March 2003 arXiv papers — page 9

A. Das, G. Mayer-Kress, C. Gershenson, P. Das

There is likeness of the Internet to human brains which has led to the metaphor of the world-wide computer network as a `Global Brain'. We consider conferences as 'binding events' in the Global Brain that can lead to metacognitive structures on a global scale. One of the critical factors for that phenomenon to happen (similar to the biological br

O. V. Yaroshchuk, A. D. Kiselev, Yu. Zakrevskyy, T. Bidna

We apply experimental technique based on the combination of methods dealing with principal refractive indices and absorption coefficients to study the photoinduced 3D orientational order in the films of liquid crystalline (LC) azopolymers. The technique is used to identify 3D orientational configurations of trans azobenzene chromophores and to characterize t

Sudhansu S. Mandal, Michael R. Peterson, Jainendra K. Jain

The two dimensional system of electrons in a high magnetic field offers an opportunity to investigate a phase transition from a quantum liquid into a Wigner solid. Recent experiments have revealed an incipient composite fermion liquid in a parameter range where theory and many experiments had previously suggested the Wigner crystal phase, thus calling into q

Flavio S. Nogueira, Hagen Kleinert

Several field theoretical approaches to the superconducting phase transition are discussed. Emphasis is given to theories of scaling and renormalization group in the context of the Ginzburg-Landau theory and its variants. Also discussed is the duality approach, which allows to access the strong-coupling limit of the Ginzburg-Landau theory.

Hiroshi Matsuda, Akihisa Yao, Hiroshi Tsukahara, Tetsuo Deguchi

We have evaluated by numerical simulation the average size $R_K$ of random polygons of fixed knot topology $K = \emptyset, 3_1, 3_1\sharp4_1$, and we have confirmed the scaling law $R^2_K \sim N^{2ν_K}$ for the number $N$ of polygonal nodes in a wide range; $N = 100$ -- 2200. The best fit gives $2 ν_K \simeq 1.11$ -- 1.16 with good fitting curves in the whol

I. G. Bostrem, A. S. Ovchinnikov, R. F. Egorov

We suggest a method of derivation of the long-wave action of the model spin Hamiltonians using the non-linear partial differential equations of motions of the individual spins. According to the Vainberg's theorem the set of these equations are (formal) potential if the symmetry analysis for the Frechet derivatives of the system is true. The case of Heise

V. D. Krevchik, A. B. Grunin, A. K. Aringazin, M. B. Semenov

The impurity magneto-optical absorption for the cases of longitudinal and transversal light polarization with respect to the quantum wire axis has been theoretically studied. Analytical expressions for the corresponding D(-)-centers photo-ionization cross sections under the action of longitudinal magnetic field have been obtained, and their spectral dependen

Daniel M. Kaplan, Victor A. Sverdlov, Konstantin K. Likharev

We have carried out numerical simulations of shot noise in 2D arrays of single-electron islands with random background charges. The results show that in contrast with the 1D arrays, at low currents the current noise is strongly colored, and its spectral density levels off at very low frequencies. The Fano factor may be much larger than unity, due to the remn

S. Mazumdar, S. Dallakyan, M. Chandross

There is currently a great need for solid state lasers that emit in the infrared. Whether or not conjugated polymers that emit in the IR can be synthesized is an interesting theoretical challenge. We show that emission in the IR can be achieved in designer polymers in which the effective Coulomb correlation is smaller than that in existing systems. We also s

Tetsuo Deguchi

We prove some part of the conjecture that regular Bethe ansatz eigenvectors of the XXZ spin chain at roots of unity are highest weight vectors of the $sl_2$ loop algebra. Here $q$ is related to the XXZ anisotropic coupling $Δ$ by $Δ=(q+q^{-1})/2$, and it is given by a root of unity, $q^{2N}=1$, for a positive integer $N$. We show that regular XXZ Bethe state

Howard E. Bond, Arne Henden, Zoltan G. Levay, Nino Panagia

Some classes of stars, including supernovae and novae, undergo explosive outbursts that eject stellar material into space. In 2002, the previously unknown variable star V838 Monocerotis brightened suddenly by a factor of about 10^4. Unlike a supernova or nova, V838 Mon did not explosively eject its outer layers; rather, it simply expanded to become a cool su

Julien Sylvestre

Various models for electromagnetic emissions correlated with the gravitational wave signals expected to be detectable by the current and planned gravitational wave detectors are studied. The position error on the location of a gravitational wave source is estimated, and is used to show that it could be possible to observe the electromagnetic counterparts to

A. Kucinskas, L. Lindegren, T. Tanabe, V. Vansevicius

We discuss the tracing of star formation histories with ESA's space astrometry mission GAIA, emphasizing the advantages of AGB stars for this purpose. GAIA's microarcsecond-level astrometry, multi-band photometry and spectroscopy will provide individual distances, motions, effective temperatures, gravities and metallicities for vast numbers of AGB st

B. A. Benson, S. E. Church, P. A. R. Ade, J. J. Bock

We have made measurements of the Sunyaev-Zel'dovich (SZ) effect in six galaxy clusters at z > 0.2 using the Sunyaev-Zel'dovich Infrared Experiment (SuZIE II) in three frequency bands between 150 and 350 GHz. Simultaneous multi-frequency measurements have been used to distinguish between thermal and kinematic components of the SZ effect, and to signif

Akira Tomimatsu, Masaaki Takahashi

We present an analytical model for describing highly relativistic acceleration of magnetically driven jets, within the framework of ideal MHD for cold, stationary and axisymmetric outflows. Our novel procedure is to treat the wind equation as an algebraic relation between the relativistic Alfvén Mach-number and the poloidal electric to toroidal magnetic fiel

Daniel D. Kelson

In two-dimensional spectrographs, the optical distortions in the spatial and dispersion directions produce variations in the sub-pixel sampling of the background spectrum. Using knowledge of the camera distortions and the curvature of the spectral features, one can recover information regarding the background spectrum on wavelength scales much smaller than a

J. S. Miller, A. I. Sheinis

We present optical spectroscopy of the host galaxies of 4 QSO&#39;s: PG1444+407, PKS 2349-147, 3C 323.1, and 4C 31.63 having a redshift range (0.1 < z < 0.3). The spectra were obtained at the Keck Observatory with the LRIS instrument offset 2-4 arcseconds from the nucleus at several position angles in each galaxy. The objects close to 3C 323.1 and PKS 2349-1

Soebur Razzaque, Peter Meszaros, Eli Waxman

Neutrinos at energies above TeV can serve as probes of the stellar progenitor and jet dynamics of gamma ray bursts arising from stellar core collapses. They can also probe collapses which do not lead to gamma-rays, which may be much more numerous. We calculate detailed neutrino spectra from shock accelerated protons in jets just below the outer stellar envel

J. Carlson, S. Y. Chang, V. R. Pandharipande, K. E. Schmidt

We report quantum Monte Carlo calculations of superfluid Fermi gases with short-range two-body attractive interactions with infinite scattering length. The energy of such gases is estimated to be $(0.44 \pm 0.01)$ times that of the noninteracting gas, and their pairing gap is approximately twice the energy per particle.

J. D. Franson, M. M. Donegan, B. C. Jacobs

We describe several different methods for generating the entangled ancilla states that are required for linear optics quantum computing. We show that post-selection can be used in combination with linear optical elements to generate the entangled ancilla, but with an exponentially-small efficiency. Alternatively, the ancilla can be efficiently generated usin

Gerald Cleaver

The second string revolution, which begin around 1995, has led to a drastic alteration in our perception of the universe, perhaps even more so then did the first string revolution of 1984. That is, extending 10-dimensional string theory to 11-dimensional M-theory has had more profound implications than did the original extension of 4-dimensional quantum mech

Carlos Vásquez-Romero, R. Paredes-Villegas, A. Hasmy, R. Jullien

Encouraged by experiments on $^4$He in aerogels, we confine planar spins in the pores of simulated aerogels (diffusion limited cluster-cluster aggregation) in order to study the effect of quenched disorder on the critical behavior of the three-dimensional XY model. Monte Carlo simulations and finite-size scaling are used to determine critical couplings $K_c$

Hamza Balci, C. P. Hill, M. M. Qazilbash, R. L. Greene

The Nernst effect of Pr$_{2-x}$Ce$_{x}$CuO$_4$ (x=0.13, 0.15, and 0.17) has been measured on thin film samples between 5-120 K and 0-14 T. In comparison to recent measurements on hole-doped cuprates that showed an anomalously large Nernst effect above the resistive T$_c$ and H$_{c2}$ \cite{xu,wang1,wang2,capan}, we find a normal Nernst effect above T$_c$ and

Torsten Bringmann, Martin Eriksson, Michael Gustafsson

The lightest Kaluza-Klein particle appearing in models with universal extra dimensions has recently been proposed as a viable dark matter candidate when the extra dimensions are compactified on a scale of the order of 1 TeV. Underlying assumptions of this proposal are that the size of the extra dimensions stays constant and that the evolution of the universe

Michael R. Douglas

We discuss systematic approaches to the classification of string/M theory vacua, and physical questions this might help us resolve. To this end, we initiate the study of ensembles of effective Lagrangians, which can be used to precisely study the predictive power of string theory, and in simple examples can lead to universality results. Using these ideas, we

W. Detmold, W. Melnitchouk, A. W. Thomas

We analyze the moments of parton distribution functions in the pion calculated in lattice QCD, paying particular attention to their chiral extrapolation. Using the lowest three non-trivial moments calculated on the lattice, we assess the accuracy with which the x dependence of both the valence and sea quark distributions in the pion can be extracted. The res

J. Mas, A. V. Ramallo

We study supersymmetric intersections of M2 and M5 branes with different pp-waves of M-theory. We consider first M-brane probes in the background of pp-waves and determine under which conditions the embedding is supersymmetric. We particularize our formalism to the case of pp-waves with 32, 24 and 20 supersymmetries. We also construct supergravity solutions

J. -P. Blaizot, E. Iancu, A. Rebhan

We review the various methods which have been employed recently to describe the thermodynamics of the high temperature quark-gluon plasma using weak coupling techniques, and we compare their results with those of most recent lattice gauge calculations. Many of the difficulties encountered with perturbation theory at finite temperature are in fact not specifi

Miguel Alcubierre, Alejandro Corichi, Jose A. Gonzalez, Dario Nunez

We show that the Kidder-Scheel-Teukolsky family of hyperbolic formulations of the 3+1 evolution equations of general relativity remains hyperbolic when coupled to a recently proposed modified version of the Bona-Masso slicing condition.

G. Duplancic, B. Nizic

We present a systematic method for reducing an arbitrary one-loop N-point massless Feynman integral with generic 4-dimensional momenta to a set comprised of eight fundamental scalar integrals: six box integrals in D=6, a triangle integral in D=4, and a general two-point integral in D space time dimensions. All the divergences present in the original integral

F. Bigazzi, A. L. Cotrone, M. Petrini, A. Zaffaroni

This article contains an overview of some recent attempts at understanding supergravity and string duals of four dimensional gauge theories using the AdS/CFT correspondence. We discuss the general philosophy underlying the various ways to realize Super Yang-Mills theories in terms of systems of branes. We then review some of the existing duals for N=2 and N=

Stephan J. Huber

Extra dimensions have interesting consequences for flavor physics. We consider a setup where the standard model fermions and gauge fields reside in the bulk of a warped extra dimension. Fermion masses and mixings are explained by flavor dependent fermion locations, without relying on hierarchical Yukawa couplings. We discuss various flavor violating processe

H. Makino, S. Tasaki

Along the line of thoughts of Berry and Robnik\cite{[1]}, we investigated the gap distribution function of systems with infinitely many independent components, and discussed the level-spacing distribution of classically integrable quantum systems. The level spacing distribution is classified into three cases: Case 1: Poissonian if $\barμ(+\infty)=0$, Case 2:

G. von Gehlen, S. Pakuliak, S. Sergeev

A large class of 3-dimensional integrable lattice spin models is constructed. The starting point is an invertible canonical mapping operator in the space of a triple Weyl algebra. This operator is derived postulating a current branching principle together with a Baxter Z-invariance. The tetrahedron equation for this operator follows without further calculati

H. Makino, S. Tasaki

By extending the approach of Berry and Robnik, the limiting level spacing distribution of a system consisting of infinitely many independent components is investigated. The limiting level spacing distribution is characterized by a single monotonically increasing function $\barμ(S)$ of the level spacing $S$. Three cases are distinguished: (i) Poissonian if $\

R. Lefevere, A. Schenkel

We compute the first-order correction to the correlation functions of the stationary state of a stochastically forced harmonic chain out of equilibrium when a small on-site anharmonic potential is added. This is achieved by deriving a suitable formula for the covariance matrix of the invariant state. We find that the first-order correction of the heat curren

V. Meden, S. Andergassen, W. Metzner, U. Schollwoeck

The conductance G of an interacting nano-wire containing an impurity and coupled to non-interacting semi-infinite leads is studied using a functional renormalization group method. We obtain results for microscopic lattice models without any further idealizations. For an interaction which is turned on smoothly at the contacts we show that one-parameter scalin

Marek Biesiada, Beata Malec

In this paper we derive a bound on the rate of change of the gravitational constant G coming from the pulsating white dwarf G117-B15A. This star is a ZZ Ceti pulsator extensively studied with astroseismological techniques for last three decades. The most recent determination of {\dot P} = (2.3 \pm 1.4) * 10^{-15} s/s^{-1} for the 215.2s fundamental mode agre

Deog Ki Hong, Taekoon Lee, Dong-Pil Min, D. Seo

We find a (nonlocal) gauge where the wavefunction renormalization constant does not get any corrections for all momenta in the hard-dense loop approximation. In this gauge, we solve the Schwinger-Dyson equations for the diquark condensate in dense QCD to calculate the Cooper pair gap. We determine not only the exponent but also the prefactor of the gap in a

R. Folch, M. Plapp

We construct a diffuse-interface model of two-phase solidification that quantitatively reproduces the classic free boundary problem on solid-liquid interfaces in the thin-interface limit. Convergence tests and comparisons with boundary integral simulations of eutectic growth show good accuracy for steady-state lamellae, but the results for limit cycles depen

Hao Jin, Hai-Hu Wen, Hai-Peng Yang, Zhi-Yong Liu

Magnetic relaxation of high-pressure synthesized MgB$_2$ bulks with different thickness is investigated. It is found that the superconducting dia-magnetic moment depends on time in a logarithmic way; the flux-creep activation energy decreases linearly with the current density (as expected by Kim-Anderson model); and the activation energy increases linearly w

D. Tournear, E. Raffauf, E. D. Bloom, W. Focke

Narayan and Heyl (2002) have developed a theoretical framework to convert suitable upper limits on type I X-ray bursts from accreting black hole candidates (BHCs) into evidence for an event horizon. However, no appropriate observational limit exists in the literature. In this paper we survey 2101.2 ks of data from the Unconventional Stellar Aspect (USA) X-ra

F. Ritort

We investigate violations of the fluctuation-dissipation theorem in two classes of trap models by studying the influence of the perturbing field on the transition rates. We show that for perturbed rates depending upon the value of the observable at the arrival trap, a limiting value of the fluctuation-dissipation ratio does exist. However, the mechanism behi

C. Polachic, C. Rangacharyulu, A. van den Berg, M. Harakeh

In an experiment designed to overcome the loophole of observer dependent reality and satisfying the counterfactuality condition, we measured polarization correlations of 1S0 proton pairs produced in 12C(d,2He) and 1H(d,He) reactions in one setting. The results of these measurements are used to test the Bell and Wigner inequalties against the predictions of q

Pawel Zin, Andrzej Dragan, Szymon Charzynski, Norbert Herschbach

We present a model describing the decay of a Bose-Einstein condensate, which assumes the system to remain in thermal equilibrium during the decay. We show that under this assumption transfer of atoms occurs from the condensate to the thermal cloud enhancing the condensate decay rate.

F. Delgado, J. G. Muga, A. Ruschhaupt, G. Garcia-Calderon

We obtain the solution of a relativistic wave equation and compare it with the solution of the Schroedinger equation for a source with a sharp onset and excitation frequencies below cut-off. A scaling of position and time reduces to a single case all the (below cut-off) nonrelativistic solutions, but no such simplification holds for the relativistic equation

M. Grigorescu, G. W. F. Drake

The leading relativistic and QED corrections to the ground state energy of the three-body system (epe) are calculated numerically using a Hylleraas correlated basis set. The accuracy of the nonrelativistic variational ground state wave function is discussed with respect to the convergence properties at the increase of the basis dimension and to the variance

J. H. Hannay, A. Thain

The exact Green function for the scalar wave equation in a plane with any set of perfectly reflecting straight mirrors, which may be joined to form corners, is given as a diffraction scattering series. Instances would be slit diffraction in optics, or the Schrodinger equation inside (or outside) a general polygonal enclosure (&#39;quantum polygon billiards&#

A. S. Kirilov, F. V. Levchanovski, V. I. Prikhodko

In the period 2003-2009 in the Frank Laboratory of Neutron Physics, JINR, the total modernization of the IBR-2 pulsed reactor which is mainly used for investigations in condensed matter physics using thermal neutron scattering will be carried out (it is planned to replace the movable and stationary reflectors and reactor jacket, to conduct fuel reloading, to

Germano D&#39;Abramo

In this paper we define the a posteriori probability W. This quantity is introduced with the aim of suggesting a reliable interpretation of the actual threat posed by a newly discovered Near Earth Asteroid (NEA), for which impacting orbital solutions (now commonly known as Virtual Impactors or VIs) can not be excluded on the basis of the available astrometri

Eed M. Darwish

Incoherent photoproduction of pions on the deuteron in the Delta(1232) resonance region is investigated in order to study the influence of final state NN and PiN rescattering. For the elementary production operator an effective Lagrangian model is used which describes well the elementary reaction. The interactions in the final two-body subsystems are taken i

Hugo L. D. de S. Cavalcante, J. R. Rios Leite

The natural measure in a map with type-III intermittent chaos is used to define critical exponents for the average of a variable from a dynamical system near bifurcation. Numerical experiments were done with maps and verify the analytical predictions. Physical experiments to test the usefulness of such exponents to characterize the nonlinearity at bifurcatio

Jack Xin, Yingyong Qi

We study a class of nonlinear nonlocal cochlear models of the transmission line type, describing the motion of basilar membrane (BM) in the cochlea. They are damped dispersive partial differential equations (PDEs) driven by time dependent boundary forcing due to the input sounds. The global well-posedness in time follows from energy estimates. Uniform bounds

Hugo L. D. de S. Cavalcante, J. R. Rios Leite

The dynamical bifurcations of a laser with a saturable absorber were calculated, with the 3-2 level model, as function of the gain parameter. The average power of the laser is shown to have specific behavior at bifurcations. The succession of periodic-chaotic windows, known to occur in the homoclinic chaos, was studied numerically. A critical exponent of 1/2

Andras Lorincz, Gabor Szirtes

In this paper we argue that no forms of Turing test are either necessary or sufficient to establish if a machine is conscious or not. Furthermore, from a modeling point of view, the problem is that the Turing test does not really provide testable predictions. We believe that the model structure should explain the function (of consciousness). We argue that th

L. Molinari

I consider a general block tridiagonal matrix and the corresponding transfer matrix. By allowing for a complex Bloch parameter in the boundary conditions, the two matrices are related by a spectral duality. As a consequence, I derive some analytic properties of the exponents of the transfer matrix in terms of the eigenvalues of the (non-Hermitian) block matr

Alberto Pambira

In this paper we generalize harmonic maps and morphisms to the \emph{degenerate semi-Riemannian category}, in the case when the manifolds $M$ and $N$ are \emph{stationary} and the map $ϕ:M\to N$ is \emph{radical-preserving}. We characterize geometrically the notion of \emph{(generalized) horizontal (weak) conformality} and we obtain a characterization for (g

Yurii A. Neretin

There are several ways of a construction of a boundary of a symmetric space using pencils of geodesics: the Karpelevich boundary, the visibility boundary, the associahedral boundary, and the sea urchin. We give explicit descriptions of these boundaries. We obtain some moduli space like polyhedra as sections of these compactifications by Cartan subspaces. For

Dominic Joyce

This is the last in a series of five papers math.DG/0211294, math.DG/0211295, math.DG/0302355, math.DG/0302356 studying compact special Lagrangian submanifolds (SL m-folds) X in (almost) Calabi-Yau m-folds M with singularities x_1,...,x_n locally modelled on special Lagrangian cones C_1,...,C_n in C^m with isolated singularities at 0. Readers are advised to

Nikolaos Halidias

In this paper we consider two elliptic problems. The first one is a Dirichlet problem while the second is Neumann. We extend all the known results concerning Landesman-Laser conditions by using the Mountain-Pass theorem with the Cerami $(PS)$ condition.

Yi-Zhi Huang

We discuss the recent results of the author on the existence of systems of differential equations for chiral genus-zero and genus-one correlation functions in conformal field theories.

Ross Street

This is a report on a talk to high school mathematics students. It gives some combinatorial connections for the entries of the boustrophedon triangle whose sides are the Taylor coefficients for the tangent and secant functions.

Leo Liberti

The theorem presented in this paper allows the creation of large prime numbers (of order up to o(n^2)) given a table of all primes up to n.

Dominic Joyce

This is the fourth in a series of five papers math.DG/0211294, math.DG/0211295, math.DG/0302355, math.DG/0303272 studying compact special Lagrangian submanifolds (SL m-folds) X in (almost) Calabi-Yau m-folds M with singularities x_1,...,x_n locally modelled on special Lagrangian cones C_1,...,C_n in C^m with isolated singularities at 0. Readers are advised t

Dominic Joyce

This is the third in a series of five papers math.DG/0211294, math.DG/0211295, math.DG/0302356, math.DG/0303272 studying compact special Lagrangian submanifolds (SL m-folds) X in (almost) Calabi-Yau m-folds M with singularities x_1,...,x_n locally modelled on special Lagrangian cones C_1,...,C_n in C^m with isolated singularities at 0. Readers are advised to

Dominic Joyce

This is the first in a series of five papers math.DG/0211295, math.DG/0302355, math.DG/0302356, math.DG/0303272 studying special Lagrangian submanifolds (SL m-folds) X in (almost) Calabi-Yau m-folds M with singularities x_1,...,x_n locally modelled on special Lagrangian cones C_1,...,C_n in C^m with isolated singularities at 0. Readers are advised to begin w

Nobuya Sato, Michihisa Wakui

In this article, we discuss a (2+1)-dimensional topological quantum field theory, for short TQFT, with a Verlinde basis. As a conclusion of this general theory, we have a Dehn surgery formula. We show that Turaev-Viro-Ocneanu TQFT has a Verlinde basis. Several applications of this theorem are exposed. Based on Izumi&#39;s data of subfactors, we list several

E. A. Ivanov, B. M. Zupnik

We elaborate on the duality-symmetric nonlinear electrodynamics in a new formulation with auxiliary tensor fields. The Maxwell field strength appears only in bilinear terms of the corresponding generic Lagrangian, while the self-interaction is presented by a function E depending on the auxiliary fields. Two types of dualities inherent in the nonlinear electr

Sergei Alexandrov

In the Matrix Quantum Mechanical formulation of 2D string theory it is possible to introduce arbitrary tachyonic perturbations. In the case when the tachyonic momenta form a lattice, the theory is known to be integrable and, therefore, it can be used to describe the corresponding string theory. We study the backgrounds of string theory obtained from these ma

A. Berard, J. Lages, H. Mohrbach

We consider a classical spinning particle in the frame of the relativistic physics by means of a covariant Hamiltonian and of a generalization of Poisson brackets which take into account the gauge fields. We obtain different equations of motion and evolution in this context and we compare our results with those of Bargmann-Michel-Telegdi. An extension to the

B. Henrich, K. Z. Hatsagortsyan, C. H. Keitel

The dynamics and radiation of positronium is investigated in intense laser fields.

M. Mintchev, E. Ragoucy, P. Sorba

Inspired by factorized scattering from delta-type impurities in (1+1)-dimensional space-time, we propose and analyse a generalization of the Zamolodchikov-Faddeev algebra. Distinguished elements of the new algebra, called reflection and transmission generators, encode the particle-impurity interactions. We describe in detail the underlying algebraic structur

S. Bellucci, I. L. Buchbinder, V. A. Krykhtin

We consider the one-loop renormalization of dimension four composite operators and the energy-momentum tensor in noncommutative ϕ^4 scalar field theory. Proper operator bases are constructed and it is proved that the bare composite operators are expressed via renormalized ones, with the help of a mixing matrix, whose explicit form is calculated. The correspo

Marijan Ribaric, Luka Sustersic

Using the path-integral formalism, we generalize the &#39;t Hooft-Veltman method of unitary regulators to put forward a framework for finite, alternative quantum theories to a given quantum field theory. Feynman-like rules of such a finite, alternative quantum theory lead to alternative, perturbative Green functions. Which are acceptably regularized perturba

S. Dawson

The role of the top quark in completing the Standard Model quark sector is reviewed, along with a discussion of production, decay, and theoretical restrictions on the top quark properties. Particular attention is paid to the top quark as a laboratory for perturbative QCD. As examples of the relevance of QCD corrections in the top quark sector, the calculatio

P. Mitra

In the standard model, the Cabibbo-Kobayashi-Maskawa matrix, which incorporates the time-reversal violation shown by the charged current weak interactions, originates from the Higgs-quark interactions. The Yukawa interactions of quarks with the physical Higgs particle can contain further complex phase factors, but nevertheless conserve T, as shown by constru

Luis F. Urrutia

The construction of effective Hamiltonians arising from Loop Quantum Gravity and incorporating Planck scale corrections to the dynamics of photons and spin 1/2 particles is summarized. The imposition of strict bounds upon some parameters of the model using already existing experimental data is also reviewed.

Kazuo Fujikawa, Robert Shrock

In Phys. Rev. Lett. 89, 101802 (2002); erratum, ibid. 89, 229902(E) (2002), Bernabeu, Papavassiliou, and Vidal claim that they can extract a gauge-independent neutrino charge radius (NCR) which is, therefore, a physical observable. We show here that this claim is incorrect by demonstrating that the NCR is, in general, gauge-dependent.

Anjan Giri, Yuval Grossman, Abner Soffer, Jure Zupan

We propose a method for determining $γ$ using $B^\pm\to D K^\pm$ decays followed by a multibody $D$ decay, such as $D \to K_S π^-π^+$, $D \to K_S K^-K^+$ and $D \to K_S π^-π^+π^0$. The main advantages of the method is that it uses only Cabibbo allowed $D$ decays, and that large strong phases are expected due to the presence of resonances. Since no knowledge

Nikolaos Kidonakis

I present a unified approach to calculating the next-to-next-to-leading order (NNLO) soft and virtual QCD corrections to cross sections for electroweak, Higgs, QCD, and SUSY processes. I derive master formulas that can be used for any of these processes in hadron-hadron and lepton-hadron collisions. The formulas are based on a unified threshold resummation f

Sameer M. Ikhdair, Ramazan Sever

In the framework of potential models for heavy quarkonium, we compute the mass spectrum of the bottom-charmed $B_{c}$ meson system and spin-dependent splittings from the Schrödinger equation using the shifted-large-N expansion technique. The masses of the lightest vector $B_{c}^{+}$ and pseudoscalar $B_{c}$ states as well as the higher states below the thres

Ashok Goyal

Recently there have been important developments in the determination of neutron star masses which put severe constraints on the composition and equation of state (EOS) of the neutron star matter. Here we study the effect of quark and nuclear matter mixed phase on mass radius relationship of neutron stars employing recent models from two classes of EOS&#39;s

Jiri Chyla

There a sizable and systematic discrepancy between experimental data on the $\bar{b}b$ production in $\bar{\mathrm p}$p, $\gamma$p and $\gamma\gamma$ collisions and existing theoretical calculations within perturbative QCD. Before interpreting this discrepancy as a signal of new physics, it is important to understand quantitatively the ambiguities of convent

Zhi-zhong Xing

We show that the recent WMAP data can impose a generous upper bound on the effective masses of electron, muon and tau neutrinos defined in the kinematic measurements: $<m>^2_e + < m>^2_μ+ < m>^2_τ= m^2_1 + m^2_2 + m^2_3 < 0.5 ~ {\rm eV}^2$, or $<m>_α< 0.71$ eV (for $α= e, μ, τ$). When current neutrino oscillation data are taken into account, we obtain $<m>_e

M. Fukugita, M. Tanimoto, T. Yanagida

We revisit the Fritzsch-type lepton mass matrix models confronted with new experiments for neutrino mixings. It is shown that the model is viable and leads to a rather narrow range of free parameters. Using empirical mixing information between $ν_e$ and $ν_μ$, and between $ν_μ$ and $ν_τ$, it is predicted that the mixing angle between $nu_e$ and $ν_τ$ is in t

W. Krolikowski

In the first part of the note, we consider a neutrino texture, where the Dirac and righthanded Majorana masses are proportional. If the former are approximately proportional also to the charged lepton masses, then taking $Δm^2_{32}\sim3\times 10^{-3}$ eV$^2$ we estimate approximately that $Δm^2_{21}\sim{\cal O}(10^{-5}$ eV$^2)$, what is not very different fr

Alberto Accardi

I compare the available theoretical models that describe the Cronin effect on hadron and minijet production in proton-nucleus collisions, pointing out similarities and differences among them. The effect may be summarized by the value of two variables. Their values computed in the different models are compared in the energy range 27.4 GeV - 5500 GeV. Finally,

Leonard S. Kisslinger

Using the liquid instanton model continued into Minkowski space and modified for finite temperature, the energy momentum tensor and the surface tension for buble walls during the QCD phase transition are derived. The resulting surface tension is in agreement with lattice calculations. Application to bubble collisions is discussed.

The BABAR Collaboration, B. Aubert

We present preliminary measurements of branching fractions of the b -> s\bar{s}s penguin-dominated decays B+ -> phi K+ and B0 -> phi K0 in a sample of approximately 89 million BBbar pairs collected by the BaBar detector at the PEP-II asymmetric-energy B-meson Factory at SLAC. We determine BF(B+ -> phi K+) = (10.0^{+0.9}_{-0.8} (stat.) \pm 0.5 (syst.)) * 10^{

B. M. Pimentel, P. J. Pompeia, J. F. da Rocha-Neto, R. G. Teixeira

We analyze the Teleparallel Equivalent of General Relativity (TEGR) from the point of view of Hamilton-Jacobi approach for singular systems

Alberto Nicolis

A stochastic background of gravitational waves can be generated during a cosmological first order phase transition, at least by two distinct mechanisms: collisions of true vacuum bubbles and turbulence in the cosmic fluid. I compare these two contributions, analyzing their relative importance for a generic phase transition. In particular, a first order elect

Marek Biesiada

In a recent paper Abramowicz and Klu{ź}niak have discussed the problem of epicyclic oscillations in Newton&#39;s and Einstein&#39;s dynamics and have shown that Newton&#39;s dynamics in a properly curved three-dimensional space is identical to test-body dynamics in the three-dimensional optical geometry of Schwarzschild space-time. One of the main results of

Luciano Rezzolla

I present results of two-dimensional general relativistic hydrodynamical simulations of constant specific angular momentum tori orbiting around a Schwarzschild black hole. After introducing axisymmetric perturbations, these objects either become unstable to the runaway instability or respond with regular oscillations. The latter, in particular, are responsib

Dawei Hong, Jean-Camille Birget, Shushuang Man

We extend a result of Goldreich and Ron about estimating the collision probability of a hash function. Their estimate has a polynomial tail. We prove that when the load factor is greater than a certain constant, the estimator has a gaussian tail. As an application we find an estimate of an upper bound for the average search time in hashing with chaining, for

V. P. Maslov

The author uses the entropy of the ideal Bose-Einstein gas to minimize losses in computer-oriented languages.

I. E. Smolyarenko, B. D. Simons

We establish a general framework to explore parametric statistics of individual energy levels in unitary random matrix ensembles. For a generic confinement potential $W(H)$, we (i) find the joint distribution functions of the eigenvalues of $H$ and $H&#39;=H+V$ for an arbitrary fixed $V$ both for finite matrix size $N$ and in the ``thermodynamic&#39;&#39; $N

Chen-Shan Chin, Manoj Pratim Samanta

In this paper, we study the large-scale protein interaction network of yeast uti lizing a stochastic method based upon percolation of random graphs. In order to find the global features of connectivities in the network, we introduce numeric al measures that quantify (1) how strongly a protein ties with the other parts o f the network and (2) how significantl

N. A. Frederick, M. B. Maple

The temperature $T$ and magnetic field $H$ dependencies of the electrical resistivity $ρ$ of the recently discovered heavy fermion superconductor \PrOsSb{} have features that are associated with the splitting of the Pr$^{3+}$ Hund&#39;s rule multiplet by the crystalline electric field (CEF). These features are apparently due to magnetic exchange and aspheric

A. Gamba, D. Ambrosi, A. Coniglio, A. de Candia

Experiments of in vitro formation of blood vessels show that cells randomly spread on a gel matrix autonomously organize to form a connected vascular network. We propose a simple model which reproduces many features of the biological system. We show that both the model and the real system exhibit a fractal behavior at small scales, due to the process of migr

Stephan M. Dammer, Haye Hinrichsen

The spreading of infectious diseases with and without immunization of individuals can be modeled by stochastic processes that exhibit a transition between an active phase of epidemic spreading and an absorbing phase, where the disease dies out. In nature, however, the transmitted pathogen may also mutate, weakening the effect of immunization. In order to stu