January 1997 arXiv papers — page 4

Marc Voyer, Louis Marchildon

We investigate Lie symmetries of the self-dual Yang-Mills equations in four-dimensional Euclidean space (SDYM). The first prolongation of the symmetry generating vector fields is written down, and its action on SDYM computed. Determining equations are then obtained and solved completely. Lie symmetries of SDYM in Euclidean space are in exact correspondence w

Jorge G. Hirsch, Peter O. Hess, Osvaldo Civitarese

An exactly solvable model is introduced, which is equivalent to the exact shell-model treatment of protons and neutrons in a single j-shell for Fermi-type excitations. Exact energies, quasiparticle numbers and double beta decay Fermi amplitudes are computed and compared with the results of both the standard quasiparticle random phase approximation (QRPA) and

Ulrich Heinz

By measuring hadronic single-particle spectra and two-particle correlations in heavy-ion collisions, the size and dynamical state of the collision fireball at freeze-out can be reconstructed. I discuss the relevant theoretical methods and their limitations. By applying the formalism to recent pion correlation data from Pb+Pb collisions at CERN we demonstrate

R. Scheibl, U. Heinz

In the frame of the Wigner function formalism, we derive a coalescence model to use with a hydrodynamical picture of the reaction zone

Soon-Tae Hong, Dong-Pil Min

The $η-η^{\prime}$ mixture is discussed in the chiral bag model to calculate the pseudoscalar octet-singlet mixing angle consistent with the experimental data. The color anomaly is taken into account with the modified boundary conditions, which shows the relation between the $η^{\prime}$ mass and the gluon condensate inside the chiral bag. We show, however,

A. Matytsin, P. Zaugg

The large spacing phase of the infinite random matrix chain, which represents the strongly coupled two-dimensional O(2) model on a random planar lattice, is explored. A class of solutions valid for large lattice spacings is constructed. It is proved that these solutions exhibit the critical exponents characteristic of pure two-dimensional gravity. The charac

Kenji Mohri

We investigate D=4, N=1 F theory models realized by type IIB string compactification on toric threefolds. Massless spectra, gauge symmetries, phase transitions associated with divisor contractions and flops, and non-perturbative superpotentials are analyzed using elementary toric methods.

A. Buonanno, M. Gasperini, M. Maggiore, C. Ungarelli

We discuss the possibility of quantum transitions from the string perturbative vacuum to cosmological configurations characterized by isotropic contraction and decreasing dilaton. When the dilaton potential preserves the sign of the Hubble factor throughout the evolution, such transitions can be represented as an anti-tunnelling of the Wheeler--De Witt wave

M. Billo', M. Caselle, A. D'Adda

In a 2+1-dimensional pure LGT at finite temperature the critical coupling for the deconfinement transition scales as $β_c(n_t) = J_c n_t + a_1$, where $n_t$ is the number of links in the ``time-like'' direction of the symmetric lattice. We study the effective action for the Polyakov loop obtained by neglecting the space-like plaquettes, and we are ab

G. Amelino-Camelia, J. Ellis, N. E. Mavromatos, D. V. Nanopoulos

Within a Liouville approach to non-critical string theory, we argue for a non-trivial commutation relation between space and time observables, leading to a non-zero space-time uncertainty relation $δx δt > 0$, which vanishes in the limit of weak string coupling.

Faheem Hussain, Roberto Iengo, Carmen Núñez

We study axion-graviton scattering from a system of two D$0$-branes in a Type II superstring theory, a process which does not occur on a single brane. The two D$0$-branes interact via the exchange of closed string states which form a cylinder joining them. By compactifying on the $Z_3$ orbifold we find a non vanishing amplitude coming from the odd spin struc

R. R. Metsaev

Conformal isometry algebras of plane wave geometry are studied. Then, based on the requirement of conformal invariance, a definition of masslessness is introduced and gauge invariant equations of motion, subsidiary conditions, and corresponding gauge transformations for all plane wave geometry massless spin fields are constructed. Light cone representation f

Carl E. Carlson

We present one viewpoint plus some general information on the plans for energy upgrades and physics research at the Jefferson Laboratory.

T. van Ritbergen, J. A. M. Vermaseren, S. A. Larin

We present the analytical calculation of the four-loop QCD beta-function within the minimal subtraction scheme.

Torben Hannah

The inverse amplitude method is analysed to two-loop order in the chiral expansion in the case of $ππ$ scattering and the pion form factors. The analysis is mainly restricted to the elastic approximation but the possible extension to the inelastic case is also discussed in some detail. It is shown how the two-loop approach improves the inverse amplitude meth

K. Huitu, J. Maalampi, A. Pietila, M. Raidal

We review possible tests of the left-right electroweak model at future linear colliders, concentrating on signatures of the central predictions of the model, i.e. right-handed currents, massive neutrinos and triplet Higgs bosons. We analyse processes in e+e-, e-e- and e-γcollision modes. We present the mass reaches for the new particles at linear collider an

Jan Govaerts

Precision measurements in muon capture on 3He to the triton channel provide for interesting tests of the charged electroweak interaction, whether within the Standard Model or beyond it. Based on the statistical capture rate and the triton asymmetry, both the object of recent and on-going experiments using polarised 3He targets, examples of such tests are pre

A. Acus, E. Norvaišas

The Skyrme model is considered quantum mechanically ab initio in various irreducible representations of the SU(2) group. The canonical quantization procedure yields negative mass correction ensuring existence of stabile soliton solution even in chiral limit. The evaluated static properties of nucleons (masses, magnetic moments, radii etc.) are in a good agre

Jihn E. Kim, Pyungwon Ko, Dae-Gyu Lee

We present a new class of constraints to the lepton-family number and R-parity violating couplings from muonium conversion, $μ^{-} + {_{22}^{48}} Ti \to e^{-} + {_{22}^{48}} Ti$, a class of tau decays, $τ\to l +$ (light meson) with $l= μor e$, and $J/ψ$ and $π^0$ decays into a lepton pair. We find that $μ^{-} + {_{22}^{48}} Ti \to e^- + {_{22}^{48}} Ti$ prov

The ZEUS FNC Group, S. Bhadra, I. Bohnet, M. Cardy

A lead scintillator sandwich sampling calorimeter has been installed in the HERA tunnel 105.6 m from the central ZEUS detector in the proton beam direction. It is designed to measure the energy and scattering angle of neutrons produced in charge exchange ep collisions. Before installation the calorimeter was tested and calibrated in the H6 beam at CERN where

V. I. Valtchinov, G. Kalman, K. Blagoev

The pair correlation functions for a bilayer system of classical electrons has been calculated through a two-component HNC formalism. The results show changes in the structure of the correlation functions as the interlayer distance is increased from zero to about twice the Wigner-Seitz radius. These changes are indicative of structural phase transitions whic

Alice Ruini, Raffaele Resta, Stefano Baroni

For both molecules and periodic solids, the ionic dynamical charge tensors which govern the infrared activity are known to obey a dynamical neutrality condition. This condition enforces their sum to vanish (over the whole finite system, or over the crystal cell, respectively). We extend this sum rule to the non trivial case of the surface of a semiinfinite s

Toru Ohira, Ryusuke Sawatari

We propose here a method to estimate a delay from a time series taking advantage of analysis of random walks with delay. This method is applicable to a time series coming out of a system which is or can be approximated as a linear feedback system with delay and noise. We successfully test the method with a time series generated by discrete Langevin equation

R. Moessner, R. Brandenberger

We study the accretion of hot dark matter onto moving cosmic string loops, using an adaptation of the Zeldovich approximation to HDM. We show that a large number of nonlinear objects of mass greater than $10^{12}M_\odot$, which could be the hosts of high redshift quasars, are formed by a redshift of $z=4$.

M. Giard, J. L. Puget, E. Crete, F. Scoupe

We have developed an excitation model for small molecules including radiative pumping by dust photons from near infrared to submillimeter wavelengths. This model applies to molecules within bright photodissociation regions in galactic star-forming regions and starburst galaxies. In such environments, the near infrared photons emitted by polycyclic aromatic h

L. Festin

An area large enough (180 sq arcmin) to put constraints on a possible low mass brown dwarf population in the Pleiades has been surveyed to very faint magnitudes in I, J and K. The completeness limit, I=21.6, corresponds to a mass of 0.01 Msun for a cluster age of 70 Myr and 0.035 Msun for 120 Myr. The result is consistent with previous investigations at high

Ralf Bender

The structural properties of elliptical galaxies are consistent with their formation in a merging hierarchy. In this picture, the role of gaseous processes and dissipation decreased with increasing mass creating preferentially rotationally flattend disky ellipticals (and S0s) at lower luminosities and boxy, anisotropic ellipticals (often with peculiar kinema

Marina Gibilisco

In this paper, I investigate a local effect of polarization of the Cosmic Microwave Background (CMB) in clusters of galaxies, due to the Thomson scattering of the anisotropic radiation. A local anisotropy of the CMB is produced by some gravitational and scattering effects, as, for instance, the Sunyaev Zel'dovich effect, the Doppler shift due to the clus

F. H. Briggs, E. Brinks, A. M. Wolfe

Radio spectroscopy at 323 MHz using the Arecibo Telescope and the VLA has produced a tentative detection of the 21cm line of neutral hydrogen at Z_abs=3.38716+-0.00007 in absorption against the radio continuum of the QSO MG0201+113 (Z_em = 3.61). This redshift roughly agrees with one determined by the Westerbork Synthesis Radio Telescope and reported earlier

Kazuhiro Shimasaku

We investigate the gas mass function of clusters of galaxies to measure the density fluctuation spectrum on cluster scales. The baryon abundance confined in rich clusters is computed from the gas mass function and compared with the mean baryon density in the universe which is predicted by the Big Bang Nucleosynthesis. This baryon fraction and the slope of th

R. Di Stefano, L. A. Nelson

The ability to perform detailed evolutionary calculations is essential to the development of a well-defined and testable binary model. Unfortunately, traditional evolutionary calculations cannot be used to follow a significant fraction of possible close-binary supersoft sources (CBSSs). It is therefore important to examine the input physics carefully, to be

Hélène Esnault

We propose an algebraic Riemann-Roch formula for moving flat bundles on contant families in characteristic zero with values in the ring of algebraic differential characters. This formula lifts Grothendieck-Riemann-Roch formula in the Chow groups and Bismut-Lott formula in the odd dimensional Betti cohomology with $\C/\Z$ coefficients over the field of comple

Philippe de Forcrand, Margarita Garcia Perez, Ion-Olimpiu Stamatescu

We study the topological structure of the SU(2) vacuum at zero temperature: topological susceptibility, size, shape and distance distributions of the instantons. We use a cooling algorithm based on an improved action with scale invariant instanton solutions. This algorithm needs no monitoring or calibration, has an inherent cut off for dislocations and leave

Pijush K. Ghosh

We study soliton solutions in 1+1 dimensional gauged sigma models, obtained by dimensional reduction from its 2+1 dimensional counterparts. We show that the Bogomol'nyi bound of these models can be expressed in terms of two conserved charges in a similar way to that of the BPS dyons in 3+1 dimensions. Purely magnetic vortices of the 2+1 dimensional compl

Bo-Yu Hou, Liu Zhao, Xiang-Mao Ding

We derive a free boson representation of the Yangian double $DY_\hbar(sl_N)$ with arbitrary level k using the observation that there is a correspondence between the q-affine algebra and Yangian double associated with the same Cartan matrix. Vertex operator and screening currents are not obtained in the same way.

Michael W. Moore, Martin J. Savage

We examine the radiative decays of the Lambda (1405) to octet baryons, Lambda + gamma and Sigma + gamma. In the limit of SU(3) symmetry the decay rates for these two modes are related, and we compute the leading correction to the relation in chiral perturbation theory. Such measurements will allow the sign of the strong coupling $g_{Λ^*}$ to be determined. T

Adam Parusinski

Let X be a complex analytic space and let f:X -> C be a proper complex analytic function with nonsingular generic fibres. By adapting the blowanalytic methods of Kuo we construct a retraction of a neighbourhood of the central fibre f^{-1}(0) onto f^{-1}(0). Our retraction is defined by the flow of a real analytic vector field on an oriented real analytic blo

Boris Apanasov

We study geometry, topology and deformation spaces of noncompact complex hyperbolic manifolds (geometrically finite, with variable negative curvature), whose properties make them surprisingly different from real hyperbolic manifolds with constant negative curvature. This study uses an interaction between Kähler geometry of the complex hyperbolic space and th

Marek Czachor

Manifestly covariant formulation of discrete-spin, real-mass unitary representations of the Poincaré group is given. We begin with a field of spin-frames associated with 4-mometa p and use them to simplify the eigenvalue problem for the Pauli-Lubanski vector projection in a direction given by a world-vector t. As opposed to the standard treatments where t is

E. V. Gedalin

The primary inclusive spectra and correlation functions of particles created by color tube fission are considered. Using the previously obtained expression for probability of the tube breaking in n points we have calculated the one and two particle inclusive spectra of tube pieces as well as pseudoscalar and vector mesons in plateau area. It is shown that th

Rafael D. Sorkin

We present evidence that, below a certain threshold scale, the horizon of a black hole is strongly wrinkled, with its shape manifesting a self-similar (``fractal'') spectrum of fluctuations on all scales below the threshold. This threshold scale is small compared to the radius of the black hole, but still much larger than the Planck scale. If present

Rosanne Di Stefano

In some luminous supersoft X-ray sources (SSSs), hydrogen accretes onto the surface of a white dwarf at rates more-or-less compatible with steady nuclear burning. The white dwarfs in these systems therefore have a good chance to grow in mass. Here we review what is known about the rate of Type Ia supernovae that may be associated with SSSs. Observable conseq

F. H. Briggs

Analyses of QSO absorption lines are showing that HI content has evolved over the redshift range z=5 to z= 0. The 21cm line measurements of the z=0 HI content avoid several biases inherent in the absorption line technique, such as the influence of evolving dust content in the absorbers, and will produce a reliable measure to anchor theories of galaxy evoluti

David Tytler

Cosmology with large interferometric telescopes is a rich and largely unexplored subject, involving three types of measurement: astrometric measurement of absolute distances and proper motions, dispersions of relative proper motions, and images. The ground based interferometers can have huge apertures, which are necessary for faint cosmological targets. But,

Donu Arapura

In very rough terms, the main theorem is that the set, which consists of semistable vector bundles with trivial rational Chern classes and nontrivial kth cohomology on a smooth complex projective variety, is a degeneration of a union of abelian varieties. More precisely, we consider the subset of the moduli space of Higgs bundles satisfying the analogous coh

Richard E. Borcherds, Ludmil Katzarkov, Tony Pantev, N. I. Shepherd-Barron

We use automorphic forms to prove that a compact family of Kaehler K3 surfaces with constant Picard number is isotrivial.

Robert de Mello Koch, João P. Rodrigues

In this letter, classical chiral $QCD_{2}$ is studied in the lightcone gauge $A_{-}=0$. The once integrated equation of motion for the current is shown to be of the Lax form, which demonstrates an infinite number of conserved quantities. Specializing to gauge group SU(2), we show that solutions to the classical equations of motion can be identified with a ve

Andrey V. Kravtsov, Anatoly A. Klypin, Alexei M. Khokhlov

We present a new high-resolution N-body algorithm for cosmological simulations. The algorithm employs a traditional particle-mesh technique on a cubic grid and successive multilevel relaxations on the finer meshes, introduced recursively in a fully adaptive manner in the regions where the density exceeds a predefined threshold. The mesh is generated to effec

J. Wosiek

In analogy with the quantum field theory of free bosons a simple integral representation is derived for recently proposed corrections describing the Bose Einstein effect. The saddle point approximation to these integrals results in a compact expression which sums effectively over all permutations of n particles with accuracy better than 2 per cent for more t

Santiago E. Perez Bergliaffa

We analyze the existence of inflationary solutions in an inhomogeneous Kaluza-Klein cosmological model in 4+n dimensions. It is shown that the 5-dimensional case is the exception rather than the rule, in the sense that the system is integrable (under the assumption of the equation of state $ρ= kp$) for any value of k. It is also shown that the cases k=0 and

A. A. Nersesyan, A. M. Tsvelik

In their paper Ziegler et al. claim that the model of 2D Dirac fermions in a random gauge potential has a finite density of states at zero energy. We point out that the approach used in this paper fails to reproduce the perturbation theory results for this problem.

E. M. Baskin, M. V. Entin

The 2D "Swiss-cheese" model of conducting media with round insulator inclusions is studied in the 2nd order of inclusion concentration and near the percolation threshold. The electric field distribution function is found to have power asymptotics for fields much exceeding the average field, independently on the vicinity to the threshold, due to finit

E. M. Baskin, M. V. Entin, A. K. Sarychev, A. A. Snarskii

The a.c. electric field distribution is studied in a composite, containing materials with small local losses. The possibility that 2D two-component system can have effective absorption in the absence of local absorption was evidented. We study the second and higher moments of electric field and show that they diverge with the decrease of local absorption. Th

N. S. Witte

We present the exact solution to the moment problem for the spin-1/2 isotropic antiferromagnetic XY chain with explicit forms for the moments with respect to the Neel state, the cumulant generating function, and the Resolvent Operator. We verify the correctness of the Horn-Weinstein Theorems, but the analytic structure of the generating function <e^{-tH}> in

Ewa Gudowska-Nowak, Gabor Papp, Juergen Brickmann

By using the random matrix approach and generalized Blue&#39;s function representation we solve analytically the model of an effective two-level system coupled to a noise reservoir. We show that calculated spectral properties of the system are in agreement with the numerically simulated results. We outline possible applications of the model in the field of c

Qingrong Zheng, Jian Wang, Hong Guo

The low frequency quantum transport properties of a three-probe mesoscopic conductor are studied using Büttiker&#39;s AC transport formalism. The static transmission coefficients and emittance matrix of the system were computed by explicitly evaluating the various partial density of states (PDOS). We have investigated the finite size effect of the scattering

Xiang-Ping Wu, Li-Zhi Fang

We present a statistical comparison of three different estimates of cluster mass, namely, the dynamical masses obtained from the velocity dispersion of optical galaxies, the X-ray masses measured from the temperature of X-ray emitting gas under the assumption of isothermal hydrostatic equilibrium, and the gravitational lensing masses derived from the strong/

Alexei M. Khokhlov

A fully threaded tree (FTT) for adaptive refinement of regular meshes is described. By using a tree threaded at all levels, tree traversals for finding nearest neighbors are avoided. All operations on a tree including tree modifications are O(N), where N is a number of cells, and are performed in parallel. An efficient implementation of the tree is described

E. Izadi

Mumford defined a natural isomorphism between the intermediate jacobian of a conic-bundle over $P^2$ and the Prym variety of a naturally defined étale double cover of the discrminant curve of the conic-bundle. Clemens and Griffiths used this isomorphism to give a proof of the irrationality of a smooth cubic threefold and Beauville later generalized the isomo

G. Wang, R. Ye

We construct Bott-type and stable equivariant Seiberg-Witten Floer homology and cohomology for rational homology spheres, and prove their diffeomorphism invariance.

Oren Bergman, Matthias R. Gaberdiel

A non-supersymmetric ten-dimensional open string theory is constructed as an orbifold of type I string theory, and as an orientifold of the bosonic type B theory. It is purely bosonic, and cancellation of massless tadpoles requires the gauge group to be SO(32)xSO(32). The spectrum of the theory contains a closed string tachyon, and open string tachyons in th

H. Aratyn, E. Nissimov, S. Pacheva

The method of squared eigenfunction potentials (SEP) is developed systematically to describe and gain new information about Kadomtsev-Petviashvili (KP) hierarchy and its reductions. Interrelation to the tau-function method is discussed in detail. The principal result, which forms the basis of our SEP method, is the proof that any eigenfunction of the general

H. Boschi-Filho, C. C. Buthers

We study the second virial coefficient, $B(T)$, for simple real gases at high temperature. Theoretical arguments imply that there exists a certain temperature, $T_i$, for each gas, for which this coefficient is a maximum. However, the experimental data clearly exhibits this maximum only for the Helium gas. We argue that this is so because few experimental da

Viacheslav V. Nikulin

By the fundamental result of I.I. Piatetsky-Shapiro and I.R. Shafarevich (1971), the automorphism group Aut(X) of a K3 surface X over C and its action on the Picard lattice S_X are prescribed by the Picard lattice S_X. We use this result and our method (1980) to show finiteness of the set of Picard lattices S_X of rank $\ge 3$ such that the automorphism grou

Haim Goldberg

Consider a gauge singlet superfield S coupled to a pair of adjoint fields in a SUSY-GUT. If the tree-level vacuum is flat in S, the vev <S> which defines the GUT scale will be determined via dimensional transmutation at a scale M where the soft-breaking (mass)^2 vanishes as a result of running from $M_{Pl} = (8 πG_N)^{-1/2}$. Because of the large number of a

Noriaki Kitazawa, Nobuchika Okada

We present a supersymmetric composite model with dynamical supersymmetry breaking. The model is based on the gauge group $SU(2)_S \times SU(2)_H \times SU(3)_c \times SU(2)_L \times U(1)_Y$. Supersymmetry is dynamically broken by the non-perturbative effect of the $SU(2)_S$ `supercolor&#39; interaction. The large top Yukawa coupling is naturally generated by

M. Gluck, S. Kretzer, E. Reya

Neutrino induced deep inelastic charm production off strange sea partons in the nucleon is studied in the framework of the MSbar fixed flavor factorization scheme. The momentum (z) distributions of the produced D mesons as calculated in the next-to-leading order QCD analysis are presented and compared to their leading order counterparts. Perturbative stabili

Elisa Ercolessi, Pierbiagio Pieri, Marco Roncaglia

We study the t-J model with the inclusion of the so called three-site term which comes out from the t/U --> 0 expansion of the Hubbard model. We find that this singlet pair hopping term has no qualitative effect on the structure of the pure mean field phase diagram for nonmagnetic states. In accordance with experimental data on high-T_c materials and some nu

S. Cacciatori, G. Preparata, S. Rovelli, I. Spagnolatti

In order to gain insight into the possible Ground State of Quantized Einstein&#39;s Gravity, we have devised a variational calculation of the energy of the quantum gravitational field in an open space, as measured by an asymptotic observer living in an asymptotically flat space-time. We find that for Quantum Gravity (QG) it is energetically favourable to per

Feng Yuan, Cong-Feng Qiao, Kuang-Ta Chao

We present an analysis of the preliminary experimental data of direct j/psi production in e^e- process at low energies. We find that the color-octet contributions are crucially important to the cross section at this energy region, and their inclusion produces a good description of the data. By fitting to the data, we extract the individual values of two colo

Changhyun Ahn, Soonkeon Nam

Generalizing the work of Sen, we analyze special points in the moduli space of the compactification of the F-theory on elliptically fibered Calabi-Yau threefolds where the coupling remains constant. These contain points where they can be realized as orbifolds of six torus $T^6$ by $Z_m \times Z_n (m, n=2, 3, 4, 6)$. At various types of intersection points of

Marek Gazdzicki

It is shown that data on pion and strangeness production in central nucleus-nucleus collisions are consistent with the hypothesis of a Quark Gluon Plasma formation between 15 A GeV/c (BNL AGS) and 160 A GeV/c (CERN SPS) collision energies. The experimental results interpreted in the framework of a statistical approach indicate that the effective number of de

K. Tsushima, K. Saito, A. W. Thomas

The quark-meson coupling (QMC) model, which has been successfully used to describe the properties of both finite nuclei and infinite nuclear matter, is applied to a study of $\Lambda$ hypernuclei. With the assumption that the (self-consistent) exchanged scalar, and vector, mesons couple only to the u and d quarks, a very weak spin-orbit force in the $\Lambda

Muktish Acharyya

The nonequilibrium dynamic phase transition, in the kinetic Ising model in presence of an oscillating magnetic field, has been studied by Monte Carlo simulation. The fluctuation of dynamic order parameter has been studied as a function of temperature near the dynamic transition point. The temperature variation of appropriately defined `susceptibility&#39; ha

Mark Hillery, Vladimir Buzek

How well one can copy an arbitrary qubit? To answer this question we consider two arbitrary vectors in a two-dimensional state space and an abstract copying transformation which will copy these two vectors. If the vectors are orthogonal, then perfect copies can be made. If they are not, then errors will be introduced. The size of the error depends on the inn

Min-Ho Lee, Hyeong-Chan Kim, Jeong-Young Ji

The generalized invariant and its eigenstates of a general quadratic oscillator are found. The Schrödinger wave functions for the eigenstates are also found in analytically closed forms. The conditions for the existence of the cyclic initial state (CIS) are studied and the corresponding nonadiabatic Berry phase is calculated explicitly.

M. Ardehali

An inequality is deduced from Einstein&#39;s locality and a supplementary assumption. This inequality defines an experiment which can actually be performed with present technology to test local realism. Quantum mechanics violate this inequality a factor of 1.5. In contrast, quantum mechanics violates previous inequalities (for example, Clauser-Horne-Shimony-

L. Schulman

When a confined system interacts with its walls (treated quantum mechanically), there is an intertwining of degrees of freedom. We show that this need not lead to entanglement, hence decoherence. It will generally lead to error. The wave function optimization required to avoid decoherence is also examined.

Richard Dipper, Gordon James, Andrew Mathas

In this paper we use the Hecke algebra of type $B$ to define a new algebra $\Sch$ which is an analogue of the q-Schur algebra. We construct Weyl modules for $\Sch$ and obtain, as factor modules, a family of irreducible $\Sch$-modules over any field.

W. Ebeling, B. Militzer

We study a partially ionized hydrogen plasma by means of quantum molecular dynamics, which is based on wave packets. We introduce a new model which distinguishes between free and bound electrons. The free electrons are modelled as Gaussian wave packets with fixed width. For the bound states the 1s-wave function of the hydrogen atom is assumed. In our simulat

Bao-An Li, C. M. Ko

Using phenomenological equations of state, we study the chemical and mechanical instabilities in hot isospin-asymmetric nuclear matter. Both instabilities are found to depend strongly on the isospin asymmetry of the nuclear matter. For a chemically and mechanically stable asymmetric nuclear matter, a lower neutron excess is found in the liquid phase than in

Bao-An Li, C. M. Ko, Z. Z. Ren

The ratio of pre-equilibrium neutrons to protons from collisions of neutron-rich nuclei is studied as a function of their kinetic energies. This ratio is found to be sensitive to the density dependence of the nuclear symmetry energy, but is independent of the compressibility of symmetric nuclear matter and the in-medium nucleon-nucleon cross sections. The ex

Nikolai Saveliev

In this paper we answer the question posed by M.~Atiyah and give an explicit formula for Floer homology of Brieskorn homology spheres in terms of their branching sets over the 3--sphere. We further show how Floer homology is related to other invariants of knots and 3--manifolds, among which are the $\barμ$--invariant of W.~Neumann and L.~Siebenmann and the J

Abhay Ashtekar, Alejandro Corichi

It is shown that there is a precise sense in which the Heisenberg uncertainty between fluxes of electric and magnetic fields through finite surfaces is given by (one-half $\hbar$ times) the Gauss linking number of the loops that bound these surfaces. To regularize the relevant operators, one is naturally led to assign a framing to each loop. The uncertainty

T. E. Clark, S. T. Love

Renormalization group methods are used to determine the evolution of the low energy Wilson effective action for supersymmetric nonlinear sigma models in four dimensions. For the case of supersymmetric $CP^{(N-1)}$ models, the Kähler potential is determined exactly and is shown to exhibit a nontrivial ultraviolet fixed point in addition to a trivial infrared

F. Ferrari, J. T. Sobczyk

In this talk the main features of the operator formalism for the $b-c$ systems on general algebraic curves developed in refs. [1-2] are reviewed. The first part of the talk is an introduction to the language of algebraic curves. Some explicit techniques for the construction of meromorphic tensors are explained. The second part is dedicated to the discussion

Leopoldo A. Pando Zayas

We herein set forth intrinsically four-dimensional string solutions and analyze some of its properties. The solutions are constructed as gauged WZW models of the coset $SO(2,2)/SO(2)\times SO(1,1)$. We recover backgrounds having metric and antisymmetric tensors, dilaton fields and two electromagnetic fields. The theories describe anisotropically expanding an

Marcos Marino

We review the relations between (twisted) supersymmetric gauge theories in four dimensions and moduli problems in four-dimensional topology, and we study in detail the non-abelian monopole equations from this point of view. The relevance of exact results in N=1 and N=2 supersymmetric gauge theories to the computation of topological invariants is emphasized.

Igor Bandos, Dmitri Sorokin, Mario Tonin

The action for the D=10 type II Dirichlet super-p-branes, which has been obtained recently, is reconstructed in a more geometrical form involving Lorentz harmonic variables. This new (Lorentz-harmonic) formulation possesses kappa-symmetry in an irreducible form and is used as a basis for applying a generalized action principle that provides the superfield eq

R. Akhoury, V. I. Zakharov

We discuss the renormalon-based approach to power corrections in non-singlet deep inelastic scattering structure functions and compare it with the general operator product expansion. The renormalon technique and its variations relate the power corrections directly to infrared-sensitive parameters such as the position of the Landau pole Λ_{QCD} or the infinit

Gerhard Buchalla

The phenomenology of rare kaon decays is reviewed, with emphasis on tests of standard model flavordynamics.

I. I. Tkachev

We review results of a numerical study of resonant inflaton decay in a wide range of realistic models and parameters. Wide enough parametric resonance can withstand the expansion of the Universe, though account for the expansion is very important for determining precisely how wide it should be. For example, the effective production of particles with mass ten

G. Amorós, M. Beneke, M. Neubert

We find that the anomalous dimension (in the $\bar{MS}$ scheme) of the chromo-magnetic operator $g_s\bar h_vσ_{μν} G^{μν} h_v$ in the heavy-quark effective theory is γ_{mag} = (C_Aα_s / 2π) [1 + ( 17/18 C_A - 13/18 T_F n_f)α_s/π+ O(α_s^2)] generalizing the one-loop expression known previously. To derive the two-loop result, we use the reparametrization invar

Lyndon Alvero, John C. Collins, Juan Terron, Jim Whitmore

We extract diffractive parton densities from diffractive, deep inelastic (DIS) ep data from the ZEUS experiment. Then we use these fits to predict the diffractive production of jets and of W&#39;s and Z&#39;s in p\bar p collisions at the Tevatron. Although the DIS data require a hard quark density in the pomeron, we find fairly low rates for the Tevatron pro

M. Baillargeon, G. Bélanger, F. Boudjema

The effect of anomalous couplings in $γγ\to W^+ W^-$ is studied for different energies of the $γγ$ mode of the next linear collider. The analysis based on the maximum likelihood method exploits the variables in the four-fermion semi-leptonic final state. Polarised differential cross sections based on the complete set of diagrams for these channels with the i

V. Korotkov, W. -D. Nowak

The physics scope of polarized nucleon-nucleon collisions originating from an internal polarized target in the HERA proton beam is summarized. Based on 240 pb^{-1} integrated luminosity at 40 GeV c.m. energy, statistical sensitivities are given over a wide (x_F, p_T)-range for a variety of inclusive and exclusive final states. By measuring single spin asymme

Yu. A. Baurov, A. V. Kopajev

Smooth anomalous in time dependence recordings of a high accuracy quartz gravimeter with a constant magnet attached to it, were revealed. These anomalies of minute&#39;s duration have amplitudes sometimes by more than an order of magnitude greater than that of the Moon tide, and may not be explained with the aid of current physical concepts. The experimental

M. Baillargeon, G. Bélanger, F. Boudjema

We calculate the process $γγ\rightarrow e^- \barν_e u \bar{d}$ with the full set of Feynman diagrams. We consider different implementations of the $W$ width and different combinations of the photon polarisations. The results of an improved narrow width approximation based on $γγ\rightarrow W^+ W^-$ with full spin-correlations that takes into account differen

Jin-Ping Li, Mu-Lin Yan, Rong-Hua Yu

The higher order corrections of SU(3) rotating excited states to the Gell-Mann-Okubo Relations (or GOR) are presented in the standard SU(3) Skyrme model.The Improved GOR (or IGOR) are obtained. The results show the IGOR for decuplet up to the third order and for octet up to the second order are much compatible with the experimental data. But things becomes q

A. D. Martin, M. G. Ryskin, T. Teubner

We use perturbative QCD and parton-hadron duality to estimate the cross sections for the diffractive electroproduction of rhoprime(1-) and rho(3-) resonances which occur in the 1.3-1.8 GeV mass interval. We present the cross sections and the ratios sigma_L/sigma_T as a function of Q^2. We compare the predictions with those for the diffractive electroproducti