Research archive

arXiv papers from August 1997

The most recent 100 records published that month. Open any paper for its original abstract, citation metadata, related research, and reading tools.

  1. R. B. Laughlin

    I propose that the phase transition in Bi2Sr2CaCu2O8 recently observed by by Krishana et al [Science 277, 83 (1997)] is the development of a small d-xy superconducting order parameter phased by pi/2 with respect to the principal d-(x2-y2) one to produce a minimum energy gap delta. The violation of both parity and time-reversal symmetry allows the development

  2. I. Oda

    Starting from topological quantum field theory, we derive space-time uncertainty relation with respect to the time interval and the spatial length proposed by Yoneya through breakdown of topological symmetry in the large N matrix model. This work suggests that the topological symmetry might be an underlying higher symmetry behind the space-time uncertainty p

  3. D. Montes, E. L. Martin

    We present a library of Utrecht echelle spectrograph (UES) observations of a sample of F, G, K and M field dwarf stars covering the spectral range from 4800 AA to 10600 AA with a resolution of 55000. These spectra include some of the spectral lines most widely used as optical and near-infrared indicators of chromospheric activity such as H_beta, Mg I b tripl

  4. K. Bering

    We describe gauge-fixing at the level of virtual paths in the path integral as a non-symplectic BRST-type of flow on the path phase space. As a consequence a gauge-fixed, non-local symplectic structure arises. Restoring of locality is discussed. A pertinent anti-Lie-bracket and an infinite dimensional group of gauge fermions are introduced. Generalizations t

  5. F. Podesta', A. Spiro

    We investigate compact Kahler manifolds, which are acted on by a semisimple compact Lie group G of isometries with one hypersurface orbit. In case of ordinary action and projectable complex structure, we set up a one to one correspondence between such manifolds and abstract models. The Ricci tensor is then computed and we fully characterize the Kahler-Einste

  6. M. Cederwall, P. K. Townsend

    We present a manifestly Sl(2;Z)-covariant action for the type IIB superstring, and prove kappa-symmetry for on-shell IIB supergravity backgrounds.

  7. David G. Cory, Mark D. Price, Timothy F. Havel

    We present experimental results which demonstrate that nuclear magnetic resonance spectroscopy is capable of efficiently emulating many of the capabilities of quantum computers, including unitary evolution and coherent superpositions, but without attendant wave-function collapse. Specifically, we have: (1) Implemented the quantum XOR gate in two different wa

  8. J. Kaluzny, R. W. Hilditch, C. Clement, S. M. Rucinski

    We describe here results of a photometric time-sequence survey of the globular cluster M3 (NGC 5272), in a search for contact and detached eclipsing binary stars. We have discovered only one likely eclipsing binary and one SX Phe type star in spite of monitoring 4077 stars with $V<20.0$ and observing 25 blue stragglers. The newly identified SX Phe star, V237

  9. P. Colangelo, M. Ladisa, G. Nardulli, T. N. Pham

    Using the Cottingham formula, we give an estimate of the electromagnetic mass splitting of pseudoscalar heavy mesons in the beauty and charm sector. We include in the dispersion relation the Born term, the $1^-$ resonance and the positive parity $1^+$ resonance. We also evaluate the contribution to the mass difference from the isospin breaking quark mass dif

  10. S. Cho, J. Madore, K. S. Park

    The $h$-deformed quantum plane is a counterpart of the $q$-deformed one in the set of quantum planes which are covariant under those quantum deformations of GL(2) which admit a central determinant. We have investigated the noncommutative geometry of the $h$-deformed quantum plane. There is a 2-parameter family of torsion-free linear connections, a 1-paramete

  11. J. Madore

    A review is made of recent efforts to add a gravitational field to noncommutative models of space-time. Special emphasis is placed on the case which could be considered as the noncommutative analog of a parallelizable space-time. It is argued that, at least in this case, there is a rigid relation between the noncommutative structure of the space-time on the

  12. A. Marshakov

    In this note it is demonstrated how the Seiberg-Witten solutions and related integrable systems may arise from certain brane configurations in M-theory. Some subtleties of the formulation of the Seiberg-Witten theory via integrable systems are discussed and interpreted along the lines of general picture of string/M-theory dualities.

  13. Keiichi Akama

    We derived and solved the compositeness condition in the Nambu-Jona-Lasinio model at the next-to-leading order in 1/N, and obtained the expressions for the effective coupling constants in terms of the compositeness scale. In the NJL model with a scalar composite, the next to leading contributions are too large for N=3. In the induced gauge theory with abelia

  14. Ying Shen, Shunhui Zhu

    Using an analogue of Myers' theorem for minimal surfaces and three dimensional topology, we prove the diameter sphere theorem for Ricci curvature in dimension three and a corresponding eigenvalue pinching theorem. This settles these two open problems for closed 3 manifolds with positive Ricci curvature since they are both false in dimensions greater than thr

  15. M. Hilke, J. C. Flores

    Continuous One-dimensional models supporting extended states are studied. These delocalized statesoccur at well defined values of the energy and are consequences of simple statistical correlation rules. We explicitly study alloys of delta-barrier potentials as well as alloys and liquids of quantum well as.The divergence of the localization length is studied

  16. Huai-Dong Cao, Ying Shen, Shunhui Zhu

    We provide a new topological obstruction for complete stable minimal hypersurfaces in R^n. For $n\geq 4$, we prove that any complete orientable stable hypersurfaces in R^n has only one end. This follows from a more general analytic theorem we prove in the paper.

  17. Michael Hilke

    We consider diagonal disordered one-dimensional Anderson models with an underlying periodicity. We assume the simplest periodicity, i.e., we have essentially two lattices, one that is composed of the random potentials and the other of non-random potentials. Due to the periodicity special resonance energies appear, which are related to the lattice constant of

  18. Nathan Argaman

    Wide mesoscopic superconducting - normal-metal - superconducting (S-N-S) junctions exhibit Andreev bound states which carry substantial supercurrents, even at temperatures for which the equilibrium Josephson effect is exponentially small --- the currents carried by different states can cancel each other. This cancellation is incomplete whenever the junctions

  19. V. V. Sokolov, V. G. Kurt, S. V. Zharikov, A. I. Kopylov

    In the framework of the hypothesis on potential sources of some gamma-ray bursts being single compact objects of neutron star type with finite surface temperature in the vicinity of the Sun a method of search in the optical range for a corresponding candidate in the region of a powerful short burst localization is considered. The localization region of the G

  20. S. G. Djorgovski

    Our understanding of the nature of DLA systems at large redshifts, ostensibly progenitors of normal disk galaxies, depends critically on their direct identifications with galaxies, and the resulting measurements of their properties. A few such objects have now been found, reaching out to z ~ 4.1. Their observed luminosities are L ~ L_*, star formation rates

  21. M. Hilke, D. Shahar, S. H. Song, D. C. Tsui

    We examine the magnetic field driven insulator-quantum Hall-insulator transitions of the two dimensional hole gas in a Ge/SiGe quantum well. We observe direct transitions between low and high magnetic field insulators and the $\nu=1$ quantum Hall state. With increasing magnetic field, the transitions from insulating to quantum Hall and quantum Hall to insula

  22. L. Dabrowski, P. M. Hajac, P. Siniscalco

    The exact sequence of ``coordinate-ring'' Hopf algebras A(SL(2,C)) -> A(SL_q(2)) -> A(F) determined by the Frobenius map Fr, and the same way obtained exact sequence of (quantum) Borel subgroups, are studied when q is a cubic root of unity. An A(SL(2,C))-linear splitting of A(SL_q(2)) making A(SL(2,C)) a direct summand of A(SL_q(2)) is constructed and used t

  23. Joerg Schmalian, David Pines, Branko Stojkovic

    We report on an exact solution of the nearly antiferromagnetic Fermi liquid spin fermion model in the limit \pi T << \omega_{sf}, which demonstrates that the broad high energy features found in ARPES measurements of the spectral density of the underdoped cuprate superconductors are determined by strong antiferromagnetic (AF) correlations and precursor effect

  24. I. M. Krichever, D. H. Phong

    We develop a Hamiltonian theory for 2D soliton equations. In particular, we identify the spaces of doubly periodic operators on which a full hierarchy of commuting flows can be introduced, and show that these flows are Hamiltonian with respect to a universal symplectic form $\omega={1\over 2}\r_{\infty} <\Psi_0^*\delta L\wedge\delta\Psi_0>\d k$. We also cons

  25. E. Zaremba

    We study the normal modes of a cylindrical Bose condensate at $T = 0$ using the linearized time-dependent Gross-Pitaevskii equation in the Thomas-Fermi limit. These modes are relevant to the recent observation of pulse propagation in long, cigar-shaped traps. We find that pulses generated in a cylindrical condensate propagate with little spread at a speed $c

  26. J. Málek, S. -L. Drechsler, G. Paasch, K. Hallberg

    Using exact diagonalizations we consider self-consistently the lattice distortions in odd Peierls-Hubbard and spin-Peierls periodic rings in the adiabatic harmonic approximation. From the tails of the inherent spin soliton the dimerization d_\infty of regular even rings is found by extrapolations to infinite ring lengths. Considering a wide region of electro

  27. L. Burakovsky, T. Goldman

    We show that the application of Regge phenomenology to SU(4) meson multiplets leads to a new Gell-Mann-Okubo mass-mixing formula in the SU(3) sector, 3m_1^2 + (cos theta)^2 m_0^2 + (sin theta)^2 m_{0'}^2 + sqrt{2} sin(2theta) (m_0^2 - m_{0'}^2) = 4m_{1/2}^2, where m_1,m_{1/2},m_0,m_{0'} are the masses of the isovector, isodoublet, isoscalar mostly octet and

  28. B. Jegerlehner

    We present a general method to construct multiple mass solvers from standard algorithms. As an example, the BiCGstab-M algorithm is derived.

  29. G. Abal, A. J. Pereira, A. Romanelli, A. Sicardi-Schifino

    Quantum systems with chaotic classical counterparts cannot be treated by perturbative techniques or any kind of adiabatic approximations. This is so, in spite of the quantum suppression of classical chaos. We explicitly calculate the adiabaticity parameter for the case of a Fermi Accelerator and show that the adiabatic expansion of the evolution operator is

  30. Frank Sottile

    We give an elementary proof of the Pieri-type formula in the cohomology of a Grassmannian of maximal isotropic subspaces of an odd orthogonal or symplectic vector space. This proof proceeds by explicitly computing a triple intersection of Schubert varieties. The decisive step is an explicit description of the intersection of two Schubert varieties, from whic

  31. R. N. Mohapatra, S. Nussinov

    We discuss the cosmological implications as well as possible observability of massive, stable, colored particles which often appear in the discussion of physics beyond the standard model. We argue that if their masses are more than a few hundred GeV and if they saturate the halo density and/or occur with closure density of the universe, they are ruled out by

  32. A. I. M. Rae, E. M. Forgan, R. A. Doyle

    In the high-temperature superconductor BSCCO, local measurements of magnetic field at the surface of a crystal in the mixed state show sharp changes as a function of applied field or temperature. We show that if `intermediate state' effects are accounted for, a first-order transition leads to a sharp jump in the global magnetisation only in the case of sampl

  33. G. C. Hegerfeldt, T. I. Sachse, D. G. Sondermann

    We investigate the interaction of an atom with a multi-channel squeezed vacuum. It turns out that the light coming out in a particular channel can have anomalous spectral properties, among them asymmetry of the spectrum, absence of the central peak as well as central hole burning for particular parameters. As an example plane-wave squeezing is considered. In

  34. Eli Hawkins

    The quantization of vector bundles is defined. Examples are constructed for the well controlled case of equivariant vector bundles over compact coadjoint orbits. (Coadjoint orbits are symplectic spaces with a transitive, semisimple symmetry group.) In preparation for the main result, the quantization of coadjoint orbits is discussed in detail. This subject s

  35. G. N. Stratopoulos

    In the context of a dynamical Ginzburg-Landau model it is shown numerically that under the influence of a homogeneous external current J the vortex drifts against the current with velocity $V= -J$ in agreement to earlier analytical predictions. In the presence of dissipation the vortex undergoes skew deflection at an angle $90^{\circ} < \delta < 180^{\circ}$

  36. F. Hautmann

    I discuss recent theoretical results for inclusive decays of quarkonia into a photon plus hadrons, and summarize the status of perturbative calculations.

  37. B. C. Allanach, H. Dreiner, P. Morawitz, M. D. Williams

    We propose a new method of detecting supersymmetry at LEP2 when R-parity is violated by an LLE operator. We consider the processes $e\gamma\ra\snu_j e_k$ and $e\gamma \ra \slep_k \bar{\nu}_j$. These are sensitive to seven of the nine LLE-operators. A Monte-Carlo analysis is performed to investigate the sensitivity to the sneutrino signal, and the 5$\sigma$ d

  38. Joan Sola

    We discuss the supersymmetric quantum effects on top quark decays within the MSSM. It turns out that t-> H+ b is the most promising candidate for carrying large quantum SUSY signatures. As a result, the recent (tan(beta) M_H) exclusion plots presented by the CDF Collaboration should be thoroughly revised in the light of the MSSM.

  39. Geert Jan van Oldenborgh, Gerrit Burgers, Stephan Venzke, Christian Eckert

    The adjoint of an ocean general circulation model is used as a tool for investigating the causes of changes in ENSO SST indices. We identify adjoint Kelvin and Rossby waves in the sensitivities to sea level and wind stress at earlier times, which can be traced back for more than a year through western and weak eastern boundary reflections. Depending on the t

  40. Walter Wilcox, Bruce Lindsay

    A comparison of the noise variance between algorithms for calculating disconnected loop signals in lattice QCD is carried out. The methods considered are the Z(N) noise method and the Volume method. We find that the noise variance is strongly influenced by the Dirac structure of the operator.

  41. Amit Giveon, Oskar Pelc

    SU(N_L) X SU(N_R) gauge theories are investigated as effective field theories on D_4 branes in type IIA string theory. The classical gauge configuration is shown to match quantitatively with a corresponding classical U(N_L) X U(N_R) gauge theory. Quantum effects freeze the U(1) gauge factors and turn some parameters into moduli. The SU(N_L) X SU(N_R) quantum

  42. Nemanja Kaloper, Krzysztof A. Meissner

    In this article we review a recent calculation of the two-loop $\sigma$-model corrections to the T-duality map in string theory. Using the effective action approach, and focusing on backgrounds with a single Abelian isometry, we give the $O(\alpha')$ modifications of the lowest-order duality transformations. The torsion plays an important role in the theory

  43. J. F. Cariñena, A. M. Perelomov

    The integral representation on the orthogonal groups for zonal spherical functions on the symmetric space $SU(N)/SO(N,\R)$ is used to obtain a generating function for such functions. For the case N=3 the three-dimensional integral representation reduces to a one-dimensional one.

  44. G. M. T. Watts

    We consider the perturbations of the 3-state Potts conformal field theory introduced by Cardy as a description of the chiral 3-state Potts model. By generalising Zamolodchikov's counting argument and by explicit calculation we find new inhomogeneous conserved currents for this theory. We conjecture the existence of an infinite set of conserved currents of th

  45. Jan Smit

    We discuss an explorative computation of real time autocorrelation functions, in the classical approximation. The results for the `plasmon' frequencies and damping rates appear compatible with the divergencies expected from perturbation theory.

  46. Brad M. S. Hansen, E. Sterl Phinney

    We use the grid of models described in paper~I to analyse those millisecond pulsar binaries whose secondaries have been studied optically. In particular, we find cooling ages for these binary systems that range from $< 1 \rm Gyr$ to $\sim \rm 15 Gyr$. Comparison of cooling ages and characteristic spin down ages allows us to constrain the initial spin periods

  47. S. Choi, K. Burnett

    A simple model for atom optical elements for Bose condensate of trapped, dilute alkali atomns is proposed and numerical simulations are presented to illustrate its characteristics. We demonstrate ways of focusing and splitting the condensate by modifying experimentally adjustable parameters. We show that there are at least two ways of implementing atom optic

  48. Brad M. S. Hansen, E. Sterl Phinney

    The presence of low mass, degenerate secondaries in millisecond pulsar binaries offers the opportunity to determine an age for the binary system independent of the rotational properties of the pulsar. To this end, we present here a detailed calculation of the evolution of a grid of low mass ($<0.5 M_{\odot}$) helium core white dwarfs. We investigate the effe

  49. Kazuhiro Sano, Yoshiaki Ono

    Using the numerical diagonalization method, we investigate the one-dimensional $d$-$p$ model, simulating a Cu-O linear chain with strong Coulomb repulsions. Paying attention to the effect of the transfer energy $t_{pp}$ between the nearest neighbor oxygen-sites, we calculate the critical exponent of correlation functions $K_{\rho}$ based on the Luttinger liq

  50. John P. D'Angelo

    This paper considers some work done by the author and Catlin [CD1,CD2,CD3] concerning positivity conditions for bihomogeneous polynomials and metrics on bundles over certain complex manifolds. It presents a simpler proof of a special case of the main result in [CD3], providing also a self-contained proof of a generalization of the main result from [CD1]. Som

  51. Yoshiaki Mizuno, Takami Tohyama, Sadamichi Maekawa, Tatsuaki Osafune

    The electronic states and magnetic properties for the copper oxides containing edge-sharing Cu-O chains such as Li$_2$CuO$_2$, La$_6$Ca$_8$Cu$_{24}$O$_{41}$ and CuGeO$_3$ are systematically studied. The optical conductivity $\sigma(\omega)$ and the temperature dependence of the magnetic susceptibility $\chi(T)$ for single crystalline samples Li$_2$CuO$_2$ ar

  52. Joao D. Correia, Behrouz Mirza, John F. Wheater

    We show that by coupling complex three-state systems to branched-polymer like ensembles we can obtain models with gamma-string different from one half. It is also possible to study the interpolation between dynamical and crystalline graphs for these models; we find that only when geometry fluctuations are completely forbidden is there a crystalline phase.

  53. D. Sornette

    [Takayasu et al., Phys. Rev.Lett. 79, 966 (1997)] revisited the question of stochastic processes with multiplicative noise, which have been studied in several different contexts over the past decades. We focus on the regime, found for a generic set of control parameters, in which stochastic processes with multiplicative noise produce intermittency of a speci

  54. Carlo Pierleoni, Gianluigi Arialdi, Jean-Paul Ryckaert

    We present Monte Carlo data for a linear chain with excluded volume subjected to a uniform stretching. Simulation of long chains (up to 6000 beads) at high stretching allows us to observe the signature of tensile blobs as a crossover in the scaling behavior of the chain scattering function for wave vectors perpendicular to stretching. These results and corre

  55. Sonia Stanciu

    We investigate boundary states of D-branes wrapped around supersymmetric cycles in Kazama--Suzuki models. We show that the geometry of the D-branes corresponds to a generalisation of calibrated geometry. We comment on the link with the geometry of the coset space and discuss how T-duality maps between these boundary states.

  56. F. Zimmerschied, D. H. Tchrakian, H. J. W. Mueller-Kirsten

    The reduced O(3)-sigma model with an O(3)->O(2) symmetry breaking potential is considered with an additional Skyrmionic term, i.e. a totally antisymmetric quartic term in the field derivatives. This Skyrme term does not affect the classical static equations of motionwhich, however, allow an unstable sphaleron solution. Quantum fluctuations around the static

  57. Sergio Ferrara

    We will report on recent advances in the understanding of non-perturbative interconnections between different string dualities. Weak-strong coupling duality (S-duality) and T-duality (symmetry under compactification on dual tori) allows one to compare and explore the strong coupling regime of seemingly unrelated theories. These theories naturally merge in a

  58. R. H. Sanders

    On the basis of ``sticky particle'' calculations, it is argued that the gas features observed within 10 pc of the Galactic Centre-- the circumnuclear disk (CND) and the ionized gas filaments-- as well as the newly formed stars in the inner one parsec can be understood in terms of tidal capture and disruption of gas clouds on low angular momentum orbits in a

  59. L. P. Kouwenhoven, T. H. Oosterkamp, M. W. S. Danoesastro, M. Eto

    We study ground states and excited states in semiconductor quantum dots containing 1 to 12 electrons. For the first time, it is possible to identify the quantum numbers of the states in the excitation spectra and make a direct comparison to exact calculations. A magnetic field induces transitions between excited states and ground state. These transitions are

  60. J. F. Cariñena, C. López, J. Nasarre

    We will show the usefulness of the tools of Symplectic and Presymplectic Geometry and the corresponding Lie algebraic methods in different problems in Geometric Optics.

  61. R. Moessner, B. Jain, J. V. Villumsen

    The angular correlation function \wth of faint galaxies is affected both by nonlinear gravitational evolution and by magnification bias due to gravitational lensing. We compute the resulting \wth for different cosmological models and show how its shape and redshift evolution depend on \Omega and \Lambda. For galaxies at redshift greater than 1 (R magnitude f

  62. S. Kuznetsov, M. Gilfanov, E. Churazov, R. Sunyaev

    The entire dataset of the GRANAT/SIGMA observations of Cyg X-1 and 1E1740.7-2942 in 1990-1994 was analyzed in order to search for correlations between primary observational characteristics of the hard X-ray (40-200 keV) emission - hard X-ray luminosity, hardness of the spectrum (quantified in terms of the best-fit thermal bremsstrahlung temperature kT) and t

  63. K. Huitu, P. N. Pandita, K. Puolamäki

    We'll review our study of the constraints on the scales in the supersymmetric left-right model (SUSYLR). The conservation of color and electromagnetism in the ground state of the theory implies a relation between right-handed gauge boson mass and soft squark mass. Furthermore, in general for heavy $W_R$, $\tan\alpha$ is larger than one, and the right-handed

  64. K. Huitu, J. Maalampi, K. Puolamäki

    We review the consequences of spontaneously broken R-parity in present and planned lepton-lepton colliders. In the left-right models the R-parity, $R=(-1)^{3(B-L)+2S}$, is preserved due to the gauge symmetry, but it must be spontaneously broken in order to the scalar spectrum to be physically consistent. The spontaneous breaking is generated via a non-vanish

  65. Ivan G. Avramidi, Giampiero Esposito

    Recent work in Euclidean quantum gravity has studied boundary conditions which are completely invariant under infinitesimal diffeomorphisms on metric perturbations. On using the de Donder gauge-averaging functional, this scheme leads to both normal and tangential derivatives in the boundary conditions. In the present paper, it is proved that the correspondin

  66. Jan Kalinowski

    In supersymmetric theories with R-parity breaking, sleptons could be produced singly in $e^+e^-$ collisions at LEP2 and in $q\bar{q}$ annihilation at the Tevatron through interactions in which two quark or two lepton fields are coupled to a slepton field. At LEP they could manifest themselves in Bhabha scattering, and in the annihilation to $\mu^+\mu^-$, \ta

  67. Denis Comelli, Massimo Pietroni

    We apply a gauge invariant formulation of Wilson Renormalization Group (RG) to the computation of the Debye and transverse gluon masses in pure gauge SU(N) at high temperature. Following the Hard Thermal Loop effective field theory as a guideline, we develop an approximation scheme to the exact evolution equations. The Debye mass receives sizable corrections

  68. Liang Zuo-tang, C. Boros

    It is shown that the polarization of hyperons observed in high energy collisions using unpolarized hadron beams and unpolarized nucleon or nuclear targets is closely related to the left-right asymmetries observed in single spin inclusive hadron production processes. The relationship is most obvious for the production of the hyperons which have only one commo

  69. Chang-Ho Kim, Young-Jai Park

    We study ten-dimensional N=2 maximal chiral supergravity in the context of Lie superalgebra SU(8/1). The possible successive superalgebraic truncations from ten dimensional N=2 chiral theory to the lower dimensional supergravity theories are systematically realized as sub-superalgebraic chains of SU(8/1) by using the Kac-Dynkin weight techniques.

  70. Georg Hein

    We show for the moduli space of rank-2 coherent sheaves on an algebraic surface that there exists a 'dual' moduli space. This dual space allows a construction of the first one without using the GIT construction. Furthermore, we obtain a Barth-morphism, generalizing the concept of jumping lines. This morphism is by construction a finite morphism.

  71. M. Biehl, W. Kinzel, S. Schinzer

    A discrete solid-on-solid model of epitaxial growth is introduced which, in a simple manner, takes into account the effect of an Ehrlich-Schwoebel barrier at step edges as well as the local relaxation of incoming particles. Furthermore a fast step edge diffusion is included in 2+1 dimensions. The model exhibits the formation of pyramid-like structures with a

  72. Peter Schneider

    The correlation between cosmic shear as measured by the image distortion of high-redshift galaxies and the number counts of foreground galaxies is calculated. For a given power spectrum of the cosmic density fluctuations, this correlation is proportional to the bias factor, which can thus directly be measured. In addition, this correlation provides a first-o

  73. P. Ackerbauer, D. V. Balin, V. M. Baturin, G. A. Beer

    The muon capture rate in the reaction mu- 3He -> nu + 3H has been measured at PSI using a modular high pressure ionization chamber. The rate corresponding to statistical hyperfine population of the mu-3He atom is (1496.0 +- 4.0) s^-1. This result confirms the PCAC prediction for the pseudoscalar form factors of the 3He-3H system and the nucleon.

  74. Santanu Pal, Tapan Mukhopadhyay

    The chaos weighted wall formula developed earlier for systems with partially chaotic single particle motion is applied to large amplitude collective motions similar to those in nuclear fission. Considering an ideal gas in a cavity undergoing fission-like shape evolutions, the irreversible energy transfer to the gas is dynamically calculated and compared with

  75. A. Díaz-Sánchez, A. Möbius, M. Ortuño, A. Pérez-Garrido

    We have implemented a new numerical method to obtain the low-energy many-particle states of the Coulomb glass. First, this method creates an initial set of low-energy states by a hybrid of local search and simulated annealing approaches. Then, systematically investigating the surroundings of the states found, this set is completed. The transition rates betwe

  76. H. Fujisaki, S. Sano, K. Nakagawa

    The thermofield dynamics of the $D = 10$ heterotic thermal string theory is exemplified at any finite temperature through the infrared behaviour of the one-loop cosmological constant in proper reference to the thermal duality symmetry in association with the global phase structure of the thermal string ensemble.

  77. Mannque Rho

    The meson-exchange current in nuclei, a long-standing problem in nuclear physics, is described in modern theory of strong interactions, namely, QCD expressed in terms of effective chiral Lagrangian field theory. Some old results are given a modern interpretation and some new results are predicted. Among the topics treated are an accurate calculation of the r

  78. V. M. H. Ruutu, J. Kopu, M. Krusius, Ü. Parts

    We have measured the critical velocity v_c at which 3He-A in a rotating cylinder becomes unstable against the formation of quantized vortex lines with continuous (singularity-free) core structure. We find that v_c is distributed between a maximum and minimum limit, which we ascribe to a dependence on the texture of the orbital angular momentum l(r) in the cy

  79. W. Eholzer, L. Feher, A. Honecker

    Fermionic and bosonic ghost systems are defined each in terms of a single vertex algebra which admits a one-parameter family of conformal structures. The observation that these structures are related to each other provides a simple way to obtain character formulae for a general twisted module of a ghost system. The U(1) symmetry and its subgroups that underl

  80. T. Hirano, S. Muroya, M. Namiki

    We calculate thermal photon and electron pair distribution from hot QCD matter produced in high energy heavy-ion collisions, based on a hydrodynamical model which is so tuned as to reproduce the recent experimental data at CERN SPS, and compare these electromagnetic spectra with experimental data given by CERN WA80 and CERES. We investigate mainly the effect

  81. M. I. Kotsky, O. I. Yakovlev

    The decay of the Higgs boson into two photons is discussed. Using Sudakov technicue, we study a new type of double logarithms in the case of the light quark loop. First, we examine the origin of such logarithms at the one loop level. Then we perform a two-loop analysis, and finally we present an explicit result of the resummation of double logarithms in all

  82. C. J. Phillips, R. P. Norris, S. P. Ellingsen, D. P. Rayner

    We have used the Australia Telescope Compact Array (ATCA) to search for 6.7-GHz methanol maser emission towards 87 galaxies. We chose the target sources using several criteria, including far-IR luminosities and the presence of known OH megamasers. In addition, we searched for methanol masers in the nearby starburst galaxy NGC 253, making a full spectral-line

  83. K. Huitu, P. N. Pandita, K. Puolamäki

    We consider the lightest Higgs boson in naturally R-parity conserving supersymmetric left-right models. We obtain an upper bound on the tree level mass of this lightest Higgs boson. This upper bound depends on the $SU(2)_L$ and $SU(2)_R$ gauge couplings, and the vacuum expectation values of bidoublet Higgs fields, which are needed to break $SU(2)_L\times U(1

  84. S. M. Alamoudi, D. Boyanovsky, F. I. Takakura

    We study the non-equilibrium dynamics of solitons in model Hamiltonians for Peierls dimerized quasi-one dimensional conducting polymers and commensurate charge density wave systems. The real time equation of motion for the collective coordinate of the soliton and the associated Langevin equation is found in a consistent adiabatic expansion in terms of the ra

  85. Xue-Bing Wu, Qi-Bin Li, Yong-Heng Zhao, Li Cao

    The low dispersion (400$\AA$/mm) spectrum of the optical counterpart of a flat-spectrum radio source 87GB 080315.5+512613, which is one of two possible radio counterparts of 2EG J0809+5117, was obtained recently. The optical counterpart, which is $2.02''$ away from 87GB 080315.5+512613 and $19.3'$ away from 2EG J0809+5117, was identified as a quasar with red

  86. A. W. Thomas, W. Melnitchouk

    Few-body systems offer a unique challenge to those interested in deep inelastic scattering. Using the deuteron as the simplest and most easily solvable nuclear system we review the main physics issues in the valence and sea quark regimes. For the former the key issue is the understanding of Fermi motion and binding corrections, and our ability to extract the

  87. M. Switkes, A. G. Huibers, C. M. Marcus, K. Campman

    We report transport measurements as a function of bias in open semiconductor quantum dots. These measurements are well described by an effective electron temperature derived from Joule heating at the point contacts and cooling by Wiedemann-Franz out-diffusion of thermal electrons. Using this model, we propose and analyze a quantum dot based sensor which meas

  88. Stefan Scheidl, Valerii M. Vinokur

    We analyze the large-scale dynamics of vortex lattices and charge density waves driven in a disordered potential. Using a perturbative coarse-graining procedure we present an explicit derivation of non-equilibrium terms in the renormalized equation of motion, in particular Kardar-Parisi-Zhang non-linearities and dynamic strain terms. We demonstrate the absen

  89. A. J. Buchmann, Georg Wagner, Amand Faessler

    We calculate the mass and structure of a J^P=0^-, T=0 six-quark system using a colored diquark-tetraquark cluster wave function and a nonrelativistic quark model Hamiltonian. The calculated mass is some 350 MeV above the empirical value if the same confinement strength as in the nucleon is used. If the effective two-body confinement strength is weaker in a c

  90. I. T. Obukhovsky, K. Itonaga, Georg Wagner, A. J. Buchmann

    We study the pionic decay of a possible dibaryon d' --> N N \pi in the microscopic quark shell model. The initial d' dibaryon wave function (J^P=0^-, T=0) consists of one 1\hbar\omega six-quark shell-model s^5p[51]_X configuration. The most important final six-quark configurations s^6[6]_X, s^4p^2[42]_X and (s^4p^2-s^52s)[6]_X are properly projected onto the

  91. Tom Chou

    We use a one dimensional symmetric exclusion model to study pressure and osmosis driven flows through molecular-sized channels, such as biological membrane channels and zeolite pores. Analytic expressions are found for the steady-state flow which show rich nonlinear behavior. We find a maximum in the flow rates depending upon pore radius, pore energetics, re

  92. Jian Ge, J. R. P. Angel, B. D. Jacobsen, T. Roberts

    The first time simultaneous measurements of sodium column density and the absolute flux from a sodium laser guide star, created by a monochromatic 3 W cw laser, tuned to the peak of the sodium D2 hyperfine structure, were conducted at the MMT and CFA 60 inch telescope in 1997. The results show that linearly and circularly polarized laser returns are proporti

  93. Francesco Vissani

    Motivated by cosmological considerations, and by the atmospheric and solar neutrino flux deficits, we consider the scenario in which the three Standard Model neutrinos are endowed with a nearly equal Majorana mass in the eV range. Combined constraints coming from (1) direct search for electron neutrino mass, (2) absence of neutrinoless double beta decay, and

  94. Liviu Tatar, Radu Tatar

    The anti-BRST transformation, in its Sp(2)-symmetric version, for the general case of any stage-reducible gauge theories is implemented in the usual BV approach. This task is accomplished not by duplicating the gauge symmetries but rather by duplicating all fields and antifields of the theory and by imposing the acyclicity of the Koszul-Tate differential. In

  95. C. Kuebert, P. J. Hirschfeld

    We consider the problem of the vortex contribution to thermal properties of dirty d-wave superconductors. In the clean limit, the main contribution to the density of states in a d-wave superconductor arises from extended quasiparticle states which may be treated semiclassically, giving rise to a specific heat contribution \delta C(H)\sim H^{1/2}. We show tha

  96. G. L. Comer, Hisa-aki Shinkai

    Boson stars in zero-, one-, and two-node equilibrium states are modeled numerically within the framework of Scalar-Tensor Gravity. The complex scalar field is taken to be both massive and self-interacting. Configurations are formed in the case of a linear gravitational scalar coupling (the Brans-Dicke case) and a quadratic coupling which has been used previo

  97. Andrew Ulmer, Edward L. Fitzpatrick

    We have determined the location of the line-opacity modified Eddington limit for stars in the LMC using the most recent atmosphere models combined with a precise mapping to the HR Diagram through up-to-date stellar evolution calculations. While we find, in agreement with previous studies, that the shape of the modified Eddington limit qualitatively correspon

  98. Bin Zhang, Yang Pang, Miklos Gyulassy

    Kinetic theory is used to check the applicability of parton cascade in 1 dimensional expansion. Using the information provided by 3 dimensional parton cascade, we model the transverse expansion by an effective area. With this model, kinetic theory is able to give prediction of the time development of transverse energy which is in good agreement with the part

  99. Paul Benioff

    Quantum Turing machines are discussed and reviewed in this paper. Most of the paper is concerned with processes defined by a step operator $T$ that is used to construct a Hamiltonian $H$ according to Feynman's prescription. Differences between these models and the models of Deutsch are discussed and reviewed. It is emphasized that the models with $H$ constru

  100. J. Audretsch, M. Mensky, V. Namiot

    The previously proposed visualization of Rabi oscillations of a single atom by a continuous fuzzy measurement of energy is specified for the case of a single transition between levels caused by a $\pi$-pulse of a driving field. An analysis in the framework of the restricted-path-integral approach (which reduces effectively to a Schr\"odinger equation with a