitational coupling constant in these models helps realizing a successful chaotic inflation. The analyses are made for some different sets of the models.

Ion I. Cotaescu, Dumitru N. Vulcanov

It is shown that in general relativity some static metrics are able to simulate oscillatory motions. Their form depends on two arbitrary real parameters which determine the specific oscillation modes. The conclusion is that these metrics can be used for new geometric models of closed or even open bags. Pacs: 04.02.-q and 04.02.Jb

Matthew Colless

Summary of the highlights and main themes of a conference on the Coma cluster, &#34;A New Vision of an Old Cluster: Untangling Coma Berenices&#34;.

D. Mozyrsky, V. Privman

We study a general quantum system interacting with environment modeled by the bosonic heat bath of Caldeira and Leggett type. General interaction Hamiltonians are considered that commute with the system&#39;s Hamiltonian so that there is no energy exchange between the system and bath. We argue that this model provides an appropriate description of adiabatic

Yuri Gusev, Andrei Zelnikov

Scalar fields at finite temperature are considered in four dimensional ultrastatic curved spacetime. One loop nonlocal effective action at finite temperature is found up to the second order in curvature expansion. This action is explicitly infrared finite. In the high temperature expansion of free energy, essentially nonlocal terms linear in temperature are

Philip A. Foth

Given a compact Kaehler manifold, we consider the complement U of a divisor with normal crossings. We study the variety of unitary representations of the fundamental group of U with certain restrictions related to the divisor. We show that the possible singularities of this variety as well as of the corresponding moduli space of irreducible representations a

Sajeev John, Valery I. Rupasov

We study quantum effects of light propagation through an extended absorbing system of two-level atoms placed within a frequency gap medium (FGM). Apart from ordinary solitons and single particle impurity band states, the many-particle spectrum of the system contains massive pairs of confined gap excitations and their bound complexes - gap solitons. In additi

E. Buks, R. Schuster, M. Heiblum, D. Mahalu

We study dephasing of electrons induced by a which path detector and thus verify Bohr&#39;s complementarity principle for fermions. We utilize a double path interferometer with two slits, with one slit being replaced by a coherent quantum dot (QD). A short one dimensional channel, in the form of a quantum point contact (QPC), in close proximity to the QD, se

C. Giusti, F. D. Pacati, K. Allaart, W. J. W. Geurts

Resolution of discrete final states in the $^{16}$O(e,e$&#39;$pp)$^{14}$C reaction may provide an interesting tool to discriminate between contributions from one- and two-body currents in this reaction. This is based on the observation that the $0^+$ ground state and first $2^+$ state of $^{14}$C are reached predominantly by the removal of a $^1S_0$ pair fro

M. Debowski, P. Senger, M. Boivin, Y. LeBornec

Double differential cross sections have been measured for pi+ and K+ emitted around midraidity in d+A and He+A collisions at a beam kinetic energy of 1.15 GeV/nucleon. The total pi+ yield increases by a factor of about 2 when using an alpha projectile instead of a deuteron whereas the K+ yield increases by a factor of about 4. According to transport calculat

Kimyeong Lee, Changhai Lu

Starting from Nahm&#39;s equations, we explore BPS magnetic monopoles in the Yang-Mills Higgs theory of gauge group $Sp(4)$ which is broken to $SU(2)\times U(1)$. A family of BPS field configurations with purely Abelian magnetic charge describe two identical massive monopoles and one massless monopole. We construct the field configurations with axial symmetr

Luca Mezincescu, Rafael I. Nepomechie

We construct integrals of motion (IM) for the sine-Gordon model with boundary at the free Fermion point which correctly determine the boundary S matrix. The algebra of these IM (``boundary quantum group&#39;&#39; at q=1) is a one-parameter family of infinite-dimensional subalgebras of twisted affine sl(2). We also propose the structure of the fractional-spin

T. Inagaki, S. D. Odintsov, Yu. I. Shil&#39;nov

We investigate the effects of the external gravitational and constant magnetic fields to the dynamical symmetrybreaking. As simple models of the dynamical symmetry breaking we consider the Nambu-Jona-Lasinio (NJL) model and the supersymmetric Nambu-Jona-Lasinio (SUSY NJL) model non-minimally interacting with the external gravitational field and minimally int

L. Griguolo, D. Seminara

The soliton structure of a gauge theory recently proposed to describe chiral excitations in the Fractional Quantum Hall Effect is investigated. A new type of non-linear derivative Schrödinger equation emerges as an effective description of the system that supports novel chiral solitons. We discuss the classical properties of solutions with vanishing and non-

M. Malheiro, W. Melnitchouk

We calculate the corrections to the strange matrix elements of the nucleon resulting from the breaking of rotational invariance on the light-cone. In the meson cloud model, the strange magnetic moment mu_S is seen to change sign once the spurious form factors arising from this violation are subtracted. The resulting mu_S is small and slightly positive, in ag

L. Burakovsky, T. Goldman

We rederive the new SU(3) multiplet mass formula 2M^2(s\bar{s})+3M^2(n\bar{n}, I=1)=4M^2(s\bar{n})+M^2(n\bar{n},I=0) (n=u,d}, obtained in our previous paper by using Regge phenomenology, for the pseudoscalar and scalar mesons in the Nambu-Jona-Lasinio model with instanton-induced interaction. We apply this formula to the problem of the correct q\bar{q} assig

M. E. Sainio

A dispersion framework, appropriate for discussing the low-energy pion-nucleon interaction, is reviewed. Sensitivity of the isoscalar D-amplitude at the unphysical Cheng-Dashen point to input from different phase shift analyses and low-energy experiments is discussed.

Yosef Nir

Four topics in theory of CP violation are reviewed. (a) CP violation in $B$ decays: We describe a new clean way of constraining the angle $γ$ of the unitarity triangle and how new CP violation in decay amplitudes can signal new physics. (b) CP violation in $K$ decays: We explain the special features of the decay $K_L\raπ^0ν\barν$ both as a measurement of Sta

S. Kumano, M. Miyama

Because the chiral-odd structure function h_1 will be measured in the polarized Drell-Yan process, it is important to predict the behavior of h_1 before the measurement. In order to study the Q^2 evolution of h_1, we discuss one and two loop anomalous dimensions which are calculated in the Feynman gauge and minimal subtraction scheme.

J. Ambjorn, K. N. Anagnostopoulos, G. Thorleifsson

We review recent developments in the understanding of the fractal properties of quantum spacetime of 2d gravity coupled to c>0 conformal matter. In particular we discuss bounds put by numerical simulations using dynamical triangulations on the value of the Hausdorff dimension d_H obtained from scaling properties of two point functions defined in terms of geo