April 1997 arXiv papers — page 14

Scott M. Zoldi, Henry S. Greenside

Using an innovative damped-Newton method, we report the first calculation of many distinct unstable periodic orbits (UPOs) of a large high-dimensional extensively chaotic partial differential equation. A majority of the UPOs turn out to be spatially localized in that time dependence occurs only on portions of the spatial domain. With a particular weighting o

D. A. Dicus, B. Dutta, S. Nandi

In theories with gauge mediated supersymmetry breaking, the scalar tau, (${\tilde τ_1}$) is the lightest observable superpartner for part of the parameter space. At LEP 2, the production of such a $\tilde τ_1$ pair and their subsequent decays give rise to a pair of $τ$ leptons plus missing energy from the unobserved gravitinos. The angular distributions of t

David Bowser-Chao, Wai-Yee Keung

Lepton flavor violation can be induced in supersymmetry by the mixing of two or more of the leptonic scalar partners, Krashnikov and Arkani-Hamed et al. pointed out that this effect may be observable at the Next Linear Collider, through slepton pair production with subsequent lepton flavor violating decays. If the slepton mixing involves all three generation

Ilya A. Gruzberg, N. Read, Subir Sachdev

The directed network model describing chiral edge states on the surface of a cylindrical 3D quantum Hall system is known to map to a one-dimensional quantum ferromagnetic spin chain. Using the spin wave expansion for this chain, we determine the universal functions for the crossovers between the 2D chiral metallic and 1D metallic regimes in the mean and vari

Max Tegmark

We discuss some physical consequences of what might be called ``the ultimate ensemble theory'', where not only worlds corresponding to say different sets of initial data or different physical constants are considered equally real, but also worlds ruled by altogether different equations. The only postulate in this theory is that all structures that ex

M. Magro, L. O'Raifeartaigh, I. Sachs

The low energy effective Lagrangian for N= 2 SU(2) supersymmetric Yang-Mills theory coupled to N_F<4 massless matter fields is derived from the BPS mass formula using asymptotic freedom and assuming that the number of strong coupling singularities is finite.

Arkadiusz Olech

We present a complete set of OGLE photometric measurements for 214 RR Lyrae variables in the Galactic bulge, based on four observing seasons: 1992-95. These are mostly I-band measurements, with some V-band observations obtained mainly in 1995. Based on this material we construct the Fourier decomposition of the I-band light curves and investigate different t

Wolfgang Eholzer, Nils-Peter Skoruppa

Characters of rational vertex operator algebras (RVOAs) arising in 2-dimensional conformal field theories often belong (after suitable normalization) to the (multiplicative) semigroup E^+ of modular units whose Fourier expansions are in 1+q Z_{>=0}[[q]], up to a fractional power of q. If even all characters of a RVOA share this property then we have an examp

W. A. Hofer

Considering the recently established arbitrariness the Schroedinger equation has to be interpreted as an equation of motion for a statistical ensemble of particles. The statistical qualities of individual particles derive from the unknown intrinsic energy components, they depend on the physical environment by way of external potentials. Due to these statisti

K. Ishikawa, N. Maeda, T. Ochiai, H. Suzuki

Using a momentum representation of a magnetic von Neumann lattice, we study a two-dimensional electron in a uniform magnetic field and obtain one-particle spectra of various periodic short-range potential problems in the lowest Landau level.We find that the energy spectra satisfy a duality relation between a period of the potential and a magnetic length. The

Bruno Binggeli, Helmut Jerjen

The shape of the surface brightness profile of dE galaxies, quantified by parameter n of Sersic&#39;s generalized profile law, has recently been put forward as new extragalactic distance indicator (Young & Currie 1994). Its application to the Virgo cluster has subsequently led to the claim that the Virgo dEs are not lying in the cluster core but are distribu

Hideyasu Yamashita

This paper outlines a mathematical framework of quantum probability in which the time asymmetry in describing measuring processes is avoided. The main objects of the framework are hyperfinite operations, which are constructed by using nonstandard analysis and the operational approach by Davies and Lewis. Then the notions of Bayesian conditional probability a

D. Han, Y. S. Kim, Marilyn E. Noz

In classical mechanics, the system of two coupled harmonic oscillators is shown to possess the symmetry of the Lorentz group O(3,3) applicable to a six-dimensional space consisting of three space-like and three time-like coordinates, or SL(4,r) in the four-dimensional phase space consisting of two position and two momentum variables. In quantum mechanics, th

Giovanni Felder, Alexander Varchenko

We construct symmetric and exterior powers of the vector representation of the elliptic quantum groups $E_{τ,η}(gl_N)$. The corresponding transfer matrices give rise to various integrable difference equations which could be solved in principle by the nested Bethe ansatz method. In special cases we recover the Ruijsenaars systems of commuting difference opera

H. Q. Wang

A two-particle space correlation function is derived from the single-particle momentum distribution of the emission source. A signal of a first order phase transition is obtained from this correlation function if density fluctuations are large.

T. Sato, T. -S. H. Lee, F. Myhrer, K. Kubodera

A chiral-perturbative consideration of the near-threshold pp -> pp pi0 reaction indicates that the pion-rescattering term has a substantial energy and momentum dependence. The existing calculations that incorporate this dependence give pion rescattering contributions significantly larger than those of the conventional treatment, and this enhanced rescatterin

A. Nogga, D. Hueber, H. Kamada, W. Gloeckle

We present high precision benchmark calculations for the triton binding energy using the most recent, phase equivalent realistic nucleon-nucleon (NN) potentials and the Tuscon-Melbourne pi-pi three-nucleon force (3NF). That 3NF is included with partial waves up to a total two-body angular momentum of j_max=6. It is shown that the inclusion of the 3NF slows d

S. Fritz, ALADIN collaboration

A study of emission temperatures extracted from excited state populations and of freeze out radii from light particle intensity interferometry is presented. Three high resolution dE-E-Hodoscopes with a total of 216 detectors are combined with the ALADiN setup in order to study Au+Au collisions at 1 A GeV. In contrast to measurements with the isotope thermome

C. Schwarz, ALADIN collaboration

For midrapidity fragments from central 50-200 AMeV Au+Au collisions temperatures from double ratios of isotopic yields were compared with temperatures from particle unbound states. Temperatures from particle unbound states with T = 4-5 MeV show with increasing beam energy an increasing difference to temperatures from double ratios of isotopic yields, which i

J. M. F. Labastida, M. Marino

We present a summary of the applications of duality to Donaldson-Witten theory and its generalizations. Special emphasis is made on the computation of Donaldson invariants in terms of Seiberg-Witten invariants using recent results in N=2 supersymmetric gauge theory. A brief account on the invariants obtained in the theory of non-abelian monopoles is also pre

Joseph Polchinski, Philippe Pouliot

Membrane scattering in m(atrix) theory is related to dynamics in three-dimensional $SU(2)$ gauge theory, with transfer of $p^{11}$ being an instanton process. We calculate the instanton amplitude and find precise agreement with the amplitude in eleven dimensional supergravity.

C. Barnes, W. K. Baskerville, N. Turok

The normal mode spectrum of the deuteron in the Skyrme model is computed. We find a bound doublet mode below the pion mass, which can be related to the well-known $90^{\circ}$ scattering of two skyrmions. We also find a singlet `breather&#39; mode and another doublet above the pion mass. The qualitative pattern of the spectrum is similar to that recently fou

Mikhail S. Volkov, Norbert Straumann

It is shown that the well-known non-Abelian static SU(2) black hole solutions have rotating generalizations, provided that the hypothesis of linearization stability is accepted. Surprisingly, this rotating branch has an asymptotically Abelian gauge field with an electric charge that cannot vanish, although the non-rotating limit is uncharged. We argue that t

Hideaki Aoyama, Toshiyuki Harano, Hisashi Kikuchi, Ikuo Okouchi

Path-integral approach in imaginary and complex time has been proven successful in treating the tunneling phenomena in quantum mechanics and quantum field theories. Latest developments in this field, the proper valley method in imaginary time, its application to various quantum systems, complex time formalism, asympton theory for the large order analysis of

Marc Henneaux

The (perturbative) renormalization properties of the BF formulation of Yang-Mills gauge models are shown to be identical to those of the usual, second order formulation. This result holds in any number of spacetime dimensions and is a direct consequence of cohomological theorems established by G. Barnich, F. Brandt and the author (Commun.Math.Phys., 174 (199

John M. Cornwall

We speculate that above or just below the electroweak phase transition magnetic fields are generated which have a net helicity (otherwise said, a Chern-Simons term) of order of magnitude $N_B + N_L$, where $N_{B,L}$ is the baryon or lepton number today. (To be more precise requires much more knowledge of B,L-generating mechanisms than we currently have.) Ele

Frank Cuypers, Martti Raidal

We analyze the prospects for discovering and unraveling the nature of doubly-charged bileptons at a linear collider of the next generation running in its electron-electron colliding mode. We stress the importance of initial state radiation, beam spread and polarization, and compute the discovery bounds. The gauge nature of vector bileptons can be determined

Yasuhiro Okada, Yasuhiro Shimizu, Minoru Tanaka

Rare $b$ decay processes are analyzed in the multi-Higgs doublet model. Taking account of the constraint from the $b\to s γ$ process, the branching ratio and the forward-backward asymmetry of the final leptons for the $b\to s \ell^+ \ell^-$ process are calculated. It is shown that the branching ratio can be a few times larger than the standard model predicti

K. G. Chetyrkin, R. Harlander, J. H. Kuehn, M. Steinhauser

Three-loop QCD corrections to the vector current correlator are considered. The large momentum procedure is applied in order to evaluate mass corrections up to order $(m^2/q^2)^6$. The inclusion of the first seven terms to the ratio $R=σ(e^+e^- \to hadrons)/σ(e^+e^- \to μ^+μ^-)$ leads to reliable predictions from the high energy region down to relatively clo

T. Kon, T. Kobayashi

We investigate an event excess in the reaction $e^+p \to e^+ X$ with large $x$ and high $Q^2$ observed at HERA and show that the events could naturally be interpreted as a signature of the production of the scalar top quarks (stops) in a supersymmetric model with $R$-parity breaking interactions. The HERA events are characterized by the broad mass distributi

J. Kubo, M. Mondragon, G. Zoupanos

Reduction of couplings in supersymmetric GUTs is achieved by searching for renormalization group invariant (RGI) relations among couplings which hold beyond the unification scale. Finiteness is due to the fact that there exist RGI relations among couplings that guarantee the vanishing of the beta-functions of a N=1 supersymmetric GUT even to all orders in pe

T. L. Barklow, G. Burdman, R. S. Chivukula, B. A. Dobrescu

We review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. We emphasize the direct observation of the new interactions through high-energy scattering of vector bosons. We also discuss indirect probes of the new interactions and exotic particles predicted by

Yuval Grossman

The $K_L \to π^0 ν\barν$ decay is analyzed in a model independent way. When lepton flavor is conserved, this decay mode is a manifestation of CP violating interference between mixing and decay. Consequently, a theoretically clean relation between the measured rate and electroweak parameters holds in any given model.

Robert M. Wald

The Nernst formulation of the third law of ordinary thermodynamics (often referred to as the ``Nernst theorem&#39;&#39;) asserts that the entropy, $S$, of a system must go to zero (or a ``universal constant&#39;&#39;) as its temperature, $T$, goes to zero. This assertion is commonly considered to be a fundamental law of thermodynamics. As such, it seems to s

B. Linet

In Rindler space, we determine in terms of special functions the expression of the static, massive scalar or vector field generated by a point source. We find also an explicit integral expression of the induced electrostatic potential resulting from the vacuum polarization due to an electric charge at rest in the Rindler coordinates. For a weak acceleration,

U. Hertrich-Jeromin, E. -H. Tjaden, M. T. Zuercher

In the first part, we give a self contained introduction to the theory of cyclic systems in n-dimensional space which can be considered as immersions into certain Grassmannians. We show how the (metric) geometries on spaces of constant curvature arise as subgeometries of Moebius geometry which provides a slightly new viewpoint. In the second part we characte

I. Loutsenko, D. Roubtsov

The presence of exciton phonon interactions is shown to play a key role in the exciton superfluidity. We apply the Landau criterion for an exciton-phonon condensate moving uniformly at zero temperature. It turns out that there are essentially two critical velocities in the theory. Within the range of these velocities the condensate can exist only as a bright

J. K. Jain, R. K. Kamilla

Single particle basis functions for composite fermions are obtained from which many-composite fermion states confined to the lowest electronic Landau level can be constructed in the standard manner, i.e., by building Slater determinants. This representation enables a Monte Carlo study of systems containing a large number of composite fermions, yielding new q

Michael C. Martin, M. Hase, K. Hirota, G. Shirane

Comprehensive neutron scattering studies were carried out on a series of high-quality single crystals of Cu_{1-x}Zn_xGeO_3. The Zn concentration, x, was determined for each sample using Electron Probe Micro-Analysis. The measured Zn concentrations were found to be 40-80% lower than the nominal values. Nevertheless the measured concentrations cover a wide ran

C. Rocke, S. Zimmermann, A. Wixforth, J. P. Kotthaus

The strong piezoelectric fields accompanying a surface acoustic wave on a semiconductor quantum well structure are employed to dissociate optically generated excitons and efficiently trap the created electron hole pairs in the moving lateral potential superlattice of the sound wave. The resulting spatial separation of the photogenerated ambipolar charges lea

A. L. Kuzemsky

The self-consistent theory of the correlation effects in Highly Correlated Systems(HCS) is presented. The novel Irreducible Green&#39;s Functions(IGF) method is discused in detail for the Hubbard model and random Hubbard model. The interpolative solution for the quasiparticle spectrum, which is valid for both the atomic and band limit is obtained. The (IGF)

Ramesh V. Pai, Alexander Punnoose, Rudolf A. Römer

We use the density matrix renormalization group to study the quantum transitions that occur in the half-filled one-dimensional fermionic Hubbard model with onsite potential disorder. We find a transition from the gapped Mott phase with algebraic spin correlations to a gapless spin-disordered phase beyond a critical strength of the disorder $Δ_c \approx U/2$.

Deepak Dhar, Abhishek Dhar

We study the distribution of sizes of erased loops for loop-erased random walks on regular and fractal lattices. We show that for arbitrary graphs the probability $P(l)$ of generating a loop of perimeter $l$ is expressible in terms of the probability $P_{st}(l)$ of forming a loop of perimeter $l$ when a bond is added to a random spanning tree on the same gra

S. N. Artemenko, A. G. Kobelkov

Equations describing the resistive state of a layered superconductor with anisotropic pairing are derived. The similarity with a stack of Josephson junctions is found at small voltages only, when current density in the direction perpendicular to the layers can be interpreted as a sum of the Josephson superconducting, the Ohmic dissipative and the interferenc

R. Bulla, A. C. Hewson, G. -M. Zhang

We study the single channel (compactified) models, the sigma-tau model and the O(3) symmetric Anderson model, which were introduced by Coleman et al., and Coleman and Schofield, as a simplified way to understand the low energy behaviour of the isotropic and anisotropic two channel Kondo systems. These models display both Fermi liquid and marginal Fermi liqui

Y. Bazaliy, E. Demler, S. C. Zhang

A recent theory of the resonant neutron scattering peaks in YBCO superconductors predicts the existence of a sharp spin triplet two particle collective mode (the ``πresonance&#34;) in the normal state. In this paper, we propose an experiment in which the πresonance could be probed directly in a two particle tunneling measurement.

S. P. Boughn, R. G. Crittenden, N. G. Turok

In universes with significant curvature or cosmological constant, cosmic microwave background (CMB) anisotropies are created very recently via the Rees-Sciama or integrated Sachs-Wolfe effects. This causes the CMB anisotropies to become partially correlated with the local matter density (z < 4). We examine the prospects of using the hard (2-10 keV) X-ray bac

Robert W. O&#39;Connell, Ben Dorman, Ronak Y. Shah, Robert T. Rood

We have used the Ultraviolet Imaging Telescope to obtain deep far-UV (1620 Angstrom), 40&#39; diameter images of the prototypical metal-rich globular cluster 47 Tucanae. We find a population of about 20 hot (Teff > 9000 K) objects near or above the predicted UV luminosity of the hot horizontal branch (HB) and lying within two half-light radii of the cluster

John D. Barrow, Janna Levin

We present the geodesics on homogeneous and isotropic negatively curved spaces in a simple form suitable for application to cosmological problems. We discuss how the patterns in the microwave sky of anisotropic homogeneous universes can be predicted qualitatively by looking at the invariances that generate their three-geometries.

Michael S. Turner

Inflation is a bold and expansive extension of the Standard Cosmology. It holds the promise to extend our understanding of the Universe to within 10^{-32}sec of the big bang and answer most of the pressing questions in cosmology. Its boldest assertion is that all the structure observed in the Universe today arose from quantum-mechanical fluctuations on subat

M. E. Prokhorov, V. M. Lipunov, K. A. Postnov

Merging rates of compact binaries (double neutron stars or black holes) are calculated based on the modern concept of binary stellar evolution. It is found that the initial laser interferometers with an rms-sensitivity of $10^{-21}$ at the frequency 100 Hz can detect 10-700 black holes and only \sim 1 neutron star coalescences in a 1-year integration time. I

M. Salaris, I. Dominguez, E. Garcia-Berro, M. Hernanz

In this paper we compute detailed evolutionary models providing chemical profiles for white dwarfs having progenitors in the mass range from 1.0 to $7 M_{\sun}$ and we examine the influence of such profiles in the cooling process. The influence of the process of separation of carbon and oxygen during crystallization is decreased as a consequence of the initi

STACEE Collaboration

There are currently no experiments, either satellite or ground-based, that are sensitive to astrophysical gamma-rays at energies between 20 and 250 GeV. We are developing the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) to explore this energy range. STACEE will use heliostat mirrors at a solar research facility to collect Cherenkov light from

Gian Luigi Granato, Luigi Danese, Alberto Franceschini

Two families of models of dusty tori in AGNs (moderately thick and extended versus very thick and compact) are tested against available observations. The confrontation suggests that the former class better explains the IR broad-band spectra of both broad and narrow line AGNs, the anisotropy of the emission deduced by comparing IR properties of Seyfert 1 and

Romain Teyssier, Jean-Pierre CHIEZE, Jean-Michel Alimi

We reconsider the collapse of cosmic structures in an Einstein-de Sitter Universe, using the self similar initial conditions of Fillmore & Goldreich (1984). We first derive a new approximation to describe the dark matter dynamics in spherical geometry, that we refer to the &#34;fluid approach&#34;. This method enables us to recover the self-similarity soluti

Jean-Pierre CHIEZE, Romain Teyssier, Jean-Michel Alimi

We investigate the formation of spherical cosmological structures following both dark matter and gas components. We focus on the dynamical aspect of the collapse assuming an adiabatic, $γ= 5/3$, fully ionized primordial plasma. We use for that purpose a fully Lagrangian hydrodynamical code designed to describe highly compressible flows in spherical geometry.

Claude Carignan, Stephanie Cote, Ken Freeman, Peter Quinn

The spectra of 34 galaxies within 20 arcmins (\sim 100 kpc) of the lenticular galaxy NGC 5084 have been obtained using the FOCAP system on the Anglo-Australian 3.9m telescope. Nine objects are found with projected separations \lesssim 80 kpc and with radial velocities within \pm 630 km/s of the parent galaxy redshift. Using various techniques, their velocity

Stephanie Cote, Ken Freeman, Claude Carignan

Five nearby dwarf irregular galaxies, amongst the recently surveyed dwarf members of the Sculptor and Centaurus A groups (at 2.5 Mpc and 3.5 Mpc), have been imaged in neutral hydrogen (HI) with the Australia Telescope and the Very Large Array. These objects have absolute magnitudes M_B in the range -14.9 to -12.7, yet they are clearly rotationally supported,

Stephanie Cote, Ken Freeman, Claude Carignan, Peter Quinn

We report the discovery of a large population of dwarf irregular galaxies in the two nearest groups of galaxies outside the Local Group, the Sculptor and the Centaurus A groups (2.5 and 3.5 Mpc). Total areas of approximately 940 and 910 square degrees in these groups were scanned visually on the SRC J films to find dwarf candidates. Redshifts were obtained b

Naohito Nakasato, Masao Mori, Ken&#39;ichi Nomoto

We have developed Remote-GRAPE, a subroutine library to use the special purpose computer GRAPE-3A. The GRAPE-3A can efficiently calculate gravitational force between particles, and construct neighbor lists. All other calculations are performed on the host workstation (WS) which is directly connected to GRAPE. The use of GRAPE for Smoothed Particle Hydrodynam

I. F. Ginzburg, I. P. Ivanov

A Higgs boson within the mass range $M_H=140-190$ GeV can be discovered at a photon collider in the reaction $γγ\to WW$ (with real or virtual W) with the luminosity integral about 1 fb$^{-1}$. The reasonable resolution in the effective mass of the WW system is required.

M. Abou Zeid, C. M. Hull

We obtain forms of Born-Infeld and D-brane actions that are quadratic in derivatives of $X$ and linear in $F_{μν}$ by introducing an auxiliary `metric&#39; which has both symmetric and anti-symmetric parts, generalising the simplification of the Nambu-Goto action for $p$-branes using a symmetric metric. The abelian gauge field appears as a Lagrange multiplie

Klaus Behrndt, Stefan Forste, Stefan Schwager

We consider the gauge dyonic string solution of the K3 compactified heterotic string theory in a four dimensional cosmological context. Since for this solution Green-Schwarz as well as Chern-Simons corrections have been taken into account it contains both world sheet and string loop corrections. The cosmological picture is obtained by rotating the world volu

R. Dijkgraaf, E. Verlinde, H. Verlinde

We derive the world-volume theory, the (non)-extremal entropy and background geometry of black holes and black strings constructed out of the NS IIA fivebrane within the framework of matrix theory. The CFT description of strings propagating in the black hole geometry arises as an effective field theory.

Martin Kerscher, Jens Schmalzing, Thomas Buchert, Herbert Wagner

An analysis of the IRAS 1.2 Jy redshift catalogue with emphasis on the separate examination of northern and southern parts (in galactic coordinates) is performed using a complete set of morphological descriptors (Minkowski functionals), nearest neighbour distributions and the variance of the galaxy counts. We find large fluctuations in the clustering propert

P. Podles, E. Muller

We give an elementary introduction to the theory of algebraic and topological quantum groups (in the spirit of S. L. Woronowicz). In particular, we recall the basic facts from Hopf (*-) algebra theory, theory of compact (matrix) quantum groups and the theory of their actions on compact quantum spaces. We also provide the most important examples, including th

Chris Barnes, Kim Baskerville, Neil Turok

The Skyrme model of nuclear physics requires quantisation if it is to match observed nuclear properties. A simple technique is used to find the normal mode spectrum of the baryon number B=4 Skyrme soliton, representing the $\alpha$ particle. We find sixteen vibrational modes and classify them under the cubic symmetry group $O_h$ of the static solution. The s

Erik Luijten, Henk W. J. Blöte

We present the results of extensive Monte Carlo simulations of Ising models with algebraically decaying ferromagnetic interactions in the regime where classical critical behavior is expected for these systems. We corroborate the values for the exponents predicted by renormalization theory for systems in one, two, and three dimensions and accurately observe t

Rohan Mahadevan, Ramesh Narayan, Julian Krolik

We calculate the flux and spectrum of γ-rays emitted by a two-temperature advection-dominated accretion flow (ADAF) around a black hole. The γ-rays are from the decay of neutral pions produced through proton-proton collisions. We discuss both thermal and power-law distributions of proton energies and show that the γ-ray spectra in the two cases are very diff

D. V. Alekseevsky, V. Cortés, C. Devchand, U. Semmelmann

A supermanifold M is canonically associated to any pseudo Riemannian spin manifold (M_0,g_0). Extending the metric g_0 to a field g of bilinear forms g(p) on T_p M, p\in M_0, the pseudo Riemannian supergeometry of (M,g) is formulated as G-structure on M, where G is a supergroup with even part G_0\cong Spin(k,l); (k,l) the signature of (M_0,g_0). Killing vect

Giampiero Esposito

This paper is devoted to mathematical and physical properties of the Dirac operator and spectral geometry. Spin-structures in Lorentzian and Riemannian manifolds, and the global theory of the Dirac operator, are first analyzed. Elliptic boundary-value problems, index problems for closed manifolds and for manifolds with boundary, Bott periodicity and K-theory

D. Augier, D. Poilblanc, S. Haas, A. Delia

Dynamical properties of the novel inorganic spin-Peierls compound α&#39;--NaV2O5 are investigated using a one-dimensional dimerized Heisenberg model. By exact diagonalizations of chains with up to 28 sites, supplemented by a finite-size scaling analysis, the dimerization parameter δis determined by requiring that the model reproduces the experimentally obser

Ji-Ho Jang, Yeong Gyun Kim, Jae Sik Lee

We investigate the effects of R-parity violation on the semileptonic decays of B-meson in the minimal supersymmetric standard model with explicit R-parity violation and discuss its physical implications. We find that the semileptonic decays of B-meson can be largely affected by the R-parity violation.

J. Bijnens, P. Gosdzinsky, P. Talavera

We discuss the vector meson masses within the context of Chiral Perturbation Theory performing an expansion in terms of the momenta, quark masses and 1/Nc. We extend the previous analysis to include isospin breaking effects and also include up to order $p^4$. We discuss vector meson chiral perturbation theory in some detail and present a derivation from a re

A. V. Radyushkin

Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive electroproduction processes require a generalization of usual parton distributions for the case when long-distance information is accumulated in nonforward matrix elements <p&#39;|O|p> of quark and gluon light-cone operators. We describe two types of nonperturbative func

G. Cicogna

It is shown that the presence of Lie-point-symmetries of (non-Hamiltonian) dynamical systems can ensure the convergence of the coordinate transformations which take the dynamical sytem (or vector field) into Poincaré-Dulac normal form.

L. S. F. Olavo

In this paper we will turn our attention to the problem of obtaining phase-space probability density functions. We will show that it is possible to obtain functions which assume only positive values over all its domain of definition.

Cesar Miquel, Juan Pablo Paz, Wojciech Hubert Zurek

We present results of numerical simulations of the evolution of an ion trap quantum computer made out of 18 ions which are subject to a sequence of nearly 15000 laser pulses in order to find the prime factors of N=15. We analyze the effect of random and systematic phase drift errors arising from inaccuracies in the laser pulses which induce over (under) rota

D. W. Leung, M. A. Nielsen, I. L. Chuang, Y. Yamamoto

We present relaxed criteria for quantum error correction which are useful when the specific dominant noise process is known. These criteria have no classical analogue. As an example, we provide a four-bit code which corrects for a single amplitude damping error. This code violates the usual Hamming bound calculated for a Pauli description of the error proces

Feng Xu

We show that the Jones-Wassermann subfactors for disconnected intervals, which are constructed from the representations of loop groups of type $A$, are finite-depth subfactors. The index value and the dual principal graphs of these subfactors are completely determined. The square root of the index value in the case of two disjoint intervals for vacuum repres

T. D. Palev, N. I. Stoilova

A class of highest weight irreducible representations of the quantum algebra U_h(gl_\infty) is constructed. Within each module a basis is introduced and the transformation relations of the basis under the action of the Chevalley generators are explicitly written.

V. S. Varadarajan

This paper discusses the role of the Skorokhod space and the convergence of probability measures on it in some recent studies of the foundations of quantum mechanics, both in the conventional setting over the real number field and in the more speculative one of nonarchimedean local fields.

W. S. Chung, G. Q. Li, C. M. Ko

Phi meson production in heavy-ion collisions at SIS/GSI energies ($\sim 2$ GeV/nucleon) is studied in the relativistic transport model. We include contributions from baryon-baryon, pion-baryon, and kaon-antikaon collisions. The cross sections for the first two processes are obtained in an one-boson-exchange model, while that for the last process is taken to

Hugo R. Christiansen

We analyze the chiral symmetries of flavored quantum chromodynamics in two dimensions and show the existence of chiral condensates within the path-integral approach. The massless and massive cases are discussed as well, for arbitrary finite and infinite number of colors. Our results put forward the question of topological issues when matter is in the fundame

N. P. Chitaia, S. A. Gogilidze, Yu. S. Surovtsev

In the Dirac approach to the generalized Hamiltonian formalism, dynamical systems with first- and second-class constraints are investigated. The classification and separation of constraints into the first- and second-class ones are presented with the help of passing to an equivalent canonical set of constraints. The general structure of second-class constrai

C. Kristjansen, P. Olesen

We show that a recently proposed Yang-Mills matrix model with an auxiliary field, which is a candidate for a non-perturbative description of type IIB superstrings, captures the Euler characteristic of moduli space of Riemann surfaces. This happens at the saddle point for the Yang-Mills field. It turns out that the large-n limit in this matrix model correspon

D. C. Cabra

We introduce a set of gauge invariant fermion fields in fermionic coset models and show that they play a very central role in the description of several Conformal Field Theories (CFT&#39;s). In particular we discuss the explicit realization of primaries and their OPE in unitary minimal models, parafermion fields in $Z_k$ CFT&#39;s and that of spinon fields i

A. Mikovic, V. Radovanovic

We study the one-loop effective action for a generic two-dimensional dilaton gravity theory conformally coupled to $N$ matter fields. We obtain an explicit expression for the effective action in the weak-coupling limit under a suitable restriction of the dilaton potential asymptotics. Our result applies to the CGHS model as well as to the spherically symmetr

Christophe Fraser, Timothy J. Hollowood

At a generic point in the moduli space of vacua of an N=4 supersymmetric gauge theory with arbitrary gauge group the Higgs force does not cancel the magneto-static force between magnetic monopoles of distinct charge. As a consequence the moduli space of magnetically charged solutions is related in a simple way to those of the SU(2) theory. This leads to a ra

Takeo Inami, Hiroaki Kanno, Tatsuya Ueno

We construct a generalization of the two-dimensional Wess-Zumino-Witten model on a $2n$-dimensional Kähler manifold as a group-valued non-linear sigma model with an anomaly term containing the Kähler form. The model is shown to have an infinite-dimensional symmetry which generates an $n$-toroidal Lie algebra. The classical equation of motion turns out to be

S. Ying

The role that quasiparticles play in a strong interaction system with spontaneous symmetry breaking is examined. We find, using a non- perturbative cluster decomposition method, that the quasiparticles do not saturate the physical local observables at small distances. The fermion number density serves as a clearcut example. A component due to localized rando

Tao Han

We discuss the model independent parameterization for a strongly interacting electroweak sector. Phenomenological studies are made to probe such a sector for future colliders such as the LHC, $e^+e^-$ Linear collider and a muon collider.

C. Friberg, E. Norrbin, T. Sjöstrand

If a leptoquark is produced at HERA as a narrow resonance, various effects tend to broaden the measurable mass distribution considerably. These effects are discussed here, with special emphasis on initial- and final-state QCD radiation. A proper understanding is important to assess the significance of data and to devise strategies for better mass reconstruct

G. Barenboim, M. Raidal

We investigate the allowed ranges of masses for an unstable tau neutrino in the context of SO(10) GUT-s. In light of the new nucleosynthesis results we obtain that there is a narrow window for m_{ν_τ} where the LEP, neutrino oscillation and nucleosynthesis data are compatible. This window, which depends on the effective number of neutrinos contributing to nu

John P. Costella, Bruce H. J. McKellar, Andrew A. Rawlinson

We review how antiparticles may be introduced in classical relativistic mechanics, and emphasize that many of their paradoxical properties can be more transparently understood in the classical than in the quantum domain.

Han Liang, Ma Wen-Gan, Yu Zeng-hui

QCD corrections to top quark pair production via fusion of both polarized and unpolarized photons are calculated in Supersymmetric Model. The corrections are found to be sizable. The dependence of the corrections on the masses of the supersymmetric particles is also investigated. Furthermore, we studied CP asymmetry effects arising from the complex couplings

Stefan Sint, Peter Weisz

We present results at one-loop order of perturbation theory for various improvement coefficients in on-shell O($a$) improved lattice QCD. In particular we determine the additive counterterm required for on-shell improvement of the isovector vector current. Employing a general mass-independent renormalization scheme we also obtain the coefficients of the O($a

John Ellison

We present electroweak physics results from the D0 and CDF experiments using data from p \bar p collisions at \sqrt s = 1.8 TeV. Measurements of the cross sections times branching ratios for W and Z production, the inclusive width of the W boson and the W boson mass are presented. Direct tests of the WWγand WWZ trilinear gauge boson couplings are also presen

Diego F. Torres

We study equilibrium configurations of boson stars in the framework of general scalar-tensor theories of gravitation. We analyse several possible couplings, with acceptable weak field limit and, when known, nucleosynthesis bounds, in order to work in the cosmologically more realistic cases of this kind of theories. We found that for general scalar-tensor gra

Maxim Kazarian, Richard Montgomery, Boris Shapiro

There is a remarkable type of field of two-planes special to four dimensions known as an Engel distributions. They are the only stable regular distributions besides the contact, quasi-contact and line fields. If an arbitrary two-plane field on a four-manifold is slightly perturbed then it will be Engel at generic points. On the other hand, if a manifold admi