March 2001 arXiv papers — page 16

M. R. Panzera, S. Campana, S. Covino, L. Guzzo

In collaboration with the Observatories of Palermo and Rome and the SAX-SDC we are constructing a multi-site interactive archive system featuring specific analysis tools. In this context we developed a detection algorithm based on the Wavelet Transform (WT) and performed a systematic analysis of all ROSAT-HRI public data (~3100 observations +1000 to come). T

Robert C. Duncan

The prototype for events that we call MFs - "March Fifth" events or "Magnetar Flares" - was observed on March 5, 1979. There is evidence that MFs are powered by catastrophic magnetic instabilities in ultramagnetized neutron stars. These events begin with brief (~ 0.1 - 1 s), intense, hard spikes of gamma rays followed by long (~ 100 s) softer

P. Bonifacio, E. Caffau, M. Centurion, P. Molaro

By using UV spectra for the O star HD 93521 taken with the ORFEUS II echelle spectrograph, we determine an ``astrophysical'' f value for the SII 94.7 nm line: f = 0.00498 (+0.00172)(-0.00138), error at 1 sigma level.This is almost a factor of 30 smaller than the guessed value found in the Kurucz database (f=0.1472), which was up to now the only one a

G. Giardino, A. J. Banday, P. Fosalba, K. M. Gorski

We have analysed the Rhodes/HartRAO survey at 2326 MHz and derived the global angular power spectrum of Galactic continuum emission. In order to measure the angular power spectrum of the diffuse component, point sources were removed from the map by median filtering. A least-square fit to the angular power spectrum of the entire survey with a power law spectr

I. Marquez, P. Petitjean, B. Theodore, M. Bremer

We present the results of adaptive-optics imaging in the H and K bands of 12 low and intermediate redshift (z<0.6) quasars using the PUEO system mounted on the Canada-France-Hawaii telescope. Five quasars are radio-quiet and seven are radio-loud. The images, obtained under poor seeing conditions, and with the QSOs (mV>15.0) themselves as reference for the co

Akio K. Inoue, Hiroyuki Hirashita, Hideyuki Kamaya

We re-examine the effect of Lyman continuum ($λ\leq 912$ Å) extinction (LCE) by dust in H {\sc ii} regions in detail and discuss how it affects the estimation of the global star formation rate (SFR) of galaxies. To clarify the first issue, we establish two independent methods for estimating a parameter of LCE ($f$), which is defined as the fraction of Lyman

Banibrata Mukhopadhyay, Sandip K. Chakrabarti

We study the effect of nuclear reaction on a thin, axisymmetric, differentially rotating, inviscid, steady accretion flow around a black hole from an analytical point of view. We find that for most of the reasonable disk parameters, when $p-p$-reaction, dissociation of deuterium and helium are taken into account, the transonic region of the disk continues to

Scott F. Anderson, Xiaohui Fan, Gordon T. Richards, Donald P. Schneider

We present results on over 100 high-redshift quasars found in the Sloan Digital Sky Survey (SDSS), using automated selection algorithms applied to SDSS imaging data and with spectroscopic confirmation obtained during routine spectroscopic operations of the Sloan 2.5-m telescope. The SDSS spectra cover the wavelength range 3900--9200 Angstroms at a spectral r

Hantao Ji, Jeremy Goodman, Akira Kageyama

Although the magnetorotational instability (MRI) has been widely accepted as a powerful accretion mechanism in magnetized accretion disks, it has not been realized in the laboratory. The possibility of studying MRI in a rotating liquid-metal annulus (Couette flow) is explored by local and global stability analysis and magnetohydrodynamic (MHD) simulations. S

A. Kempf, J. C. Niemeyer

It has been pointed out that the perturbation spectrum predicted by inflation may be sensitive to a natural ultraviolet cutoff, thus potentially providing an experimentally accessible window to aspects of Planck scale physics. A priori, a natural ultraviolet cutoff could take any form, but a fairly general classification of possible Planck scale cutoffs has

Jaume Gomis

We show that M-theory on spaces with irreducible holonomy represent Type IIA backgrounds in which a collection of D6-branes wrap a supersymmetric cycle in a manifold with a holonomy group different from the one appearing in the M-theory description. For example, we show that D6-branes wrapping a supersymmetric four-cycle on a manifold with G_2 holonomy is de

M. B. Hastings

A fast method is presented for simulating the dielectric-breakdown model using iterated conformal mappings. Numerical results for the dimension and for corrections to scaling are in good agreement with the recent RG prediction of an upper critical $η_c=4$, at which a transition occurs between branching fractal clusters and one-dimensional nonfractal clusters

C. Bernard, T. DeGrand, C. DeTar, S. Gottlieb

The separation of a heavy quark and antiquark pair leads to the formation of a tube of flux, or &#34;string&#34;, which should break in the presence of light quark-antiquark pairs. This expected zero-temperature phenomenon has proven elusive in simulations of lattice QCD. We study mixing between the string state and the two-meson decay channel in QCD with tw

E. Minguzzi

Starting from the experimental fact that light propagates over a closed path at speed c (L/c law), we show to what extent the isotropy of the speed of light can be considered a matter of convention. We prove the consistence of anisotropic and inhomogenous conventions, limiting the allowed possibilities. All conventions lead to the same physical theory even i

J. Dietel

We consider the energy density of a spin polarized $ν=1/2$ system for low temperatures. We show that due to the elimination of the magnetic field and the field of the positive background charge in the calculation of the grand canonical potential of Chern-Simons systems through a mean field formalism one gets corrections to the well known equations which dete

Stephan Dürr

Recent lattice data from CP-PACS, UKQCD, SESAM/TXL and the Pisa group regarding the quark mass dependence of the topological susceptibility in 2-flavour QCD are compared to each other and to theoretical expectations. The latter get specified by referring to the QCD finite-volume partition function with ``granularity&#39;&#39; which accounts for the entropy b

A. Iqbal, A. H. Toor

We investigate the role of quantum mechanical effects in the central stability concept of evolutionary game theory i.e. an Evolutionarily Stable Strategy (ESS). Using two and three-player symmetric quantum games we show how the presence of quantum phenomenon of entanglement can be crucial to decide the course of evolutionary dynamics in a population of inter

G. Baskaran

We view $MgB_2$ as electronically equivalent to (non-staggered) graphite ($B^-$ layer) that has undergone a zero gap semiconductor to a superconductor phase transition by a large c-axis (chemical) pressure due to $Mg^{++}$ layers. Further, like the \ppi bonded planar organic molecules, graphite is an old resonating valence bond (RVB) system. The RVB&#39;s ar

N. F. Benschop

The product m_k of the first k primes (2..p_k) has neighbours m_k +/- 1 with all prime divisors beyond p_k, implying there are infinitely many primes [Euclid]. All primes between p_k and m_k are in the group G_1 of units in semigroup Z_{m_k}(.) of mutiplication mod m_k. Due to the squarefree modulus Z_{m_k} is a disjoint union of 2^k groups, with as many ide

Pran Nath, Raza M. Syed

We develop techniques for the analysis of SO(2N) invariant couplings which allow a full exhibition of the SU(N) invariant content of the spinor and tensor representations. The technique utilizes a basis consisting of a specific set of reducible SU(N) tensors in terms of which the SO(2N) invariant couplings have a simple expansion. The technique is specially

J. M. Miller, H. L. Marshall, R. Wijnands, T. Di Matteo

On two occasions, we obtained nearly simultaneous ~ 4 kilosecond snapshot observations of the Galactic black hole and microquasar XTE J1550-564 with Chandra and RXTE near the peak of its May, 2000 outburst. The low-energy sensitivity of Chandra and the resolution of the High Energy Transmission Grating Spectrometer (HETGS), coupled with the broad energy rang

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

We present the Monte Carlo event generator YFSWW3 version 1.16 for theprocess of W-pair production and decay in electron-positron collisions. It includes ${\cal O}(α)$ electroweak radiative corrections in the WW production stage together with the ${\cal O}(α^3)$ initial-state-radiation (ISR) corrections in the leading-logarithmic (LL) approximation, implemen

Massimo Bianchi

I summarize perturbative and non-perturbative field theory tests of the holographic correspondence between type IIB superstring on AdS_5xS^5 and N=4 SYM theory. The holographic duality between D-instantons and YM instantons is briefly described. Non renormalization of two- and three-point functions of CPO's and their extremal and next-to-extremal correlators

Zeng-Bing Chen, Yong-De Zhang

As a development of our previous work, this paper is concerned with the Greenberger-Horne-Zeilinger (GHZ) nonlocality for continuous variable cases. The discussion is based on the introduction of a pseudospin operator, which has the same algebra as the Pauli operator, for each of the $N$ modes of a light field. Then the Bell-CHSH (Clauser, Horne, Shimony and

Santo Fortunato, Helmut Satz

The critical behaviour of many spin models can be equivalently formulated as percolation of specific site-bond clusters. In the presence of an external magnetic field, such clusters remain well-defined and lead to a percolation transition, even though the system no longer shows thermal critical behaviour. We investigate the 2-dimensional Ising model and the

Piero Olla

The statistical properties of heavy particle trajectories in high Reynolds numbers turbulent flows are analyzed. Dimensional analysis assuming Kolmogorov scaling is compared with the result of numerical simulation using a synthetic turbulence advecting field. The non-Markovian nature of the fluid velocity statistics along the solid particle trajectories is p

Ming-Chiang Chung, Ingo Peschel

We consider non-interacting fermions on a lattice and give a general result for the reduced density matrices corresponding to parts of the system. This allows to calculate their spectra, which are essential in the DMRG method, by diagonalizing small matrices. We discuss these spectra and their typical features for various fermionic quantum chains and for the

V. E. R. Lemes, M. S. Sarandy, S. P. Sorella, O. S. Ventura

An algebraic criterion for the vanishing of the beta function for renormalizable quantum field theories is presented. Use is made of the descent equations following from the Wess-Zumino consistency condition. In some cases, these equations relate the fully quantized action to a local gauge invariant polynomial. The vanishing of the anomalous dimension of thi

Y. Koma, E. -M. Ilgenfritz, H. Toki, T. Suzuki

The string tensions of flux tubes associated with static charges in various SU(3) representations are studied within the dual Ginzburg-Landau (DGL) theory. The ratios of the string tensions between higher and fundamental representations, $d_{D} \equiv \sigma_{D}/\sigma_{F}$, are found to depend only on the Ginzburg-Landau (GL) parameter, $\kappa = m_{\chi}/m

Joern Stenger, Christian Tamm, Nils Haverkamp, Stefan Weyers

We have measured the frequency of the $6s^2S_{1/2} - 5d^2D_{3/2}$ electric-quadrupole transition of $^{171}$Yb$^+$ with a relative uncertainty of $1\times 10^{-14}$, $ν_{Yb}$ = 688 358 979 309 312 Hz $\pm$ 6 Hz. A femtosecond frequency comb generator was used to phase-coherently link the optical frequency derived from a single trapped ion to a cesium fountai

O. V. Utyuzh, G. Wilk, Z. Wlodarczyk

We provide a critical overview of the $Φ$ measure of fluctuations and correlations. In particular we show that its discriminating power is rather limited in situations encountered in experiment.

Miao Li

Unlike noncommutative space, when space and time are noncommutative, it seems necessary to modify the usual scheme of quantum mechanics. We propose in this paper a simple generalization of the time evolution equation in quantum mechanics to incorporate the feature of a noncommutative spacetime. This equation is much more constraining than the usual Schröding

Gianguido Dall&#39;Agata, Carl Herrmann, Marco Zagermann

We construct the general form of matter coupled N=4 gauged supergravity in five dimensions. Depending on the structure of the gauge group, these theories are found to involve vector and/or tensor multiplets. When self-dual tensor fields are present, they must be charged under a one-dimensional Abelian group and cannot transform non-trivially under any other

G. Montagna, M. Moretti, O. Nicrosini, M. Osmo

The production of four fermions plus a visible photon in electron-positron collisions is analyzed, with particular emphasis on the LEP2 energy range. The study is based on the calculation of exact matrix elements, including the effect of fermion masses. In the light of the present measurements performed at LEP, triple and quartic anomalous gauge couplings ar

Ehud Nakar, Tsvi Piran

We analyze a sample of bright long bursts and find that the pulses duration have a lognormal distribution while the intervals between pulses have an excess of long intervals (relative to lognormal distribution). This excess can be explained by the existence of quiescent times, long periods with no signal above the background. The lognormal distribution of th

E. Pazy, I. D&#39;Amico, P. Zanardi, F. Rossi

In the context of a semiconductor based implementation of a quantum computer the idea of a quantum storage bit is presented and a possible implementation using a double quantum dot structure is considered. A measurement scheme using a stimulated Raman adiabatic passage is discussed.

P. Leboeuf, N. Pavloff

We compute the stationary profiles of a coherent beam of Bose condensed atoms propagating through a guide. Special emphasis is put on the effect of an obstacle present on the trajectory of the beam. The obstacle considered (such as a bend in the guide, or a laser field perpendicular to the beam) results in a repulsive or an attractive potential acting on the

A. Cucchieri, F. Karsch, P. Petreczky

We investigate the large distance behavior of the electric and magnetic propagators of hot SU(2) gauge theory in different gauges using lattice simulations of the full 4d theory and the effective, dimensionally reduced 3d theory. Comparison of the 3d and 4d propagators suggests that dimensional reduction works surprisingly well down to the temperature T=2 T_

Hans-Christian Pauli, Asmita Mukherjee

The form factor and the mean-square radius of the pion are calculated analytically from a parametrized form of a $q\bar q$ wave function. The numerical wave function was obtained previously by solving numerically an eigenvalue equation for the pion in a particular model. The analytical formulas are of more general interest than just be valid for the pion and

Peter Gillin, Hidetoshi Nishimori, David Sherrington

We consider the thermodynamics of an infinite-range Ising p-spin glass model with an additional r-spin ferromagnetic interaction. For r=2 there is a continuous transition to a ferromagnetic phase, while for r>2 the transition is first order. We find both glassy and non-glassy ferromagnetic phases, with replica symmetry breaking of both the one step and full

Giorgio Torrieri, Johann Rafelski

We study the production and the observability of Lambda*(1520), K*0(892), and Sigma*(1385), strange hadron resonances as function of the freeze-out conditions within the statistical model of hadron production. We obtain an estimate of how many decay products are rescattered in evolution towards thermal freeze-out following chemical freeze-out, and find that

H. L. Marshall, R. Rutledge, D. W. Fox, J. M. Miller

We present observations of the Rapid Burster (RB, also known as MXB 1730-335) using the Chandra High Energy Transmission Grating Spectrometer. The average interval between type II (accretion) bursts was about 40 s. There was one type I (thermonuclear flash) burst and about 20 &#34;mini-bursts&#34; which are probably type II bursts whose peak flux is 10-40% o

Haijun Pan, G. Cheng

We advance a method used to analyse the neutrino properties (masses and mixing) in the seesaw mechanism. Assuming the hierarchical Dirac and light neutrino masses we establish rather simple relations between the light and the heavy neutrino parameters in the favored region of the solar and the atmospheric neutrino experiments. A empirical condition satisfied

Enrique Vazquez-Semadeni, Nieves Garcia

(Abridged) We discuss the probability distribution function (PDF) of column density resulting from density fields with lognormal PDFs, applicable to isothermal gas (e.g., probably molecular clouds). We suggest that a ``decorrelation length'' can be defined as the distance over which the density auto-correlation function has decayed to, for example, 10% of it

A. Bouda, T. Djama

Using the quantum Hamilton-Jacobi equation within the framework of the equivalence postulate, we construct a Lagrangian of a quantum system in one dimension and derive a third order equation of motion representing a first integral of the quantum Newton&#39;s law. We then integrate this equation in the free particle case and compare our results to those of Fl

Berry Groisman, Lev Vaidman

An alternative proof for existence of ``quantum nonlocality without entanglement&#39;&#39;, i.e. existence of variables with product-state eigenstates which cannot be measured locally, is presented. A simple``nonlocal&#39;&#39; variable for the case of one-way communication is given and the limit for its approximate measurability is found.

Paulo A. Maia Neto, Diego A. R. Dalvit

The radiation pressure coupling with vacuum fluctuations gives rise to energy damping and decoherence of an oscillating particle. Both effects result from the emission of pairs of photons, a quantum effect related to the fluctuations of the Casimir force. We discuss different alternative methods for the computation of the decoherence time scale. We take the

Lev Vaidman

Interaction-free measurements introduced by Elitzur and Vaidman [Found. Phys. 23, 987 (1993)] allow finding infinitely fragile objects without destroying them. Many experiments have been successfully performed showing that indeed, the original scheme and its modifications lead to reduction of the disturbance of the observed systems. However, there is a contr

G. Mauro D&#39;Ariano, Matteo G. A. Paris, Paolo Perinotti

We address the problem of the optimal quantum estimation of the coupling parameter of a bilinear interaction, such as the transmittivity of a beam splitter or the internal phase-shift of an interferometer. The optimal measurement scheme exhibits Heisenberg scaling of the measurement precision versus the total energy.

Rob Clifton, D. T. Pope

By exhibiting a violation of a novel form of the Bell-CHSH inequality, Zukowski has recently established that the quantum correlations exploited in the standard perfect teleportation protocol cannot be recovered by any local hidden variables model. Allowing the quantum channel state in the protocol to be given by any density operator of two spin-1/2 particle

G. Bjork, P. Jonsson, L. L. Sanchez-Soto

We propose a single-particle experiment that is equivalent to the conventional two-particle experiment used to demonstrate a violation of Bell&#39;s inequalities. Hence, we argue that quantum mechanical nonlocality can be demonstrated by single-particle states. The validity of such a claim has been discussed in the literature, but without reaching a clear co

Yuri I. Ozhigov

Quantum algorithms speeding up classical counterparts are proposed for the problems: 1. Recognition of eigenvalues with fixed precision. Given a quantum circuit generating unitary mapping $U$ and a complex number the problem is to determine is it an eigenvalue of $U$ or not. 2. Given a molecular structure find thermodynamic functions like partitioning functi

P. Pieranski, S. Przybyl

The most tight conformation of the trefoil knot found by the SONO algorithm is presented. Structure of the set of its self-contact points is analyzed.

D. M. Snyder

Maxwell&#39;s equations hold in inertial reference frames in uniform translational motion relative to one another. In conjunction with the Lorentz coordinate transformation equations, the transformation equations for the electric and magnetic field components in these reference frames can be derived. As the derivation of the Lorentz coordinate transformation

Frederic C. Marton, Joel Ita, Ronald E. Cohen

The composition of the lower mantle can be investigated by examining densities and seismic velocities of compositional models as functions of depth. In order to do this it is necessary to know the volumes and thermoelastic properties of the compositional constituents under lower mantle conditions. We determined the thermal equation of state (EOS) of MgSiO3 p

L. Mornas, E. Gallego, A. Perez

We obtain the RPA summed one-meson exchange potential between nucleons in symmetric nuclear matter at zero temperature, from a model which includes $ρ$, $σ$, $ω$ and $π$ mesons. The behavior of rho mesons inside the medium is first discussed using different schemes to extract a finite contribution from the vacuum polarization. These schemes give qualitativel

Christoph M. Keil, Horst Lenske

New experimental data on medium to heavy single Lambda hypernuclei revealed a much larger spin-orbit splitting than observed in older measurements of light hypernuclei. Taking into account particle threshold effects and the density-dependence of in-medium coupling constants the apparent suppression of spin-orbit strength in light hypernuclei as well as the s

Tapas Sil, B. K. Agrawal, J. N. De, S. K. Samaddar

A detailed microscopic study of the temperature dependence of the shapes of some rare-earth nuclei is made in the relativistic mean field theory. Analyses of the thermal evolution of the single-particle orbitals and their occupancies leading to the collapse of the deformation are presented. The role of the non-linear $σ-$field on the shape transition in diff

Sourav Sarkar, Jan-e Alam, T. Hatsuda

We show that the dilepton spectra measured by the CERES collaboration in Pb + Au interactions for various charge multiplicities can be reproduced by a hadronic initial state with reduction in the masses of the vector mesons in the thermal bath. Though such an effect may also be achieved by a large broadening of the spectral function we show that the photon s

M. Yu. Kuchiev, B. L. Altshuler, V. V. Flambaum

In conventional nuclear experiments a beam of accelerated nuclei collides with a target nucleus that is surrounded by other nuclei in a molecule, in condensed matter, or in a plasma environment. It is shown that for low collision energies possible nuclear reactions (including deuterium fusion) are strongly boosted by the environment. The effect originates fr

L. Tassan-Got

We propose a new functional for the charge and mass identification in Delta E-E telescopes. This functional is based on Bethe&#39;s formula, allowing safe interpolation or extrapolation in regions with low statistics. When applied to telescopes involving detectors delivering a linear response, as silicon detectors or ionization chambers, a good mass and char

G. Boffetta, M. Cencini, S. Espa, G. Querzoli

Lagrangian chaos is experimentally investigated in a convective flow by means of Particle Tracking Velocimetry. The Fnite Size Lyapunov Exponent analysis is applied to quantify dispersion properties at different scales. In the range of parameters of the experiment, Lagrangian motion is found to be chaotic. Moreover, the Lyapunov depends on the Rayleigh numbe

Tomoyuki Takenawa

A geometric charactrization of the equation found by Hietarinta and Viallet, which satisfies the singularity confinement criterion but which exhibits chaotic behavior, is presented. It is shown that this equation can be lifted to an automorphism of a certain rational surface and can therefore be considered to be a realization of a Cremona isometry on the Pic

B. Konopelchenko, L. Martinez Alonso

It is shown that the dispersionless scalar integrable hierarchies and, in general, the universal Whitham hierarchy are nothing but classes of integrable deformations of quasiconformal mappings on the plane. Examples of deformations of quasiconformal mappings associated with explicit solutions of the dispersionless KP hierarchy are presented.

Haisheng Li

This is the second paper in a series to study regular representations for vertex operator algebras. In this paper, given a module $W$ for a vertex operator algebra $V$, we construct, out of the dual space $W^{*}$, a family of canonical (weak) $V\otimes V$-modules called ${\cal{D}}_{Q(z)}(W)$ parametrized by a nonzero complex number $z$. We prove that for $V$

R. Chakrabarti, J. Segar

We introduce and investigate a one parameter family of quantum spaces invariant under the left (right) coactions of the group-like element ${\cal T}_{h}^{(j=1)}$ of the Jordanian function algebra $Fun_{h}(SL(2))$. These spaces may be regarded as Jordanian quantization of the two-dimensional spheres.

Ha Huy Tai

Let X be a set of smooth points in P^2, and I = \oplus_{t >= d} I_t the defining ideal of X. In this paper, we give a set of defining equations for the Rees algebra R(I_{d+1}) of the ideal generated by I_{d+1}. This study give information to completely answer questions on the defining ideals of projective embeddings of the blowup of P^2 along the points in X

Malgorzata Rowicka-Kudlicka

We consider quantum group theory on the Hilbert space level. We find all solutions for scalar and general exponential equations for the quantum ``az+b&#39;&#39; group. It turns out that there is a simple formula for all of them involving the quantum exponential function F_N. The very interesting theorem we prove by the way is the one on the existence of norm

F. J. Castro-Jimenez, J. M. Ucha

The relationship between ${\cal D}$-modules and free divisors has been studied in a general setting by L. Narváez and F.J. Calderón. Using the ideas of these works we prove in this article a duality formula between two ${\cal D}$-modules associated to a class of free divisors on ${\bf C}^n$ and we give some applications

Nobuyuki Kakimi

We define and calculate the weighted multiplicities of non Gorenstein terminal singularities on threefolds and some quotient singularities. We improve freeness conditions on threefolds.

Robert Friedman, John W. Morgan

This paper continues the study of holomorphic semistable principal G-bundles over an elliptic curve. In this paper, the moduli space of all such bundles is constructed by considering deformations of a minimally unstable G-bundle. The set of all such deformations can be described as the C^* quotient of the cohomology group of a sheaf of unipotent groups, and

W. Lerche, P. Mayr, J. Walcher

The boundary chiral ring of a 2d gauged linear sigma model on a Kähler manifold $X$ classifies the topological D-brane sectors and the massless open strings between them. While it is determined at small volume by simple group theory, its continuation to generic volume provides highly non-trivial information about the $D$-branes on $X$, related to the derived

Christian Fronsdal

Quantization is still a central problem of modern physics. One example of an unsolved problem is the quantization of Nambu mechanics. After a brief comment on the role of Harrison cohomology, this review concentrates on the central problem of quantization of QCD and, more generally, quark confinement seen as a problem of quantization. Several suggestions are

Jussi Kalkkinen, Dario Martelli, Wolfgang Mueck

The Weyl anomaly in the Holographic Renormalisation Group as implemented using Hamilton-Jacobi language is studied in detail. We investigate the breakdown of the descent equations in order to isolate the Weyl anomaly of the dual field theory close to the (UV) fixed point. We use the freedom of adding finite terms to the renormalised effective action in order

D. Alba, H. Crater, L. Lusanna

In the semiclassical approximation of Grassmann-valued electric charges for regularizing Coulomb self-energies, we extract the unique acceleration-independent interaction hidden in any Lienard-Wiechert solution for the system of N positive-energy spinning particles plus the electromagnetic field in the radiation gauge of the rest-frame instant form. With the

Danny Birmingham, Soussan Mokhtari

We consider the conformal field theory which is dual to the Taub-Bolt-AdS spacetime. It is shown that the Cardy-Verlinde formula for the entropy of the conformal field theory agrees precisely with the entropy of the Taub-Bolt-AdS spacetime, at high temperatures. This result may be viewed as providing a conformal field theory interpretation of Taub-Bolt-AdS e

David B. Fairlie, Tatsuya Ueno

The purpose of this article is to initiate a study of a class of Lorentz invariant, yet tractable, Lagrangian Field Theories which may be viewed as an extension of the Klein-Gordon Lagrangian to many scalar fields in a novel manner. These Lagrangians are quadratic in the Jacobians of the participating fields with respect to the base space co-ordinates. In th

Tatsuo Suzuki

In this thesis, we investigate various integral submodels and generalize them. In part I, we study the submodel of the nonlinear $\mathbf{C}P^1$-model and the related submodels in $(1+2)$ dimensions. In part II, we construct integrable submodels of the nonlinear Grassmann models in any dimension. We call them the Grassmann submodels. To show that our submode

I. Antoniadis

1. Preliminaries. 2. Heterotic string and motivations for large volume compactifications; 2.1 Gauge coupling unification; 2.2 Supersymmetry breaking by compactification. 3. M-theory on S^1/Z_2 \times Calabi-Yau. 4. Type I/I&#39; string theory and D-branes; 4.1 Low-scale strings and extra-large transverse dimensions; 4.2 Relation type I/I&#39; -- heterotic. 5

Gerhard Buchalla

We introduce and discuss basic topics in the theory of kaons and charmed particles. In the first part, theoretical methods in weak decays such as operator product expansion, renormalization group and the construction of effective Hamiltonians are presented, along with an elementary account of chiral perturbation theory. The second part describes the phenomen

C. J. Maxwell, A. Mirjalili

We perform an all-orders resummation of the QCD Adler D-function for the vector correlator, in which the portion of perturbative coefficients involving the leading power of b, the first beta-function coefficient, is resummed. To avoid a renormalization scale dependence when we match the resummation to the exactly known NLO and NNLO results, we employ the Com

M. Guchait, J. Kalinowski, P. Roy

The occurrence of a significant amount of supersymmetric lepton flavour violation at laboratory energies, through $\tildeν_μ- \tildeν_τ$ mixing, has become a realistic possibility in the wake of the super-Kamiokande atmospheric neutrino result. This effect can be observed in an e+e- linear collider with the distinct final state tau+mu+ jets+E_T. We show that

Alfonso R. Zerwekh

Recently has been shown that the physical (mass eigenstate) color-octet technirho does not couple to two gluons. In this letter we study how this result affects the presently accepted limits for the color-octet technirho mass obtained from the study of dijets production at the Tevatron. First we show that data from Tevatron Run 1b can not exclude any mass ra

Alfonso R. Zerwekh, Rogerio Rosenfeld

We show that the usual vector meson dominance method does not apply directly to the mixing of a color-octet vector boson (color-octet technirho) with the gluon because of gauge invariance. We propose a gauge invariant method where one works in a physical basis with mass eigenstate fields. As a result, we show that the physical technirho does not couple to tw

J. Gasser, V. E. Lyubovitskij, A. Rusetsky, A. Gall

We construct an effective non-relativistic quantum field theory that describes bound states of pi+ pi- pairs and their hadronic decays. We then derive a general expression for the lifetime of the ground state at next-to-leading order in isospin breaking. Chiral perturbation theory allows one to relate the decay rate to the two S-wave pi pi scattering lengths

J. Zimanyi, P. Levai, T. Csorgo, T. S. Biro

Quark coalescence predictions for various multi-strange baryon to anti-baryon ratios for central Au+Au collisions at RHIC energies are compared to preliminary data of the STAR collaboration. The formation of Quark Matter and the sudden recombination of its constituent quarks into hadrons is found to be in agreement with these preliminary data. It seems that

Junjie Cao, Gongru Lu, Zhenjun Xiao

Based on the low-energy effective Hamiltonian, we calculate the new physics corrections to the branching ratio and the differential distributions of the rare decay $B \to X_s γγ$ induced by the new gluonic and electroweak charged-Higgs penguin diagrams in the general two-Higgs-doublet model with the restriction $λ_{ij}^{U,D}=0$ for $i\neq j$. Within the cons

Sergey L. Cherkas

T-violating P-even magnetism is considered. The magnetism arises from the T-violating P-conserving vertex of a spin 1/2 particle interaction with the electromagnetic field. The vertex varnishes for a particle on the mass shell. Considering the particle interaction with a point electric charge we have obtained the T-violating P-even spin dependent potential w

Zhenjun Xiao, Wenjun Li, Libo Guo, Gongru Lu

Using the low energy effective Hamiltonian with the generalized factorization, we calculate the new physics contributions to $B \to π^+ π^-, K π$ and $K \etap$ in the Topcolor-assisted-Technicolor(TC2) model, and compare the results with the available data. By using $F_0^{\rm Bπ}(0)=0.20\pm 0.04$ preferred by the CLEO data of $B \to π^+ π^-$ decay, we find t

Dumitru Ghilencea, Hans Peter Nilles

We investigate the so-called ``Kaluza-Klein regularisation&#39;&#39; procedure in supersymmetric extensions of the standard model with additional compact dimensions and Scherk-Schwarz mechanism for supersymmetry breaking. This procedure uses a specific mathematical manipulation to obtain a finite result for the scalar potential. By performing the full calcul

Shinji Tsujikawa, Hiroki Yajima

We study massive spin-1/2 fermion production in nonsingular superstring cosmology, taking into account one-loop quantum corrections to a superstring effective action with dilaton and modulus fields. While no creation occurs in the massless limit, massive fermions can be produced by the existence of a time-dependent frequency. Due to the increase of the Hubbl

Edmond L. Berger

A new contribution from pair-production of light gluinos, of mass 12 to 16 GeV, with two-body decays into bottom quarks and light bottom squarks, helps to obtain a bottom-quark production rate in better agreement with hadron collider data. The masses of the gluino and bottom squark are further restricted by the ratio of like-sign to opposite-sign leptons at

Paul de Jong

The studies of colour reconnection in e+e- -> WW -> 4 jets events at LEP are reviewed. It is shown that the analysis of the particle- and energy flow between jets is sensitive to realistic model predictions. The effects on the W mass measurement are discussed.

NOMAD Collaboration, P. Astier

The inclusive production of the meson resonances $ρ^{0}(770)$, $f_0(980)$ and $f_2(1270)$ in neutrino-nucleus charged current interactions has been studied with the NOMAD detector exposed to the wide band neutrino beam generated by 450 GeV protons at the CERN SPS. For the first time the $f_{0}(980)$ meson is observed in neutrino interactions. The statistical

Charro Gruver, Richard Hammond, P. F. Kelly

A theory of gravity with torsion is examined in which the torsion tensor is constructed from the exterior derivative of an antisymmetric rank two potential plus the dual of the gradient of a scalar field. Field equations for the theory are derived by demanding that the action be stationary under variations with respect to the metric, the antisymmetric potent

A. M. Khvedelidze, Yu. G. Palii

The classical and quantum dynamics of the Friedmann-Robertson-Walker Universe with massless scalar and massive fermion matter field as a source is discussed in the framework of the Dirac generalized Hamiltonian formalism. The Hamiltonian reduction of this constrained system is realized for two cases of minimal and conformal coupling between gravity and matte

Claus Lämmerzahl

The compatibility axiom in Ehlers, Pirani and Schild&#39;s (EPS) constructive axiomatics of the space-time geometry that uses light rays and freely falling particles with high velocity, is replaced by several constructions with low velocity particles only. For that purpose we describe in a space-time with a conformal structure and an arbitrary path structure

M. Adak, T. Dereli, L. H. Ryder

The gravitational neutrino oscillation problem is studied by considering the Dirac Hamiltonian in a Riemann-Cartan space-time and calculating the dynamical phase. Torsion contributions which depend on the spin direction of the mass eigenstates are found. These effects are of the order of Planck scales.

Marcus Hutter

In evolutionary algorithms, the fitness of a population increases with time by mutating and recombining individuals and by a biased selection of more fit individuals. The right selection pressure is critical in ensuring sufficient optimization progress on the one hand and in preserving genetic diversity to be able to escape from local optima on the other. We

Florin D. Buzatu, Daniela Buzatu, John G. Albright

We consider a lattice model for three-component systems in which the lattice bonds are covered by molecules of type AA, BB, and AB, and the only interactions are between the molecular ends of a common lattice site. The model is equivalent to the standard Ising model, and the coexistence curves for different lattices and/or some specific form of the interacti