July 2002 arXiv papers — page 9

Mario Everaldo de Souza

General Classification of Matter; Prequarks and Number of Quarks; Structure of Nucleons; Generation of Quark Masses; Seas and Sizes of Nucleons; Contributions of Nucleons Seas to the Structure Functions; Higgs Bosons; Bosons of the Strong and Superstrong Interactions; The Nature of Gluons, Super QCD, The Energies of Baryons and Mesons; The Sizes of Baryons a

A. Gawron, J. Kwiecinski

The system of CCFM equations for unintegrated parton distributions in a photon is considered in the single loop approximation. We include quarks and non-singular parts of the splitting functions in the corresponding evolution equations. We solve the system of CCFM equations utilising the transverse coordinate representation which diagonalises these equations

Francis Bernardeau, Jean-Philippe Uzan

This article investigates the generation of non-Gaussianity during inflation. In the context of multi-field inflation, we detail a mechanism that can create significant primordial non-Gaussianities in the adiabatic mode while preserving the scale invariance of the power spectrum. This mechanism is based on the generation of non-Gaussian isocurvature fluctuat

Wei-Shu Hou, Gwo-Guang Wong

The spectrum of two-gluon glueballs below 3 GeV is investigated in a potential model with dynamical gluon mass using variational method. The short distance potential is approximated by one-gluon exchange, while the long distance part is taken as a breakable string. The mass and size of the radial as well as orbital excitations up to principle quantum number

H. Jung

The effect of formally next-to-leading contributions to the CCFM evolution equation are discussed.

Nathan F. Lepora

Withdrawn. Work never submitted.

John P. Costella

In a previous paper I showed how the ideal SLAC derivative and second-derivative operators for an infinite lattice can be obtained in simple closed form in position space, and implemented very efficiently in a stochastic fashion for practical calculations on finite lattices. In this second paper I show how the small (order 1/N) errors introduced by truncatin

The BABAR Collaboration, B. Aubert

This paper describes preliminary results on the inclusive process b --> s gamma obtained from 20.7 fb^-1 of data recorded with the BaBar detector during 1999-2000. Signal event yields are found from a combination of twelve exclusive decay channels after subtracting continuum and BBbar backgrounds. Cross-feed from incorrectly reconstructed b --> s gamma event

The BABAR Collaboration, B. Aubert

A search for the exclusive radiative decays B->rho(770) gamma and B^0->omega(782) gamma is performed on a sample of 84 million BB-bar events collected by the BABAR detector at the PEP-II asymmetric e^+e^- collider. No significant signal is seen in any of the channels. We set preliminary upper limits of BR[B^0->rho^0 gamma]< 1.4 times 10^{-6}, BR[B^+ -> rho^+

The BABAR Collaboration, B. Aubert

We present a measurement of time-dependent CP asymmetries and an updated determination of the CP-odd fraction in the decay B^0 --> D^{*+}D^{*-}. The measurements are derived from a data sample of 88 times 10^{6} B bar{B} pairs collected by the BaBar detector at the PEP-II energy asymmetric B Factory at SLAC. All results are preliminary.

B. Aubert, The BABAR Collaboration

We measure the B0 lifetime tau_B0 and the B-Bbar oscillation frequency Deltam_d with a sample of approximately 14,000 exclusively reconstructed B0 -> D*- l+ nu_l signal events, selected from 23 million B-Bbar pairs recorded at the Upsilon(4S) resonance with the BABAR detector at the Stanford Linear Accelerator Center. The b-quark flavor of the other B at the

B. Aubert

We present a preliminary measurement of the time-dependent CP-violating asymmetry in the neutral B decay B0 --> phi K0S, with phi --> K+K- and K0S --> pi+pi-. The measurement uses a data sample of about 87 million Y(4S) --> B Bbar decays collected between 1999 and 2002 with the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC. In this sample

B. Aubert

We present a preliminary search for the flavor-changing neutral current decay B^+ -> K^+ nunubar using 56 million Y(4S) decays recorded with the BABAR detector at the SLAC B factory. Identification of the B^+ -> K^+ nunubar final state, with two neutrinos, requires the reconstruction of the companion B in the event. The companion B is reconstructed in the de

B. Aubert

We present preliminary measurements of direct and indirect CP-violating asymmetries in the decays of neutral B mesons to pi+pi-pi0 and K+-pi-+pi0 final states dominated by the rho+- resonance, using a time-dependent maximum likelihood analysis. The data sample comprises 88 10^ Upsilon(4S) -> BBb decays (80.8 fb-1) collected with the BaBar detector at the PEP

B. Aubert

We present preliminary results for the measurement of the branching fraction of the decay B+- -> chi_c0 K+- from a sample of 75 million BB pairs collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The chi_c0 meson is reconstructed through its two-body decays to pi+ pi- and K+ K-. We measure BR(B+- -> chi_c0 K+-) * BR(chi_c0 ->

B. Aubert

We present preliminary results of the analyses of B^+ --> h^+ pi^0 (with h^+ = pi^+, K^+) and B^0 --> K^0 pi^0 decays from a sample of approximately 88 million B bar{B} pairs collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure the pi^+ pi^0 branching fraction and we obtain B(B^+ --> pi^+ pi^0) = (5.5^{+1.0}_{-0.9} +/

A. Bornheim, CLEO Collaboration

We present an analysis of the composition of inclusive semileptonic B meson decays using 9.4/fb of e+ e- data taken with the CLEO detector at the Upsilon(4S) resonance. In addition to measuring the charged lepton kinematics, the neutrino 4-vector is inferred using the hermeticity of the detector. We perform a maximum likelihood fit over the full three-dimens

The BABAR Collaboration, B. Aubert

We present a search for the decay B^0 --> pi^0 pi^0 by the BABAR experiment at the PEP-II asymmetric-energy B-factory at SLAC. Using approximately 88 million B bar{B} pairs collected between 1999 and 2002, we place a 90% confidence level upper limit on the branching fraction of B(B^0 --> pi^0 pi^0) < 3.6 times 10^{-6}. This result is preliminary.

Piotr Traczyk, Grzegorz Wrochna

The ability of the CMS experiment to detect massive Kaluza-Klein excitations of gravitons, predicted by the Randall-Sundrum model, is studied. The search reach is estimated for the channel with the graviton, produced in proton-proton collision, decaying into a pair of electrons or muons.

S. E. Csorna, CLEO Collaboration

The CLEO III experiment has recently accumulated a large statistics sample of 4.73 x 10^6 Upsilon(3S) decays. We present the first evidence for the production of the triplet Upsilon(1D) states in the four-photon cascade, Upslion(3S) -> gamma chi_b(2P), chi_b(2P) -> gamma Upsilon(1D), Upsilon(1D) -> gamma chi_b(1P), chi_b(1P) -> gamma Upsilon(1S), followed by

S. Anderson

Using the combined CLEO II and CLEO II.V data sets of 9.1 fb^{-1} at the Upsilon(4S), we measure properties of Psi mesons produced directly from decays of the B meson, where ``B&#39;&#39; denotes an admixture of B+, B-, B0, and B0bar, and ``Psi&#39;&#39; denotes either J/Psi or Psi(2S). We report first measurements of Psi polarization in B -> Psi(direct) X:

A. H. Mahmood, CLEO Collaboration

We have searched for the bottomonium eta_b(1S) via the hindered magnetic dipole (M1) photon transition Upsilon(3S) -> gamma eta_b(1S). No evidence for such a transition is found in the data sample of 4.7 x 10^6 Upsilon(3S)&#39;s collected with the CLEO-III detector. We set upper limits on the branching ratio from 9.30 to 9.43 GeV/c^2 of eta_b(1S) masses. The

ALEPH Collaboration

The results of searches for selectrons, charginos and neutralinos performed with the data collected by the ALEPH detector at LEP at centre-of-mass energies up to 209 GeV are interpreted in the framework of the Minimal Supersymmetric extension of the Standard Model with R-parity conservation. Under the assumptions of gaugino and sfermion mass unification and

Yuk Tung Liu

A self-consistent field method is developed, which can be used to construct models of differentially rotating stars to first post-Newtonian order. The rotation law is specified by the specific angular momentum distribution j(m), where m is the baryonic mass fraction inside the surface of constant specific angular momentum. The method is then used to compute

Patrick R. Brady, Matthew W. Choptuik, Carsten Gundlach, David W. Neilsen

Numerical studies of the gravitational collapse of a stiff (P=rho) fluid have found the now familiar critical phenomena, namely scaling of the black hole mass with a critical exponent and continuous self-similarity at the threshold of black hole formation. Using the equivalence of an irrotational stiff fluid to a massless scalar field, we construct the criti

J. Frauendiener

Some issues in the numerical treatment of the conformal field equations are discussed. In particular, the problem of obtaining smooth initial data for the hyperboloidal initial value problem is described and solution methods are presented.

J. Frauendiener

In this paper we discuss stability properties of various discretizations for axisymmetric systems including the so called cartoon method which was proposed by Alcubierre, Brandt et.al. for the simulation of such systems on Cartesian grids. We show that within the context of the method of lines such discretizations tend to be unstable unless one takes care in

A. V. Toporensky, P. V. Tretyakov, V. O. Ustiansky

Several aspects of scalar field dynamics on a brane which differs from corresponding regimes in the standard cosmology are investigated. We consider asymptotic solution near a singularity, condition for inflation and bounces and some detail of chaotic behavior in the brane model. Each results are compared with those known in the standard cosmology.

Sergio Dain

The interaction energy between two black holes at large separation distance is calculated. The first term in the expansion corresponds to the Newtonian interaction between the masses. The second term corresponds to the spin-spin interaction. The calculation is based on the interaction energy defined on the two black holes initial data. No test particle appro

G. S. Asanov

Granted the post-Lorentzian relativistic kinematic transformations are described in the Finslerian framework, the uniformity between the actual light velocity anisotropy change and the anisotropic deformation of measuring rods can be the reason proper for the null results of the Michelson-Morley-type experiments at the first-order level.

Alejandro Corichi, Jeronimo Cortez, Hernando Quevedo

It is generally known that linear (free) field theories are one of the few QFT that are exactly soluble. In the Schroedinger functional description of a scalar field on flat Minkowski spacetime and for flat embeddings, it is known that the usual Fock representation is described by a Gaussian measure. In this paper, arbitrary globally hyperbolic space-times a

Robert D. Klauber

Non-time-orthogonal frame analysis is applied to determine the frequency and wavelength of light as observed i) in a relativistically rotating frame when emission is from a source fixed in the non-rotating frame, ii) in a non-rotating frame when emission is from a source fixed in the rotating frame, and iii) when both source and observer are fixed in the rot

Henry E. Kyburg, Choh Man Teng

We seek to find normative criteria of adequacy for nonmonotonic logic similar to the criterion of validity for deductive logic. Rather than stipulating that the conclusion of an inference be true in all models in which the premises are true, we require that the conclusion of a nonmonotonic inference be true in ``almost all&#39;&#39; models of a certain sort

David Eppstein

We provide a data structure for maintaining an embedding of a graph on a surface (represented combinatorially by a permutation of edges around each vertex) and computing generators of the fundamental group of the surface, in amortized time O(log n + log g(log log g)^3) per update on a surface of genus g; we can also test orientability of the surface in the s

Marshall Bern, David Eppstein

We propose an interpolation method that is invariant under Moebius transformations; that is, interpolation followed by transformation gives the same result as transformation followed by interpolation. The method uses natural (Delaunay) neighbors, but weights neighbors according to angles formed by Delaunay circles.

N. -C. Yeh, C. -T. Chen, R. P. Vasquez, C. U. Jung

Quasiparticle tunneling spectra of both hole-doped (p-type) and electron-doped (n-type) cuprates are studied using a low-temperature scanning tunneling microscope. The results reveal that neither the pairing symmetry nor the pseudogap phenomenon is universal among all cuprates, and that the response of n-type cuprates to quantum impurities is drastically dif

Daw-Wei Wang, S. Das Sarma, Eugene Demler, Bertrand I. Halperin

We study the magnetoplasmon collective mode excitations of integer quantum Hall systems in a parabolically confined quantum well nanostructure in the presence of a tilted magnetic field by using the time-dependent Hartree-Fock approximation. For even integer filling, we find that the dispersion of a spin density mode has a magneto-roton minimum at finite wav

Shaun C. Hendy

Transparent glass ceramic materials, with microstructures comprised of dispersed nanocrystallites in a residual glass matrix, offer the prospect of nonlinear optical properties. However, good transparency requires low optical scattering and low atomic absorption. The attenuation of light due to scattering (turbidity) will depend upon the difference in refrac

N. O. Nnolim, T. A. Tyson, L. Axe

In order to predict the stable and metastable phases of the bcc metals in the block of the Periodic Table defined by groups 5B to 6B and periods 4 to 6, as well as the structure dependence of their transport properties, we have performed full potential computations of the total energies per unit cell as a function of the c/a ratio at constant experimental vo

M. Yokoyama, J. Nozaki, H. Amitsuka, K. Watanabe

We have investigated the nature of the antiferromagnetic (AF) phase induced by uniaxial stress sigma in URu2Si2, by performing elastic neutron scattering measurements up to 0.4 GPa. We have found that the AF Bragg-peak intensity shows a clear hysteresis loop with sigma under the zero-stress cooling condition. The result strongly suggests that the sigma-induc

Michael L. Hart, David Lamper, Neil F. Johnson

Complex systems can exhibit unexpected large changes, e.g. a crash in a financial market. We examine the large endogenous changes arising within a non-trivial generalization of the Minority Game: the Grand Canonical Minority Game (GCMG). Using a Markov Chain description, we study the many possible paths the system may take. This &#39;many-worlds&#39; view no

Theo M. Nieuwenhuizen, Armen E. Allahverdyan

The experimental verification of the Fluctuation Theorem by Wang et al. is not a violation but even a confirmation of the second law, resulting from their observations in a proper interpretation.

P. Samuelsson, M. Buttiker

We present a semiclassical theory of current correlations in multiterminal chaotic dot-superconductor junctions, valid in the absence of the proximity effect in the dot. For a dominating coupling of the dot to the normal terminals and a nonperfect dot-superconductor interface, positive cross correlations are found between currents in the normal terminals. Th

Lydie Staron, Jean-Pierre Vilotte, Farhang Radjai

We investigate numerically the transition between static equilibrium and dynamic surface flow of a 2D cohesionless granular system driven by a continuous gravity loading. This transition is characterized by intermittent local dynamic rearrangements and can be described by an order parameter defined as the density of critical contacts, e.g. contacts where the

F. Celarie, S. Prades, D. Bonamy, A. Dickele

We have studied the low speed fracture regime for different glassy materials with variable but controlled length scales of heterogeneity in a carefully mastered surrounding atmosphere. By using optical and atomic force (AFM) microscopy techniques we tracked in real-time the crack tip propagation at the nanometer scale on a wide velocity range (1 mm/s and 0.1

Bhargavi Srinivasan, Marie-Bernadette Lepetit

We study a 3-band extended Hubbard model on a CuO_3 system by the density matrix renormalization group (DMRG) method. Our system has geometry similar to that of a section of the CuO_2 plane of the copper-oxide superconductors. We have studied the effects of nearest-neighbour repulsions on the current-current correlations of two model CuO_3 systems. We show t

Pui-Man Lam, S. J. Liu, C. H. Woo

Using the Monte Carlo method, we have studied the pulsed laser deposition process at the sub-monolayer regime. In our simulations, dissociation of an atom from a cluster is incorporated. Our results indicate that the pulsed laser deposition resembles molecular beam epitaxy at very low intensity, and that it is characteristically different from molecular beam

C. Senatore, M. Polichetti, D. Zola, T. Di Matteo

The flux lines dynamics have been investigated on MgB2 bulk superconductors obtained by reactive liquid infiltration by measuring the ac magnetic susceptibility. The fundamental and third harmonics have been studied as a function of temperature, dc magnetic field, ac field amplitude and frequency. In order to determine the dynamical regimes governing the vor

Frithjof B. Anders

We show that the two-channel Anderson lattice model leads to the development of an unconventional superconductivity out of a metallic non Fermi-liquid phase. It is characterized by a composite order parameter comprising of a local spin or orbital degree of freedom bound to triplet Cooper pairs with an isotropic and a nearest neighbour form factor. The superc

T. Maehira, M. Higuchi, A. Hasegawa

The relativistic energy-band calculations have been carried out for UFeGa_{5}, UCoGa_{5} and URhGa_{5} under the assumption that 5f-electrons are itinerant. A hybridization between the U 5f state and Ga 4p state occurs in the vicinity of the Fermi level. The Fermi surface of UCoGa_{5} is quite similar to that of URhGa_{5}, which are all small in size and clo

G. F. Zharkov

The self-consistent solutions of a nonlinear Ginzburg--Landau equations, which describe the behavior of a superconducting plate of thickness 2D in a magnetic field H parallel to its surface (provided that there are no vortices inside the plate), are studied. We distinguish two types of superconductors according to the behavior of their magnetization M(H) in

Md. Ashrafuzzaman, Hans Beck

No abstract. It&#39;s a review article beginning with introduction.

N. G. Zhang, C. L. Henley

In our model, spinless fermions (or hardcore bosons) on a square lattice hop to nearest neighbor sites, and also experience a hard-core repulsion at the nearest neighbor separation. This is the simplest model of correlated electrons and is more tractable for exact diagonalization than the Hubbard model. We study systematically the dilute limit of this model

P. Gegenwart, J. Custers, T. Tayama, K. Tenya

We report low temperature specific heat, C, magnetization, M, susceptibility, chi, and electrical resistivity, rho, measurements on high-quality single crystals of the heavy-fermion system YbRh_2(Si_{1-x} Ge_x)_2 (x=0 and 0.05). The undoped compound shows weak antiferromagnetic (AF) order at T_N=70 mK which is suppressed to below 10 mK by a tiny volume expan

Gyorgy Szabo, Christoph Hauert

Cooperative behavior among unrelated individuals in human and animal societies represents a most intriguing puzzle to scientists in various disciplines. Here we present a simple yet effective mechanism promoting cooperation under full anonymity by allowing for voluntary participation in public goods games. This natural extension leads to rock--scissors--pape

Tomio Koyama

We investigate the extended quasi-particle states in the mixed state of d-wave superconductors on the basis of the Bogoliubov-de Gennes equation. We prove that the quasi-particle eigen-states can be classified in terms of new topological quantum numbers which are related to the topological nature of the non-trivial phases of the quasi-particles. Numerical re

Cesar Meirelles Filho, Celso L. Lima, Hideaki Miyake, Varese Timoteo

Neutron production via ^{4}He breakup and p(p, n{pi}^+)p is considered in the innermost region of an accretion disk surrounding a Kerr Black Hole. These reactions occur in a plasma in Wien equilibrium, where (radiatively produced) pair production equals annihilation. Cooling of the disk is assumed to be due to unsaturated inverse Comptonization of external s

Andrew N. Youdin, Frank H. Shu

We investigate the formation of planetesimals via the gravitational instability of solids that have settled to the midplane of a circumstellar disk. Vertical shear between the gas and a subdisk of solids induces turbulent mixing which inhibits gravitational instability. Working in the limit of small, well-coupled particles, we find that the mixing becomes in

Ignacio Ferreras, Evan Scannapieco, Joseph Silk

We present a phenomenological model of feedback in early-type galaxies that tracks the evolution of the interstellar medium gas mass, metallicity, and temperature. Modeling the star formation rate as a Schmidt law with a temperature-dependent efficiency, we find that intermittent episodes of star formation are common in moderate-size ellipticals. Our model i

James S. Bullock, Andrew R. Zentner

Although the currently favored cold dark matter plus cosmological constant model for structure formation assumes an n=1 scale-invariant initial power spectrum, most inflation models produce at least mild deviations from n=1. Because the lever arm from the CMB normalization to galaxy scales is long, even a small ``tilt&#39;&#39; can have important implication

T. Montaruli

The ANTARES deep-sea neutrino telescope will be located at a depth of 2400 m in the Mediterranean Sea. Deployment of the detector will commence this Autumn and is expected to be completed by the end of 2004. With a surface area of the order of 0.1 km^2 it will be one of the largest European detectors. The aim of neutrino telescopes is to detect high-energy n

Pablo F. Velazquez, Gloria M. Dubner, W. Miller Goss, Anne J. Green

The distribution and kinematics of neutral hydrogen have been studied in a wide area around the supernova remnant W28. A 2.5 x 2.5 arcdeg field centered at l = 6.5 arcdeg, b = 0 arcdeg was surveyed using the Parkes 64-m radio telescope (HPBW 14.7 arcmin at lambda 21 cm). Even though W28 is located in a complex zone of the Galactic plane, we have found differ

Jurgen Knodlseder

With the launch of ESA&#39;s INTEGRAL satellite in october 2002, a gamma-ray observatory will be placed in orbit providing a multiwavelength coverage from a few keV up to 10 MeV for the study of high energy phenomena in the universe. Among the major scientific objectives of INTEGRAL are the study of compact objects, and in particular of microquasars, stellar

Frode K. Hansen, Krzysztof M. Gorski

We extend the analysis of Gabor transforms on a Cosmic Microwave Background (CMB) temperature map (Hansen, Gorski and Hivon 2002) to polarisation. We study the temperature and polarisation power spectra on the cut sky, the so-called pseudo power spectra. The transformation kernels relating the full-sky polarisation power spectra and the polarisation pseudo p

P. Venkatakrishnan, Brajesh Kumar, S. C. Tripathy

The acoustic spectra in sunspots are known to be richer in higher frequency power. We have attempted a generalized study of the effect of magnetic fields on the shape of the acoustic spectrum using GONG+ bread-board data (spatial scale of ~ 2 arc-sec per pixel) of 11 May, 2000 and 12 June, 2000. The mean power spectra of the velocity oscillations were obtain

M. Jardine, K. Wood, A. Collier Cameron, J. -F. Donati

We have modelled the X-ray emission from the young rapid rotator AB Doradus (P = 0.514 days) using as a basis Zeeman-Doppler maps of the surface magnetic field. This allows us to reconcile the apparently conflicting observations of a high X-ray emission measure and coronal density with a low rotational modulation in X-rays. The technique is to extrapolate th

M. S. Oey

The processes that disperse the products of massive stars from their birth sites play a fundamental role in determining the observed abundances. I discuss parameterizations for element dispersal and their roles in chemical evolution, with an emphasis on understanding present-day dispersion and homogeneity in metallicity. Turbulence dominates mixing processes

Masamune Oguri

We predict the fraction of dark halo lenses, that is, the fraction of lens systems produced by the gravitational potential of dark halos, on the basis of a simple parametric model of baryonic compression. The fraction of dark halo lenses primarily contains information on the effect of baryonic compression and the density profile of dark halos, and is expecte

Shaun C. Hendy, Jonathan P. K. Doye

We describe a new family of icosahedral structures for lead clusters. In general, structures in this family contain a Mackay icosahedral core with a reconstructed two-shell outer-layer. This family includes the anti-Mackay icosahedra, which have have a Mackay icosahedral core but with most of the surface atoms in hexagonal close-packed positions. Using a man

R. A. Barankov, S. N. Burmistrov

The dissipative dynamics of a Josephson junction in the Bose-gases is considered within the framework of the model of a tunneling Hamiltonian. The effective action which describes the dynamics of the phase difference across the junction is derived using functional integration method. The dynamic equation obtained for the phase difference across the junction

Alex Buchel, Peter Langfelder, Johannes Walcher

Time-dependent solutions of supergravity and string theory are studied. The examples are obtained from de Sitter deformation of gauge/gravity dualities, analytical continuation of static solutions, and ``exactly solvable&#39;&#39; worldsheet models. Among other things, it is shown that turning on a Hubble parameter in the background of a confining gauge theo

The BABAR Collaboration, B. Aubert

We present measurements of branching fractions and CP-violating asymmetries for neutral B meson decays to two-body final states of charged pions and kaons based on a sample of about 88 million Y(4S)-->BB decays. From a time-independent fit we measure the charge-averaged branching fractions B(B0-->pi+pi-) = (4.7 +/- 0.6 +/- 0.2) x 10^-6, B(B0-->K+pi-) = (17.9

J. L. Friar

My talk will consist of three parts: (a) what every atomic physicist needs to know about the physics of light nuclei [and no more]; (b) what nuclear physicists can do for atomic physics; (c) what atomic physicists can do for nuclear physics. A brief qualitative overview of the nuclear force and calculational techniques for light nuclei will be presented, wit

Andrei Alexandru, Anna Hasenfratz

We performed dynamical simulations with HYP smeared staggered fermions using the recently proposed partial-global stochastic Metropolis algorithm with fermion matrix reduction and determinant breakup improvements. In this paper we discuss our choice of the action parameters and study the autocorrelation time both with four and two fermionic flavors at differ

G. Cvetic, R. Koegerler

We discuss resummation strategies for free energy in quantum field theories at nonzero temperatures T. We point out that resummations should be performed for the short- and long-distance parts separately in order to avoid spurious interference effects and double-counting. We then discuss and perform Pade resummations of these two parts for QCD at high T. The

Pavel Kroupa, Christian Boily

Clusters that form in total 10^3 < N < 10^5 stars (type II clusters) lose their gas within a dynamical time as a result of the photo-ionising flux from O stars. Sparser (type I) clusters get rid of their residual gas on a timescale longer or comparable to the nominal crossing time and thus evolve approximately adiabatically. This is also true for massive emb

I. V. Gornyi, A. D. Mirlin

We study interaction-induced quantum correction to the conductivity tensor of electrons in two dimensions for arbitrary T tau, where T is the temperature and tau the transport mean free time. A general formula is derived, expressing the correction in terms of classical propagators (&#34;ballistic diffusons&#34;). The formalism is used to calculate the intera

E. Gabrielli, S. Khalil

We analyze the chargino contributions to B_d - B-bar_d mixing and CP asymmetry of the B_d --> J/psi K_S decay, in the framework of the mass insertion approximation. We derive model independent bounds on the relevant mass insertions. Moreover, we study these contributions in supersymmetric models with minimal flavor violation, Hermitian flavor structure, and

J. M. An, S. Y. Savrasov, H. Rosner, W. E. Pickett

The phonon-mode decomposition of the electron-phonon coupling in the MgB2-like system Li_{1-x}BC is explored using first principles calculations. It is found that the high temperature superconductivity of such systems results from extremely strong coupling to only ~2% of the phonon modes. Novel characteristics of E_2g branches include (1) ``mode lambda&#39;&

J. Burgy, M. Mayr, E. Dagotto

The unusual magneto-transport properties of manganites are widely believed to be caused by mixed-phase tendencies and concomitant percolative processes. However, dramatic deviations from &#34;standard&#34; percolation have been unveiled experimentally. Here, a semi-phenomenological description of Mn oxides is proposed based on coexisting clusters with smooth

Fazal-e-Aleem, Sohail Afzal Tahir

This has critical errors

Pascal Grange

The boundary state formalism is used to confirm predictions from non-commutativity for the derivative corrections to the Dirac--Born--Infeld and Chern--Simons actions, at all orders in derivatives. As anticipated by S. Mukhi, the method applies by induction to every coupling in the Chern--Simons action. It is also used to derive the corrections to the Dirac-

Micol Bolzonella, Roser Pello&#39;, Dario Maccagni

We have developed a Monte Carlo method to compute the luminosity function of galaxies, based on photometric redshifts, which takes into account the non-gaussianity of the probability functions, and the presence of degenerate solutions in redshift. In this paper we describe the method and the mock tests performed to check its reliability. The NIR luminosity f

A. A. Schekochihin, S. C. Cowley, G. W. Hammett, J. L. Maron

The growth and saturation of magnetic field in conducting turbulent media with large magnetic Prandtl numbers are investigated. This regime is very common in low-density hot astrophysical plasmas. During the early (kinematic) stage, weak magnetic fluctuations grow exponentially and concentrate at the resistive scale, which lies far below the hydrodynamic vis

I. Borozan, M. H. Seymour

We introduce an eikonal Monte Carlo model (running in conjunction with HERWIG) for simulating multiparticle production in hadron-hadron interactions. We compare our simulated data to the CDF Tevatron measurement of the underlying event activity in hard inelastic proton-antiproton scattering at sqrt(s)=1.8 TeV. By fixing the only free parameter in our model,

Xavier Illa, Eduard Vives, Antoni Planes

We present a simple model that allows hysteresis loops with exchange bias to be reproduced. The model is a modification of the T=0 random field Ising model driven by an external field and with synchronous local relaxation dynamics. The main novelty of the model is that a certain fraction f of the exchange constants between neighbouring spins is enhanced to a

R. Casalbuoni, L. Marconi

In this paper we evaluate, in the context of the linear BESS model the cross-section for the double Higgs-strahlung process. We find that, within the bounds given by the actual experimental data, significant deviations with respect to the SM may arise. In the linear BESS model not only the self-couplings of the Higgs are modified, but also the Z-Higgs coupli

N. Graham, R. L. Jaffe, V. Khemani, M. Quandt

We study the Casimir problem as the limit of a conventional quantum field theory coupled to a smooth background. The Casimir energy diverges in the limit that the background forces the field to vanish on a surface. We show that this divergence cannot be absorbed into a renormalization of the parameters of the theory. As a result, the Casimir energy of the su

Maciej Horowski, Anatol Odzijewicz, Agnieszka Tereszkiewicz

In the paper we investigate the theory of quantum optical systems. As an application we integrate and describe the quantum optical systems which are generically related to the classical orthogonal polynomials. The family of coherent states related to these systems is constructed and described. Some applications are also presented.

Apostolos Pilaftsis

We perform a comprehensive study of the dominant two- and higher-loop contributions to the $^{205}$Tl, neutron and muon electric dipole moments induced by Higgs bosons, third-generation quarks and squarks, charginos and gluinos in the Minimal Supersymmetric Standard Model (MSSM). We find that strong correlations exist among the contributing CP-violating oper

The NuTeV Collaboration, G. P. Zeller, K. S. McFarland

In a recent comment, Miller and Thomas assert that differences in nuclear shadowing effects between neutrino neutral current (NC) and charged current (CC) interactions could explain the difference between NuTeV&#39;s measurement of the weak mixing angle and the prediction from other electroweak data. We argue that the proposed effect could have only a small

Adil Belhaj

Using mirror pairs (M_3, W_3) in type II superstring compactifications on Calabi-Yau threefolds, we study, geometrically, F-theory duals of M-theory on seven manifolds with G_2 holonomy. We first develop a way for getting Landau Ginzburg (LG) Calabi-Yau threefols W_3, embedded in four complex dimensional toric varieties, mirror to sigma model on toric Calabi

Antonio L. Maroto

We consider a supersymmetric model with a single matter supermultiplet in a five-dimensional space-time with orbifold compactification along the fifth dimension. The boundary conditions on the two orbifold planes are chosen in such a way that supersymmetry remains unbroken on the boundaries. We calculate the vacuum energy-momentum tensor in a configuration i

Ben E. K. Sugerman, Arlin P. S. Crotts

Using the technique of PSF-matched image subtraction, we have analyzed archival HST/WFPC2 data to reveal details of at least two light-echo structures, including some unknown before now, around SN 1993J in the galaxy M81. In particular, we see one partial sheet of material 81 pc in front of the SN and tilted ~60 deg relative to the disk plane of M81, and ano

M. Domokos, R. Fioresi, T. H. Lenagan

Conjugation coactions of the quantum general linear group on the algebra of quantum matrices have been introduced in an earlier paper and the coinvariants have been determined. In this paper the notion of orbit is considered via co-orbit maps for these coactions. The co-orbit maps are calculated explicitly for 2 by 2 quantum matrices. In the NxN case we cons

L. Arturo Urena-Lopez, Andrew R. Liddle

Ultra-light scalar fields provide an interesting alternative to WIMPS as halo dark matter. In this paper we consider the effect of embedding a supermassive black hole within such a halo, and estimate the absorption probability and the accretion rate of dark matter onto the black hole. We show that the accretion rate would be small over the lifetime of a typi

S. Kubis, M. Kutschera

The cooling of neutron stars by URCA processes in the kaon-condensed neutron star matter for various forms of nuclear symmetry energy is investigated. The kaon-nucleon interactions are described by a chiral lagrangian. Nuclear matter energy is parametrized in terms of the isoscalar contribution and the nuclear symmetry energy in the isovector sector. High de

Kazushi Mimura, Tomoyuki Kimoto, Masato Okada

In the development of the brain, it is known that synapses are pruned following over-growth. This pruning following over-growth seems to be a universal phenomenon that occurs in almost all areas -- visual cortex, motor area, association area, and so on. It has been shown numerically that the synapse efficiency is increased by systematic deletion. We discuss

E. Gómez González, J. M. Muñoz Porras, F. J. Plaza Martín

The aim of the paper is twofold. First, some results of Shiota and Plaza-Martin on Prym varieties of curves with an involution are generalized to the general case of an arbitrary automorphism of prime order. Second, the equations defining the moduli space of curves with an automorphism of prime order as a subscheme of the Sato Grassmannian are given.

Mingxing Luo, Yong Xiao

Two-loop renormalization group equations in the standard model are re-calculated. A new coefficient is found in the beta-function of the quartic coupling and a class of gauge invariants are found to be absent in the beta-functions of hadronic Yukawa couplings. The two-loop beta-function of the Higgs mass parameter is presented in complete form.