December 1997 arXiv papers — page 11

Dean Lee

We study the singular Landau surfaces of planar diagrams contributing to scattering of a massless quark and antiquark in 3+1 dimensions. In particular, we look at singularities which remain after integration with respect to the various angular degrees of freedom. We derive a general relation between these singularities and the singularities of quark- antiqua

M. Asorey, F. Falceto

We show that parity symmetry is not spontaneously broken in the CP^N sigma model for any value of N when the coefficient of the $θ$--term becomes $θ=π$ (mod $2π$). The result follows from a non-perturbative analysis of the nodal structure of the vacuum functional $ψ_0(z)$. The dynamical role of sphalerons turns out to be very important for the argument. The

M. T. Batchelor, K. A. Seaton

The exact perturbation approach is used to derive the elementary correlation lengths $ξ_i$ and related mass gaps $m_i$ of the two-dimensional dilute A_L lattice model in regimes 1 and 2 for L odd from the Bethe Ansatz solution. In regime 2 the A_3 model is the E_8 lattice realisation of the two-dimensional Ising model in a magnetic field at T=T_c. The calcul

Adam F. Falk

I review the use of the Heavy Quark Effective Theory in the computation of total rates and differential kinematic distributions in inclusive semileptonic and radiative B decays. Particular attention is paid to strategies for the extraction of V_{cb} and V_{ub}.

M. Kachelriess

Massless neutrino exchange leads to a new long-range force between matter. Recently, it was claimed both that the potential energy due to this interaction i) dominates the total energy of neutron stars and ii) that it is zero. We recalculate the energy of a neutrino propagating in a classical, uniform background of neutrons and find a negligible, but non-zer

J. C. Romao

If supersymmetry is realized with spontaneous breaking of R-parity, there will be important consequences in several different areas which can be tested through different types of experiments. In this talk we review the phenomenological implications of these theories, with special emphasis on new signals at the present and future accelerators.

H. Päs, M. Hirsch, S. G. Kovalenko, H. V. Klapdor-Kleingrothaus

Double beta decay has been proven to be a powerful tool to constrain $B-L$ violating physics beyond the standard model. We present a representation for the long-range part of the general $0νββ$ decay rate allowed by Lorentz-invariance. Combined with the short range part this general parametrization in terms of effective $B-L$ violating couplings will provide

S. S. Gau, T. Paul, J. Swain, L. Taylor

We calculate the squared matrix element for the process e+ e- --> tau+ tau- gamma allowing for anomalous magnetic and electric dipole moments at the tau tau gamma vertex. No interferences are neglected and no approximations of light fermion masses are made. We show that anomalous moments affect not only the cross section, but also the shape of the photon ene

Z. Chacko, R. N. Mohapatra

We point out that in a large class of supersymmetric left-right models with automatic R-parity conservation there are a pair of light doubly charged Higgs bosons and Higgsinos. Requiring the mass of these particles to satisfy the LEP Z-width bound implies that $W_R$ mass must be above $10^{9}$ GeV.

L. T. Handoko

The possibility to test the unitarity triangle of CKM matrix is examined by using the semileptonic rare $B$ decays, $B \rightarrow X_q \, ł^+ \, ł^-$ with $q = d, s$ and $ł$'s are leptons. The discussion is emphasized on the CP asymmetry in the framework of standard and beyond the standard models. For the beyond standard model, a minimal extension of the

M. N. Dubinin, V. A. Ilyin, V. I. Savrin

We discuss the SM Higgs discovery potential of the LHC in the channel pp->H+jet->gamma+gamma+jet when the jet is observed at sufficiently high Pt and a small rapidity to be reliably identified. We calculate all the signal subprocesses and the irreducible background with realistic kinematical cuts. The reducible QCD background is also estimated. We conclude t

Seyong Kim, Shigemi Ohta

We report our light hadron mass calculation based on an increased statistics of 250 quenched gauge configurations on a (48^3 \times 64) lattice at (β= 6.5). Quark propagators are calculated for each of these configurations with staggered wall source and point sink at quark mass values of (m_q = 0.01, 0.005, 0.0025) and (0.00125). We also did additional calcu

Jochen Schwiening

The DIRC, a new type of Cherenkov imaging device, has been selected as the primary particle identification system for the BABAR detector at the asymmetric B-factory, PEP-II. It is based on total internal reflection and uses long, rectangular bars made from synthetic fused silica as Cherenkov radiators and light guides. In this paper, the principles of the DI

The UA8 Collaboration, A. Brandt, J. B. Cheze, S. Erhan

We report results of inclusive measurements of anti-Lambda, produced in the forward direction at the SPS with sqrt(s) = 630 GeV, using the UA8 small angle Roman Pot spectrometers. These measurements cover the range in Feynman-x_f and transverse momentum, 0.6 < x_f < 1.0 and 0.4 < p_t < 0.7 GeV, respectively. Within a systematic uncertainty of +-20% on the ab

Lucas Taylor

The properties of the W boson are reviewed. Particular emphasis is placed on recent measurements from the LEP2 and Tevatron experiments.

J. Swain, L. Taylor

The standard method for the propagation of errors, based on a Taylor series expansion, is approximate and frequently inadequate for realistic problems. A simple and generic technique is described in which the likelihood is constructed numerically, thereby greatly facilitating the propagation of errors.

D. H. Coule

The pre-big bang&#39;s kinetic driven inflationary mechanism is not an adequate form of inflation: the Planck length grows more rapidly than the scale factor. In order to explain our large universe, the resulting post-big bang universe requires the same unnatural constants (Planck problem) as those of any other non-inflationary big bang model.

Jose-Luis Rosales

In the spirit of general relativity, spacetime should become curved due to the presence of a particle of a given mass and charge, We try to understand this fact in the quantum theory of a thin shell of matter. It leads to a generalization of the potential energy of the shell in the semiclassical highest dominant order of Planck mass. Rather surprisingly, the

Jose-Luis Rosales

We develop the argument that initial real tunneling in quantum gravity be contemplated as a thermodynamical analogous to a black hole condensate in equilibrium with Hawking&#39;s radiation in a box. The total entropy is always maximized in the Lorentzian sector of the manifold, and, in this sense, tunneling is predicted.

Magnus Herberthson

We consider space-times which are asymptotically flat at spacelike infinity, i^0. It is well known that, in general, one cannot have a smooth differentiable structure at i^0, but have to use direction dependent structures. Instead of the oftenly used C^{>1}-differentiabel structure, we suggest a weaker differential structure, a C^{1^+} structure. The reason

Yasushi Mino, Misao Sasaki, Masaru Shibata, Hideyuki Tagoshi

We present analytic calculations of gravitational waves from a particle orbiting a black hole. We first review the Teukolsky formalism for dealing with the gravitational perturbation of a black hole. Then we develop a systematic method to calculate higher order post-Newtonian corrections to the gravitational waves emitted by an orbiting particle. As applicat

Yasushi Mino, Misao Sasaki, Takahiro Tanaka

We consider the radiation reaction to the motion of a point-like particle of mass $m$ and specific spin $S$ traveling on a curved background. Assuming $S=O(Gm)$ and $Gm\ll L$ where $L$ is the length scale of the background curvature, we divide the spacetime into two regions; the external region where the metric is approximated by the background metric plus p

Matthew J. W. Dodgson, Vadim B. Geshkenbein, Henrik Nordborg, Gianni Blatter

Using the London approximation within the high field scaling regime, we calculate the jump in the specific heat $Δc$ at the first-order melting transition of the vortex lattice in YBa$_2$Cu$_3$O$_{7-δ}$. This has recently been measured [A. Schilling et al., Phys. Rev. Lett. (78), 4833 (1997)] and reported to be at least 100 times higher than expected from th

D. L. Sawkey, D. Deptuck, D. Greenwood, J. P. Harrison

Measurements are presented of the thermomechanical coefficient of normal liquid He-3 confined in a porous plug pre-plated with four monoloyers of He-4. These non-magnetic monolayers displace the magnetic solid-like He-3 monolayers that are adjacent to the pore surfaces when the plug is filled with pure He-3. In the low temperature limit (T < 10 mK) the coeff

D. E. Steinhauer, C. P. Vlahacos, S. K. Dutta, F. C. Wellstood

We describe near-field imaging of sample sheet resistance via frequency shifts in a resonant coaxial scanning microwave microscope. The frequency shifts are related to local sample properties, such as surface resistance and dielectric constant. We use a feedback circuit to track a given resonant frequency, allowing measurements with a sensitivity to frequenc

Guy B. Standen, David J. Toms

The statistical mechanics of a system of non-relativistic charged particles in a constant magnetic field is discussed. The spatial dimension $D$ is arbitrary with $D\geq 3$ assumed. Calculations are presented from first principles using the effective action method. For $D\geq 5$ the system has a phase transition with a Bose condensate. We show how the effect

Z. Toroczkai, G. Korniss, B. Schmittmann, R. K. P. Zia

The disordering of an initially phase segregated system of finite size, induced by the presence of highly mobile vacancies, is shown to exhibit dynamic scaling in its late stages. A set of characteristic exponents is introduced and computed analytically, in excellent agreement with Monte Carlo data. In particular, the characteristic time scale, controlling t

A. V. Prokofiev, F. Büllesfeld, W. Assmus, H. Schwenk

Experimental results on magnetic resonance (ESR) and magnetic susceptibility are given for single crystalline (VO)$_2$P$_2$O$_{7}$. The crystal growth procedure is briefly discussed. The susceptibility is interpreted numerically using a model with alternating spin chains. We determine $J$=51 K and $δ$=0.2. Furthermore we find a spin gap of $\approx 6$meV fro

M. Fischer, P. H. M. van Loosdrecht, P. Lemmens, G. Güntherodt

Pressure and temperature dependent susceptibility and Raman scattering experiments on single crystalline Cu_xZn_(1-x)GeO_3 have shown an unusually strong increase of the spin-Peierls phase transition temperature upon applying hydrostatic pressure. The large positive pressure coefficient (7.5 K/GPa) - almost twice as large as for the pure compound (4.5 K/GPa)

Ryotaro Arita, Kazuhiko Kuroki, Hideo Aoki, Michele Fabrizio

The spin gap of a one-dimensional repulsive Hubbard model is numerically calculated with the density matrix renormalization group, with a special emphasis on the effect of a next-nearest neighbor hopping (t&#39;) and the nearest-neighbor ferromagnetic exchange (J) interaction. At half-filling, a significant spin gap opens if |t&#39;| \simeq |t| and J=0, in a

Avinash Khare

I consider several N-body problems for which exact (bosonic) ground state and a class of excited states are known in case the N-bodies are also interacting via harmonic oscillator potential. I show that for all these problems the exact (bosonic) ground state and a class of excited states can also be obtained in case they interact via an N-body potential of t

Henrik Bohr, Patrick McGuire, Chris Pershing, Johann Rafelski

We study the diversity of complex spatio-temporal patterns of random synchronous asymmetric neural networks (RSANNs). Specifically, we investigate the impact of noisy thresholds on network performance and find that there is a narrow and interesting region of noise parameters where RSANNs display specific features of behavior desired for rapidly `thinking&#39

Danny Yang, Wick Haxton

We present the results of a numerical study of the 2 by L spin 1/2 Heisenberg ladder. Ground state energies and the singlet-triplet energy gaps for L = (4-14) and equal rung and leg interaction strengths were obtained in a Lanczos calculation and checked against earlier calculations by Barnes et al. (even L up to 12). A related moments technique is then empl

Yoshiki Niwa, Shingo Nishioka, Makoto Iwayama, Akihiko Takano

To make an interactive guidance mechanism for document retrieval systems, we developed a user-interface which presents users the visualized map of topics at each stage of retrieval process. Topic words are automatically extracted by frequency analysis and the strength of the relationships between topic words is measured by their co-occurrence. A major factor

D. Pingel, P. Schmelcher, F. K. Diakonos

Analytical solutions to the chaotic and ergodic motion of a certain class of one-dimensional dissipative and discrete dynamical systems are derived. This allows us to obtain exact expressions for physical properties like the time correlation function. We illustrate our solutions by means of a few examples for which conventional numerical trajectory calculati

Giovanni Gallavotti

A review of some recent results and ideas about the expected behaviour of large chaotic systems and fluids.

Robert J. Nemiroff, Jay P. Norris, Jerry T. Bonnell, Gabriela F. Marani

GRBs vary more rapidly than any other known cosmological phenomena. The lower limits of this variability have not yet been explored. Improvements in detectors would reveal or limit the actual rate of short GRBs. Were microsecond &#34;spike&#34; GRBs to exist and be detectable, they would time-resolve stellar mass objects throughout the universe by their grav

Joel N. Bregman, Caroline V. Cox

Infrared emission has been detected from normal elliptical galaxies and from clusters of galaxies at 60um and 100um with the IRAS satellite. In both cases, the emission has the characteristics of cool dust with a temperature near 30K. For the elliptical galaxies, there is a correlation between the optical luminosities and the far infrared luminosities. The l

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

We use data obtained with the PCA onboard RXTE to analyze the spectral variations of the black hole candidate and superluminal source GRS 1915+105. Our results suggest that despite the complicated structure of the X-ray light curve, all spectral changes observed in this source can be explained as a sudden disappearing of the inner part of the accretion disk

G. A. Mamon, J. Borsenberger, M. Tricottet, V. Banchet

The numerous extragalactic and cosmological motivations of the DENIS and 2MASS near infrared surveys are outlined. The performance of the DENIS survey is estimated from 50 deg^2 of high galactic latitude data (20 deg < |b| < 60 deg). Simple star/galaxy separation methods are presented and comparison with 300 visually classified objects as well as COSMOS and

Pushpa Khare, S. Ikeuchi

We have analyzed high resolution data of absorption lines of Si and C in the absorption systems observed in the spectra of QSOs, in order to study the ionization state and the overabundance of Si with respect to C in the absorbers and also to study the change in these properties with redshift. No correlation is found between column density ratios of Si IV to

G. Ghisellini, F. Haardt, R. Svensson

The high energy continuum in Seyfert galaxies and galactic black hole candidates is likely to be produced by a thermal plasma. There are difficulties in understanding what can keep the plasma thermal, especially during fast variations of the emitted flux. Particle-particle collisions are too inefficient in hot and rarefied plasmas, and a faster process is ca

Halton Arp

Analysis of ROSAT observations demonstrate that X-ray sources are associated with bright Seyfert galaxies up to distances of about 40 arc min. These X-ray sources are predominantly identified with blue stellar objects (BSO&#39;s) some of which are already catalogued as quasars. The X-ray sources tend to pair and align across the nucleus of the active Seyfert

Y. C. Andredakis

Collisionless N-body simulations are used in an effort to reproduce the observed tendency of the surface brightness profile of bulges to change progressively from a de Vaucouleurs law to an exponential, going from early to late type spirals. A possible cause for this is the formation of the disc, later in the history of the galaxy, and this is simulated by a

T. P. Devereaux, A. Virosztek, A. Zawadowski, M. Opel

It is argued that the origin of the buckling of the CuO$_{2}$ planes in certain cuprates as well as the strong electron-phonon coupling of the $B_{1g}$ phonon is due to the electric field across the planes induced by atoms with different valence above and below. The magnitude of the electric field is deduced from new Raman results on YBa$_{2}$Cu$_{3}$O$_{6+x

O. Aharony, M. Berkooz, N. Seiberg

We study the (2,0) superconformal theories in six dimensions, which arise from the low-energy limit of k coincident 5-branes, using their discrete light-cone formulation as a superconformal quantum mechanical sigma model. We analyze the realization of the superconformal symmetry in the quantum mechanics, and the realization of primary operators. As an exampl

Rob Ivison, Ian Smail, J. -F. Le Borgne, A. W. Blain

We present a detailed study of SMM 02399-0136, a hyperluminous, active galaxy selected from a sub-mm survey of the distant Universe. This galaxy is the brightest source in the fields of seven rich, lensing clusters - total area 0.01 deg^2 - that we have mapped with a sensitivity of ~2 mJy/bm at 850um. We identify a compact optical counterpart with B ~ 23 and

Abhay Ashtekar, Viqar Husain

Certain features associated with the symmetry reduction of the vacuum Einstein equations by two commuting, space-like Killing vector fields are studied. In particular, the discussion encompasses the equations for the Gowdy $T^3$ cosmology and cylindrical gravitational waves. We first point out a relation between the $SL(2,R)$ (or SO(3)) $σ$ and principal chi

M. Aizenman, P. Contucci

While the Gibbs states of spin glass models have been noted to have an erratic dependence on temperature, one may expect the mean over the disorder to produce a continuously varying ``quenched state&#39;&#39;. The assumption of such continuity in temperature implies that in the infinite volume limit the state is stable under a class of deformations of the Gi

Misha Verbitsky

Given a compact hyperkaehler manifold $M$ and a holomorphic bundle B over $M$, we consider a Hermitian connection $\nabla$ on B which is compatible with all complex structures on $M$ induced by the hyperkaehler structure. Such a connection is unique, because it is Yang-Mills. We call the bundles admitting such connections hyperholomorphic bundles. A stable b

Soojong Pak, D. T. Jaffe, Ewine F. van Dishoeck, L. E. B. Johansson

The chemical structure of neutral clouds in low metallicity environments is examined with particular emphasis on the H to H_2 and C+ to CO transitions. We observed near-IR H_2 lines and the CO J=1-0 line from 30 Doradus and N159/N160 in the Large Magellanic Cloud and from DEM S 16, DEM S 37, and LI-SMC 36 in the Small Magellanic Cloud. We find that the H_2 e

E. Bergshoeff, Y. Lozano, T. Ortin

We investigate the effective worldvolume theories of branes in a background given by (the bosonic sector of) 10-dimensional massive IIA supergravity (``massive branes&#39;&#39;) and their M-theoretic origin. In the case of the solitonic 5-brane of type IIA superstring theory the construction of the Wess-Zumino term in the worldvolume action requires a dualiz

H. G. Dosch, E. Ferreira, M. Nielsen, R. Rosenfeld

We set up sum rules for heavy lambda decays in a full QCD calculation which in the heavy quark mass limit incorporates the symmetries of heavy quark effective theory. For the semileptonic $\La_c$ decay we obtain a reasonable agreement with experiment. For the $\La_b$ semileptonic decay we find at the zero recoil point a violation of the heavy quark symmetry

G. Barenboim, J. Bernabeu, M. Raidal

We study time dependent CP asymmetries in B^0_{d,s} decays in the left-right model with spontaneous breakdown of CP. Due to the new contributions to B^0-\bar B^0 mixing the CP asymmetries can be substantially modified. Moreover, there can be significant new contributions to the $B$-meson decay amplitudes from the magnetic penguins. Most promising for detecti

CLEO Collaboration, M. Chadha et al

We present a new determination of the Ds decay constant, f_{Ds} using 5 million continuum charm events obtained with the CLEO II detector. Our value is derived from our new measured ratio of widths for Ds -> mu nu/Ds -> phi pi of 0.173+/- 0.021 +/- 0.031. Taking the branching ratio for Ds -> phi pi as (3.6 +/- 0.9)% from the PDG, we extract f_{Ds} = (280 +/-

Nobuyuki Sakai, Naoshi Sugiyama, Jun&#39;ichi Yokoyama

We study the effect of a void network on the CMB anisotropy in the Einstein-de Sitter background using Thompson &Vishniac&#39;s model. We consider comprehensively the Sacks-Wolfe effect, the Rees-Sciama effect and the gravitational lensing effect. Our analysis includes the model of primordial voids existing at recombination, which is realized in some inflati

K. Golec-Biernat, L. Goerlich, J. Turnau

QCD coherence effects in initial state radiation at small x in deep inelastic scattering in HERA kinematics are studied with the help of the Monte Carlo model SMALLX. Theoretical assumptions based on the CCFM evolution equation are reviewed and the basic properties of the partonic final states are investigated. The results are compared with those obtained in

Mario Abud, Giulia Ricciardi, George Sterman

Penguin diagrams for decays such as $b\to (s,d)γ$ involve virtual loops of $u$ or other light quarks. Logarithms of the virtual quark mass could, in principle, influence the phenomenological analysis of the decay. It is thus important to study these logarithms to all orders in QCD perturbation theory. In this paper we show that, at arbitrary order, the matri

Uwe R. Fischer

In the semiclassical domain the exponent of vortex quantum tunneling is dominated by a volume which is associated with the path the vortex line traces out during its escape from the metastable well. We explicitly show the influence of geometrical quantities on this volume by describing point vortex motion in the presence of an ellipse. It is argued that for

N. E. Mavromatos, E. Winstanley

We establish the existence of hairy black holes in su(N) Einstein-Yang-Mills theories, described by N-1 parameters, corresponding to the nodes of the gauge field functions.

Tony Gherghetta

The effect of spin-0 goldstino superpartners is considered on the nucleosynthesis bounds arising when a superlight gravitino appears as an effective massless neutrino species. When the scalar and pseudoscalar superpartners are relativistic they will decouple at much later times than the goldstino and consequently will be the dominant effect when obtaining a

Pascal Cedraschi, Markus Buttiker

We investigate an ensemble of systems formed by a ring enclosing a magnetic flux. The ring is coupled to a side stub via a tunneling junction and via Coulomb interaction. We generalize the notion of level hybridization due to the hopping, which is naturally defined only for one-particle problems, to the many-particle case, and we discuss the competition betw

K. Scharnhorst

4x4 Dirac (gamma) matrices (irreducible matrix representations of the Clifford algebras C(3,1), C(1,3), C(4,0)) are an essential part of many calculations in quantum physics. Although the final physical results do not depend on the applied representation of the Dirac matrices (e.g. due to the invariance of traces of products of Dirac matrices), the appropria

Michiyasu NAGASAWA

The damping of the axionic string motion due to the surrounding plasma is estimated by a detailed calculation of the fermion scatter from a global string and it is shown that the friction force on the string can be neglected before the axionic domain wall formation in most cases, which is one of the important necessary conditions for the scaling distribution

T. Tsuchiya

Cold collapse of a cluster composed of small identical clumps, each of which is in virial equilibrium, is considered. Since the clumps have no relative motion with respect to each other initially, the cluster collapses by its gravity. At the first collapse of the cluster, most of the clumps are destroyed, but some survive. In order to find the condition for

M. Jimbo, H. Konno, S. Odake, J. Shiraishi

The Yang-Baxter equation admits two classes of elliptic solutions, the vertex type and the face type. On the basis of these solutions, two types of elliptic quantum groups have been introduced (Foda et al., Felder). Fronsdal made a penetrating observation that both of them are quasi-Hopf algebras, obtained by twisting the standard quantum affine algebra U_q(

L. Frankfurt, V. Guzey, M. Strikman

We explain that the generalized vector meson dominance (GVMD) model is successful in describing hard high energy processes because it contains expected in QCD Color Coherent Phenomena. Within the model, which reproduces Bjorken scaling and nuclear shadowing for deep inelastic processes, we calculate $P_γ(σ,Q^2)$, the probability for the photon to interact wi

Z. Maassarani

A class of recently introduced multi-states XX models is generalized to include a deformation parameter. This corresponds to an additional nearest-neighbor CC interaction in the defining quadratic hamiltonian. Complete integrability of the one-dimensional models is shown in the context of the quantum inverse scattering method. The new R-matrix is derived. Th

H. -J. Briegel, W. Dür, S. J. van Enk, J. I. Cirac

We show how to create maximally entangled EPR pairs between spatially distant atoms, each of them inside a high-Q optical cavity, by sending photons through a general, noisy channel, such as a standard optical fiber. An error correction scheme that uses few auxiliary atoms in each cavity effectively eliminates photoabsorption and other transmission errors. T

A. Verçin

It has been shown that the Cartan subalgebra of $W_{\infty}$- algebra is the space of the two-variable, definite-parity polynomials. Explicit expressions of these polynomials, and their basic properties are presented. Also has been shown that they carry the infinite dimensional irreducible representation of the $su(1,1)$ algebra having the spectrum bounded f

Paul Cockshott

The approach given by Grover can be generalised to set an upper complexity limit to the basic operations of relational algebra on a quantum computer. Except in special cases where indices can be used on a classical machine, the quantum upper complexity limit is lower than the classical one.

Anthony Giaquinto, Timothy J. Hodges

Explicit solutions of the quantum Yang-Baxter equation are given corresponding to the non-unitary solutions of the classical Yang-Baxter equation for sl(5).

Pavel Etingof, Shlomo Gelaki

Kaplansky conjectured that if H is a finite-dimensional semisimple Hopf algebra over an algebraically closed field k of characteristic 0, then H is of Frobenius type (i.e. if V is an irreducible representation of H then dimV divides dimH). It was proved by Montgomery and Witherspoon that the conjecture is true for H of dimension p^n, p prime, and by Nichols

Reinhard Häring-Oldenburg

A Potts model with a reflecting boundary is introduced and it is shown that its partition function can be expressed as a Markov trace on the Temperley-Lieb Algebra of Coxeter type B.

Reinhard H&#34;aring-Oldenburg

Categorial actions of braided tensor categories are defined and shown to be the right framework for a discussion of the categorial structure related to the group of braids in the cylinder. A Kauffman polynomial of links in the solid torus is constructed.

Reinhard Häring-Oldenburg

We introduce an Ariki-Koike like extension of the Birman-Murakami-Wenzl Algebra and show it to be semi-simple. This algebra supports a faithful Markov trace that gives rise to link invariants of closures of Coxeter type B braids.

Valeriy N. Tolstoy

We discuss two-parameter deformations of an universal enveloping algebra $U(g[u])$ of a polynomial loop algebra $g[u]$, where $g$ is a finite-dimensional complex simple Lie algebra (or superalgebra). These deformations are Hopf algebras. One deformation called Drinfeldian is a quantization of $U(g[u])$ in the direction of a classical r-matrix which is a sum

Margit Rösler

For a finite reflection group on $\b R^N,$ the associated Dunkl operators are parametrized first-order differential-difference operators which generalize the usual partial derivatives. They generate a commutative algebra which is - under weak assumptions - intertwined with the algebra of partial differential operators by a unique linear and homogeneous isomo

Roy Maartens, David Taylor

We define affine transport lifts on the tangent bundle by associating a transport rule for tangent vectors with a vector field on the base manifold. The aim is to develop tools for the study of kinetic/ dynamical symmetries in relativistic particle motion. The transport lift unifies and generalises the various existing lifted vector fields, with clear geomet

A. Krueger, W. Gloeckle

It is shown that the ten generators of the Poincare group acting in the Fock space of nucleons and mesons and based on standard Lagrangians can be blockdiagonalized by one and the same unitary transformation such that the space of a fixed number of nucleons is separated from the rest of the Fock space. The existence proof is carried through in a formal power

H. Kowata, M. Arima, K. Masutani

The mass spectra of nucleon resonances with spin 1/2, 3/2, and 5/2 are systematically studied in the constituent quark model with meson-quark coupling, which is inspired by the spontaneous breaking of chiral symmetry of QCD. The meson-quark coupling gives rise not only to the one-meson-exchange potential between quarks but also to the self-energy of baryon r

V. Yu. Ponomarev, C. A. Bertulani, A. V. Sushkov

We report on the first microscopic study of the properties of two-phonon giant resonances in deformed nuclei. The cross sections of the excitation of the giant dipole and the double giant dipole resonances in relativistic heavy ion collisions are calculated. We predict that the double giant dipole resonance has a one-bump structure with a centroid 0.8 MeV hi

Ye. S. Golubeva, L. A. Kondratyuk, A. Bianconi, S. Boffi

The problem of nuclear propagation through the nuclear medium in quasielastic A(e,e&#39;p) reactions is discussed in the kinematic range 1<Q^2<7 (GeV/c)^2. The coefficient of nuclear transparency is calculated for each Q^2 in the framework of the intranuclear cascade model (INC) and of the eikonal approximation (EA). The predictions of both models are in goo

S. Marcos, R. J. Lombard, J. Mares

We calculate the binding energy of two $Λ$ hyperons bound to a nuclear core within the relativistic mean field theory. The starting point is a two-body relativistic equation of the Breit type suggested by the RMFT, and corrected for the two-particle interaction. We evaluate the 2 $Λ$ correlation energy and estimate the contribution of the $σ^*$ and $Φ$ meson

C. A. Ur, D. Bucurescu, S. M. Lenzi, G. Martinez-Pinedo

Excited states in 52Fe have been determined up to spin 10\hbar in the reaction 28Si + 28Si at 115 MeV by using γ-ray spectroscopy methods at the GASP array. The excitation energy of the yrast 10+ state has been determined to be 7.381 MeV, almost 0.5 MeV above the well known β+-decaying yrast 12+ state, definitely confirming the nature of its isomeric charact

A. Wagner, C. Müntz, H. Oeschler, C. Sturm

Double differential production cross sections of negative and positive pions and the number of participating protons have been measured in central Au+Au collisions at 1 GeV per nucleon incident energy. At low pion energies the pi^- yield is strongly enhanced over the pi^+ yield. The energy dependence of the pi^-/pi^+ ratio is assigned to the Coulomb interact

Ross Willard

We derive a Mal&#39;cev condition for congruence meet-semidistributivity and then use it to prove two theorems. Theorem A: if a variety in a finite language is congruence meet-semidistributive and residually less than some finite cardinal, then it is finitely based. Theorem B: there is an algorithm which, given m<w and a finite algebra in a finite language,

Mathieu Meyer, Elisabeth Werner

We give geometric interpretations of certain affine invariants of convex bodies. The affine invariants are the p-affine surface areas introduced by Lutwak. The geometric interpretations involve generalizations of the Santaló-bodies introduced by the authors in a previous paper.

Markus Fulmek, Christian Krattenthaler

We compute the number of rhombus tilings of a hexagon with sides $N,M,N,N,M,N$, which contain a fixed rhombus on the symmetry axis that cuts through the sides of length $M$.

Jens Mund

We show that a quantum field theoretic model of anyons cannot be ``free&#39;&#39; in the (restrictive) sense that the basic fields create only one-particle states out of the vacuum.

Mirjam Cvetic, Finn Larsen

We compute the emission spectrum of minimally coupled particles with spin that are Hawking radiated from four dimensional black holes in string theory. For a range of the black hole parameters the result has a product structure that may be interpreted in terms of the respective right- and left-moving thermal correlation functions of an effective string model

Peter Cho

The low energy structures of N=1 supersymmetric models with E_6, F_4 and E_7 gauge groups and fundamental irrep matter contents are studied herein. We identify sets of gauge invariant composites which label all flat directions in the confining/Higgs phases of these theories. The impossibility of mapping several of these primary operators rules out previously

D. V. Antonov

The one-loop free energy of the four-dimensional compact QED, which is known to be equivalent to the vector Sine-Gordon model, is calculated in the strong coupling regime. In the case, when the norm of the strength tensor of the saddle-point value of the corresponding Sine-Gordon model is much larger than the typical inverse area of a loop in the gas of the

A. Chamblin, M. J. Perry

In this paper we perform a detailed investigation of the Dirichlet eight-brane of the Type IIA string theory, when the effects of gravity are included. In particular, consider what happens when one allows the ten-form field strength $F_{10}$ to vary discontinuously across the worldvolume of the brane. Since the ten-form is constant on each side of the brane

G. Delfino, J. L. Cardy

We consider the scaling limit of the two-dimensional $q$-state Potts model for $q\leq 4$. We use the exact scattering theory proposed by Chim and Zamolodchikov to determine the one and two-kink form factors of the energy, order and disorder operators in the model. Correlation functions and universal combinations of critical amplitudes are then computed withi

G. Bertoldi, M. Matone

We derive a new set of WDVV equations for N=2 SYM in which the renormalization scale $Λ$ is identified with the distinguished modulus which naturally arises in topological field theories.

Alfredo T. Suzuki, Alexandre G. M. Schmidt

Negative dimensional integration is a step further dimensional regularization ideas. In this approach, based on the principle of analytic continuation, Feynman integrals are polynomial ones and for this reason very simple to handle, contrary to the usual parametric ones. The result of the integral worked out in $D<0$ must be analytically continued again ---

D. V. Antonov

String representations of the Wilson loop and of the non-Abelian analog of the &#39;t Hooft loop, defined on the string world-sheet, are studied in the Londons&#39; limit of the 4D Georgi-Glashow model. In the first case, massive gauge bosons yield only perimeter type terms, whereas in the second case, they also interact with the string, which enables one to

W. T. Giele, E. W. N. Glover

Conventional jet algorithms are based on a deterministic view of the underlying hard scattering process. Each outgoing parton from the hard scattering is associated with a hard, well separated jet. This approach is very successful because it allows quantitative predictions using lowest order perturbation theory. However, beyond leading order in the coupling

G. Moortgat-Pick, H. Fraas

We study the process e^{-}e^{+} \to \tildeχ^0_1\tildeχ^0_2 with the subsequent decay \tildeχ^0_2 \to \tildeχ^0_1 \ell^{+}\ell^{-} taking into account the complete spin correlations between production and decay. We present numerical results for the lepton angular distribution and the distribution of the opening angle between the outgoing leptons for \sqrt{s}=