December 1999 arXiv papers — page 10
Showing 901–1,000 of 2,544 papers
N. M. Hassan, N. El-Harby, M. T. Hussein
A Monte Carlo simulator is presented to reproduce data of nucleus-nucleus interactions at high energies. The program is designed in a microscopic point of view, where the cascade approach is applied. Moreover, each nucleon from both the target and the projectile is followed up on the time scale along the collision time. The effect of the mean field that depe
G. Corcella, I. G. Knowles, G. Marchesini, S. Moretti
A new version of the Monte Carlo program HERWIG (version 6.1) is now available. This note gives brief details of the new features relative to the previous version (5.9). A fully updated manual will follow shortly. The main new features are: supersymmetric processes (both R-parity conserving and R-parity violating) in hadron-hadron collisions; the new process
UKQCD Collaboration, Craig McNeile
We report on our progress in using the overlap-Dirac fermion operator in simulations of lattice QCD. We have investigated the Lanczos based method of Borici, as well as various rational approximations, to calculate the step function in the overlap-Dirac operator. The QCD simulations were performed at beta = 5.85 with a lattice volume of 8**3*32.
Giles Barr
A report on the recent measurement of epsilon-prime, which characterises direct CP violation in the neutral kaon system, by the NA48 collaboration.
Aurelio Juste
We study the feasibility of a precise measurement of the mass of a 120 GeV MSM Higgs boson through direct reconstruction of ZH->qqH events that would be achieved in a future e+e- linear collider operating at a center-of-mass energy of 500 GeV. Much effort has been put in a ``realistic simulation'' by including irreducible and reducible backgrounds, r
Dieter Brill
Exact solutions of Einstein's equations in 2+1-dimensional anti-de Sitter space containing any number of black holes are described. In addition to the black holes these spacetimes can possess ``internal'' structure. Accordingly the generic spacetime of this type depends on a large number of parameters. Half of these can be taken as mass parameter
Tekin Dereli, Yuri N. Obukhov
The exact static solutions in the higher dimensional Einstein-Maxwell-Klein- Gordon theory are investigated. With the help of the methods developed for the effective dilaton type gauge gravity models in two dimensions, we find new spherically and hyperbolically symmetric solutions which generalize the four dimensional configurations of Dereli-Eris. We show t
Bill Devlin, Jim Gray, Bill Laing, George Spix
Defines a vocabulary for scaleable systems: Geoplexes, Farms, Clones, RACS, RAPS, clones, partitions, and packs and dicusses the design tradeoffs of using clones, partitons, and packs.
Shoji Yamamoto
A theoretical interpretation is given to recent proton spin relaxation-time (T_1) measurements on NiCu(C_7H_6N_2O_6)(H_2O)_3$\cdot$2H_2O, which is an ideal one-dimensional ferrimagnetic Heisenberg model system of alternating spins 1 and 1/2. The relaxation rate T_1^{-1} is formulated in temrs of the spin-wave theory and is evaluated by the use of a quantum M
Paolo De Los Rios, Guido Caldarelli
We introduce a polymer model where the transition from swollen to compact configurations is due to interactions between the monomers and the solvent. These interactions are the origin of the effective attractive interactions between hydrophobic amminoacids in proteins. We find that in the low and high temperature phases polymers are swollen, and there is an
Joseph T. Francis, Paul So, Bruce J. Gluckman, Steven J. Schiff
Recent work has identified nonlinear deterministic structure in neuronal dynamics using periodic orbit theory. Troublesome in this work were the significant periods of time where no periodic orbits were extracted - "dynamically dark" regions. Tests for periodic orbit structure typically require that the underlying dynamics are differentiable. Since c
J. Craig Wheeler
This meeting covered the range of cosmic explosions from solar flares to gamma-ray bursts. A common theme is the role of rotation and magnetic fields. A rigorous examination is underway to characterize systematic effects that might alter the Type Ia supernova results suggesting an accelerating Universe. The discovery of the central point of X-ray emission in
G. G. Williams, D. H. Hartmann, H. S. Park, R. A. Porrata
GRB 990123 established the existence of prompt optical emission from gamma-ray bursts (GRBs). The Livermore Optical Transient Imaging System (LOTIS) has been conducting a fully automated search for this kind of simultaneous low energy emission from GRBs since October 1996. Although LOTIS has obtained simultaneous, or near simultaneous, coverage of the error
Collision rates in the present-day Kuiper Belt and Centaur Regions: Applications to surface activation and modification on Comets, Kuiper Belt Objects, Centaurs, and Pluto-Charon
astro-phDaniel D. Durda, S. Alan Stern
We extend previous results showing that the surfaces of Edgeworth-Kuiper Belt objects are not primordial and have been moderately to heavily reworked by collisions. Objects smaller than about $r = 2.5$ km have collisional disruption lifetimes less than 3.5 Gyr in the present-day collisional environment and have been heavily damaged in their interiors by larg
Ya. V. Pavlenko, L. A. Yakovina, H. W. Duerbeck
Theoretical spectral energy distributions were computed for a grid of hydrogen-deficient and carbon-rich model atmospheres of T(eff) in the range of 5000-6250 K and log g = 1.0 - 0.0 by the technique of opacity sampling, taking into account continuous, molecular band and atomic line absorption. These energy distributions were compared with the spectrum of V4
H. Hirashita
On the basis of the propagating star-formation model, we investigated the star-formation activities of dwarf irregular galaxies (dIrrs) by considering two processes: the heating from stellar feedback and the cooling of the heated gas. After examining the timescales of the two processes, we propose that continuous global star-formation activity is difficult i
Andrew R. King, Ronald E. Taam, Mitchell C. Begelman
We consider possible evolutionary models for SS 433. We assume that common-envelope evolution is avoided if radiation pressure is able to expel most of a super-Eddington accretion flow from a region smaller than the accretor's Roche lobe. This condition is satisfied, at least initially, for largely radiative donors with masses in the range 4-12 solar mas
A Simple Method for Computing the Non-Linear Mass Correlation Function with Implications for Stable Clustering
astro-phR. R. Caldwell, Roman Juszkiewicz, Paul J. Steinhardt, Francois Bouchet
We propose a simple and accurate method for computing analytically the mass correlation function for cold dark matter and scale-free models that fits N-body simulations over a range that extends from the linear to the strongly non-linear regime. The method, based on the dynamical evolution of the pair conservation equation, relies on a universal relation bet
J. Grindlay, L. Bildsten, D. Chakrabarty, M. Elvis
A deep all-sky imaging hard x-ray survey and wide-field monitor is needed to extend soft (ROSAT) and medium (ABRIXAS2) x-ray surveys into the 10-100 keV band (and beyond) at comparable sensitivity (~0.05 mCrab). This would enable discovery and study of >3000 obscured AGN, which probably dominate the hard x-ray background; detailed study of spectra and variab
Kazumitsu Sakai, Zengo Tsuboi
The thermodynamic Bethe ansatz (TBA) and the excited state TBA equations for an integrable spin chain related to the Lie superalgebra osp(1|2) are proposed by the quantum transfer matrix (QTM) method. We introduce the fusion hierarchy of the QTM and derive the functional relations among them (T-system) and their certain combinations (Y-system). Their analyti
Yuval Grossman, Matthias Neubert
We study bulk fermion fields in the localized gravity model with non-factorizable metric recently proposed by Randall and Sundrum, and Gogberashvili. In addition to a tower of weak-scale Kaluza-Klein states we find a zero mode for any value of the fundamental fermion mass. If the fermion mass is larger than half the curvature of the compact dimension, the ze
Thomas Mark
We prove a conjecture of Hutchings and Lee relating the Seiberg-Witten invariants of a closed 3-manifold X with b_1 > 0 to an invariant that `counts' gradient flow lines--including closed orbits--of a circle-valued Morse function on the manifold. The proof is based on a method described by Donaldson for computing the Seiberg-Witten invariants of 3-manifo
J. X. Lu, S. Roy
We consider systems of non-threshold bound states (D(p$-$2), Dp), for $2\le p \le 6$, in type II string theories. Each of them can be viewed as Dp branes with a nonzero (rank two) Neveu-Schwarz $B$ field. We study the noncommutative effects in the gravity dual descriptions of noncommutative gauge theories for these systems in the limit where the brane worldv
I. Karakurt, D. Herman, H. Mathur, A. J. Dahm
Studies of weak localization by scattering from vapor atoms for electrons on a liquid helium surface are reported. There are three contributions to the dephasing time. Dephasing by the motion of vapor atoms perpendicular to the surface is studied by varying the holding field to change the characteristic width of the electron layer at the surface. A change in
M. Kaplinghat, G. Steigman, T. P. Walker
An upper bound to the supernova relic neutrino background from all past Type II supernovae is obtained using observations of the Universal metal enrichment history. We show that an unambiguous detection of these relic neutrinos by the Super-Kamiokande detector is unlikely. We also analyze the event rate in the Sudbury Neutrino Observatory (where coincident n
F. Knechtli
We present a method for finding lines of constant physics in the confinement phase of the SU(2) Higgs model on the lattice. The model is considered at finite values of the cut-off where it behaves like an effective field theory with three independent couplings. In particular, a renormalised quantity sensitive to a variation of the bare Higgs quartic self-cou
Herbi Dreiner, Peter Richardson, Michael H. Seymour
We study the colour connection structure of R-parity violating decays and production cross sections, and construct a Monte Carlo simulation of these processes including colour coherence effects. We then present some results from the implementation of these processes in the HERWIG Monte Carlo event generator. We include the matrix elements for the two-body sf
Riccardo Rattazzi, Alessandro Strumia, James D. Wells
We explore the phenomenology of a class of models with anomaly-mediated supersymmetry breaking. These models retain the successful flavor properties of the minimal scenario while avoiding the tachyons. The mass spectrum is predicted in terms of a few parameters. However various qualitatively different spectra are possible, often strongly different from the o
Christos Charmousis, Ruth Gregory, Valery A. Rubakov
We calculate the linearized metric perturbation corresponding to a massless four-dimensional scalar field, the radion, in a five-dimensional two-brane model of Randall and Sundrum. In this way we obtain relative strengths of the radion couplings to matter residing on each of the branes. The results are in agreement with the analysis of Garriga and Tanaka of
M. Balucinska-Church, M. J. Church
We report the discovery of emission features in the X-ray spectrum of GRO J1655-40 obtained with RXTE during the observation of 1997, Feb 26. We have fitted the features firstly by two Gaussian lines which in four spectra analysed have average energies of 5.85 +/- 0.08 keV and 7.32 +/- 0.13 keV, strongly suggestive that these are the red and blue shifted win
Non-linear screening corrections of stellar nuclear reaction rates and their effects on solar neutrino fluxes
nucl-thTheodore E. Liolios
Non-linear electron screening corrections of stellar nuclear fusion rates are calculated analytically in the framework of the Debye-Huckel model and compared with the respective ones of Salpeter's weak screening approximation. In typical solar conditions, the deviation from Salpeter's screening factor is less than one percent, while for hotter stars
Expectations For an Interferometric Sunyaev-Zel'dovich Effect Survey for Galaxy Clusters
astro-phGilbert P. Holder, Joseph J. Mohr, John E. Carlstrom, August E. Evrard
Non-targeted surveys for galaxy clusters using the Sunyaev-Zel'dovich effect (SZE) will yield valuable information on both cosmology and evolution of the intra-cluster medium (ICM). The redshift distribution of detected clusters will constrain cosmology, while the properties of the discovered clusters will be important for studies of the ICM and galaxy f
Neven Bilic, Hrvoje Nikolic, Raoul D. Viollier
We study in detail gravitational lensing caused by a supermassive fermion star and compare it with lensing by a black hole of the same mass. It is argued that lensing effects, being very distinct, may shed some light on the yet unexplained nature of the compact dark massive object at the Galactic center.
The Effect of Chemical Doping and Hydrostatic Pressure on Tc of Y1-yCayBa2Cu3Ox Single Crystals
cond-mat.supr-conS. I. Schlachter, W. H. Fietz, K. Grube, Th. Wolf
We performed susceptibility measurements on Y1-yCayBa2Cu3Ox single crystals under high He pressure. For each Ca content various samples with different oxygen contents have been prepared to probe the influence of Ca on Tc(x), dTc/dp(x) and Tc,max. Starting from the parabolic Tc(nh) behavior we calculated nh values from Tc and Tc,max for each sample. It is sho
Ugo Bastolla, Michele Vendruscolo, H. Eduardo Roman
We simulate the evolution of a protein-like sequence subject to point mutations, imposing conservation of the ground state, thermodynamic stability and fast folding. Our model is aimed at describing neutral evolution of natural proteins. We use a cubic lattice model of the protein structure and test the neutrality conditions by extensive Monte Carlo simulati
V. V. Ezhela, B. V. Polishchuk
We have made the comparison of three parametrizations of the proton electromagnetic form factors in the space-like region using the largest data set on $e^{\pm} p$ elastic scattering ever used. All models have a correct analytical structure with a minimal set of well known singularities. For the first time an effective two-pion intermediate coulombic bound s
G. Amorós, J. Bijnens, P. Talavera
We have calculated the form-factors F and G in K ---> pi pi e nu decays (Kl4) to two-loop order in Chiral Perturbation Theory (ChPT). Combining this together with earlier two-loop calculations an updated set of values for the L's, the ChPT constants at p^4, is obtained. We discuss the uncertainties in the determination and the changes compared to previou
John Schliemann, A. H. MacDonald
We present an exact diagonalisation study of bilayer quantum Hall systems at a filling factor of two in the spherical geometry. We find the high-Zeeman-coupling phase boundary of the broken symmetry canted antiferromagnet is given exactly by previous Hartree-Fock mean-field theories, but that the state's stability at weak Zeeman coupling has been qualita
Different approaches to the study of the gravitational radiation emitted by astrophysical sources
gr-qcValeria Ferrari
Stars and black holes are sources of gravitational radiation in many phases of their life, and the signals they emit exhibit features that are characteristic of the generating process. Emitted since the beginning of star formation, these signals also contribute to create a stochastic background of gravitational waves. We shall show how the spectral propertie
Sigitas Alisauskas
Seven different triple sum formulas for $9j$ coefficients of the quantum algebra $u_q(2)$ are derived, using for these purposes the usual expansion of $q$-$9j$ coefficients in terms of $q$-$6j$ coefficients and recent summation formula of twisted $q$-factorial series (resembling the very well-poised basic hypergeometric $_5ϕ_4$ series) as a $q$-generalizatio
N. N. Achasov, V. V. Gubin
It is shown that the study of the $ω-ρ^0$ interference pattern in the $J/ψ\to (ρ^0+ω)η\toπ^+π^-η$ decay provides the evidence for the large (nearly $90^\circ$) relative phase between the one-photon and the three-gluon decay amplitudes.
Tadashi Takayanagi
We investigate the anomalous creation of fundamental strings using the boundary state formalism of fractional D-branes on ALE spaces in the orbifold limit. The open string Witten index plays a crucial role in this calculation and so the result remains unchanged even if we blow up the orbifold geometrically, matching the anomaly inflow argument. Further we co
Kyungsik Kim, K. H. Chang, Y. S. Kong
We propose the deterministic rate equation of three-species in the reaction - diffusion system. For this case, our purpose is to carry out the decay process in our three-species reaction-diffusion model of the form $A+B+C\to D$. The particle density and the global reaction rate are also shown analytically and numerically on a two-dimensional square lattice w
Kirill Melnikov, Timo van Ritbergen
The analytic relation between the \bar {MS} and the pole quark masses is computed to O(α_s^3) in QCD. Using this exact result, the accuracy of the large β_0 approximation is critically examined and the implications of the obtained relation for semileptonic B decays are discussed.
Jeffrey A. Newman, Marc Davis
The classical dN/dz test allows the determination of fundamental cosmological parameters from the evolution of the cosmic volume element. This test is applied by measuring the redshift distribution of a tracer whose evolution in number density is known. In the past, ordinary galaxies have been used as such a tracer; however, in the absence of a complete theo
Christof Schmidhuber
The hypothesis is discussed that our universe is really 5--dimensional with a nonzero cosmological constant that produces a large negative curvature. In this scenario, the observable flat 4--dimensional universe is identified with the holographic projection of the 5--dimensional world onto its own boundary.
Christof Schmidhuber
An analogy is noted between RG flow equations in 4-dimensional gauge theory, as derived from the AdS/CFT correspondence, and the RG flow equations in 4-dimensional field theory coupled to a particular limit of Weyl supergravity. This suggests a possible theory of dynamical 3-branes with fluctuating 4-dimensional conformal factor. The argument involves a map
Seth Lloyd
This paper shows that universal quantum computers possess decoherent histories in which complex adaptive systems evolve with high probability.
Luigi Accardi, Masanori Ohya
Quantum teleportation has been introduced by Benett et al. and dis cussed by a number of authors in the framework of the singlet state. Recentl y, a rigorous formulation of the teleportation problem of arbitrary quantum states by means of quantum channel was given in [IOS] based on the general c hannel theoretical formulation of the quantum gates introduced
Seth Lloyd
Arrays of weakly-coupled quantum systems can be made to compute by subjecting them to a sequence of electromagnetic pulses of well-defined frequency and length. Such pulsed arrays are true quantum computers: bits can be placed in superpositions of 0 and 1, logical operations take place coherently, and dissipation is required only for error correction. Progra
A. Lambrecht, S. Reynaud
We comment on a recently published measurement of the Casimir force for distances in the 0.6 to 6 micrometer range between two Au surfaces (Phys. Rev. Lett. 78, 5(1997)) and the net discrepancy reported for the comparison with theoretical predictions (Phys. Rev. Lett. 81, 5475 (1998)).
Karl-Heinz Fichtner, Masanori Ohya
Quantum teleportation is rigorously discussed with coherent entang led states given by beam splittings. The mathematical scheme of beam splitti ng has been used to study quantum communication and quantum stochastic. We d iscuss the teleportation process by means of coherent states in this scheme for the following two cases: (1) Delete the vacuum part from co
V. Pleitez
One of the main activities in science teaching, and in particular in Physics teaching, is not only the discussion of both modern problems and problems which solution is an urgent matter. It means that the picture of an active and alive science should be transmitted to the students, mainly to the College students. A central point in this matter is the issue w
J. Ortner, V. M. Rylyuk
Nonlinear relativistic ionization phenomena induced by a strong laser radiation with elliptically polarization are considered. The starting point is the classical relativistic action for a free electron moving in the electromagnetic field created by a strong laser beam. The application of the relativistic action to the classical barrier-suppression ionizatio
Cantorian Fractal Space-Time Fluctuations in Turbulent Fluid Flows and the Kinetic Theory of Gases
physics.gen-phA. M. Selvam
Fluid flows such as gases or liquids exhibit space-time fluctuations on all scales extending down to molecular scales. Such broadband continuum fluctuations characterise all dynamical systems in nature and are identified as selfsimilar fractals in the newly emerging multidisciplinary science of nonlinear dynamics and chaos. A cell dynamical system model has
S. Donev, D. Trifonov
This paper aims to present the pure field part of the newly developed nonlinear {\it Extended Electrodynamics} [1]-[3] in non-relativistic terms, i.e. in terms of the electric and magnetic vector fields (${\mathbf E},{\mathbf B}$), and to give explicitly those (3+1)-soliton solutions of the new equations which have the integral properties of photons. The set
J. Carlson, H. Heiselberg, V. R. Pandharipande
The kaon energy in neutron matter is calculated analytically with the Klein-Gordon equation, by making a Wigner-Seitz cell approximation and employing a $K^-N$ square well potential. The transition from the low density Lenz potential, proportional to scattering length, to the high density Hartree potential is found to begin at fairly low densities. Exact non
A. O. Macchiavelli, P. Fallon, R. M. Clark, M. Cromaz
We present a new analysis of the pairing vibrations around 56Ni, with emphasis on odd-odd nuclei. This analysis of the experimental excitation energies is based on the subtraction of average properties that include the full symmetry energy together with volume, surface and Coulomb terms. The results clearly indicate a collective behavior of the isovector pai
Bronislaw Wajnryb
We consider an oriented surface S and a cellular complex X of curves on S, defined by Hatcher and Thurston in 1980. We prove by elementary means, without Cerf theory, that the complex X is connected and simply connected. From this we derive an explicit simple presentation of the mapping class group of S, following the ideas of Hatcher-Thurston and Harer.
Jason Fulman
We consider potential theory on Bratteli diagrams arising from Macdonald polynomials. The case of Hall-Littlewood polynomials is particularly interesting; the elements of the diagram are partitions, the branching multiplicities are integers, the combinatorial dimensions are Green's polynomials, and the Jordan form of a randomly chosen unipotent upper tri
C. Dong, C. H. Lam, H. Yamada
We determine the decomposition of V_{\sqrt{2}D_l} into a sum of irreducible T-modules for general l where D_l is the root lattice of type D_l and T is the tensor product of l+1 Virasoro vertex operator algebras with central charges c_{1}=1/2, c_{2}=7/10, c_{3}=4/5, and c_{i}=1 for 4\le i\le l+1.
Anton Deitmar
We deduce from Arthur's trace formula a formula with only orbital integrals on the geometric side.
Roy M. Skjelnes
Let A[X]_U be a fraction ring of the polynomial ring A[X] in the variable X over a commutative ring A. We show that the Hilbert functor {Hilb}^n_{A[X]_U} is represented by an affine scheme $\text{Symm}^n_A(A[X]_U)$ give as the ring of symmetric tensors of $\otimes_A^nA[X]_U$. The universal family is given as $\text{Symm}^{n-1}_A(A[X]_U)\times_A \text{Spec}(A
Joaquim Ortega-Cerda
We study some size estimates for the solution of the equation d-bar u=f in one variable. The new ingredient is the use of holomorphic functions with precise growth restrictions in the construction of explicit solutions to the equation.
Roy M. Skjelnes
Let $k[x]_{(x)}$ be the polynomial ring $k[x]$ localized in the maximal ideal $(x)\subseteq k[x]$. We study the Hilbert functor parameterizing ideals of colength $n$ in this ring {\it having support at the origin}. The main result of this article is that this functor is not representable. We also give a complete description of the functor as a limit of repre
The Hilbert scheme parameterizing finite length subschemes of the line with support at the origin
math.AGDan Laksov, Roy M. Skjelnes
We introduce symmetrizing operators of the polynomial ring $A[x]$ in the varible $x$ over a ring $A$. When $A$ is an algebra over a field $k$ these operators are used to characterize the monic polynomials $F(x)$ of degree $n$ in $A[x]$ such that $A\otimes_k k[x]_{(x)}/(F(x))$ is a free $A$-module of rank $n$. We use the characterization to determine the Hilb
Jens Hoppe
Some ideas are presented concerning the question which of the harmonic wavefunctions constructed in [hep-th/9909191] may be annihilated by all supercharges.
Calculating the tension of domain wall junctions and vortices in generalized Wess-Zumino models
hep-thM. Shifman, T. ter Veldhuis
We study BPS saturated objects with axial geometry (wall junctions, vortices) in generalized Wess-Zumino models. It is observed that the tension of such objects is negative in general (although ``exceptional'' models are possible). We show how an ambiguity in the definition of central charges does not affect physical quantities, and we comment on the
Paolo Di Vecchia, Antonella Liccardo
In these lectures we present a detailed description of the origin and of the construction of the boundary state that is now widely used for studying the properties of D branes. (Lectures given at NATO-ASI on "Quantum Geometry" in Akureyri, Iceland, August 1999).
P. M. Llatas, J. M. Sanchez de Santos
The S-duality transformations in type IIB string theory can be seen as local U(1) transformations in type IIB supergravity. We use this approach to construct the $SL(2,Z)$ multiplets associated to supersymmetric backgrounds of type IIB string theory and the transformation laws of their corresponding Killing spinors.
R. Marotta, F. Pezzella
Using the {\em cutting and sewing} procedure we show how to get Feynman diagrams, up to two-loop order, of $Φ^{4}$-theory with an internal SU(N) symmetry group, starting from tachyon amplitudes of the open bosonic string theory. In a properly defined field theory limit, we easily identify the corners of the string moduli space reproducing the correctly norma
U. Cotti, J. L. Diaz-Cruz, J. J. Toscano
A complete study for the production of neutral (h^0, H^0, A^0 (= ϕ^0_i)) and charged Higgs (H^\pm) bosons at electron-photon colliders is presented in the context of the minimal supersymmetric standard model. A particular choice of the non-linear R_ξgauge is used to evaluate the amplitudes of the reaction e-gamma --> e ϕ^0_i. The resulting cross section indi
K. Huitu, J. Maalampi, P. N. Pandita, K. Puolamaki
The left-right model is a gauge theory of electroweak interactions based on the gauge symmetry SU(2)_R . The main motivations for this model are that it gives an explanation for the parity violation of weak interactions, provides a mechanism (see-saw) for generating neutrino masses, and has B-L as a gauge symmetry. The quark-lepton symmetry in weak interacti
A. A. Osipov, B. Hiller, A. H. Blin
We use proper-time regularizations to define the one-loop fermion determinant in the form suggested by Gasser and Leutwyler some years ago. We show how to obtain the polynomial by which this definition of ln det D needs to be modified in order to arrive at the fermion determinant whose modulus is invarinat under chiral transformations. As an example it is sh
Eugene Levin
In this talk, given at "RunII QCD and weak boson WS", we give the highest of reasonable estimates for the value of cross section of the double Pomeron Higgs meson production and suggest a new mechanism for heavy quark diffractive production which will dominate at the Tevatron energies.
Eugene Levin
In this talk, given at "RunII QCD and weak boson WS", we report on calculations of the survival probability of the large rapidity gap (LRG) processes and its energy behaviour.
F. Zomer
A new global QCD analysis of DIS data is presented. The νFe and \barνFe differential cross-section data are included to constrain the strange component of the nucleon sea. As a result we found a hard strangeness at high-x and some evidence for an asymmetry between xs(x) and x\bar{s}(x).
B. R. Webber
These lectures describe some of the latest data on particle production in high-energy collisions and compare them with theoretical calculations and models based on QCD. The main topics covered are: fragmentation functions and factorization, small-x fragmentation, hadronization models, differences between quark and gluon fragmentation, current and target frag
G. G. Raffelt, W. Rodejohann
An introduction to various topics in neutrino astrophysics is given for students with little prior exposure to this field. We explain neutrino production and propagation in stars, neutrino oscillations, and experimental searches for this effect. We also touch upon the cosmological role of neutrinos. A number of exercises is also included.
R. M. Godbole, A. Grau, G. Pancheri
We discuss models for total cross-sections, show their predictions for photon-photon collisions and compare them with the recent LEP measurements. We show that the extrapolations to high center of mass energies within various models differ by large factors at high energies and discuss the precision required from future measurements at the proposed Linear Col
S. Cebrian, E. Garcia, D. Gonzalez, I. G. Irastorza
Annual modulation due to the Earth's motion around the Sun is a well known signature of the expected WIMP signal induced in a solid state underground detector. In the present letter we discuss the prospects of this technique on statistical grounds, introducing annual-modulation sensitivity plots for the WIMP-nucleon scalar cross section for different mat
T. Munehisa, J. Fujimoto, Y. Kurihara, Y. Shimizu
We develop an event generator, NLL-QEDPS, based on the QED shower including the next-to-leading logarithm correction in the e^+e^- annihilation. The shower model is the Monte Carlo technique to solve the renormalization group equation so that they can calculate contributions of alpha^m log^n(S/m_e^2) for any m and n systematically. Here alpha is the QED coup
E. A. Paschos
A calculation of the hadronic matrix elements for K\toππincluding π-πrescattering effects in a dispersion integral is presented. I study the dependence of the results on the matching scale μand use them to calculate the CP-parameter (ε\prime/ε). I find improved stability on the matching scale and good agreement with the experimental results.
J. Lorenzo Diaz-Cruz
We study the inclusion of non-standard soft-breaking terms in the minimal SUSY extension of the SM, considering it as a model of weak-scale SUSY. These terms modify the sfermion mass matrices, which can induce new sources of flavour violation. Bounds on the new soft parameters can be estimated from current data. The results are then applied to evaluate FCNC
J. J. Godina, Y. Meurice, M. B. Oktay
We use polynomial truncations of the Fourier transform of the local measure to calculate the connected q-point functions of Dyson's hierarchical model in the broken symmetry phase. We show that accurate values of the connected 1, 2 and 3 point functions can be obtained at large volume and in a limited range of constant external field coupled linearly to
Massimo Testa
Some problems related to Gribov copies in lattice gauge-fixing and their possible solution are discussed.
G. K. Mallot
The present status of the nucleon's spin structure is reviewed with emphasis on new experimental results.
Particle - antiparticle asymmetries in the production of baryons in 500 GeV/c pi^- Nucleon interactions
hep-exAnjos by the E791 Collaboration
We present the Fermilab E791 measurement of baryon - antibaryon asymmetries in the production of Lambda^0, Cascade, Omega and Lambda_c in 500 GeV/c pi^- Nucleon interactions. Asymmetries have been measured as a function of x_F and p_T**2 over the range -0.12 < x_F < 0.12 and p_T**2 < 4$ (GeV/c)**2 for hyperons and -0.1 < x_F < 0.3 and p_T**2 < 8 (GeV/c)**2 f
Guy Blaylock
This paper emphasizes four topics that represent some of the year's highlights in heavy quark physics. First of all, a review is given of charm lifetime measurements and how they lead to better understanding of the mechanisms of charm decay. Secondly, the CLEO collaboration's new search for charm mixing is reported, which significantly extends the se
M. Medinnis
The HERA-B experiment is designed for studying aspects of B-physics at DESY's HERA proton-electron storage ring, with emphasis on CP violation, particularly in the B->J/psi Kzero decay channel. The apparatus is nearing completion and the triggering system is being commissioned. A brief description of HERA-B is given and its present status is summarized.
Ntina Savvidou, Charis Anastopoulos
We develop a new algorithm for the quantisation of systems with first-class constraints. Our approach lies within the (History Projection Operator) continuous-time histories quantisation programme. In particular, the Hamiltonian treatment (either classical or quantum) of parameterised systems is characterised by the loss of the notion of time in the space of
Konstantina Savvidou
We discuss the case of histories labelled by a continuous time parameter in the {\em History Projection Operator} consistent-histories quantum theory. We describe how the appropriate representation of the history algebra may be chosen by requiring the existence of projection operators that represent propositions about time averages of the energy. We define t
Can the post-Newtonian gravitational waveform of an inspiraling binary be improved by solving the energy balance equation numerically?
gr-qcWolfgang Tichy, Eanna E. Flanagan, Eric Poisson
The detection of gravitational waves from inspiraling compact binaries using matched filtering depends crucially on the availability of accurate template waveforms. We determine whether the accuracy of the templates' phasing can be improved by solving the post-Newtonian energy balance equation numerically, rather than (as is normally done) analytically w
Donald Marolf
These notes present an introduction to branes in ten and eleven dimensional supergravity and string/M-theory which is geared to an audience of traditional relativists, especially graduate students and others with little background in supergravity. They are designed as a tutorial and not as a thorough review of the subject; as a result, many topics of current
D. Roubtsov, Y. Lepine, I. Loutsenko
We explore a nonlinear field model to describe the interplay between the ability of excitons to be Bose condensed and their interaction with other modes of a crystal. We apply our consideration to the long-living paraexcitons in Cu2O. Taking into account the exciton-phonon interaction and introducing a coherent phonon part of the moving condensate, we solve
J. J. McGuire, M. Windt, T. Startseva, T. Timusk
The ab-plane optical spectra of one underdoped and one nearly optimally doped single crystal of HgBa_2Ca_2Cu_3O_{8+delta} were investigated in the frequency range from 40 to 40,000 cm^-1. The frequency dependent scattering rate was obtained by Kramers Kronig analysis of the reflectance. Both crystals have a scattering rate gap of about 1000 cm^-1 which is mu
Mark O. Robbins
The connection between friction and jamming in granular media, molecular glasses, and complex fluids is explored. The paper first reviews the way friction is measured, the types of results that are observed, and what is known about the geometry of contacts between macroscopic surfaces. Then simple models for the origin of static friction are described. These
I. Albert, P. Tegzes, B. Kahng, R. Albert
We investigate the dynamic evolution of jamming in granular media through fluctuations in the granular drag force. The successive collapse and formation of jammed states give a stick-slip nature to the fluctuations which is independent of the contact surface between the grains and the dragged object -- thus implying that the stress-induced collapse is nuclea
Frank Schweitzer, Benno Tilch, Werner Ebeling
We consider Brownian particles with the ability to take up energy from the environment, to store it in an internal depot, and to convert internal energy into kinetic energy of motion. Provided a supercritical supply of energy, these particles are able to move in a ``high velocity'' or active mode, which allows them to move also against the gradient o
In-Plane and Out-of-Plane Optical Properties of NdBa2Cu3Ox Single Crystals close to x = 7.0
cond-mat.supr-conR. Hauff, M. Goeppert, B. Obst, Th. Wolf
We present results of reflectivity measurements with E parallel to c and E perpendicular to c on NdBa2Cu3Ox (Nd123) single crystals close to full oxygen doping. Along the c-axis the optical conductivity shows a well developed absorption band around 450 cm^-1 at all temperatures. The in-plane optical properties are dominated by crystal-field excitations at lo