May 1997 arXiv papers — page 5

V. A. Yerokhin, V. M. Shabaev, A. N. Artemyev

The one-loop self-energy correction to the hyperfine structure splitting of the 1s and 2s states of hydrogenlike ions is calculated both for the point and finite nucleus. The results of the calculation are combined with other corrections to find the ground state hyperfine splitting in lithiumlike ^{209}Bi^{80+} and ^{165}Ho^{64+}.

M. J. Ramsey-Musolf, H. -W. Hammer

The leading non-zero electric moment of the nucleon strange-quark vector current is the mean square strangeness radius, $<r_s^2>$. We evaluate the lightest OZI-allowed contribution to $<r_s^2>$, arising from the kaon cloud, using dispersion relations. Drawing upon unitarity constraints as well as $K^{+}N$ scattering and $e^+e^-\to K\bar{K}$ cross section dat

Takao Ohta, David Jasnow

We investigate dynamics of large scale and slow deformations of layered structures. Starting from the respective model equations for a non-conserved system, a conserved system and a binary fluid, we derive the interface equations which are a coupled set of equations for deformations of the boundaries of each domain. A further reduction of the degrees of free

R. Sappey, E. Vincent, N. Hadacek, ; F. Chaput

We have performed magnetic measurements on a diluted system of gamma-Fe2O3 nanoparticles (~7nm), and on a ferritin sample. In both cases, the ZFC-peak presents a non-monotonic field dependence, as has already been reported in some experiments,and discussed as a possible evidence of resonant tunneling. Within simple assumptions, we derive expressions for the

C. Mauz, A. Rosch, P. Woelfle

We study the dimensional crossover of weak localization in strongly anisotropic systems. This crossover from three-dimensional behavior to an effective lower dimensional system is triggered by increasing temperature if the phase coherence length gets shorter than the lattice spacing $a$. A similar effect occurs in a magnetic field if the magnetic length $L_m

Stavros Garoufalidis, James Pommersheim

This is an expanded version. We study relations among special values of zeta functions, invariants of toric varieties, and generalized Dedekind sums. In particular, we use invariants arising in the Todd class of a toric variety to give a new explicit formula for the values of the zeta function of a real quadratic field at nonpositive integers. We also expres

Daijiro Suematsu

A lepton flavor violating process $μ\to eγ$ is investigated in the supersymmetric extra U(1) models, which often appear as the low energy effective models of superstring and can potentially solve the $μ$-problem. The branching ratio of this process is calculated. It is numerically estimated and compared with that of the MSSM. In this study we take account of

Alexei Yung

We consider N=2 SUSY QCD with gauge group SU(2) and N_f flavours of matter with nonzero mass. Using the method of the instanton-induced effective vertex we calculate higher derivative corrections to the Seiberg-Witten result in the momentum expansion of the low energy effective Lagrangian in various regions of the modular space. Then we focus on a certain hi

Toshiaki Ito, Masahisa Matsuda, Yoshimitsu Matsui

We discuss the problem of the large discrepancy between the observed lifetime ratio of $Λ_b$ to $B_d$ and the theoretical prediction obtained by the heavy quark effective theory. A new possibility of solving this problem is proposed from the viewpoint of operator product expansion and the lifetime ratio of $Ω_b$ to $B_d$ is predicted.

Izumi Tsutsui, Shogo Tanimura, Hiroyuki Kobayashi

The Hopf term in the $2 + 1$ dimensional O(3) nonlinear sigma model, which is known to be responsible for fractional spin and statistics, is re-examined from the viewpoint of quantization ambiguity. It is confirmed that the Hopf term can be understood as a term induced quantum mechanically, in precisely the same manner as the $θ$-term in QCD. We present a de

Burkhard Kleihaus, Jutta Kunz, Abha Sood

We consider asymptotically flat static spherically symmetric black hole solutions in SU(N) Einstein-Yang-Mills theory. Embedding the N-dimensional representation of $su(2)$ in $su(N)$, the purely magnetic gauge field ansatz contains $N-1$ functions. When one or more of these gauge field functions are identically zero, magnetically charged EYM black hole solu

F. Dalfovo, S. Giorgini, M. Guilleumas, L. Pitaevskii

The density of states of a Bose-condensed gas confined in a harmonic trap is investigated. The predictions of Bogoliubov theory are compared with the ones of Hartree-Fock theory and of the hydrodynamic model. We show that the Hartree-Fock scheme provides an excellent description of the excitation spectrum in a wide range of energy, revealing a major role pla

Krishnendu Mukherjee

We investigate the two-loop gap equation for the thermal mass of hot massless $g^2ϕ^4$ theory and find that the gap equation itself has a non-zero finite imaginary part. This indicates that it is not possible to find the real thermal mass as a solution of the gap equation beyond $g^2$ order in perturbation theory. We have solved the gap equation and obtain t

B. A. DiDonna, T. A. Witten, J. B. Young

We investigate several means of coupling between a sonoluminescing bubble and an applied magnetic field. Recent experiments show a strong quadratic dependence between the forcing pressures required for stable sonoluminescence and magnetic field amplitude. However, all coupling mechanisms calculated here for comparable magnetic fields involve energies no more

Andrzej Sitarz

We show that for $q\not=-1$ the q-graded tensor product fails to preserve the q-differential structure of the product algebra and therefore there is no natural tensor product construction for q-differential algebras.

Sergiu I. Vacaru

We generalize the geometry of Santilli&#39;s locally anisotropic and inhomogeneous isospaces to the geometry of vector isobundles provided with nonlinear and distinguished isoconnections and isometric structures. We present, apparently for the first time, the isotopies of Lagrange, Finsler and Kaluza-Klein spaces. We also continue the study of the interior,

Klaus Geiger, Ronald Longacre

We introduce a Monte Carlo space-time model for high-energy collisions with nuclei, involving the dynamical interplay of perturbative QCD parton production and evolution, with non-perturbative parton-cluster formation and `afterburner&#39; cascading of formed pre-hadronic clusters plus hadron excitations. This approach allows us to trace the space-time histo

Thomas Waindzoch, Jochen Wambach

The unstable manifold of the B=2 sector of the Skyrme model is constructed numerically using the gradient-flow method. Following paths of steepest descent from the B=2 hedgehog, we apply a collective coordinate description for the motion on the manifold to extract a Hamiltonian, approximately valid for the quantum description of the low-energy nucleon-nucleo

Toshiki Maruyama, Koji Niita, Kazuhiro Oyamatsu, Tomoyuki Maruyama

Quantum molecular dynamics is applied to study the ground state properties of nuclear matter at subsaturation densities. Clustering effects are observed as to soften the equation of state at these densities. The structure of nuclear matter at subsaturation density shows some exotic shapes with variation of the density.

C. Athanassopoulos, L. B. Auerbach, R. L. Burman, I. Cohen

Charged current scattering of nu_mu on 12C has been studied using a pi+ decay-in-flight nu_mu beam at the Los Alamos Meson Physics Facility. A sample of 56.8 +- 9.6 events satisfying criteria for the exclusive reaction 12C + nu_mu -> mu- + 12N_g.s. was obtained using the large Liquid Scintillator Neutrino Detector (LSND). The observed flux-averaged cross sec

C. Athanassopoulos, L. B. Auerbach, R. L. Burman, I. Cohen

Charged current reactions of nu_e on 12C have been studied using a mu decay-at-rest nu_e beam from the Los Alamos Meson Physics Facility. More than 500 events from the exclusive reaction 12C + nu_e -> e- + 12N g.s. were measured in a large Liquid Scintillator Neutrino Detector (LSND). The observed energy dependence of the cross section and the angular distri

Franck Barthe

We prove a reverse form of the multidimensional Brascamp-Lieb inequality. Our method also gives a new way to derive the Brascamp-Lieb inequality and is rather convenient for the study of equality cases.

Anastasia Doikou, Luca Mezincescu, Rafael I. Nepomechie

The antiferromagnetic Heisenberg spin chain with N spins has a sector with N=odd, in which the number of excitations is odd. In particular, there is a state with a single one-particle excitation. We exploit this fact to give a simplified derivation of the boundary S matrix for the open antiferromagnetic spin-1/2 Heisenberg spin chain with diagonal boundary m

Fidel A. Schaposnik

I discuss in this talk a bosonization approach recently developed. It leads to the (exact) bosonization rule for fermion currents in d > 2 dimensions and also provides a systematic way of constructing the bosonic action in different regimes.

Marco Laucelli Meana, M. A. R. Osorio, Jesús Puente Peñalba

The computation of the microcanonical density of states for a string gas in a finite volume needs a one by one count because of the discrete nature of the spectrum. We present a way to do it using geometrical arguments in phase space. We take advantage of this result in order to obtain the thermodynamical magnitudes of the system. We show that the results fo

Theodora Ioannidou

The O(3) sigma model in two spatial dimensions admits topological (Bogomol&#39;nyi) lower bound on its energy. This paper proposes a lattice version of this system which maintains the Bogomol&#39;nyi bound and allows the explicit construction of static solitons on the lattice. Numerical simulations show that these lattice solitons are unstable undersmall per

D. C. Cabra, A. Honecker, G. Mussardo, P. Pujol

We study the N -> 0 limit of the O(N) Gross-Neveu model in the framework of the massless form-factor approach. This model is related to the continuum limit of the Ising model with random bonds via the replica method. We discuss how this method may be useful in calculating correlation functions of physical operators. The identification of non-perturbative fix

Fuad M. Saradzhev

We study the influence of the anomaly on the physical quantum picture of the generalized chiral Schwinger model defined on the circle. We show that the anomaly i) results in the background linearly rising electric field and ii) makes the spectrum of the physical Hamiltonian nonrelativistic without a massive boson. The physical matter fields acquire exotic st

N. A. Saulina

A vacuum solution of anomaly-free N=1, D=10 Dual Supergravity is constructed. This vacuum corresponds to the presence of two 5-branes, intersecting along M_4, and possesses N=1, D=4 supersymmetry.

S. V. Bashinsky, R. L. Jaffe

We consider the interplay of a quark state and a hadronic threshold in the framework of the P-matrix formalism, which is reviewed and extended for use together with conventional methods of computing quark-gluon dynamics. We provide a quantitative dynamical interpretation of the reduced R or K matrices and their poles that suggests a natural classification of

K. Huitu, J. Maalampi, K. Puolamaki

We study the production of neutralinos and charginos at LEP and at a linear collider in the case of spontaneously broken R-parity. We first investigate the constraints on the single neutralino and chargino production from the LEP 1 experiments, and then we consider the production at LEP 2 and at a linear collider. We concentrate on the supersymmetric $SU(2)_

Robert Fleischer

CP-violating effects in non-leptonic $B_s$-meson decays are reviewed. Special emphasis is given to implications arising from the width difference $ΔΓ_s$ between the $B_s$ mass eigenstates. If $ΔΓ_s$ is found to be sizable, certain untagged $B_s$-meson decays may allow interesting probes of CP violation, extractions of the CKM angle $γ$ and the Wolfenstein pa

Michael Spira

The determination of the full SUSY QCD corrections to the production of squarks and gluinos at hadron colliders is reviewed. The inclusion of the NLO corrections stabilizes the theoretical predictions of the various production cross sections significantly and leads to sizeable enhancements of the most relevant cross sections. We discuss the phenomenological

A. V. Anisovich, A. V. Sarantsev

A K-matrix re-analysis of the K-pi S-wave is performed in the mass region 900-2100 MeV, and solutions which describe the data well are found. The solution with two resonances in the (IJ^P=1/2 0^+)-wave has poles at (1415 pm 25)- i(165 pm 25) MeV and (1820 pm 40) -i(125 pm 50) MeV, close to the previous result of D. Aston et al., Nucl.Phys., B296 (1988) 493.

Gustavo Burdman

The effects of the electroweak symmetry breaking sector in rare $B$ and $K$ decays are considered in the presence of new strong dynamics at a large energy scale. In the context of the low energy effective lagrangian of the symmetry breaking sector, we focus on the contributions that are not constrained by bounds on oblique corrections or anomalous triple gau

P. Pennanen, A. M. Green, C. Michael

The spatial distribution of the action and energy in the colour fields of flux-tubes is studied in lattice SU(2) field theory for static quarks at separations up to 1 fm at beta=2.4, 2.5. The ground and excited states of the colour fields are considered. Sum rules are used to get estimates of generalised beta-functions.

K. Abe

We have measured the neutron structure function g$_{2}^{n}$ and the virtual photon-nucleon asymmetry A$_{2}^{n}$ over the kinematic range $0.014\leq x \leq 0.7$ and $1.0 \leq Q^{2} \leq 17.0$ by scattering 48.3 GeV longitudinally polarized electrons from polarized $^{3}$He. Results for A$_{2}^{n}$ are significantly smaller than the $\sqrt{R}$ positivity limi

G. Dissertori

A summary of the measurements of the QCD colour factors at LEP is presented. Such measurements provide a test of the gauge group structure underlying the theory of strong interactions. A variety of methods have been applied by the various experiments, and perfect consistency with the expectation of QCD with SU(3) as gauge group is found.

Robert C. Myers

Recently, string theory has provided some remarkable new insights into the microphysics of black holes. I argue that a simple and important lesson is also provided with regards to the information loss paradox, namely, pure quantum states do not form black holes! Thus it seems black hole formation, as well as evaporation, must be understood within the framewo

David Nicholson, Alberto Vecchio

A global network of laser interferometric gravitational wave detectors is projected to be in operation by around the turn of the century. Here, the noisy output of a single instrument is examined. A gravitational wave is assumed to have been detected in the data and we deal with the subsequent problem of parameter estimation. Specifically, we investigate the

K. H. Cho, J. Y. Ji, S. P. Kim, C. H. Lee

We present the Heisenberg-picture approach to the quantum evolution of the scalar fields in an expanding FRW universe which incorporates relatively simply the initial quantum conditions such as the vacuum state, the thermal equilibrium state, and the coherent state. We calculate the Wightman function, two-point function, and correlation function of a massive

L. L. Bonilla, P. J. Hernando, M. A. Herrero, M. Kindelan

We present an asymptotic analysis of the Gunn effect in a drift-diffusion model---including electric-field-dependent generation-recombination processes---for long samples of strongly compensated p-type Ge at low temperature and under dc voltage bias. During each Gunn oscillation, there are different stages corresponding to the generation, motion and annihila

Ravi Bhagavatula, David Jasnow, Takao Ohta

Interface equations are derived for both binary diffusive and binary fluid systems subjected to non-equilibrium conditions, starting from the coarse-grained (mesoscopic) models. The equations are used to describe thermo-capillary motion of a droplet in both purely diffusive and fluid cases, and the results are compared with numerical simulations. A mesoscopi

C. W. H. Mace, A. C. C. Coolen

We describe the application of tools from statistical mechanics to analyse the dynamics of various classes of supervised learning rules in perceptrons. The character of this paper is mostly that of a cross between a biased non-encyclopedic review and lecture notes: we try to present a coherent and self-contained picture of the basics of this field, to explai

I. C. Charret, E. V. Correa Silva, S. M. de Souza, M. T. Thomaz

We calculate the exact analytical coefficients of the $β$ expansion of the grand-canonical partition function of the unidimensional Hubbard model up to order $β^5$, using an alternative method, based on properties of the Grassmann algebra. The results derived are non-perturbative and no restrictions on the set of parameters that characterize the model are re

Murray T Batchelor, John Cardy

The extraordinary transition which occurs in the two-dimensional O(n) model for $n<1$ at sufficiently enhanced surface couplings is studied by conformal perturbation theory about infinite coupling and by finite-size scaling of the spectrum of the transfer matrix of a simple lattice model. Unlike the case of $n\geq1$ in higher dimensions, the surface critical

R. Benzi, L. Biferale, E. Trovatore

Ultrametric structure of the energy cascade process in a dynamical model of turbulence is studied. The tree model we use can be viewed as an approximated one-dimensional truncation of the wavelets resolved Navier-Stokes dynamics. Varying the tree connectiveness, the appearance of a scaling transition in the two-points moments of energy dissipation is detecte

C. R. Keeton, C. S. Kochanek

We study gravitational lensing by spiral galaxies, using realistic models consisting of halo, disk, and bulge components combined to produce a flat rotation curve. Proper dynamical normalization of the models is critical because a disk requires less mass than a spherical halo to produce the same rotation curve---a face-on Mestel disk has a lensing cross sect

J. H. Krolik, G. A. Kriss

We present the results of ultraviolet spectral monitoring of the Seyfert galaxy NGC 4151 performed by the Hopkins Ultraviolet Telescope during the Astro-2 mission. We show how the response of the Lyman continuum optical depth to variations in the continuum flux may be used to derive estimates of the distance of the absorbing gas from the central object. In t

S. Huettemeister, R. Mauersberger, C. Henkel

Multilevel observations of formaldehyde (H_2CO) and methanol (CH_3OH) toward the nearby spiral galaxies NGC 253, Maffei 2, IC 342, M 82 and NGC 6946 are presented. H_2CO was detected in all galaxies (tentatively in NGC 6946). CH_3OH was detected in all objects with the notable exception of M 82. H_2CO line intensity ratios point out differences in gas densit

L. G. Dedenko, A. V. Furduev, Ya. S. Karlik, J. G. Learned

An attractive technique to explore for super-high-energy cosmic neutrino fluxes, via deep underwater acoustic detection, is discussed. Acoustic signals emitted by the neutrino induced cascades at large distances (10-50 km) from cascades are considered. It is argued that an existing hydroacoustic array of 2400 hydrophones, which is available in the Great Ocea

Xue-Bing Wu

The relations among the relative changes of surface density, temperature, disk height and vertical integrated pressure in three kinds of thermally unstable accretion disks were quantitatively investigated by assuming local perturbations. The surface density change was found to be very small in the long perturbation wavelength case but can not be ignored in t

John C. Lattanzio, Arnold I. Boothroyd

We present a review of the main phases of stellar evolution with particular emphasis on the nucleosynthesis and mixing mechanisms in low- and intermediate-mass stars. In addition to explicit studies of the effects of the first, second and third dredge-up, we also discuss cool bottom processing and hot bottom burning.

Xiang-Ping Wu, Xiao-Hong Zhu, Yi-Peng Jing, Li-Zhi Fang

Using numerical simulations of cluster formation in the standard CDM model (SCDM) and in a low-density, flat CDM model with a cosmological constant (LCDM), we investigate the gravitational lensing explanation for the reported associations between background quasars and foreground clusters. Under the thin-lens approximation and the unaffected background hypot

G. Cleaver, M. Cvetic, J. R. Espinosa, L. Everett

We address intermediate scales within a class of string models. The intermediate scales occur due to the SM singlets S_i acquiring non-zero VEVs due to radiative breaking; the mass-square (m_i)^2 of S_i is driven negative at mu_{RAD} due to order(1) Yukawa couplings of S_i to exotic particles (calculable in a class of string models). The actual VEV of S_i de

T. Stelzer, Z. Sullivan, S. Willenbrock

Single-top-quark production via W-gluon fusion at hadron colliders provides an opportunity to directly probe the charged-current interaction of the top quark. We calculate the next-to-leading-order corrections to this process at the Fermilab Tevatron, the CERN Large Hadron Collider, and DESY HERA. Using a b-quark distribution function to sum collinear logari

Kailash C. Sahu, Mario Livio, Larry Petro, F. Duccio Macchetto

Although more than 2,000 astronomical gamma-ray bursts (GRBs) have been detected, and numerous models proposed to explain their occurrence, they have remained enigmatic owing to the lack of an obvious counterpart at other wavelengths. The recent ground-based detection of a transient source in the vicinity of GRB 970228 may therefore have provided a breakthro

Zurab Kakushadze, Gary Shiu

In this paper we consider Type I string theory compactified on a Z_7 orbifold. The model has N=1 supersymmetry, a U(4) \otimes U(4) \otimes U(4) \otimes SO(8) gauge group, and chiral matter. There are only D9-branes (for which we discuss tadpole cancellation conditions) in this model corresponding to a perturbative heterotic description in a certain region o

B. Andreas, G. Curio, D. Lust

We construct two chains of fourdimensional F-theory/heterotic dual string pairs with N=1 supersymmetry. On the F-theory side as well as on the heterotic side the geometry of the involved manifolds relies on del Pezzo surfaces. We match the massless spectra by using, for one chain of models, an index formula to count the heterotic bundle moduli and determine

Shamit Kachru

We review several topics of interest in the study of 4d N=1 supersymmetric compactifications of the heterotic string. After a brief introduction to the construction of such models, our focus is on the novel physics which occurs at singularities in the moduli space of vacua. Among the phenomena we discuss are nonperturbative superpotentials, dynamical generat

David N. Spergel, Matias Zaldarriaga

We study the auto-correlation function of CMB polarization anisotropies and their cross correlation with temperature fluctuations as probe of the causal structure of the universe. Because polarization is generated at the last scattering surface, models in which fluctuations are causally produced on sub-horizon scales cannot generate correlations on scales la

S. Jadach, W. Placzek, B. F. L. Ward

We discuss the leptoquark interpretation of the anomalous HERA positron-jet events in the context of the YFS exponentiated Monte Carlo event generator treatment of the attendant multiple photon radiative effects for both the would-be signal and the SM background, wherein finite-$p_T$ photon effects are properly taken into account and wherein infrared singula

Klaus Behrndt, Dieter Lust, Wafic. A. Sabra

We discuss general bosonic stationary configurations of N=2, D=4 supergravity coupled to vector multiplets. The requirement of unbroken supersymmetries imposes constraints on the holomorphic symplectic section of the underlying special Kähler manifold. The corresponding solutions of the field equations are completely determined by a set of harmonic functions

Sergio Pastor, Saurabh D. Rindani, Jose W. F. Valle

We consider in this paper a Left-Right symmetric gauge model in which a global lepton-number-like symmetry is introduced and broken spontaneously at a scale that could be as low as 10^4 GeV or so. The corresponding physical Nambu-Goldstone boson, which we call majoron and denote J, can have tree-level flavour-violating couplings to the charged fermions, lead

V. E. Rochev

A method for solving Schwinger-Dyson equations for the Green function generating functional of non-Abelian gauge theory is proposed. The method is based on an approximation of Schwinger-Dyson equations by exactly soluble equations. For the SU(2) model the first step equations of the iteration scheme are solved which define a gauge field propagator. Apart fro

D. Bruss, D. P. DiVincenzo, A. Ekert, C. A. Fuchs

We establish the best possible approximation to a perfect quantum cloning machine which produces two clones out of a single input. We analyze both universal and state-dependent cloners. The maximal fidelity of cloning is shown to be 5/6 for universal cloners. It can be achieved either by a special unitary evolution or by a novel teleportation scheme. We cons

B. V. Ivanov

An exact solution is found describing the collision of axisymmetric pp-waves with M=0. They are impulsive in character and their coordinate singularities become point curvature singularities at the boundaries of the interaction region. The solution is conformally flat. Concrete examples are given, involving an ultrarelativistic black hole against a burst of

A. P. C. Malbouisson, F. S. Nogueira, N. F. Svaiter

We consider the phase transition in a model which consists of a Ginzburg-Landau free energy for superconductors including a Chern-Simons term. The mean field theory of Halperin, Lubensky and Ma [Phys. Rev. Lett. 32, 292 (1974)] is applied for this model. It is found that the topological mass, $θ$, drives the system into different regimes of phase transition.

X. Barcons, A. C. Fabian, F. J. Carrera

The precision of intensity measurements of the extragalactic X-ray Background (XRB) on an angular scale of about a degree is dominated by spatial fluctuations caused by source confusion noise. X-ray source counts at the flux level responsible for these fluctuations will soon be accurately measured by new missions and it will then be possible to detect the we

S. P. Baranov, L. V. Fil&#39;kov, N. A. Loktionova

We consider the evolution of a spherically symmetric Quark-Gluon Plasma (QGP) drop with limited size in the framework of relativistic hydrodynamics. In the presence of the boundary, the expanding and cooling of QGP drop may appear as oscillating processes, which realize via multiple traveling of rarefaction and compression waves through the plasma and lead t

P. Antonioli, C. Ghetti, E. V. Korolkova, V. A. Kudryavtsev

We present a new three-dimensional Monte-Carlo code MUSIC (MUon SImulation Code) for muon propagation through the rock. All processes of muon interaction with matter with high energy loss (including the knock-on electron production) are treated as stochastic processes. The angular deviation and lateral displacement of muons due to multiple scattering, as wel

S. Moretti

In a recent study by Dittmar and Dreiner it was shown that with appropriate selection cuts the signature of events containing two charged leptons and missing energy represents the best chance of detecting the Standard Model Higgs scalar in the mass range between 155 and 180 GeV, the primary decay of the Higgs being into pairs of charged gauge bosons. The lar

A. K. Nguyen, A. Sudbø

Monte-Carlo simulations in conjunction with finite-size scaling analysis are used to investigate the $(H,T)$-phase diagram in uniaxial anisotropic high- $T_c$ superconductors, both in zero magnetic field and in intermediate magnetic fields for various mass-anisotropies. The model we consider is the uniformly frustrated anisotropic Villain Model. In zero magn

M. J. W. Dodgson, V. B. Geshkenbein, H. Nordborg, G. Blatter

We derive expressions for the jumps in entropy and magnetization characterizing the first-order melting transition of a flux line lattice. In our analysis we account for the temperature dependence of the Landau parameters and make use of the proper shape of the melting line as determined by the relative importance of electromagnetic and Josephson interaction

Victor S. L&#39;vov, Evgenii Podivilov, Itamar Procaccia

All statistical models of turbulence take into account Kolmogorov&#39;s exact result known as the &#34;4/5 law&#34; which stems from energy conservation. This law states that the energy flux expressed as a spatial derivative of the 3rd order velocity correlator equals the rate of energy dissipation. We have found an additional exact result which stems from t

Takahiro Masuda, Toru Sasaki, Hisao Suzuki

In SU(2) Seiberg-Witten theory, it is known that the dual pair of fields are expressed by hypergeometric functions. As for the theory with SU(3) gauge symmetry without matters, it was shown that the dual pairs of fields can be expressed by means of the Appell function of type F_4. These expressions are convenient for analyzing analytic properties of fields.

Girish S. Setlur

We introduce an exactly solvable model of a fermi gas in one dimension and compute the momentum distribution exactly. This is based on a generalisation of the ideas of bosonization in one dimension. It is shown that in the RPA limit(the ultra-high density limit) the answers we get are the exact answers for a homogeneous fermi gas interacting via a two-body r

Partha Guha, Kanehisa Takasaki

The dispersionless KP and Toda hierarchies possess an underlying twistorial structure. A twistorial approach is partly implemented by the method of Riemann-Hilbert problem. This is however still short of clarifying geometric ingredients of twistor theory, such as twistor lines and twistor surfaces. A more geometric approach can be developed in a Hamilton-Jac

R. Vilela Mendes

Semiclassical methods form a bridge between classical systems and their quantum counterparts. An interesting phenomenon discovered in this connection is the scar effect, whereby energy eigenstates display enhancement structures resembling the path of unstable periodic orbits. This paper deals with collision states in charged three-body problems, in periodic

V. I. Man&#39;ko, R. Vilela Mendes

q-oscillators are associated to the simplest non-commutative example of Hopf algebra and may be considered to be the basic building blocks for the symmetry algebras of completely integrable theories. They may also be interpreted as a special type of spectral nonlinearity, which may be generalized to a wider class of f-oscillator algebras. In the framework of

Robert L. Gluckstern, Sergey S. Kurennoy

Beam stability and halo formation in high-intensity axisymmetric 2D beams in a uniform focusing channel are analyzed using particle-in-cell simulations. The tune depression - mismatch space is explored for the uniform (KV) distribution of the particle transverse-phase-space density, as well as for more realistic ones (in particular, the water-bag distributio

Holger F. Hofmann, Ortwin Hess

A rate equation model describing the laser dynamics of general one or two dimensional vertical cavity surface emitting laser (vcsel) arrays is introduced. It is shown that the theory includes both the previous theory for edge emitting semiconductor laser arrays and the theory of polarization dynamics in single quantum well vcsels in a single unified descript

P. Collet

We consider the development of instabilities of homogeneous stationary solutions of discrete time lattice maps. Under some generic hypothesis we derive an amplitude equation which is the space-time continuous Ginzburg-Landau equation. Using dynamical renormalization group methods we control the accuracy of this approximation in a large ball of its basin of a

David R. Harrington

A finite-dimensional matrix model for the nucleon-nucleon cross section operator is used to calculate the dispersive correction to nucleon-nucleus total cross sections, and the leading terms in its expansion in the number of inelastic transitions in the high-energy limit where the longitudnal momentum transfers can be ignored.

L. Faddeev, A. J. Niemi

Previously we have proposed that in certain relativistic quantum field theories knotlike configurations may appear as stable solitons. Here we present a detailed investigation of the simplest knotted soliton, the torus-shaped unknot.

Micha Berkooz, Moshe Rozali

We suggest that the (2,0) six dimensional field theory compactified on $S^1\times K3$ is the Matrix model description of both M-theory on $K3$ and the Heterotic string on $T^3$. This proposal is different from existing proposals for the Heterotic theory. Different limits of the base space geometry give the different space-time interpretations, making M-theor

Brandon Carter

This course provides a self contained introduction to the general theory of relativistic brane models, of the category that includes point particle, string, and membrane representations for phenomena that can be considered as being confined to a worldsheet of the corresponding dimension (respectively one, two, and three) in a thin limit approximation. The fi

Renat Zhdanov

An efficient procedure for constructing quasi-exactly solvable matrix models is suggested. It is based on the fact that the representation spaces of representations of the algebra sl(2,R) within the class of first-order matrix differential operators contain finite dimensional invariant subspaces.

Stuart Samuel

Energy eigenstates for N=2 supersymmetric gauged quantum mechanics are found for the gauges groups SU(n) and U(n). The analysis is aided by the existence of an infinite number of conserved operators. The spectum is continuous. Perturbative eigenstates for $N>2$ are also presented, a case which is relevant for the conjectured description of M theory in the in

K. S. Babu, Christopher Kolda, John March-Russell

A recent proposal seeks to explain the anomaly in the HERA high-Q^2 neutral current e^+p data by modifying the parton distribution functions at moderate-to-high-x and large Q^2. We investigate the consequences of this proposal for the HERA high-Q^2 data itself, in the neutral current e^-p channel and especially in the charged current e^\pm p channels. We fin

S. Pakvasa

I would like to discuss $D^0-\bar{D}^0$ the mixing and rare D decays as manifestations of Flavor Changing Neutral Currents (FCNC) in the charm sector. I will first review the expectations in the Standard Model (SM) and then summarize some typical expectations in new physics scenarios. I would like to argue that the charm case offers a large window of opportu

A. N. Kamal, C. W. Luo

We study the role played by the final-state interactions (fsi) in heavy quark decays using Pomeron and Regge exchanges to describe high energy scattering. At center of mass energy $\sqrt{s}\sim 5GeV $, Pomeron dominance does not apply. We study the behavior of the decay amplitudes as $\sqrt{s} $ is varied close to the B mass. We also investigate the behavior

John Collins

I give a pedagogical summary of the methods of light-cone variables, rapidity and pseudo-rapidity. Then I show how these methods are useful in analyzing diffractive high-energy collisions.

M. Maris, S. T. Petcov

Using the results of a high precision calculation of the solar neutrino survival probability for Earth crossing neutrinos in the case of MSW $ν_e \to ν_{μ(τ)}$ transition solution of the solar neutrino problem, performed in an earlier study, we derive predictions for the one-year averaged day-night (D-N) asymmetry in the deformations of the $e^-$ - spectrum

P. Colangelo, C. A. Dominguez, G. Nardulli

We examine the origin of possible failures of the quark-hadron local duality. In particular, we consider a correlator of two currents comprising heavy quark operators, and compare the evaluation by the Operator Product Expansion with the result obtained inserting an infinite set of hadronic states, in the N_c to infinity limit. Whereas the smeared spectral f

S. Moretti, K. Odagiri

The complete matrix elements for $e^+e^-\to b\bar bW^\pm H^\mp$ and $e^+e^-\to b\bar bH^+H^-$ are computed at tree-level within the Minimal Supersymmetric Standard Model. Rates of interest to phenomenological analyses at the Next Linear Collider are given. In particular, we analyse: (i) $t\bar t$ pair production followed by the top decays into $b\bar bW^\pm

A. P. Bukhvostov

The analysis of Tables of particle properties shows that the probability distribution of the results of physical measurements is far from the conventional Gaussian $ρ(ξ)=exp(-ξ^2/2) $, but is more likely to follow the simple exponential law $ρ(ξ)=exp(-ξ)$ ($ξ$ is the deviation of the measured from the true value in units of the presented standard error). A g

Massimo D&#39;Elia, Adriano Di Giacomo, Enrico Meggiolaro

We study, by numerical simulations on a lattice, the behaviour of the gauge-invariant two-point correlation functions of the gauge field strengths in the QCD vacuum with dynamical fermions.

V. I. Tkach, J. J. Rosales

On the basis of the local n=2 supersymmetry we construct the supersymmetric action for a set of complex scalar supermultiplets in the FRW model. This action corresponds to the dilaton-axion and chiral components of supergravity theory.

Sukratu Barve, T. P. Singh

We examine the growth of the Weyl curvature in two examples of naked singularity formation in spherical gravitational collapse - dust and the Vaidya spacetime. We find that the Weyl scalar diverges along outgoing radial null geodesics as they meet the naked singularity in the past. The implications of this result for the Weyl curvature hypothesis are discuss