February 1997 arXiv papers — page 8

Franco Bagnoli, Michele Bezzi

We present an extension of Eigen's model for quasi-species including the competition among individuals, proposed as the simplest mechanism for the formation of new species in a smooth fitness landscape. We are able to obtain analytically the critical threshold for species formation. The comparison with numerical simulations is very good.

B. Chakraborty, T. R. Govindarajan

We study the nonrelativistic nonlinear sigma model with Hopf term in this paper. This is an important issue beacuse of its relation to the currently interesting studies in skyrmions in quantum Hall systems. We perform the Hamiltonian analysis of this system in $CP^1$ variables. When the coefficient of the Hopf term becomes zero we get the Landau-Lifshitz des

P. D. Sacramento, V. R. Vieira

We present evidence for the absence of a gap in a class of S=1 antiferromagnetic exchange models. The spin exchange is long-ranged of the type $-(-1)^{i-j}/|i-j|^α$ where $1<α<3$. We have shown previously that without the alternating factor the model for $α=2$ (S=1 Haldane-Shastry model) has a gap, exponentially decaying correlation functions and exponential

N. V. Mikheev, L. A. Vassilevskaya

The axion decay into charged fermion-antifermion pair $a ~\to f ~\tilde f$ is studied in external crossed and magnetic fields. The result we have obtained can be of use to re-examine the lower limit on the axion mass in case of possible existence of strong magnetic fields at the early Universe stage.

Ruth Durrer, Jean-Pierre Eckmann, Francesco Sylos Labini, Marco Montuori

We discuss various questions which arise when one considers the central projection of three dimensional fractal sets (galaxy catalogs) onto the celestial globe. The issues are related to how fractal such projections look. First we show that the lacunarity in the projection can be arbitrarily small. Further characteristics of the projected set---in particular

Masaaki Nakamura, Kiyohide Nomura

Asymptotic behavior of the Tomonaga-Luttinger liquid in the vicinity of the phase-separated region is investigated in the one-dimensional $t$-$J$ model, to study the universal property of the $c=1$ conformal field theory with U(1) symmetry near the $K\to\infty$ instability. On the analogy of the spinless fermion, we discuss that the compressibility behaves a

T. Simon, W. B. Landsman

Broad-band ultraviolet photometry from the TD-1 satellite and low dispersion spectra from the short wavelength camera of IUE have been used to investigate a long-standing proposal of Bohm-Vitense that the normal main sequence A- and early-F stars may divide into two different temperature sequences: (1) a high temperature branch (and plateau) comprised of slo

Kyungsik Kang, Sin Kyu Kang

We review the origin of the standard electroweak model and discuss in great detail the on-shell renormalization scheme of the standard model as a field theory. One-loop radiative corrections are calculated by the dimensional regularization and the dominant higher-order corrections are also discussed. We then show how well the standard model withstands the pr

N. Ogawa, K. Fujii, H. Miyazaki, N. Chepilko

This paper introduces the modified version of Schwinger&#39;s quantization method, in which the information on constraints and the choice of gauge conditions are included implicitly in the choice of variations used in quantization scheme. A proof of equivalence between Schwinger- and Dirac-methods for constraint systems is given.

Alexandre M. Zagoskin

We predict that the Josephson current in a clean s-wave superconductor-normal metal-d-wave superconductor junction is periodic in superconducting phase difference $ϕ$ with period $π$ instead of $2π$. The frequency of non-stationary Josephson effect is correspondingly $2ω_J = 4eV.$ The effect is due to coexistence in the normal layer of current carrying Andre

Yubing Luo

By using Symanzik&#39;s improvement program, we study on-shell improved lattice QCD with staggered fermions. We find that there are as many as 15 independent lattice operators of dimension of six~(including both gauge and fermion operators) which must be added to the unimproved action to form an $O(a^2)$ improved action. Among them, the total number of dimen

Q. P. Liu

A super Hill operator with energy dependent potentials is proposed and the associated integrable hierarchy is constructed explicitly. It is shown that in the general case, the resulted hierarchy is multi-Hamiltonian system. The Miura type transformations and modified hierarchies are also presented.

David Z. Goodson, Dustin W. Roelse, Wan-Ting Chiang, Steven M. Valone

The temperature dependence of the rate of the reaction CH_4+H \to CH_3+H_2 is studied using classical collision theory with a temperature-dependent effective potential derived from a path integral analysis. Analytical expressions are obtained for the effective potential and for the rate constant. The rate constant expressions use a temperature-dependent acti

P. O. J. Scherer, Sighart F. Fischer

The recently observed transient absorption of the lowest excited state of the special pair P* at 2710 cm-1 is assigned as a singlet which arises from the coupling of the two lowest triplets from the two dimer halves. INDO calculations are used to predict its intensity. The analogy of the coupling mechanism to the trip-doublet spectrum from P+ is shown and th

C. Giusti, F. D. Pacati, H. Arenhoevel, P. Wilhelm

The contribution of the $Δ$(1232) isobar to the electromagnetic current of the two-nucleon system and its role in ($γ$,NN) processes is investigated. The difference between the genuine $Δ$-excitation current and that part of the current connected to the deexcitation of a preformed $Δ$ in the target nucleus is stressed. The latter cannot lead to a resonant be

Manuel Cepedello Boiso

In this paper we give some results about the approximation of a Lipschitz function on a Banach space by means of $Δ$-convex functions. In particular, we prove that the density of $Δ$-convex functions in the set of Lipschitz functions for the topology of uniform convergence on bounded sets characterizes the superreflexivity of the Banach space. We also show t

Kimyeong Lee, Piljin Yi

Motivated by the recent D-brane constructions of world-volume monopoles and instantons, we study the supersymmetric SU(N) Yang-Mills theory on $S^1 \times R^{3+1}$, spontaneously broken by a Wilson loop. In addition to the usual N-1 fundamental monopoles, the N-th BPS monopole appears from the Kaluza-Klein sector. When all N monopoles are present, net magnet

J. M. F. Labastida, Carlos Lozano

We present a detailed description of the three inequivalent twists of N=4 supersymmetric gauge theories. The resulting topological quantum field theories are reobtained in the framework of the Mathai-Quillen formalism and the corresponding moduli spaces are analyzed. We study their geometric features in each case. In one of the twists we make contact with th

Pierre Binetruy, Mary K. Gaillard, Yi-Yen Wu

In the context of the field theory limit of superstrings, we consider an almost realistic model of supersymmetry breaking by gaugino condensation which includes, through nonperturbative corrections to the Kähler potential, dilaton stabilization at a value compatible with a weak coupling regime. Invariance under modular transformations is ensured through a Gr

Sergio Ferrara, Gary W. Gibbons, Renata Kallosh

We study the stabilization of scalars near a supersymmetric black hole horizon using the equation of motion of a particle moving in a potential and background metric. When the relevant 4-dimensional theory is described by special geometry, the generic properties of the critical points of this potential can be studied. We find that the extremal value of the c

Ren-Jie Zhang

A model based on an anomalous Abelian symmetry $U(1)_1\times U(1)_2$ is presented. This symmetry is responsible for both supersymmetry breaking and fermion mass generation. Quark and squark mass matrices are aligned to prevent large flavor-changing neutral current and CP-violation.

Masayasu Harada

In this talk I summarize a recently proposed mechanism to understand pi pi scattering to 1 GeV. The model is motivated by the 1/Nc expansion to QCD, and includes a current algebra contact term and resonant pole exchanges. Chiral symmetry plays an important role in restricting the form of the interactions. The existence of a broad low energy scalar (sigma) is

A. H. Hoang

The QED vacuum polarization function is calculated to O(alpha^2) (next-to-leading order) accuracy in the threshold regime by using the concept of effective field theories to resum diagrams with the instantaneous Coulomb exchange of longitudinally polarized photons. It is shown that the O(alpha^2) contributions are of order alpha^2 in size rather than alpha^2

Yu. A. Baurov

An analysis of known experiments on direct and indirect detection of the electron-type neutrino and antineutrino has been made. The analysis based on a new hypothesis that the observed physical space is formed from a finite set of byuons, &#34;one-dimensional vectorial objects&#34;. It is shown in the article that the hypothesis for existence of neutrinos ad

G. Folberth, R. Rossmann, W. Schweiger

We consider the reactions gamma p --> M B, with M B being either K+ Lambda, K+ Sigma0, or Pi n, within a diquark model which is based on perturbative QCD. The model parameters and the quark-diquark distribution amplitudes of the baryons are taken from previous investigations of electromagnetic baryon form factors and Compton-scattering off protons. Reasonabl

Boris Kayser

We discuss the quantum mechanics of B-factory experiments, and that of neutral K or B decay. Predictions for the processes to be studied at the B factories can be made through an approach based on amplitudes, rather than on wave functions. This approach avoids the puzzles of the &#34;collapse of the wave function.&#34; In the treatment of the decay of a neut

R. Casalbuoni, P. Chiappetta, A. Deandrea, S. De Curtis

We study the expected phenomenology at present (Tevatron) and future (Tevatron Upgrade, LHC) hadronic colliders of a model describing a strong electroweak symmetry breaking sector with both vector and axial vector strong interacting bosons degenerate in mass. Due to decoupling, this model at low energies is almost indistinguishable from the Standard Model, p

N. Fornengo, C. W. Kim, J. Song

Leading finite temperature effects on the neutrino decoupling temperature in the early Universe have been studied. We have incorporated modifications of the dispersion relation and the phase space distribution due to the presence of particles in the heat bath at temperature around MeV. Since both the expansion rate of the Universe and the interaction rate of

K. Holland, U. -J. Wiese

Due to the Gauss law, a single quark cannot exist in a periodic volume, while it can exist with C-periodic boundary conditions. In a C-periodic cylinder of cross section A = L_x L_y and length L_z >> L_x, L_y containing deconfined gluons, regions of different high temperature Z(3) phases are aligned along the z-direction, separated by deconfined- deconfined

CLEO Collaboration, M. Artuso

We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral B&#39;s through a partial reconstruction of B0 --> D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the Upsilon(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all Upsilon(4S) eve

2 Collaboration

The integrated luminosity about 4000 inverse nanobarn of around phi meson mass ( 5 millions of phi mesons) has been collected with the CMD-2 detector at the VEPP-2M collider. A latest analysis of the KS KL coupled decays based on 30 % of available data is presented in this paper. The KS KL pairs from phi meson decays were reconstructed in the drift chamber w

Fotini Markopoulou, Lee Smolin

A new approach to quantum gravity is described which joins the loop representation formulation of the canonical theory to the causal set formulation of the path integral. The theory assigns quantum amplitudes to special classes of causal sets, which consist of spin networks representing quantum states of the gravitational field joined together by labeled nul

Jerzy F. Plebanski, G. R. Moreno, F. J. Turrubiates

We review the language of differential forms and their applications to Riemannian Geometry with an orientation to General Relativity. Working with the principal algebraic and differential operations on forms, we obtain the structure equations and their symmetries in terms of a new product (the co-multiplication). It is showen how the Cartan - Grassmann algeb

Carolyn S. Gordon, Edward N. Wilson

Two Riemannian manifolds are said to be isospectral if the associated Laplace-Belttrami operators have the same eigenvalue spectrum. If the manifolds have boundary, one specifies DIrichlet or Neumann isospectrality depending on the boundary conditions imposed on the eigenfunctions. We construct continuous families of (Neumann and Dirichlet) isospectral metri

Ruth Gornet

The purpose of this paper is to present the first continuous families of Riemannian manifolds isospectral on functions but not on 1-forms, and simultaneously, the first continuous families of Riemannian manifolds with the same marked length spectrum but not the same 1-form spectrum. The examples presented here are Riemannian three-step nilmanifolds and thus

Serge Galam

A percolation argument and a dilute compressible random field Ising model are used to present a simple model for mixed cyanide crystals. The model reproduces quantitatively several features of the phase diagrams altough some crude approximations are made. In particular critical thresholds x_c at which ferroelastic first order transitions disappear, are calcu

E. V. L. de Mello, C. Acha

We apply a method recently derived based on the extended Hubbard Hamiltonian and the BCS approach to obtain the superconducting critical temperature dependence with carrier density for the HgBaCuO compounds. We show that this procedure can be used to study pressure effect with the assumption that pressure changes the supercondutor gap. The results reproduce

P. D. Sacramento, V. R. Vieira

The ground-state properties of the S=1 Haldane-Shastry model are studied using a modified Lanczos algorithm and diagonalizing exactly small chains. We find evidence that, as for the antiferromagnetic Heisenberg model, the spectrum shows a gap, in contrast to the S=1/2 case. The correlation functions <S^{z}(0)S^{z}(m)> decay exponentially for large m. We find

J. Ambjorn, A. Avakyan, T. Hakobyan, A. Sedrakyan

We consider exactly solvable 1d multi-band fermionic Hamiltonians, which have affine quantum group symmetry for all values of the deformation. The simplest Hamiltonian is a multi-band t-J model with vanishing spin-spin interaction, which is the affinization of an underlying XXZ model. We also find a multi-band generalization of standard t-J model Hamiltonian

C. I. Ventura, B. R. Alascio

There have been speculations about the need to find a new mechanism to explain the colossal magnetoresistance exhibited by this material, having pyrochlore structure and thus differing structurally and electronically from the manganites. We will report here our transport results based on a two band model, with conduction electrons and intermediate valence io

A. F. Barabanov, R. O. Kuzian, L. A. Maksimov, E. Zasinas

The retarded Green&#39;s function G(k,ω) of a single small spin polaron in the three-band model for the CuO_2 plane is calculated in the self-consistent Born approximation. It is shown that such a spin polaron is a good quasiparticle excitation for realistic values of spin exchange J and effective hopping τ. The polaron spectral density A_p(k,ω) demonstrates

N. Shibata, A. Tsvelik, K. Ueda

Arguments are presented that in the one-dimensional Kondo lattice model f-electron spins participate in filling of the Fermi sea. It is shown that in its paramagnetic phase this model belongs to the spin-1/2 Tomonaga-Luttinger liquid universality class. The ratio of the spin and charge velocities v_s/v_c and K_c are estimated to be of the order of (T_K/E_F)^

W. Vincent Liu, William C. Schieve

We calculate the damping rate of collective excitations for a nearly pure Bose-Einstein condensate regarding the recent experiments in MIT [M.-O. Mews et al, Phys. Rev. Lett. 77, 988 (1996)]. The decay time of collective excitations obtained in our theoretical calculations agrees well with their experimental result. We argue that the damping of collective ex

D. J. Bomans, Y. -H. Chu, U. Hopp

NGC 4449 is an irregular galaxy with a moderately high star formation activity. The massive stars in NGC 4449 have given rise to many bright HII regions, superbubbles, supergiant shells, and &#34;chimney-like&#34; radial filaments. ROSAT X-ray observations of NGC 4449 have revealed four point-like sources and a wide-spread diffuse emission. The spectral prop

C. Alcock

We present optical photometry of the eclipsing supersoft source, CAL87. These observations comprise long term data accumulated as a by-product of the MACHO Project, and high speed white light photometry of a single eclipse. We (i) derive an improved ephemeris of To = HJD 2450111.5144(3) + 0.44267714(6)E for the time of minimum light, (ii) find the eclipse st

Richard Barvainis, Philip Maloney, Robert Antonucci, Danielle Alloin

New millimeter-wavelength emission lines are reported for the Cloverleaf (H1413+117), a gravitationally lensed quasar at redshift 2.56. High signal-to-noise ratio spectra of four lines in CO (J=3-2, J=4-3, J=5-4, and J=7-6) have been obtained and are modeled using an escape probability formalism. The line brightness temperatures are flat or rising between CO

Y. Ohyama, Y. Taniguchi, R. Terlevich

We report the discovery of a starburst-driven wind (superwind) from the starburst nucleus galaxy Mrk 1259. The estimated number ratio of Wolf-Rayet (WR) to O stars amounts to ~0.09. While the nuclear emission-line region is due to usual photoionization by massive stars, the circumnuclear emission-line regions show anomalous line ratios that can be due to coo

B. Paul, P. C. Agrawal, A. R. Rao, R. K. Manchanda

The hard X-ray pulsar GX 1+4 was observed several times in the last few years with a pair of balloon-borne Xenon filled Multi-cell Proportional Counters (XMPC). In a balloon flight made on 22 March 1995, the source was detected in a bright state, the average observed source count rate being $8.0\pm0.2/s$ per detector. X-ray pulsations with a period of $121.9

B. Paul, P. C. Agrawal, A. R. Rao

The superluminal X-ray transient source GRS 1915+105 was observed during July 20-29, 1996 with the Indian X-ray Astronomy Experiment (IXAE) on the Indian satellite IRS-P3 launched on March 21, 1996 from Shriharikota Range in India. During our observations covering the energy band 2-18 keV, we have seen strong erratic intensity variations on time scale of 0.1

B. Paul, A. R. Rao, K. P. Singh

We present the detection of a positive correlation between spin-down rate $\dot{P}$ and pulsed X-ray luminosity in the BATSE archival data of the bright hard X-ray pulsar GX 1+4. We have also seen a delay of 5.6 $\pm$ 1.2 days between the luminosity change and the corresponding change in the spin-down rate. The observed correlation between $\dot{P}$ and L_X

Robert Braun

We analyze the resolved neutral hydrogen emission properties of a sample of eleven of the nearest spiral galaxies. Between 60 and 90% of the total HI line flux within the optical disk is due to a high brightness network (HBN) of emission features which are marginally resolved in their narrow dimension at about 150 pc and have a face-on covering factor of abo

Lloyd Knox, J. Richard Bond, Andrew H. Jaffe

We explore power spectrum estimation in the context of a Gaussian approximation to the likelihood function. Using the Saskatoon data, we estimate the power averaged through a set of ten filters designed to make the errors on the power estimates uncorrelated. We also present an improvement to using the window function, $W_l$, for calculating bandpower estimat

A. H. Jaffe, L. E. Knox, J. R. Bond

We discuss data compression for CMB experiments. Although &#34;radical compression&#34; to C_l bands, via quadratic estimators or local bandpowers, potentially offers a great savings in computation time, they do a considerably worse job at recovering the full likelihood than the the signal-to-noise eigenmode method of compression.

Hugh R. A. Jones, Takashi Tsuji

We have found a dramatic change in the spectra of late-type M dwarfs at wavelengths shorter than 0.75 microns. Comparisons with synthetic spectra illustrate that this change is well explained by the presence of dust. It thus seems that a substantial part of the long-standing discrepancies between late-type M dwarf models and observations arises from dust as

Ben Dorman, Ronak Y. Shah, Robert W. O&#39;Connell, Wayne B. Landsman

We used the Ultraviolet Imaging Telescope during the March 1995 Astro-2 mission to obtain a deep far-UV image of the globular cluster NGC 362, which was formerly thought to have an almost entirely red horizontal branch (HB). 84 hot (T_eff > 8500 K) stars were detected within a radius of 8&#39;.25 of the cluster center. Of these, 43 have FUV magnitudes consis

Zoltan Ligeti, Lisa Randall, Mark B. Wise

Uncertainties in the theoretical prediction for the inclusive $B\to X_sγ$ decay rate are discussed. We emphasize that there is no operator product expansion for this process. Nonetheless, some nonperturbative effects involving a virtual $c\bar c$ loop are calculable using the operator product expansion. They give a contribution to the decay rate that involve

S. Lorenz, C. Solterbeck, W. Schattke, J. Burmeister

Scattering states with LEED asymptotics are calculated for a general non-muffin tin potential, as e.g. for a pseudopotential with a suitable barrier and image potential part. The latter applies especially to the case of low lying conduction bands. The wave function is described with a reciprocal lattice representation parallel to the surface and a discretiza

Igor F. Herbut

A system of spinless fermions in $d=1+ε$ dimensions, at zero-temperature and in random potential is studied using the perturbative renormalization group to first order in disorder and to second order in interaction. We find a superconductor-to- Anderson insulator quantum fixed point at an infinitesimal value of disorder and calculate the correlation length a

Antonio Riotto, Goran Senjanović

It is generally believed that internal symmetries are necessarily restored at high temperature in supersymmetric theories. We provide simple and natural counterexamples to this no-go theorem for systems having a net background charge. We exemplify our findings on abelian models, for both cases of global and local symmetries and discuss their possible implica

Savdeep Sethi, Leonard Susskind

The matrix model formulation of M-theory can be generalized by compactification to ten-dimensional type II string theory, formulated in the infinite momentum frame. Both the type IIA and IIB string theories can be formulated in this way. In the M-theory and type IIA cases, the transverse rotational invariance is manifest, but in the IIB case, one of the tran

Alexander D. Mirlin, Yan V. Fyodorov

We study fluctuations of the local density of states (LDOS) on a tree-like lattice with large branching number $m$. The average form of the local spectral function (at given value of the random potential in the observation point) shows a crossover from the Lorentzian to semicircular form at $α\sim 1/m$, where $α= (V/W)^2$, $V$ is the typical value of the hop

J. Christensen-Dalsgaard

The overall framework for the study of solar convection and oscillations is the spherically symmetric component of solar structure. I discuss those properties of the solar interior which depend on convection and other possible hydrodynamical motion and the increasingly detailed information about the structure which is provided by helioseismic data. The most

A. K. Aiston, H. R. Morton

We use a skein-theoretic version of the Hecke algebras of type A to present three-dimensional diagrammatic views of Gyoja&#39;s idempotent elements, based closely on the corresponding Young diagram. In this context we give straightforward calculations for the eigenvalues of two natural central elements in the Hecke algebras, namely the full curl and the sum

J. A. Oller, E. Oset

We use a nonperturbative approach which combines coupled channel Lippmann Schwinger equations with meson-meson potentials provided by the lowest order chiral Lagrangians. By means of one parameter, a cut off in the momentum of the loop integrals, which results of the order of 1 GeV, we obtain singularities in the S-wave amplitudes corresponding to the σ,f_0

N. C. J. Schoonderwoerd, B. L. G. Bakker

Light-front perturbation theory has been proposed as an alternative to covariant perturbation theory. Light-front perturbation theory is only acceptable if it produces invariant S-matrix elements. Doubts have been raised concerning the equivalence of light-front and covariant perturbation theory. One of the obstacles to a rigorous proof of equivalence is the

Naoto Nagaosa, Patrick A. Lee

We study the Kondo effect due to the nonmagnetic impurity, e.g., Zn, in high-T_c cuprates based on the spin-change separated state. In the optimal or overdoped case with the Kondo screening, the residual resistivity is dominated by the spinons while the T-dependent part determined by the holons. This gives $ρ(T) = { {4 \hbar} /{e^2}} { { n_{imp.}} /{(1-x)}}

J. Richard Bond, George Efstathiou, Max Tegmark

Accurate measurements of the cosmic microwave background (CMB) anisotropies with an angular resolution of a few arcminutes can be used to determine fundamental cosmological parameters such as the densities of baryons, cold and hot dark matter, and certain combinations of the cosmological constant and the curvature of the Universe to percent-level precision.

Clay Smith, Anatoly Klypin, Michael Gross, Joel Primack

Reconstruction of the linear power spectrum from observational data provides a way to compare cosmological models to a large amount of data, as Peacock & Dodds (1994, 1996) have shown. By applying the appropriate corrections to the observational power spectrum it is possible to recover the underlying linear power spectrum for any cosmological model. Using ex

Z. Guralnik, S. Ramgoolam

We interpret instantons on a torus with twisted boundary conditions, in terms of bound states of branes. The interplay between the SU(N) and U(1) parts of the U(N) theory of N 4-branes allows the construction of a variety of bound states. The SU(N) and U(1) parts can contribute fractional amounts to the total instanton number which is integral. The geometry

Daniel Gottesman

In order to use quantum error-correcting codes to actually improve the performance of a quantum computer, it is necessary to be able to perform operations fault-tolerantly on encoded states. I present a general theory of fault-tolerant operations based on symmetries of the code stabilizer. This allows a straightforward determination of which operations can b

Peter Zoller, C. W. Gardiner

Lecture Notes for the Les Houches Summer School LXIII on Quantum Fluctuations in July 1995 to appear in Elsevier Science Publishers B.V. 1997, edited by E. Giacobino and S. Reynaud.

Peter Hoyer

Quantum mechanics requires the operation of quantum computers to be unitary, and thus makes it important to have general techniques for developing fast quantum algorithms for computing unitary transforms. A quantum routine for computing a generalized Kronecker product is given. Applications include re-development of the networks for computing the Walsh-Hadam

Marian Fecko

We consider a standard symplectic dynamics on TM generated by a natural Lagrangian L. The Lagrangian is assumed to be invariant with respect to the action TR_g of a Lie group G lifted from the free and proper action R_g of G on M. It is shown that under these conditions a connection on principal bundle pi: M \rightarrow M/G can be constructed based on the mo

S. S. Kamalov, J. A. Oller, E. Oset, M. J. Vicente-Vacas

The K^+ scattering on the lightest nuclei, d, 3He and 4He is studied in the framework of multiple scattering theory. Effects from MEC tied to the K^+N-->KNpi reaction are evaluated. We found that at momentum transfers Q^2<0.5 (GeV/c)^2 contributions from MEC are much smaller than kaon rescattering corrections. This makes the conventional multiple scattering

H. Hofmann, D. Kiderlen

We address the dynamics of damped collective modes in terms of first and second moments. The modes are introduced in a self-consistent fashion with the help of a suitable application of linear response theory. Quantum effects in the fluctuations are governed by diffusion coefficients D_{μν}. The latter are obtained through a fluctuation dissipation theorem g

C. Fuchs, L. Sehn, Amand Faessler, D. S. Kosov

In the relativistic Quantum Molecular Dynamics (RQMD) approach baryons are described within the framework of covariant hamilton constraint dynamics. The inclusion of a relativistic mean field results in a quasiparticle picture for the baryons. This requires to distinguish between canonical and kinetic variables of the particles. As resonances we include the

John R. Klauder, Sergei V. Shabanov

The conversion of second-class constraints into first-class constraints is used to extend the coordinate-free path integral quantization, achieved by a flat-space Brownian motion regularization of the coherent-state path integral measure, to systems with second-class constraints.

M. L. Horner, Alfred S. Goldhaber

The basic AB problem is to determine how an unshielded tube of magnetic flux $Φ$ affects arbitrarily long-wavelength charged particles impinging on it. For spin-1 at almost all $Φ$ the particles do not penetrate the tube, so the interaction essentially is periodic in $Φ$ (AB effect). Below-threshold bound states move freely only along the tube axis, and cons

Massimo Bianchi

Notwithstanding the central role of D-branes in many recently proposed string dualities, several interesting type I vacua have been found without resorting directly to D-brane technology. In this talk, we analyze a three-generation SO(8)xU(12) chiral type I model with N=1 supersymmetry in D=4. It descends from the type IIB compactification on the Z orbifold

I. L. Buchbinder, T. Inagaki, S. D. Odintsov

We investigate the effect of an external gravitational fields to the chiral symmetry breaking in the SUSY (supersymmetric) NJL (Nambu-Jona-Lasinio) model non-minimally interacting with external supergravity. Evaluating the effective potential in the leading order of the $1/N_{c}$-expansion and in the linear curvature approximation it is found the possibility

Michael Danos

A gap in the mathematical logic in derivations in quantum field theory arises as consequence of variation before quantization. To close this gap the present paper introduces a mathematically rigorous variational calculus for operator fields. Using quantization before variation it is demonstrated that the so-called naive results are correct; in particular bot

Will Loinaz, R. S. Willey

We examine the gauge dependence of lower bounds on the Higgs mass obtained from the requirement that the electroweak vacuum be the global minimum of the effective potential. We study a simple model, the spontaneously-broken Abelian Higgs model coupled to a chiral quark doublet in a two-parameter gauge and demonstrate that the lower bounds on the Higgs mass o

Christopher T. Hill

We review a class of dynamical models in which top condensation occurs at the weak scale, giving rise to the large top quark mass and other phenomena. This typically requires a color embedding, $SU(3)_c \rightarrow SU(3)_1\times SU(3)_2$. These models imply many signatures addressable in near term experiments at colliders and in fixed target mode.

A. Khodjamirian, R. Rückl, G. Stoll, D. Wyler

We suggest to use operator product expansion and QCD sum rule techniques to estimate the long-distance contribution to the amplitude of the exclusive rare decay $B\to K^* γ$. In contrast to a phenomenological description in terms of $ψ$ resonances converting into a photon, the virtual charm quark loop interacting with soft gluons is represented by a new quar

J. M. Frere, R. B. Nevzorov, V. A. Novikov, M. I. Vysotsky

We have shown in hep-ph/9608266 that a neutrino magnetic moment form factor $μ_ν (q^2)$ could be considerably amplified at low momentum transfer,$q^2 \leq m_N^2$, at the cost of introducing an extra light neutral fermion $N$ with mass $m_N$ and nonzero magnetic moment. It was assumed that the magnetic moment of $N$ would originate in a renormalizable way at

Bing An Li

The effects of the anomalous contact terms are taken into account in tau to eta(eta&#39;)2pi nu decay. tau to 3pi nu is computed. Theoretical result agrees with data. It is the first time the anomalous vertex eta aa is tested. An a_{1} resonance is predicted in the final state. The decay rate of tau to eta&#39;3pi nu is predicted.

Riccardo Barbieri, Lawrence J. Hall, Andrea Romanino

While solving the supersymmetric flavour problem, a U(2) flavour symmetry might be at the origin of the pattern of fermion masses and mixings. The consequences of this hypothesis are spelled out concerning the parameters of the CKM matrix and their observability in B- and K-physics. The relevance of searching for lepton flavour violation and for the electric

C. E. Picciotto

The rate for the lepton-number-violating decay K+ to pi- mu+mu+ is calculated in a model which incorporates doubly-charged Higgs bosons. We find that for reasonable values of the parameters the decay branching ratio may be as large as 2E-16. Although this is a discouragingly small number, it is of the same order of magnitude as the rate mediated by massive M

A. Ali

We review the theory and experimental measurements in the flavour changing neutral current (FCNC) processes involving B decays in the context of the standard model (SM). The role of these processes in determining the weak mixing matrix elements is stressed.

Matthias Neubert

We present the theory of inclusive decays of hadrons containing a heavy quark and discuss its most important applications to the decays of B mesons. We also review the theoretical understanding of the hadronic parameters lambda_1 and lambda_2 (or mu_pi^2 and mu_G^2) entering the heavy-quark expansion.

Ulrich Ellwanger

We discuss the perturbative running Yang-Mills coupling constant in the Wilsonian exact renormalization group approach, and compare it to the running coupling in the more conventional MS-bar scheme. The exact renormalization group approach corresponds to a particular renormalization scheme, and we relate explicitly the corresponding Lambda-parameters. The un

D. V. Ahluwalia, T. Goldman

A theoretical structure that involves neutrino mass eigenstates at non relativistic as well as relativistic energies is presented. Using this framework, we find that if the particle X, with mass 33.9 MeV, of the KARMEN collaboration anomaly is identified with the third neutrino mass eigenstate, then the present limit of 23 MeV upper bound on the tau neutrino

D. Adams

We have measured the spin-dependent structure function $g_1^p$ in inclusive deep-inelastic scattering of polarized muons off polarized protons, in the kinematic range $0.003 < x < 0.7$ and $1 GeV^2 < Q^2 < 60 GeV^2$. A next-to-leading order QCD analysis is used to evolve the measured $g_1^p(x,Q^2)$ to a fixed $Q^2_0$. The first moment of $g_1^p$ at $Q^2_0 =

T. P. Singh

Various authors have shown the occurence of naked singularities and black holes in the spherical gravitational collapse of inhomogeneous dust. In a recent preprint, Antia has criticised a statement in a paper by Jhingan, Joshi and Singh on dust collapse. We show that his criticism is invalid. Antia shows that in Eulerian coordinates a series expansion for th

A. S. Pechentsov, A. Yu. Popov

Is considered the asymptotical behavior of spectral function $ρ(λ, ε),ε> 0$, of one family of self adjoint differential operators of second order, defined in space $L_2[0,+\infty)$ with potentials, depending on $ε$. Are given evaluations for the derivative of spectral function for negative $λ$ and is proved the weak convergence of $ρ&#39;(λ, ε)$ to $ρ&#39;(λ

A. G. Us

There is constructed and considered the extension of classical Diriclet operator corresponding to uniformly log-concave measure in the space of symmetric differential forms. Sufficient conditions for its essential self-adjointness in one-dimensional case as well as for the same of its &#34;sypersymmetric&#34; part in general situations are given.

I. Ya. Spectorsky

We consider stochastic equations for the class of formal mappings. Existence and uniqueness of solution, as well as evolution property are proved.

O. V. Solonoukha

In this paper we explore solvability of steady-state variational inequalities with multivalued operators. Moreover, we are studying the connections between the class of radially semi-continuous operators with semi-bounded variation and classes of pseudo-monotone and monotone mappings, and some properties of this operators.

N. A. Kachanovsky

We introduce and study dual $n_1$-Appell-like systems which are the simple generalization of generalized dual Appell systems in Infinite-Dimensional Analysis (IDA). We study connected with these systems objects of IDA: the analogues of Kondratiev spaces, $S$-transform, characterization theorems etc. The results we obtained are useful to application in the th

Rostyslav O. Hryniv

We study the Cauchy problem for the equation of the form $$ \ddot{u}(t) + (åA + B)\dot{u}(t) + (A+G)u(t) = 0,\tag* $$ where $A$, $B$, and $G$ are øs in a Hilbert space $\Cal H$ with $A$ selfadjoint, $σ(A)=[0,\infty)$, $B\ge0$ bounded, and $G$ symmetric and $A$-subordinate in a certain sense. Spectral properties of the correspondent operator pencil $L(λ) := λ