June 1999 arXiv papers — page 17

Yoav Moriah

It is proven here that if the connected sum of two tunnel number one knots in the 3-sphere is a tunnel number two knot, then at least one of the summand knots has a genus two Heegaard splitting with a meridian as a primitive element. Hence this is a necessary and sufficient condition for tunnel number one knots to have additive tunnel number.

Hitoshi Murakami, Jun Murakami

We show that the set of colored Jones polynomials and the set of generalized Alexander polynomials defined by Akutsu, Deguchi and Ohtsuki intersect non-trivially. Moreover it is shown that the intersection is (at least includes) the set of Kashaev's quantum dilogarithm invariants for links. Therefore Kashaev's conjecture can be restated as follows: T

David Borthwick, Peter Perry

For a class of manifolds that includes quotients of real hyperbolic space by a convex co-compact discrete group, we show that the resonances of the meromorphically continued resolvent kernel for the Laplacian coincide, with multiplicities, with the poles of the meromorphically continued scattering operator. In order to carry out the proof, we use Shmuel Agmo

Valeri V. Dvoeglazov

Developing recently proposed constructions for the description of particles in the $(1/2,0)\oplus (0,1/2)$ representation space, we derive the second-order equations. The similar ones were proposed in the sixties and the seventies in order to understand the nature of various mass and spin states in the representations of the $O(4,2)$ group. We give some addi

E. Gabrielli

We present a general review about the N=1 supersymmetric SU(Nc) Yang-Mills on the lattice focusing our attention on the quenched approximation in supersymmetry. Finally we analyse and discuss the recent results obtained at strong coupling and large Nc for the mesonic and fermionic propagators and spectrum.

Frederik Denef, Joris Raeymaekers, Walter Troost

We present a brief historical overview of the classical theory of a radiating point charge, described by the Lorentz-Dirac equation. A recent development is the discovery of tunnelling of a charge through a potential barrier, in a completely classical context. Also, a concrete example is discussed of the existence of several physically acceptable solutions f

K. Lechner, P. A. Marchetti

We present a manifestly Lorentz- and SO(2)-Duality-invariant local Quantum Field Theory of electric charges, Dirac magnetic monopoles and dyons. The manifest invariances are achieved by means of the PST-mechanism. The dynamics for classical point particles is described by an action functional living on a circle, if the Dirac-Schwinger quantization condition

Bert Janssen, Sudipta Mukherji

We review the method of constructing dipole and string loop solutions from the higher-dimensional (Euclidean) Kerr black hole. We analyse the results in various dimensions, finding solutions earlier given in the literature. Then we construct a new heterotic dipole with non-trivial dilaton and gauge fields. This can, in turn, be describes as a brane/anti-bran

Y. Matsuo

By a toroidal compactification with a vortex like configuration of tachyon fields, the unoriented bosonic string in 26 dimensions becomes equivalent to 10 dimensional string theory with gauge group $SO(32)\times G$ where $G$ has rank 16. The reduction from SO(8192) to SO(32) is induced by the action of non-abelian Wilson lines which twists the tachyon. The a

O. G. Miranda, J. Segura, V. B. Semikoz, J. W. F. Valle

Neutrino-electron scattering can be used to probe neutrino electromagnetic properties at low-threshold underground detectors with good angular and recoil electron energy resolution. We propose to do this using a number of artificial neutrino and anti-neutrino sources such as $^{51}Cr_{24}$ and $^{90}Sr-Y$. The neutrino flux is known to within one percent, in

D. Yu. Peressounko, Yu. E. Pokrovsky

Yield of direct photons in Pb+Pb collisions at SpS and LHC energy is evaluated with emphasis on estimate of possible uncertainty. Possibility of experimental observation of direct photons at LHC is discussed. Predictions of several models at SpS energy are compared with experimental data.

Stanley J. Brodsky, Michael Melles, Johan Rathsman

The interaction potential V(Q^2) between static test charges can be used to define an effective charge $α_V(Q^2)$ and a physically-based renormalization scheme for quantum chromodynamics and other gauge theories. In this paper we use recent results for the finite-mass fermionic corrections to the heavy-quark potential at two-loops to derive the next-to-leadi

R. S. Thorne

I examine the form of the solution of the BFKL equation with running coupling relevant for deep inelastic scattering. The evolution of structure functions is precisely determined and well described by an effective coupling of the form 1/(beta_0(ln(Q^2/Lambda^2)+3.6(alpha_s(Q^2)ln(1/x))^1/2)) (until very small x). Corrections to the LO equation are relatively

A. H. Mueller

The early stages in the evolution of the gluons produced in the central region of a head-on high-energy heavy ion collision is studied. An equation is given for the rate of change of transverse momentum into longitudinal momentum where the longitudinal direction is along the collision axis. We are able to follow the system up to the time where equilibration

Harry J. Lipkin, Marek Karliner

We present a simple explanation of the underlying physics in the use of hyperon decay data to obtain information about proton spin structure. We also present an alternative input using nucleon magnetic moment data and show that the results from the two approaches are nearly identical. The role of symmetry breaking is clarified while pointing out that simple

S. Capitani, M. Göckeler, R. Horsley, D. Petters

A genuinely non-perturbative evaluation of higher-twist contributions to the structure functions of the nucleon, with all mixing effects and renormalon ambiguities taken care of, is presented. Higher-twist corrections turn out to be significant at moderate values of $q^2$.

V. L. Morgunov, A. V. Nefediev, Yu. A. Simonov

The spectra of light-light and heavy-light mesons are described by spinless Salpeter equation and Dirac equation respectively, which predict linear dependence of the meson mass squared M^2 on angular momentum J and number of radial nodes n. Both spectra are computed by the WKB method and shown to agree with exact numerical data within few percent even for th

Alexander Lenz

In this talk we present a calculation of the dacay rate difference in the neutral $B_s-\bar{B}_s$ system, $ΔΓ_{B_s}$, in next-to-leading order (NLO) QCD. We find a sizeable decrease compared to leading-order (LO) estimates: $ (ΔΓ/Γ)_{B_s} = (f_{B_s}/210 MeV)^2 [0.006 B(m_b) + 0.150 B_S(m_b) - 0.0063]$ in terms of the bag parameters $B$ and $B_S$ in the NDR s

Christer Friberg, Torbjörn Sjöstrand

We propose a scheme that could offer a convenient Monte Carlo sampling of next-to-leading-order matrix elements and, at the same time, allow the interfacing of such parton configurations with a parton-shower approach for the estimation of higher-order effects. No actual implementation exists so far, so this note should only be viewed as the outline of a poss

J. Hisano

It can be expected from the result for the atmospheric neutrino by the SUPERKAMIOKANDE and the CHOOZ result that the the lepton-flavor violating (LFV) interaction between the second and third generations exits at the high energy scale. This leads to a non-vanishing LFV left-handed slepton mass between the second and third generations, induced by the radiativ

Yuval Grossman, Howard E. Haber

R-parity-violating supersymmetry with a conserved baryon number B provides a framework for particle physics with lepton number (L) violating interactions. Two important probes of the L-violating physics are neutrino masses and sneutrino-antisneutrino mass-splittings. We evaluate these quantities in the context of the most general CP-conserving, R-parity-viol

V. Daniel Elvira

We have made a precise measurement of the inclusive jet cross section at 1800 GeV. The result is based on an integrated luminosity of 92 pb**-1 collected at the Fermilab Tevatron pbarp Collider with the DO detector. The measurement is reported as a function of jet transverse energy (60 GeV < ET < 500 GeV), and in the pseudorapidity intervals |eta|<0.5 and 0.

Paolo Bernardini

The flux of muons induced by atmospheric neutrinos has been measured with the MACRO detector. Different event topologies have been detected, due to neutrino interactions in the apparatus and in the rock below it. The upward-throughgoing muon sample is the larger one and is generated by neutrinos with a peak energy of ~100 GeV. The observed upward-throughgoin

P. -O. Meyer

The internal jet structure in dijet production in deep-inelastic scattering is measured with the H1 detector at HERA. Jets with transverse energies E(T,breit) > 5 GeV are selected in the Breit frame employing kt and cone jet algorithms in the kinematic region of squared momentum transfers of 10 < Q^2 < 120 GeV^2 and x-Bjorken values of 0.0002 < x < 0.008. Je

YBJ Collaboration, presented by S. M. Mari

The ARGO-YBJ experiment will be installed at YangBaJing Cosmic Ray Laboratory (Tibet, P.R. China), 4300 m a.s.l. . It consists of a full coverage of about 10^4 m^2 realized with RPC chambers. A small carpet of about 50 m^2 has been operated at YangBaJing in order to check the RPC performance in these high altitude conditions. Results concerning efficiency an

Albert Roura, Enric Verdaguer

We compute the influence action for a system perturbatively coupled to a linear scalar field acting as the environment. Subtleties related to divergences that appear when summing over all the modes are made explicit and clarified. Being closely connected with models used in the literature, we show how to completely reconcile the results obtained in the conte

Ll. Bel

We define a hierarchy of dynamic relaxed gas spheres as solutions of the Poisson equation coupled to a hierarchy of approximations of the Liouville equation leading, when this equation is satisfied, to the well-known isothermal gas spheres in the static case, but also to a new form of dynamic maximum relaxation. The two previous steps of the hierarchy corres

R. Casadio, B. Harms

In this paper we analyze a binary system consisting of a star and a rotating black hole. The electromagnetic radiation emitted by the star interacts with the background of the black hole and stimulates the production of dilaton waves. We then estimate the energy transferred from the electromagnetic radiation of the star to the dilaton field as a function of

Alejandro B. Kolton, Daniel Dominguez, Niels Gronbech-Jensen

We study driven vortices lattices in superconducting thin films. Above the critical force $F_c$ we find two dynamical phase transitions at $F_p$ and $F_t$, which could be observed in simultaneous noise measurements of the longitudinal and the Hall voltage. At $F_p$ there is a transition from plastic flow to smectic flow where the voltage noise is isotropic (

Carey Huscroft, Richard Gass, Mark Jarrell

We describe a novel method to obtain thermodynamic properties of quantum systems using Baysian Inference -- Maximum Entropy techniques. The method is applicable to energy values sampled at a discrete set of temperatures from Quantum Monte Carlo Simulations. The internal energy and the specific heat of the system are easily obtained as are errorbars on these

A. Marini, M. Cini

We propose a computationally simple model of Auger and APECS line shapes from open-band solids. Part of the intensity comes from the decay of unscreened core-holes and is obtained by the two-body Green&#39;s function $G^{(2)}_ω$, as in the case of filled bands. The rest of the intensity arises from screened core-holes and is derived using a variational descr

E. N. Bulgakov, K. N. Pichugin, A. F. Sadreev, P. Středa

The effect of spin-orbit interaction on electron transport properties of a cross-junction structure is studied. It is shown that it results in spin polarization of left and right outgoing electron waves. Consequently, incoming electron wave of a proper polarization induces voltage drop perpendicularly to the direct current flow between source and drain of th

A. Komnik, R. Egger

Transport properties of metallic single-wall nanotubes are examined based on the Luttinger liquid theory. Focusing on a nanotube transistor setup, the linear conductance is computed from the Kubo formula using perturbation theory in the lead-tube tunnel conductances. For sufficiently long nanotubes and high temperature, phonon backscattering should lead to a

W. Prellier, M. Rajeswari, T. Venkatesan, R. L. Greene

Oriented, single phase thin films of La_{1-x}Ca_{x}MnO_{3} have been deposited onto (100)-oriented LaAlO_{3} (0.1<x<0.5) substrates using the Pulsed Laser Deposition technique. While for some compositions the physical properties (transport and magnetization) of the as-grown films are higher than the bulk values, for other calcium contents the optimized prope

A. Guarino, R. Scorretti, S. Ciliberto, A. Garcimartin

The acoustic emission of fracture precursors is measured in heterogeneous materials. The statistical behaviour of these precursors is studied as a function of the load features and the geometry. We find that the time interval between events (precursors) and events energies are power law distributed and that the exponents of these power laws depend on the loa

Sean Langridge, Joerg Schmalian, C. H. Marrows, D. T. Dekadjevi

The in-plane correlation lengths and magnetic disorder of magnetic domains in a transition metal multilayer have been studied using neutron scattering techniques. A new theoretical framework is presented connecting the observed scattering to the in-plane correlation length and the dispersion of the local magnetization vector about the mean macroscopic direct

J. K. Freericks, V. Zlatic, Mark Jarrell

An approximate scaling relation is found for the transition temperature to a charge-density-wave instability in the anharmonic electron-phonon problem, which maps a wide range of interaction strengths, anharmonicities, and phonon frequencies onto a common functional form. The relation employs the wave-function renormalization parameter and is valid even for

Haranath Ghosh

We study the superconducting phase with two component order parameter scenario, such as, $d_{x^2-y^2} + e^{iθ}s_α$, where $α= xy, x^2+y^2$. We show, that in absence of orthorhombocity, the usual $d_{x^2-y^2}$ does not mix with usual $s_{x^2+y^2}$ symmetry gap in an anisotropic band structure. But the $s_{xy}$ symmetry does mix with the usual d-wave for $θ=0$

K. R. Thurber, T. Imai, T. Saitoh, M. Azuma

We probed spin-spin correlations up to 725 K with 63Cu NQR in the S= 1/2 three-leg ladder Sr2Cu3O5. We present experimental evidence that below 300 K, weak inter-ladder coupling causes dimensional crossover of the spin-spin correlation length ξfrom quasi-1d (ξ~ 1/T) to anisotropic 2d regime (ξ\~ exp[2πρ_{s}/T], where 2πρ_{s} = 290 +/- 30 K is the effective s

J. F. de Lima, M. E. G. Valerio, E. Okuno

In this work we investigate the effect of gamma and ultraviolet radiations on the thermoluminescence of Brazilian calcite. The irradiated samples presented three TL peaks at 150, 245 and 320^oC (at a linear heating rate of 1.8^oC/s), with a main emission band centered at 615nm due to the ^4G \to ^6S transition of the Mn^{2+}. The irradiated samples presented

Zoltan Neufeld, Cristobal Lopez, Peter H. Haynes

The spatial distribution of interacting chemical fields is investigated in the non-diffusive limit. The evolution of fluid parcels is described by independent dynamical systems driven by chaotic advection. The distribution can be filamental or smooth depending on the relative strength of the dispersion due to chaotic advection and the stability of the chemic

Giorgio Mantica

An elementary application of Algorithmic Complexity Theory to the polygonal approximations of curved billiards-integrable and chaotic-unveils the equivalence of this problem to the procedure of quantization of classical systems: the scaling relations for the average complexity of symbolic trajectories are formally the same as those governing the semi-classic

Christian Knigge

Mass loss appears to be a common phenomenon among disk-accreting astrophysical systems. An outflow emanating from an accretion disk can act as a sink for mass, angular momentum and energy and can therefore alter the dissipation rates and effective temperatures across the disk. Here, the radial distributions of dissipation rate and effective temperature acros

M. Serra-Ricart, A. Oscoz, T. Sanchis, E. Mediavilla

CCD observations of the gravitational lens system Q0957+561A,B in the BVRI bands are presented in this paper. The observations, taken with the 82 cm IAC-80 telescope, at Teide Observatory, Spain, were made from the beginning of 1996 February to 1998 July, as part of an on-going lens monitoring program. Accurate photometry was obtained by simultaneously fitti

Nikolai N. Chugai, Victor P. Utrobin

We analyzed the spectra and light curve of the peculiar type II-P supernova 1997D to recover ejecta parameters. The optimal hydrodynamical model of SN 1997D, which meets observational constraints at the photospheric epoch, suggests a low explosion energy of about $10^{50}$ erg, ejecta mass around $6 M_{\odot}$, and presupernova radius near $85 R_{\odot}$. We

R. D. Jeffries

I present the results of a programme to monitor the strengths of the Li I 6708A, K I 7699A and chromospheric Halpha lines in a group of cool Pleiades stars. Consistent instrumentation and analysis techniques are used to show that there is no Li I variability on timescales of 1 year that could possibly account for the apparent spread in Li abundances seen in

Letizia Stanghellini

Planetary nebulae (PNe) exist in a range of different morphologies, from very simple and symmetric round shells, to elliptical, bipolar, and even quadrupolar shapes. They present extremely complex ensembles of filaments, knots, ansae, and shell multiplicity. It is then overwhelmingly complicated to derive reasonable evolutionary paths to justify the observed

Simon P. Goodwin, Peter A. Thomas, Andrew J. Barber, John Gribbin

The effects of differences between the local and global values of the Hubble parameter on the cosmologies consistent with studies of high-redshift Type Ia supernovæare discussed. It is found that with a local Hubble parameter around 10 per cent higher than the global value then open cosmological models (such as $Ω_{M} = 0.3, Ω_Λ=0$) are prefered and if the l

M. Jamrozy, J. Machalski

The evidence are given that the radio source GB2 0909+353 (GB2 catalogue: Machalski 1978; ICRS 2000.0 coordinates: 09 12 51.7, +35 10 10) is likely one of the largest classical doubles known, though its optical identification is not certain. Our deep VLA observations at 5 GHz did not reveal a radio core brighter than 0.5 mJy/beam at this frequency. Thus a di

YBJ Collaboration, presented by S. Vernetto

The study of high energy gamma-ray bursts can be performed by large area air shower arrays operating at very high mountain altitudes. ARGO-YBJ is a detector optimized to observe small size air showers, to be constructed at the Yangbajing Laboratory (Tibet, P.R. China) at an altitude of 4300 m. One of the goals of the experiment is the study of Gamma-Ray Burs

Masahiro Nagashima, Naoteru Gouda

We examined the physical origin of the colour-magnitude relation of elliptical galaxies in clusters of galaxies in the hierarchical clustering scenario by using a semi-analytic model of galaxy formation. We particularly investigate the effects of the star formation process, the supernova feedback and the UV background on the formation and evolution of ellipt

B. D&#39;Ettorre Piazzoli

An RPC carpet covering about 10^4 m^2 (ARGO-YBJ experiment) will be installed in the YangBaJing Laboratory (Tibet, P.R. China) at an altitude of 4300 m a.s.l. . A test-module of about 50 m^2 has been put in operation in this laboratory and about 10^6 air shower events have been collected. The carpet capability of reconstructing the shower features is present

R. Tagliaferri, A. Ciaramella, L. Milano, F. Barone

Periodicity analysis of unevenly collected data is a relevant issue in several scientific fields. In astrophysics, for example, we have to find the fundamental period of light or radial velocity curves which are unevenly sampled observations of stars. Classical spectral analysis methods are unsatisfactory to solve the problem. In this paper we present a neur

Jorge Melendez

Hyperfine interaction constants and hyperfine components of MnI lines in the near-infrared J and H bands were obtained by fitting the solar spectrum. I identified the 17744-A solar absorption line as resulting from MnI and I discarded the identifications of the 13281.65-A and 16929.85-A solar features as a result of FeI and MnI, respectively

Kyu-Hyun Chae

The gravitational lens 0957+561 is modeled utilizing recent observations of the galaxy and the cluster as well as previous VLBI radio data which have been re-analyzed recently. The galaxy is modeled by a power-law elliptical mass density with a small core while the cluster is modeled by a non-singular power-law sphere as indicated by recent observations. Usi

D. S. Main, D. M. Smith, W. A. Heindl, J. Swank

We report on long-term observations of the Galactic-bulge black hole candidates 1E 1740.7-2942 and GRS 1758-258 with the Rossi X-Ray Timing Explorer. 1E 1740.7-2942 has been observed 77 times and GRS 1758-258 has been observed 82 times over the past 1000 days. The flux of each object has varied by no more than a factor of 2.5 during this period, and the indi

Monica Valluri, David Merritt

The maximally compact representation of a regular orbit is in terms of its action-angle variables. Computing the map between a trajectory&#39;s Cartesian coordinates and its action-angle variables is called torus construction. This article reviews various approaches to torus construction and their application to galactic dynamics.

Andrew J. Bunker, Stephen J. Warren, D. L. Clements, Gerard M. Williger

We present the results of a long-slit K-band spectroscopic search for H-alpha emission from eight damped Ly-alpha absorbers (DLAs) at z>2 with the goal of measuring the star-formation rates in these systems. For each system we searched for compact sources of H-alpha emission within a solid angle 11x2.5arcsec^2 (44x10 kpc^2/h^2, for q_0=0.5, H_0=100 h km/s/Mp

Chung-Pei Ma, R. R. Caldwell, Paul Bode, Limin Wang

We present simple analytic approximations for the linear and fully evolved nonlinear mass power spectrum for spatially flat cold dark matter (CDM) cosmological models with quintessence (Q). Quintessence is a time evolving, spatially inhomogeneous energy component with negative pressure and an equation of state w_Q < 0. It clusters gravitationally on large le

Thorsten Poeschel, Nikolai V. Brilliantov

The transmission of kinetic energy through chains of inelastically colliding spheres is investigated for the case of constant coefficient of restitution ε=const and impact-velocity dependent coefficient ε(v) for viscoelastic particles. We derive a theory for the optimal distribution of particle masses which maximize the energy transfer along the chain and ch

E. H. Rezayi, F. D. M. Haldane

We consider the two lowest Landau levels at half filling. In the higher Landau level (nu =5/2), we find a first order phase transition separating a compressible striped phase from a paired quantum Hall state, which is identified as the Moore-Read state. The critical point is very near the Coulomb potential and the transition can be driven by increasing the w

D. DeMille, D. Budker, N. Derr, E. Deveney

Atomic two-photon J=0 $\leftrightarrow$J&#39;=1 transitions are forbidden for photons of the same energy. This selection rule is related to the fact that photons obey Bose-Einstein statistics. We have searched for small violations of this selection rule by studying transitions in atomic Ba. We set a limit on the probability $v$ that photons are in exchange-a

Berndt Müller

I review the three broad areas where major progress has been reported: The phase structure of strongly interacting matter, the properties of matter at the instant when it freezes out into individual hadrons in the final stage of the expansion of the hot fireball, and the status of the main signatures of the formation of a quark-gluon plasma. In the final sec

M. Athanas

From a data sample of 29058 $τ^\pm\toπ^\pmπ^+π^-π^0ν_τ$ decays observed in the CLEO detector we derive a 95% confidence upper limit on the tau neutrino mass of 28 MeV.

R. C. Nichol, A. K. Romer, B. P. Holden, M. P. Ulmer

We present here initial results on the X-ray Cluster Luminosity Function (XCLF) from the Bright SHARC sample of distant X-ray clusters of galaxies. This sample is 97% complete in its optical identifications and contains 12 X-ray luminous clusters in the range 0.3 < z < 0.83 (median z = 0.42) and 1.1 < Lx(44) < 8.5 erg/s [0.5-2.0 keV]. We present a preliminar

H. Dorn, V. D. Pershin

We derive a generalised concavity condition for potentials between static sources obtained from Wilson loops coupling both to gauge bosons and a set of scalar fields. It involves the second derivatives with respect to the distance in ordinary space as well as with respect to the relative orientation in internal space. In addition we discuss the use of this f

R. Banerjee, H. J. Rothe, K. D. Rothe

We reconsider the problem of finding all local symmetries of a Lagrangian. Our approach is completely Hamiltonian without any reference to the associated action. We present a simple algorithm for obtaining the restrictions on the gauge parameters entering in the definition of the generator of gauge transformations.

Henning A. Knudsen, Alex Hansen

Comments: 4 pages RevTeX, 4 Postscript figures. References added. We study a two-dimensional granular superconducting network at the percolation threshold under the influence of an external perpendicular magnetic field. By numerical simulations on the full nonlinear problem, we determine the scaling exponent for the magnetic susceptibility. Further, we repor

S. Gukov, C. Vafa, E. Witten

We consider F/M/Type IIA theory compactified to four, three, or two dimensions on a Calabi-Yau four-fold, and study the behavior near an isolated singularity in the presence of appropriate fluxes and branes. We analyze the vacuum and soliton structure of these models, and show that near an isolated singularity, one often generates massless chiral superfields

Anastasia Doikou, Rafael I. Nepomechie

We compute by Bethe Ansatz both bulk and boundary hole scattering matrices for the critical A_{N-1}^(1) quantum spin chain. The bulk S matrix coincides with the soliton S matrix for the A_{N-1}^(1) Toda field theory with imaginary coupling. We verify our result for the boundary S matrix using a generalization of the Ghoshal-Zamolodchikov boundary crossing re

Holger Gies

Within the QED effective action approach, we study the propagation of low-frequency light at finite temperature. Starting from a general effective Lagrangian for slowly varying fields whose structure is solely dictated by Lorentz covariance and gauge invariance, we derive the light cone condition for light propagating in a thermalized QED vacuum. As an appli

T. Masuda, I. Tsukada, K. Uchinokura, Y. J. Wang

We have performed detailed magnetic susceptibility measurements as well as synchrotron x-ray diffraction studies to determine the temperature vs concentration ($T$ - $x$) phase diagram of Cu${}_{1-x}$Mg${}_x$GeO${}_3$. We observe clear double peaks in the magnetic susceptibility implying two antiferromagnetic (AF) transition temperatures in samples with Mg c

M. Lutz

We present a new chiral expansion scheme for the nucleon-nucleon scattering amplitude which preserves unitarity exactly. Our effective field theory builds on the power counting rules for 2-nucleon reducible diagrams proposed in \cite{lutz}. We evaluate the leading order terms of the isospin one scattering amplitude and elaborate in detail on the $^1S_0$ phas

Miloslav Znojil

Schroedinger equation H ψ=E ψwith PT - symmetric differential operator H=H(x) = p^2 + a x^4 + i βx^3 +c x^2+i δx = H^*(-x) on L_2(-\infty,\infty) is re-arranged as a linear algebraic diagonalization at a>0. The proof of this non-variational construction is given. Our Taylor series form of ψcomplements and completes the recent terminating solutions as obtaine

K. Benabed, F. Bernardeau

Extending the Kaiser-Stebbins mechanism we propose here a method for detecting relics of topological defects such as cosmic strings based on lens-induced small-scale B-type polarization in the CMB. Models of inflation, in which large scale structures of the Universe emerge from the inflaton fluctuations,do not exclude the formation of topological defects at

Hideaki Hiro-Oka, Hisakazu Minakata

We discuss a dynamical mechanism of pion production from disoriented chiral condensates (DCC). It leads to an explosive production of pions via the parametric amplification mechanism, which is similar to the reheating mechanism in inflationary cosmology. Classically, it is related with the instability in the solutions of the Mathieu equation and we explore t

An-Min Li, Guosong Zhao, Quan Zheng

Interpreting the number of ramified covering of a Riemann surface by Riemann surfaces as the relative Gromov-Witten invariants and applying a gluing formula, we derive a recursive formula for the number of ramified covering of a Riemann surface by Riemann surface with elementary branch points and prescribed ramification type over a special point.

Chao-Shang Huang, Chun Liu, Shi-Lin Zhu

Λ_b matrix element of four-quark operator relevant to its lifetime is reanalyzed by QCD sum rule. The new ingredients introduced are that (1) more vacuum condensates are considered; (2) different quark-hadron duality is adopted; and (3) the possible deviation from the vacuum saturation assumption for the four quark condensates is considered. With κ_1=4 the r

Kavita Dorai, Arvind, Anil Kumar

We demonstrate experimentally the usefulness of selective pulses in NMR to perform quantum computation. Three different techniques based on selective pulse excitations have been proposed to prepare a spin system in a pseudo-pure state. We describe the design of novel ``portmanteau&#39;&#39; gates using the selective manipulation of level populations. A selec

S. Y. Panitkin, D. A. Brown

The reliable extraction of information from two-proton correlation functions is a long-standing problem in two-particle interferometry. Recently introduced imaging techniques give one the ability to reconstruct source functions from the correlation data in a model independent way. We explore the applicability of two-proton imaging to realistic sources with t

James Robinson, Eric Gawiser, Joseph Silk

We show how observations of the evolution of the galaxy cluster number abundance can be used to constrain primordial non-Gaussianity in the universe. We carry out a maximum likelihood analysis incorporating a number of current datasets and accounting for a wide range of sources of systematic error. Under the assumption of Gaussianity, the current data prefer

E. V. Gorbar, A. A. Natale

Using the Cornwall-Jackiw-Tomboulis effective potential for composite operators we compute the QCD vacuum energy as a function of the dynamical quark and gluon propagators, which are related to their respective condensates as predicted by the operator product expansion. The identification of this result to the vacuum energy obtained from the trace of the ene

James A. Besley, Peter D. Miller, Nail N. Akhmediev

We use multiscale perturbation theory in conjunction with the inverse scattering transform to study the interaction of a number of solitons of the cubic nonlinear Schroedinger equation under the influence of a small correction to the nonlinear potential. We assume that the solitons are all moving with the same velocity at the initial instant; this maximizes

S. Mancini

A stochastic control of the vibrational motion for a single trapped ion/atom is proposed. It is based on the possibility to continously monitor the motion through a light field meter. The output from the measurement process should be then used to modify the system&#39;s dynamics.

S. Mancini

The interaction of a quantum deformed oscillator with the environment is studied deriving a master equation whose form strongly depends on the type of deformation.

Yakir Aharonov, Benni Reznik

A gedanken-experiment is proposed for `weighing&#39;&#39; the total mass of a closed system from within the system. We prove that for an internal observer the time $τ$, required to measure the total energy with accuracy $ΔE$, is bounded according to $τΔE >\hbar $. This time-energy uncertainty principle for a closed system follows from the measurement back-re

Bhabani Prasad Mandal

We have studied the path integral solution of a system of particle moving in certain class of non-central potential without using Kustannheimo-Stiefel transformation. The Hamiltonian of the system has been converted to a separable Hamiltonian of Liouville type in parabolic coordinates and has further reduced to a Hamiltonian corresponding to two 2- dimension

Wei-Mou Zheng

Weyl&#39;s expansion for the asymptotic mode density of billiards consists of the area, length, curvature and corner terms. The area term has been associated with the so-called zero-length orbits. Here closed nonperiodic paths corresponding to the length and corner terms are constructed.

Jaroslav Pavel

In the report submitted here, an elementary formula is presented that allows calculation of the fine structure constant, derived on the basis of the unified theory of the electromagnetic and gravitational field elaborated by the author. This theory is based on the laws of relativity and quantum mechanics, in a brand new insight into the interpretation of gra

Vladimir G. Baryshevsky

The X-ray radiation delay law dependence on the diffraction asymmetry parameters is analyzed. It is shown that the use of subpicosecond pulses allows to observe the time delay of pulse in crystal phenomenon and to investigate the delay law experimentally. It is also shown that pulse delay law depends on the quanta polarization.

A. K. Ciftci, O. Gurkan, T. Olgar, E. Recepoglu

In this paper, main parameters for linac-ring type collider desinged for producing $ϕ$ particles copiously are estimated and potential of this machine in particle physics researches is investigated. Moreover, parameters for free electron laser and synchrotron radiation obtained from electron linac and positron ring, respectively, are determined and applicati

J. Ortner

An effective method based on Hubbard-Schofield approach [Phys. Lett. A {\bf 40}, 245 (1972)] is developed to calculate the free energy of classical Coulomb systems. This method significantly simplifies the derivation of the cluster expansion. A diagrammatic representation of the cluster integrals is proposed. Simple rules providing the leading order in densi

Valery P. Dmitriyev

Earlier obtained results on mechanical analogies of physical fields and particles are reviewed. The approach rests on the concept of the substratum - a mechanical medium, which occupies all the space and serves as a seat to support the light and to transmit interactions. A turbulent ideal fluid was chosen for the substratum. The turbulence is supposed to be

M. Bender, K. Rutz, P. -G. Reinhard, J. A. Maruhn

We study the extrapolation of nuclear shell structure to the region of superheavy nuclei in self-consistent mean-field models -- the Skyrme-Hartree-Fock approach and the relativistic mean-field model -- using a large number of parameterizations. Results obtained with the Folded-Yukawa potential are shown for comparison. We focus on differences in the isospin

A. De Pace, H. Feshbach, A. Molinari

Improvements are performed on a recently proposed statistical theory of the mean field of a many-fermion system. The dependence of the predictions of the theory upon its two basic ingredients, namely the Hartree-Fock energy and the average energy of the two particle-two hole excitations, is explored.

S. Sumowidagdo, T. Mart

By using the Gerasimov-Drell-Hearn (GDH) sum rule and an isobaric model of kaon photoproduction, we calculate contributions of kaon-hyperon final states to the magnetic moment of the proton and the neutron. We find that the contributions are small. The approximation of sigma_{TT&#39;} by sigma_{T} clearly overestimates the value of the GDH integral. We find

E. Gedalin, A. Moalem, L. Razdolskaya

We consider the application of heavy fermion formalism based ChPT to meson production in nucleon-nucleon collisions. It is shown that to each lower chiral order irreducible diagram there corresponds an infinite sequence of loop diagrams which are of the same momentum power order. This destroys the one-to-one correspondence between the loop and small momentum

Takumi Muto, Toshitaka Tatsumi, Naoki Iwamoto

We investigate the thermal kaon process,in which kaons are thermally produced via nucleon-nucleon collisions.This process is relevant to nonequilibrium dynamics of kaon condensation inside neutron stars.The reaction rates for these processes are calculated, and their temperature and density dependences are compared with those of other reaction rates.It is sh

A. G. Magner, S. N. Fedotkin, K. Arita, T. Misu

We derive an analytical trace formula for the level density of the two-dimensional elliptic billiard using an improved stationary phase method. The result is a continuous function of the deformation parameter (eccentricity) through all bifurcation points of the short diameter orbit and its repetitions, and possesses the correct limit of the circular billiard

G. Casini, G. Poggi, M. Bini, S. Calamai

Light charged particles emitted by the projectile-like fragment were measured in the direct and reverse collision of $^{93}$Nb and $^{116}$Sn at 25 AMeV. The experimental multiplicities of Hydrogen and Helium particles as a function of the primary mass of the emitting fragment show evidence for a correlation with net mass transfer. The ratio of Hydrogen and