December 1996 arXiv papers — page 3

A. Bottino, F. Donato, G. Mignola, S. Scopel

It is shown that the new data of the DAMA/NaI detector, combined with recent calculations of nuclear structure functions, provide the most stringent upper bounds on the WIMP-nucleon cross-section both for spin-dependent and for scalar interactions. It is proved that, for the first time, data from an experiment of direct search for WIMPs allow the exploration

R. Baier, M. Dirks, K. Redlich

The production of soft dileptons in a thermal mesonic medium is discussed in the context of recent CERN experimental data reported by the CERES Collaboration. We do not intend to give a general and critical review, but instead concentrate mainly on our approach, however, incorporating many of the recent attempts in the literature. We calculate the contributi

R. M. Trigub

This manuscript presents shortly the results obtained by participants of the scientific seminar which is held more than twenty years under leadership of the author at Donetsk University. In the list of references main publications are given. These results are published in serious scientific journals and reported at various conferences, including internationa

D. Guido, T. Isola

A trace on the C^*-algebra A of quasi-local operators on an open manifold is described, based on the results in \cite{RoeOpen}. It allows a description `a la Novikov-Shubin \cite{NS2} of the low frequency behavior of the Laplace-Beltrami operator. The 0-th Novikov-Shubin invariant defined in terms of such a trace is proved to coincide with a metric invariant

A. N. Samukhin, V. N. Prigodin, L. Jastrabik, ;

A random hopping on a fractal network with dimension slightly above one, $d = 1 + ε$, is considered as a model of transport for conducting polymers with nonmetallic conductivity. Within the real space renormalization group method of Migdal and Kadanoff, the critical behavior near the percolation threshold is studied. In contrast to a conventional regular exp

H. A. Fertig, L. Brey, R. Cote, A. H. MacDonald

We report on a study of the charged-skyrmion or spin-texture excitations which occur in quantum Hall ferromagnets near odd Landau level filling factors. Particle-hole symmetry is used to relate the spin-quantum numbers of charged particle and hole excitations and neutral particle-hole pair excitations. Hartree-Fock theory is used to provide quantitative esti

Hsuan-Yi Chen, Yadin Y. Goldschmidt

In this paper we carry out Quantum Monte Carlo simulations of a quantum particle in a one-dimensional random potential (plus a fixed harmonic potential) at a finite temperature. This is the simplest model of an interface in a disordered medium and may also pertain to an electron in a dirty metal. We compare with previous analytical results, and also derive a

D. V. Khveshchenko, M. Reizer

We study the principal aspects of the interaction between acoustic phonons and two-dimensional electrons in quantizing magnetic fields corresponding to even denominator fractions. Using the composite fermion approach we derive the vertex of the electron-phonon coupling mediated by the Chern-Simons gauge field. We estimate acoustic phonon contribution to elec

Denis Yu. Irz

The Coulomb gas partition sum is rewritten in terms of the path integrals formalism. It is shown that perturbation theories based on the Mayer expansion and on the path integrals method lead to the identical results. The well known Debye-Hukkel result for the case of 3D Coulomb plasma is completely rederived. An analogous result is obtained for the case of t

S. T. Chui, V. N. Ryzhov

We show that many two dimensional domain patterns observed in Monte Carlo simulations can be obtained from the many soliton solutions of the imaginary time Sine Gordon equation. This opens the door to analytic physical understanding of the micromagnetics in ultra-thin films.

G. Wellein, H. Fehske, H. Büttner, A. R. Bishop

We investigate the interplay of electron-phonon (EP) coupling and strong electronic correlations in the frame of the two-dimensional (2D) Holstein t-J model (HtJM), focusing on polaronic ordering phenomena for the quarter-filled band case. The use of direct Lanczos diagonalization on finite lattices allows us to include the effects of quantum phonon fluctuat

H. Fehske, G. Wellein, B. Bäuml, R. N. Silver

Employing the Lanczos algorithm in combination with a kernel polynomial moment expansion (KPM) and the maximum entropy method (MEM), we show a way of calculating charge and spin excitations in the Holstein t-J model, including the full quantum nature of phonons. To analyze polaron band formation we evaluate the hole spectral function for a wide range of elec

D. Errandonea, A. Segura, J. F. Sánchez-Royo, V. Muñoz

In this work we report on Hall effect, resistivity and thermopower measurements in n-type indium selenide at room temperature under either hydrostatic and quasi-hydrostatic pressure. Up to 40 kbar (= 4 GPa), the decrease of carrier concentration as the pressure increases is explained through the existence of a subsidiary minimum in the conduction band. This

L. Swierkowski, A. H. MacDonald

The subbands of weakly coupled double-layer two dimensional electron gas systems consist of narrowly spaced pairs whose corresponding wavefunctions are symmetric and antisymmetric combinations of isolated layer subband wavefunctions. The energetic spacing within a pair is 2t where t is the interlayer tunneling amplitude. t is an important parameter in modeli

M. Houbiers, H. T. C. Stoof, E. A. Cornell

We investigate the possibilities of distinguishing the mean-field and fluctuation effects on the critical temperature of a trapped Bose gas with repulsive interatomic interactions. Since in a direct measurement of the critical temperature as a function of the number of trapped atoms these effects are small compared to the ideal gas results, we propose to obs

M. Rossi, S. Le Dizes

The three-dimensional stability problem of a stretched stationary vortex is addressed in this letter. More specifically, we prove that the discrete part of the temporal spectrum is only associated with two-dimensional perturbations.

A. M. Khokhlov, E. S. Oran, J. Craig Wheeler

We derive the criteria for deflagration to detonation transition (DDT) in a Type Ia supernova. The theory is based on the two major assumptions: (i) detonation is triggered via the Zeldovich gradient mechanism inside a region of mixed fuel and products, (ii) the mixed region is produced by a turbulent mixing of fuel and products either inside an active defla

E. Athanassoula, J. Makino, A. Bosma

We discuss the merging rates in compact groups of 5 identical elliptical galaxies. All groups have the same mass and binding energy. We consider both cases with individual halos and cases where the halo is common to all galaxies and enveloping the whole group. In the latter situation the merging rate is slower if the halo is more massive. The mass of individ

Wolfgang Keil, Hans-Thomas Janka, David N. Schramm, Guenter Sigl

We re-examine the very stringent limits on the axion mass based on the strength and duration of the neutrino signal from SN 1987A, in the light of new measurements of the axial-vector coupling strength of nucleons, possible suppression of axion emission due to many-body effects, and additional emission processes involving pions. The suppression of axion emis

Donald A. Smith, Edward H. Morgan, Hale Bradt

A highly coherent 523.92+-0.05 Hz periodic X-ray signal has been observed during a type I X-ray burst from the low-mass X-ray binary system KS 1731-260 with the PCA on RXTE. The spectral evolution of the burst indicates photospheric-radius expansion and contraction. The 524 Hz signal occurred at the end of the contraction phase, lasted for ~2 s, was highly c

Jose' P. S. Lemos

We present a broad review on black holes. We analyse some of the fundamental concepts in black hole theory, the observational and theoretical status of stellar and galactic black holes, and their appearance as quantum objects.

D. Sasselov, J. P. Beaulieu

We examine the overall consistency of the primary distance indicators and ways for a satisfactory resolution of the Cepheid-RR Lyrae zero point discrepancy.

Sourov Roy, Biswarup Mukhopadhyaya

We investigate a supersymmetric scenario where R-parity is explicitly broken through a term bilinear in the lepton and Higgs superfields in the superpotential. We show that keeping such a term alone can lead to trilinear interactions, similar to those that are parametrized by $λ$-and $λ'$ in the literature, involving the physical fields. The upper limits

E. A. Kolganova, A. K. Motovilov, S. A. Sofianos

We present a mathematically rigorous method suitable for solving three-body bound state and scattering problems when the inter-particle interaction is of a hard-core nature. The proposed method is a variant of the Boundary Condition Model and it has been employed to calculate the binding energies for a system consisting of three ^4He atoms. Two realistic He-

J. Terasaki, H. Flocard, P. -H. Heenen, P. Bonche

We perform the Hartree-Fock-Bogoliubov (HFB) calculations for ground states of even Mg isotopes using the Skyrme force and a density-dependent zero-range pairing force. The HFB equation is solved in a three-dimensional cartesian mesh, and a convergence of deformation is carefully examined with respect to a cut-off radius for a check of the calculations. We d

Miao Li

D-string action is constructed from IIB matrices, a spacetime commutator is essential in this construction. This hints at the central role of the spacetime uncertainty relation in a unified formulation of strings. Vertex operators of fundamental strings are also discussed.

Markus J. Pflaum, Peter Schauenburg

We introduce a category of noncommutative bundles. To establish geometry in this category we construct suitable noncommutative differential calculi on these bundles and study their basic properties. Furthermore we define the notion of a connection with respect to a differential calculus and consider questions of existence and uniqueness. At the end these con

Alexander I. Titov, Shin Nan Yang, Yongseok Oh

We analyze the process $e p \to e p ϕ$ near the threshold within $uud - s\bar s$ cluster model as a probe of the strangeness content of proton. Our consideration is based on the relativistic harmonic oscillator quark model which takes into account the Lorentz-contraction effect of the hadron wavefunctions. We find that the knockout mechanisms are comparable

Gilad Lifschytz

We discuss the proposed description of configurations with four-branes and six-branes in m(atrix) theory. Computing the velocity dependent potential between these configurations and gravitons and membranes, we show that they agree with the short distance string results computed in type IIa string theory. Due to the ``closeness'' of these configuratio

E. Sezgin

We present the chiral truncation of the eleven dimensional M-algebra down to ten and six dimensions. In ten dimensions, we obtain a topological extension of the $(1,0)$ Poincaré superalgebra that includes super one-form and super five-form charges. Closed super three- and seven-forms associated with this algebra are constructed. In six dimensions, we obtain

Robert Fleischer

The phenomenon of CP violation in the B system and strategies for extracting CKM phases are reviewed. We focus both on general aspects and on some recent developments including CP-violating asymmetries in B_d decays, the B_s system in light of a possible width difference $ΔΓ_s$, charged B decays, and SU(3) relations among certain transition amplitudes. In or

J. P. Beaulieu, D. D. Sasselov

We present a differential study of 500 Magellanic Cepheids with 3 million measurements obtained as a by-product of the EROS microlensing survey. The data-set is unbiased and provides an excellent basis for a differential analysis between LMC and SMC. We investigate the pulsational properties of the Cepheids as a function of metallicity and the constraints th

D. D. Sasselov, J. P. Beaulieu, C. Renault, P. Grison

This is an investigation of the period-luminosity relation of classical Cepheids in samples of different metallicity. It is based on 481 Cepheids in the Large and Small Magellanic Clouds from the blue and red filter CCD observations (most similar to V_J & R_J) of the French EROS microlensing project. The data-set is complete and provides an excellent basis f

J. P. Beaulieu, D. D. Sasselov, C. Renault, P. Grison

Recent HST determinations of the expansion's rate of the Universe (the Hubble constant, H_0) assumed that the Cepheid Period-Luminosity relation at V and I are independent of metallicity (Freedman, et al., 1996, Saha et al., 1996, Tanvir et al., 1995). The three groups obtain different vales for H_0. We note that most of this discrepancy stems from the a

Samar Abbas, Afsar Abbas

The passage of the Earth through dense clumps of dark matter, the presence of which are predicted by certain cosmologies, would produce large quantities of heat in the interior of this planet through the capture and subsequent annihilation of dark matter particles. This heat can cause large-scale volcanism which could in turn have caused the extinction of th

R. J. Protheroe

I give a brief critical review of the predicted intensity of diffuse high energy neutrinos of astrophysical origin over the energy range from 10^12 eV to 10^24 eV. Neutrinos from interactions of galactic cosmic rays with interstellar matter are guaranteed, and the intensity can be reliably predicted to within a factor of about 2 up to 10^17 eV. Somewhat less

R. J. Protheroe

In this lecture I give an overview of shock acceleration, interactions of high energy cosmic rays with, and propagation through, the background radiation, and the resulting electron-photon cascade. I argue that while the origin of the highest energy cosmic rays is still uncertain, it is not necessary to invoke exotic models such as emission by topological de

W. Bednarek, R. J. Protheroe

We have developed a model for the variability of gamma ray emission in jets of active galactic nuclei in which the variability arises as a result of photon-photon pair production interactions with X-rays emitted by a hot spot in the inner part of the accretion disk. As the hot spot orbits around the central engine, the amount of absorption varies periodicall

Aparna Venkatesan, M. Coleman Miller, Angela V. Olinto

The energetics, spectrum, and composition of cosmic rays with energies below about $10^{15}$ eV are fairly well explained by models involving supernova shocks. In contrast, no widely accepted theory exists for the origin of ultra-high energy cosmic rays (UHECRs), which have energies above $10^{15}$ eV. Instead of proposing a specific model, here we place str

Hugo Garcia-Compean, Jerzy F. Plebanski

We show how the reduced Self-dual Yang-Mills theory described by the Nahm equations can be carried over to the Weyl-Wigner-Moyal formalism employed recently in Self-dual gravity. Evidence of the existence of correspondence between BPS magnetic monopoles and space-time hyper-Kähler metrics is given.

John N. Bahcall, Xuelei Chen, Marc Kamionkowski

We test the Salpeter formalism for the electron screening of the solar proton-proton fusion reaction by solving numerically the relevant Schrodinger equation. We evaluate exactly the square of the overlap integral of the two-proton wave function and the deuteron wave function and compare with the usual analytic approximation. The usual WKB solution agrees wi

Morimitsu Tanimoto

We predict CP violation in the long baseline accelerator experiments taking into consideration the recent LSND data and the atmospheric neutrino data. The estimated upper bound of CP violation is 0.006, which may be observable in the long baseline accelerator experiments. It is found that the upper bound increases to 0.01 if the LSND data is excluded. The ma

Jan Bischoff, Olaf Lechtenfeld

A complete treatment of the (2,2) NSR string in flat (2+2) dimensional space-time is given, from the formal path integral over N=2 super Riemann surfaces to the computational recipe for amplitudes at any loop or gauge instanton number. We perform in detail the superconformal gauge fixing, discuss the spectral flow, and analyze the supermoduli space with emph

Helge Dennhardt, Olaf Lechtenfeld

We construct two solutions of the minimally coupled Einstein-scalar field equations, representing regular deformations of Schwarzschild black holes by a self-interacting, static, scalar field. One solution features an exponentially decaying scalar field and a triple-well interaction potential; the other one is completely analytic and sprouts Coulomb-like sca

Marcello Ciafaloni

I argue that the first-order formalism recently found to describe classical 2+1-Gravity with matter, is also able to include higher topologies. The present gauge, which is conformal with vanishing York time, is characterized by an analytic mapping from single-valued coordinates to Minkowskian ones. In the torus case, this mapping is based on four square-root

Hitoshi Ito

A relativistic equation is deduced for the bound state of two particles, by assuming a proper boundary condition for the propagation of the negative-energy states. It reduces to the (one-body)Dirac equation in the infinite limit of one of the constituent mass. It also has the symmetries to assure the existence of the anti-bound-state with the same mass. The

Anatoly D. Adamov, Gary R. Goldstein

The perturbative QCD calculation of heavy quark fragmentation into a heavy meson is extended to predict fragmentation into heavy flavor baryons. This is accomplished by implementing the quark-diquark model of the baryons. Several diquark form factors are used to enable the integration over the virtual heavy quark momentum. The resulting spin independent func

P. Binetruy, N. Irges, S. Lavignac, P. Ramond

In models with an anomalous abelian symmetry broken at a very large scale, we study which requirements to impose on the anomalous charges in order to prevent standard model fields from acquiring large vacuum expectation values. The use of holomorphic invariants to study D-flat directions for the anomalous symmetry, proves to be a very powerful tool. We find

The MILC Collaboration, C. W. Bernard, T. Blum, C. Detar

We calculate the two flavor equation of state for QCD on lattices with lattice spacing a=(6T)^{-1} and find that cutoff effects are substantially reduced compared to an earlier study using a=(4T)^{-1}. However, it is likely that significant cutoff effects remain. We fit the lattice data to expected forms of the free energy density for a second order phase tr

Tony Rothman, Peter Anninos

We attempt to find a function that characterizes gravitational clumping and that increases monotonically as inhomogeneity increases. We choose $S = lnΩ$ as the candidate ``gravitational entropy'' function, where $Ω$ is the phase-space volume below the Hamiltonian H of the system under consideration. We compute $Ω$ for transverse electromagnetic waves

C. B. Muratov

The dynamics of the domains is studied in a two-dimensional model of the microphase separation of diblock copolymers in the vicinity of the transition. A criterion for the validity of the mean field theory is derived. It is shown that at certain temperatures the ordered hexagonal pattern becomes unstable with respect to the two types of instabilities: the ra

The MACHO Collaboration, D. P. Bennett, C. Alcock, R. A. Allsman

We present the lightcurves of two microlensing events from the MACHO Project data that are likely to be due to lenses with masses similar to Jupiter's mass. Although the MACHO Project survey data are not sufficient to definitively establish the identification of planetary mass lenses in these cases, observations by microlensing follow-up networks such as

Roman Scoccimarro

We consider one-loop corrections to the bispectrum and skewness of cosmological density fluctuations induced by gravitational evolution. As has been established by comparison with numerical simulations, tree-level perturbation theory (PT) describes these quantities at the largest scales. One-loop PT provides a tool to probe the transition to the non-linear r

Alexander Unzicker

In the present paper a geometrization of electrodynamics is proposed which makes use of a generalization of Riemannian geometry considered already by Einstein and Cartan in the 20ies. Cartan's differential forms description of a teleparallel space-time with torsion is modified by introducing distortion 1-forms which correspond to the distortion tensor in

Vipul Periwal

Crossing symmetry appears in Dbrane-anti-Dbrane dynamics in the form of an analytic continuation from U(N) for N brane amplitudes to U(N-p,p) for the interactions of N-p branes with p anti-branes. I consider the consequences for supersymmetry and brane-anti-brane forces.

L. Rozansky, E. Witten

We study a 3-dimensional topological sigma-model, whose target space is a hyper-Kahler manifold X. A Feynman diagram calculation of its partition function demonstrates that it is a finite type invariant of 3-manifolds which is similar in structure to those appearing in the perturbative calculation of the Chern-Simons partition function. The sigma-model sugge

Christian Wieczerkowski

We formulate a renormalized running coupling expansion for the $β$--function and the potential of the renormalized $ϕ^4$--trajectory on four dimensional Euclidean space-time. Renormalization invariance is used as a first principle. No reference is made to bare quantities. The expansion is proved to be finite to all orders of perturbation theory. The proof in

Zhen Yun Fang, G. Lopez Castro, J. L. Lucio, J. Pestieau

We assume the stability of vacuum under radiative corrections in the context of the standard electroweak theory. We find that this theory behaves as a good effective model already at cut off energy scales as low as 0.7 TeV. This stability criterion allows to predict m_H= 318 +- 13 GeV for the Higgs boson mass.

Mario Paschke, Andrzej Sitarz

We classify 0-dimensional spectral triples over complex and real algebras and provide some general statements about their differential structure. We investigate also whether such spectral triples admit a symmetry arising from the Hopf algebra structure of the finite algebra. We discuss examples of commutative algebras and groups algebras.

Neil Cornish, Gary Gibbons

We study motion in the field of two fixed centres described by a family of Einstein-dilaton-Maxwell theories. Transitions between regular and chaotic motion are observed as the dilaton coupling is varied.

G. R. Schreiber

A generalised integer S Ising spin glass model is analysed using the replica formalism. The bilinear couplings are assumed to have a Gaussian distribution with ferromagnetic mean <J_ij> = Jo. Incorporation of a quadrupolar interaction term and a chemical potential leads to a richer phase diagram with transitions of first and second order. The first order tra

Takeshi Kawachi

This treats the base-point-freeness of the adjoint bundles on normal surfaces with a boundary. This is an extension of the non-relative version of the theorem of Ein-Lazarsfeld-Masek and the theorem of Kawachi-Masek.

Masaki Oshikawa, Ian Affleck

We study the critical two-dimensional Ising model with a defect line (altered bond strength along a line) in the continuum limit. By folding the system at the defect line, the problem is mapped to a special case of the critical Ashkin-Teller model, the continuum limit of which is the $Z_2$ orbifold of the free boson, with a boundary. Possible boundary states

A. Hart, O. Philipsen, J. D. Stack, M. Teper

The phase diagram is investigated for SU(2) lattice gauge theory in d=3, coupled to adjoint scalars. For small values of the quartic scalar coupling, lambda, the transition separating Higgs and confinement phases is found to be first-order, in agreement with earlier work by Nadkarni. The surface of second-order transitions conjectured by Nadkarni, however, i

Werner Krauth

In these lectures, given in &#39;96 summer schools in Beg-Rohu (France) and Budapest, I discuss the fundamental principles of thermodynamic and dynamic Monte Carlo methods in a simple light-weight fashion. The keywords are MARKOV CHAINS, SAMPLING, DETAILED BALANCE, A PRIORI PROBABILITIES, REJECTIONS, ERGODICITY, &#34;FASTER THAN THE CLOCK ALGORITHMS&#34;. Th

Y. Brihaye, S. Giller, P. Kosinski, J. Nuyts

The set of linear, differential operators preserving the vector space of couples of polynomials of degrees n and n-2 in one real variable leads to an abstract associative graded algebra A(2). The irreducible, finite dimensional representations of this algebra are classified into five infinite discrete sets and one exceptional case. Their matrix elements are

J. Dittrich, V. I. Inozemtsev

The spectrum of finite-difference two-magnon operator is investigated for quantum S=1/2 chain with variable range exchange of the form $h(j-k)\propto \sinh^{-2}a(j-k)$. It is found that usual bound state appears for some values of the total pseudomomentum of two magnons as for the Heisenberg chain with nearest-neighbor spin interaction. Besides this state, a

G. A. Kotel&#39;nikov

An algorithm is proposed for research into the symmetrical properties of theoretical and mathematical physics equations. The application of this algorithm to the free Schrodinger equation permited us to establish that in addition to the known Galilei symmetry, the free Schrodinger equation possesses also the relativistic symmetry in some generalized sense. T

Richard Cleve

We show that within any quantum stabilizer code there lurks a classical binary linear code with similar error-correcting capabilities, thereby demonstrating new connections between quantum codes and classical codes. Using this result -- which applies to degenerate as well as nondegenerate codes -- previously established necessary conditions for classical lin

Zong-Chao Yan, A. Dalgarno, J. F. Babb

The long-range interactions of two atoms, of an atom and a dielectric wall, of an atom and a perfectly conducting wall, and of an atom between two perfectly conducting walls are calculated, including the effects of retardation, for Li using dynamic polarizabilities determined from highly correlated, variationally determined wave functions.

J. -P. Eckmann, C. E. Wayne, P. Wittwer

In this paper we describe invariant geometrical ~structures in the phase space of the Swift-Hohenberg equation in a neighborhood of its periodic stationary states. We show that in spite of the fact that these states are only marginally stable (i.e., the linearized problem about these states has continuous spectrum extending all the way up to zero), there exi

O. Hanstein, D. Drechsel, L. Tiator

We give predictions for the partial wave amplitudes of pion photoproduction near threshold by means of dispersion relations at fixed t. The free parameters of this approach are determined by a fit to experimental data in the energy range 160 MeV $\le E_γ \le$ 420 MeV. The observables near threshold are found to be rather sensitive to the amplitudes in the re

F. M. Steffens, A. W. Thomas

We re-examine the effects of anti-symmetry on the anti-quarks in the nucleon sea arising from gluon exchange and pion exchange between confined quarks. While the effect is primarily to suppress anti-down relative to anti-up quarks, this is numerically insignificant for the pion terms.

Martin Bridson

It is shown that there exist infinitely many non-integers $r>2$ such that the Dehn function of some finitely presented group is $\simeq n^r$. For each positive rational number $s$ we construct pairs of finitely presented groups $H\subset G$ such that the distortion of $H$ in $G$ is $\simeq n^s$. And for each $s\ge 1$ we also construct finitely presented grou

D. Bernard, Z. Maassarani, P. Mathieu

A new action of the Yangians in the WZW models is displayed. Its structure is generic and level independent. This Yangian is the natural extension at the conformal point of the one unravelled in massive theories with current algebras. Expectingly, this new symmetry of WZW models will lead to a deeper understanding of the integrable structure of conformal fie

Bjørn Jensen, Ulf Lindström

Using an ``action at a distance&#39;&#39; formulation we probe the possible classical interactions for tensionless strings, (the $T\to 0$ limit of the ordinary bosonic string.) We find $G_{μν}$ and $B_{μν}$ type interactions but no dilaton interactions.

Rudolf A. Frick

We consider a particular 4-dimensional generalization of the transition from the Heisenberg to the Schrödinger picture. The space-time independent expansion with respect to the unitary irreducible representations of the Lorentz group is applied, as Fourier transformation in the Heisenberg picture, to the states of a massive relativistic particle. A new Hamil

V. B. Kopeliovich, B. E. Stern

The consideration of the bound skyrmions with large strangeness content is continued. The connection between B=2 SO(3)-hedgehog and SU(2)-torus is investigated and the quantization of the dipole- type configuration with large strangeness content is described.

Michel Bauer, Denis Bernard

Using the coset construction, we compute the root multiplicities at level three for some hyperbolic Kac-Moody algebras including the basic hyperbolic extension of $A_1^{(1)}$ and $E_{10}$.

Mauri Miettinen

We give a new interpretation for the super loop space that has been used to formulate supersymmetry. The fermionic coordinates in the super loop space are identified as the odd generators of the Weil algebra. Their bosonic superpartners are the auxiliary fields. The general N=1 supermultiplet is interpreted in terms of Weil algebras. As specific examples we

C. Glenn Boyd, Ming Lu, Martin J. Savage

We discuss the SU(3) and heavy quark spin-symmetry breaking mixing between the Xi_c and Xi&#39;_c charmed baryons. Chromomagnetic hyperfine interactions are the leading source of spin-symmetry breaking and together with the SU(3) breaking mass differences between the lightest pseudo-Goldstone bosons gives the leading contribution to the mixing. Such contribu

Thomas G. Rizzo

We summarize the results of the New Gauge Boson Subgroup on the physics of extended gauge sectors at future colliders as presented at the 1996 Snowmass workshop. We discuss the direct and indirect search reaches for new gauge bosons at both hadron and lepton colliders as well as the ability of such machines to extract detailed information on the couplings of

Pat Kalyniak, Ivan Melo

We continue our previous work on the flavour-conserving leptonic decays of the Z boson with neutral heavy leptons (NHL&#39;s) in the loops by considering box, vertex, and self-energy diagrams for the muon decay. By inclusion of these loops (they contribute to the input parameter M_W) we can probe the full parameter space spanned by the so-called flavour-cons

R. Martínez, J-Alexis Rodríguez

Using the CLEO data for $b\to sγ$, we constrain the chromomagnetic dipole moment of the top quark within the context of a decoupling effective Lagrangian approach. Our results are in agreement with the results obtained for the $e^+e^-$ and hadron colliders.

O. Bertolami, Don Colladay, V. Alan Kostelecký, R. Potting

We examine the effects on baryogenesis of spontaneous CPT violation in a string-based scenario. Under suitable circumstances, certain CPT-violating terms can produce a large baryon asymmetry at the grand-unified scale that reduces to the observed value via sphaleron or other dilution mechanisms.

A. Bartl, W. Porod, F. de Campos, M. A. Garcia-Jareno

We study the pattern of gluino cascade decays in a class of supersymmetric models where R-parity is spontaneously broken. We give a detailed discussion of the R-parity violating decays of the lightest neutralino, the second lightest neutralino and the lightest chargino. The multi-lepton and same-sign dilepton signal rates expected in these models are compare

D. Bardin, J. Blümlein, P. Christova, L. Kalinovskaya

The $O(α)$ leptonic QED corrections to neutral current polarized deep inelastic lepton-nucleon scattering are calculated in leptonic variables both for the case of longitudinal and transverse nucleon polarization. The results of the complete calculation are compared with the corresponding leading log expressions. Numerical results are presented for the corre

Martin B Einhorn, Jose Wudka

The effects of effective interactions containing the factors $\partial \cdot W^\pm$ and $\partial \cdot Z$ is studied within a consistent effective Lagrangian formalism. It is shown that such terms are redundant

David Atwood, Isard Dunietz, Amarjit Soni

The Gronau-London-Wyler (GLW) method extracts the CKM angle $γ$ by measuring $B^\pm$ decay rates involving $D^0/\overline D^0$ mesons. Since that method necessitates the interference between two amplitudes that are significantly different in magnitude, the resulting asymmetries tend to be small. CP violation can be greatly enhanced for decays to final states

P. Aurenche

Different formalisms used in the perturbative approach to Thermal Field Theory (TFT) are briefly reviewed. The rate of production of a virtual photon in a quark-gluon plasma is then discussed to illustrate some features of TFT before introducing the Hard Thermal Loop resummation which improves the behaviour of the theory in the infrared sector. Some of the s

B. G. Zakharov

A rigorous evaluation of the Landau-Pomeranchuk-Migdal effect for finite-size targets is performed within the path integral approach previously developed in ref. [4]. The bremsstrahlung rate in QED is expressed through a solution of a two-dimensional Schrödinger equation with an imaginary potential. The boundary condition for this solution is formulated in t

Gino Isidori

A short overview of theoretical predictions for various kaon decays is presented. Particular attention is devoted to pure and radiative nonleptonic decays in the framework of Chiral Perturbation Theory. The relevance of KLOE&#39;s future results to improve our knowledge of kaon physics and more generally of the Standard Model at low energy is also emphasized

Antonio Riotto, Iiro Vilja

The properties of Majorana fermions in hot plasma are studied. One-loop resummed propagator, dispersion relations and their interpretation are discussed. It is shown that particle and hole -like solutions appear as in Dirac/chiral fermion case. The dispersion relations are, however, crucially different. We find that, in presence of a large zero temperature b

S. Mallik, D. Rai Chaudhuri

We examine the calculation of density perturbation at large scales in the inflationary scenario. The formula for its magnitude is reviewed from first principles and applied to the original model of extended inflation. Our estimate is an order of magnitude bigger than the earlier ones due to the difference in the time at which the primordial fluctuation is ev

Igor Halperin, Ariel Zhitnitsky

We study the impact of the &#34;intrinsic&#34; hadron transverse momentum on the pre-asymptotic behavior of the diffractive electroproduction of longitudinally polarized $ ρ$-meson. Surprisingly, we find the onset of the asymptotic regime in this problem to be rather low, Q^2 ~ 10 GeV^2 where power corrections due to the transverse momentum do not exceed 20

H. G. Ballesteros, L. A. Fernandez, V. Martin-Mayor, A. Munoz Sudupe

Using finite-size scaling methods we measure the thermal and magnetic exponents of the site percolation in four dimensions, obtaining a value for the anomalous dimension very different from the results found in the literature. We also obtain the leading corrections-to-scaling exponent and, with great accuracy, the critical density.

Hildegard Meyer-Ortmanns, Thomas Reisz

Under quite general conditions critical phenomena can be described with high order linked cluster expansions. The coefficients of the series admit a graphical expansion that is generated with the aid of computers. Our generalization of linked cluster expansions from an infinite to a finite volume allows to perform a finite size scaling analysis. We also indi

S. Brian Edgar, Garry Ludwig

The complete class of conformally flat, pure radiation metrics is given, generalising the metric recently given by Wils.

A. T. Filippov

Integrable models of dilaton gravity coupled to electromagnetic and scalar matter fields in dimensions 1+1 and 0+1 are briefly reviewed. The 1+1 dimensional integrable models are either solved in terms of explicit quadratures or reduced to the classically integrable Liouville equation. The 0+1 dimensional integrable models emerge as sectors in generally non

Arvind Borde

The conditions are clarified under which regular (i.e., singularity-free) black holes can exist. It is shown that in a large class of spacetimes that satisfy the weak energy condition the existence of a regular black hole requires topology change.