May 2003 arXiv papers — page 18

The Milagro Collaboration

The recent advances in TeV gamma-ray astronomy are largely the result of the ability to differentiate between extensive air showers generated by gamma rays and hadronic cosmic rays. Air Cherenkov telescopes have developed and perfected the "imaging" technique over the past several decades. However until now no background rejection method has been suc

Marina Orio, Wouter Hartmann, Martin Still, Jochen Greiner

Nova LMC 1995, previously detected during 1995-1998 with ROSAT, was observed again as a luminous supersoft X-ray source with XMM-Newton in December of 2000. This nova offers the possibility to observe the spectrum of a hot white dwarf, burning hydrogen in a shell and not obscured by a wind or by nebular emission like in other supersoft X-ray sources. Notwith

Madappa Prakash, James M. Lattimer

We contrast the evolution of gravitational binary mergers for the two cases of a black hole and a normal neutron star, and a black hole and a self-bound strange quark matter star. In both cases inspiral continues until the Roche limit is reached, at which point it is expected that stable mass transfer to the balck hole ensues. Whereas a neutron star would th

Gordon T. Richards, Patrick B. Hall, Daniel E. Vanden Berk, Michael A. Strauss

We investigate the continuum and emission line properties of 4576 SDSS quasars as a function of their optical/UV SEDs. The optical/UV color distribution of our sample is roughly Gaussian, but with a red tail; we distinguish between 1) intrinsically blue (optically flat) quasars, 2) intrinsically red (optically steep) quasars, and 3) the 273 (6%) of our quasa

P. G. Jonker, G. Nelemans, Z. Wang, A. K. H. Kong

We have obtained optical and near-infrared images of the field of the accreting millisecond X-ray pulsar XTE J1751-305. There are no stars in the 0.7'' error circle (0.7'' is the overall uncertainty arising from tying the optical and X-ray images and from the intrinsic uncertainty in the Chandra X-ray astrometric solution). We derive limiting

K. Cunha, V. V. Smith, D. L. Lambert, K. H. Hinkle

The behavior of fluorine with metallicity has not yet been probed in any stellar population. In this work, we present the first fluorine abundances measured outside of the Milky Way from a sample of red giants in the Large Magellanic Cloud (LMC), as well the Galactic globular cluster Omega Centauri. The fluorine abundances are derived from vibration-rotation

R. Wischnewski

We review the present status of the Baikal Neutrino Project, present updated results on the search for high energy extraterrestrial neutrinos, fast magnetic monopoles and neutrinos induced by WIMP annihilation in the center of the Earth and compare the recorded atmospheric neutrino flux to predictions. We describe the moderate upgrade of NT-200 toward $\sim$

Roger Coziol

(Abridged) The characteristics of the starburst galaxies from the Pico dos Dias survey (PDS) are compared with those of the nearby UV-bright Markarian starburst galaxies, having the same limit in redshift ($v_h < 7500$ km s$^{-1}$) and absolute $B$ magnitude ($M_B < -18$). An important difference is found: the Markarian galaxies are generally undetected at 1

Nicos Hiotelis

An inside-out model for the formation of haloes in a hierarchical clustering scenario is studied. The method combines the picture of the spherical infall model and a modification of the extended Press-Schechter theory. The mass accretion rate of a halo is defined to be the rate of its mass increase due to minor mergers. The accreted mass is deposited at the

F. Pozzi, P. Ciliegi, C. Gruppioni, C. Lari

We have studied the optical, near-IR and radio properties of a complete sample of 43 sources detected at 15-micron in one of the deeper ELAIS repeatedly observed region. The extragalactic objects in this sample have 15-micron flux densities in the range 0.4-10 mJy, where the source counts start diverging from no evolution models. About 90% of the sources (39

A. Cattaneo, M. Bernardi

We investigate the hypothesis that quasars formed together with the stellar populations of early-type galaxies. This hypothesis, in conjunction with the stellar ages of early-type galaxies from population synthesis models, the relation of black hole mass to bulge velocity dispersion, and the velocity dispersion distribution from the Sloan Digital Sky Survey,

Atsunori Yonehara, Shin Mineshige, Yoh Takei, George Chartas

Recently, Chartas et al. (2001) detected a rapid X-ray flare in the gravitationally lensed, multiple image quasar RX J0911.4+0551. Dramatic events, such as rapid X-ray flares, are useful in providing high precision measurements of the time delays between multiple images. In this paper, we argue that there is a new possibility in measurements of time delays b

B. Vollmer, W. J. Duschl, R. Zylka

We present models the gas physics and dynamics of the inner 50 pc of the Galaxy. In a first step the gas properties of an isolated clumpy circumnuclear disk were analytically investigated. We took the external UV radiation field, the gravitational potential, and the observed gas temperature into account. The model includes a description of the properties of

A. Marin-Franch, A. Aparicio

The faint end of the differential galaxy number counts, n(m), in the Hubble Deep Field (HDF) North has been determined for the F450W, F606W, and F814W filters by means of surface-brightness fluctuation (SBF) measurements. This technique allows us to explore n(m) beyond the limiting magnitude of the HDF, providing new, stronger constraints on the faint end of

S. F. Sanchez, J. I. Gonzalez-Serrano

We present K-band images of 31 radio quasars selected from the B3-VLA quasar sample. A new method has been developed to detect and restore the host galaxies of these quasars. We have detected the host galaxies of 16 of them. Using these data together with previous data from the B3-VLA quasars (Carballo et al. 1998, hereafter Paper I) and literature data from

F. Yusef-Zadeh, M. Nord, M. Wardle, C. Law

High resolution VLA observations of the Arches cluster near the Galactic center show evidence of continuum emission at $λ$3.6, 6, 20 and 90cm. The continuum emission at $λ$90cm is particularly striking because thermal sources generally become optically thick at longer wavelengths and fall off in brightness whereas non-thermal sources increase in brightness.

Hakki Ogelman, Emre Tepedelenlioglu

PSR B0628-28 is an X-ray emitting radio pulsar which was observed with Advanced CCD Imaging Spectrometer (ACIS) on board Chandra on 2001 November 04 and on 2002 March 25 for 2000 s and 17000 s, respectively. The source countrate was 0.0111+-0.0013 cps. Making PSR B0628-28 to be the longest period X-ray emitting pulsar. The spectral distribution of counts can

James B. Hartle

We investigate the idea that different interpretations of quantum mechanics can be seen as restrictions of the consistent (or decoherent) histories quantum mechanics of closed systems to particular classes of histories,together with the approximations and descriptions of these histories that the restrictions permit. (Talk at the the workshop Quo Vadis Quantu

T. Bakeyev, M. Gockeler, R. Horsley, D. Pleiter

By considering the local vector current between nucleon states and imposing charge conservation, we determine its renormalisation constant and quark mass improvement coefficient for Symanzik $O(a)$ improved Wilson fermions. The computation is first performed for quenched fermions (and for completeness also with unimproved fermions) and compared against known

M. J. Prata

We derive analytical expressions for the solid angle subtended by a circular disc at a point source with cosine angular distribution ($f(μ)=μ/π$)under the sole condition that the disc lies in the half-space illuminated by the source ($μ\geq 0$). The expressions are given with reference to two alternative coordinate systems (S and S&#39;), S being such that t

Nick Halmagyi, Vadim Yasnov

For matrix models with measure on the Lie algebra of SO/Sp, the sub-leading free energy is given by F_{1}(S)=\pm{1/4}\frac{\del F_{0}(S)}{\del S}. Motivated by the fact that this relationship does not hold for Chern-Simons theory on S^{3}, we calculate the sub-leading free energy in the matrix model for this theory, which is a Gaussian matrix model with Haar

Samer S. Al-Ashhab, Ronald O. Fulp

In many Lagrangian field theories, there is a Poisson bracket on the space of local functionals. One may identify the fields of such theories as sections of a vector bundle. It is known that the Poisson bracket induces an sh-Lie structure on the graded space of horizontal forms on the jet bundle of the relevant vector bundle. We consider those automorphisms

J. Baker, M. Campanelli, C. O. Lousto, R. Takahashi

We compute the gravitational radiation generated in the evolution of a family of close binary black hole configurations, using a combination of numerical and perturbative approximation methods. We evolve the binaries with spins, $s$, aligned or counter-aligned with the orbital angular momentum from near the innermost stable circular orbit (ISCO) down to the

Eric V. Linder, Adrian Jenkins

Dark energy has a dramatic effect on the dynamics of the universe, causing the recently discovered acceleration of the expansion. The dynamics are also central to the behavior of the growth of large scale structure, offering the possibility that observations of structure formation provide a sensitive probe of the cosmology and dark energy characteristics. In

Kevin Haglin, Charles Gale

We study J/$ψ$ propagation in hot hadronic matter using a four-flavor chiral Lagrangian to model the dynamics and using QCD sum rules to model the finite size effects manifested in vertex interactions through form factors. Charmonium breakup due to scattering with light mesons is the primary impediment to continued propagation. Breakup rates introduce nontri

Ilka Brunner, Manfred Herbst, Wolfgang Lerche, Bernhard Scheuner

We investigate B-type topological Landau-Ginzburg theory with one variable, with D2-brane boundary conditions. We find that the allowed brane configurations are determined in terms of the possible factorizations of the superpotential, and compute the corresponding open string chiral rings. These are characterized by bosonic and fermionic generators that sati

Andrei Kryjevski

We investigate the issue of charge neutrality of the CFL$K^0$ phase of dense quark matter using the low energy effective theory of high density QCD. We show that the local electric and color charge neutrality of the ground state in a homogeneous color superconducting medium follows from its dynamics. We also consider the situation of a spatially inhomogeneou

Mina Aganagic, Albrecht Klemm, Marcos Marino, Cumrun Vafa

We construct a cubic field theory which provides all genus amplitudes of the topological A-model for all non-compact Calabi-Yau toric threefolds. The topology of a given Feynman diagram encodes the topology of a fixed Calabi-Yau, with Schwinger parameters playing the role of Kahler classes of Calabi-Yau. We interpret this result as an operatorial computation

M. Genovese

In this letter we discuss entanglement properties of neutral kaons systems and their use for testing local realism. In particular we show that, as previous proposals, also a scheme recently suggested for performing a test of hidden variable theories against standard quantum mechanics cannot be conclusive.

Arundhati Dasgupta

We determine coherent states peaked at classical space-time of the Schwarzschild black hole in the frame-work of canonical quantisation of general relativity. The information about the horizon is naturally encoded in the phase space variables, and the perturbative quantum fluctuations around the classical geometry depend on the distance from the horizon. For

Alexei Akolzin, Richard L. Weaver

We study the evolution of diffuse elastodynamic spectral energy density under the influence of weak nonlinearity. It is shown that the rate of change of this quantity is given by a convolution of the linear energy at two frequencies. Quantitative estimates are given for sample aluminum and fused silica blocks of experimental interest.

Paola Gianotti

DA$Φ$NE $e^+ e^-$ collider is an abundant source of low energy $K \bar K$ pairs suitable to explore different fields of non perturbative QCD regime. Two different experiments, DEAR and FINUDA, using different experimental techniq ues are trying to shed new light on the strong interaction at the nucleon scale by producing high precision results at this energy

A. Sarsa, J. Mur-Petit, A. Polls, J. Navarro

The binding energies of two-dimensional clusters (puddles) of $^4$He are calculated in the framework of the diffusion Monte Carlo method. The results are very well fitted by a mass formula in powers of $x=N^{-1/2}$, where $N$ is the number of particles. The analysis of the mass formula allows for the extraction of the line tension, which turns out to be 0.12

Masato Ito

Motivated by recent accelerating cosmological model, we derive the solutions to vacuum Einstein equation in $(d+1)$-dimensional Minkowski space with $n$-dimensional hyperbolic manifold. The conditions of accelerating expansion are given in such a set up.

A. Gusso, C. A. de S. Pires, P. S. Rodrigues da Silva

In the minimal 3-3-1 model charged leptons come in a non-diagonal basis. Moreover the Yukawa interactions of the model lead to a non-hermitian charged lepton mass matrix. In other words, the minimal 3-3-1 model presents a very complex lepton mixing. In view of this we check rigorously if the possible textures of the lepton mass matrices allowed by the minima

P. S. Howe, D. Tsimpis

A theoretical analysis of higher-order corrections to D=11 supergravity is given in a superspace framework. It is shown that any deformation of D=11 supergravity for which the lowest-dimensional component of the four-form $G_4$ vanishes is trivial. This implies that the equations of motion of D=11 supergravity are specified by an element of a certain spinori

Andrew R Liddle, Samuel M Leach

We reconsider the issue of the number of e-foldings before the end of inflation at which observable perturbations were generated. We determine a plausible upper limit on that number for the standard cosmology which is around 60, with the expectation that the actual value will be up to 10 below this. We also note a special property of the $λϕ^4$ model which r

Tomohiro Harada, Hideo Iguchi, Masaru Shibata

Nonspherical stellar collapse to a black hole is one of the most promising gravitational wave sources for gravitational wave detectors. We numerically study gravitational waves from a slightly nonspherical stellar collapse to a black hole in linearized Einstein theory. We adopt a spherically collapsing star as the zeroth-order solution and gravitational wave

Mattias Marklund, Gert Brodin, Lennart Stenflo

The nonlinear interaction, due to quantum electrodynamical (QED) effects, between an electromagnetic pulse and a radiation background is investigated, by combining the methods of radiation hydrodynamics with the QED theory for photon-photon scattering. For the case of a single coherent electromagnetic pulse we obtain a Zakharov-like system, where the radiati

S. Wehrli, E. Koch, M. Sigrist

We investigate the possibility of doping C60 crystals by applying a strong electric field. For an accurate description of a C60 field-effect device we introduce a multipole expansion of the field, the response of the C60 molecules, and the Stark splitting of the molecular levels. The relevant response coefficients and splittings are calculated ab initio for

John N. Bahcall, Carlos Pena-Garay

We analyze all available solar and related reactor neutrino experiments, as well as simulated future 7Be, p-p, pep, and ^8B solar neutrino experiments. We treat all solar neutrino fluxes as free parameters subject to the condition that the total luminosity represented by the neutrinos equals the observed solar luminosity (the `luminosity constraint'). Existi

Taksu Cheon

A game-theoretic model of social preference and enlightened self-interest is formulated. Existence of symmetry and duality in the game matrices with altruistic social preference is revealed. The model is able to quantitatively describe the dynamical evolution of altruism in prisoner&#39;s dilemma and the regime change in prey-predator dynamics.

Fabrizio Tavecchio, Gabriele Ghisellini, Davide Lazzati

We reanalyze the XMM--Newton data of GRB 011211 showing that the spectral features, interpreted by Reeves et al. (2002, 2003) as due thermal emission from a collisionally ionized plasma, can be also reproduced by a reflection model (with ionization parameter $ξ\sim 10^2$). We discuss the implications of this interpretation, estimating the total mass required

Peter Larsson, Erik Sjöqvist

In polarimetry, a superposition of internal quantal states is exposed to a single Hamiltonian and information about the evolution of the quantal states is inferred from projection measurements on the final superposition. In this framework, we here extend the polarimetric test of Pancharatnam&#39;s relative phase for spin$-{1/2}$ proposed by Wagh and Rakhecha

Sanjeev Kumar, Pinaki Majumdar

We propose a scheme for constructing classical spin Hamiltonians from Hunds coupled spin-fermion models in the limit J_H/t \to \infinity. The strong coupling between fermions and the core spins requires self-consistent calculation of the effective exchange in the model, either in the presence of inhomogeneities or with changing temperature. In this paper we

C. Godrèche, J. M. Luck

We investigate the motion of a tagged spin in a ferromagnetic Ising chain evolving under Kawasaki dynamics. At equilibrium, the displacement is Gaussian, with a variance growing as $A t^{1/2}$. The temperature dependence of the prefactor $A$ is derived exactly. At low temperature, where the static correlation length $ξ$ is large, the mean square displacement

Luca Lista

A procedure to include the uncertainty on the background estimate for upper limit calculations using Poissonian sampling is presented for the case where a Gaussian assumption on the uncertainty can be made. Under that hypothesis an analytic expression of the likelihood is derived which can be written in terms of polynomials defined by recursion. This express

Andrea Merloni, Sebastian Heinz, Tiziana Di Matteo

We examine the disc--jet connection in stellar mass and supermassive black holes by investigating the properties of their compact emission in the X-ray and radio bands. We compile a sample of ~100 active galactic nuclei with measured mass, 5 GHz core emission, and 2-10 keV luminosity, together with 8 galactic black holes with a total of ~50 simultaneous obse

A. Y. Potekhin, D. G. Yakovlev, G. Chabrier, O. Y. Gnedin

We study the thermal structure of neutron stars with magnetized envelopes composed of accreted material, using updated thermal conductivities of plasmas in quantizing magnetic fields, as well as equation of state and radiative opacities for partially ionized hydrogen in strong magnetic fields. The relation between the internal and local surface temperatures

Giovanni Amelino-Camelia

Over the last few years the study of possible Planck-scale departures from classical Lorentz symmetry has been one of the most active areas of quantum-gravity research. We now have a satisfactory description of the fate of Lorentz symmetry in the most popular noncommutative spacetimes and several studies have been devoted to the fate of Lorentz symmetry in l

Kazuhide Ichikawa, Masahiro Kawasaki

We reconsider the evolution of strongly degenerate neutrinos in the early universe. Our chief concern is the validity of the entropy conservation after the neutrino annihilation process has frozen out (so that the establishment of chemical equilibrium is not trivial). We argue that the entropy indeed conserves because elastic scattering keeps the neutrino an

Yaakov S. Weinstein, Constantino Tsallis, Seth Lloyd

We explore the border between regular and chaotic quantum dynamics, characterized by a power law decrease in the overlap between a state evolved under chaotic dynamics and the same state evolved under a slightly perturbed dynamics. This region corresponds to the edge of chaos for the classical map from which the quantum chaotic dynamics is derived and can be

J. J. Halliwell

We investigate the decoherence of histories of local densities for linear oscillators models. It is shown that histories of local number, momentum and energy density are approximately decoherent, when coarse-grained over sufficiently large volumes. Decoherence arises directly from the proximity of these variables to exactly conserved quantities (which are ex

Stefan Scheel, Kae Nemoto, William J. Munro, Peter L. Knight

We investigate the generation of nonlinear operators with single photon sources, linear optical elements and appropriate measurements of auxiliary modes. We provide a framework for the construction of useful single-mode and two-mode quantum gates necessary for all-optical quantum information processing. We focus our attention generally on using minimal physi

V. A. Dzuba, V. V. Flambaum, M. V. Marchenko.

A possibility for fundamental constants to vary in time is suggested by theories unifying gravity with other interactions. In this article we examine proposals to use optical transitions of Sr, Dy, YbII and YbIII for the search of the time variation of the fine structure constant $α$. Frequencies of atomic transitions are calculated using relativistic Hartre

John Lekner

The polarization properties of monochromatic light beams are studied. In contrast to the idealization of an electromagnetic plane wave, finite beams which are everywhere linearly polarized in the same direction do not exist. Neither do beams which are everywhere circularly polarized in a fixed plane. It is also shown that transversely finite beams cannot be

John Lekner

In a coherent monoenergetic beam of non-interacting particles, the phase velocity and the particle transport velocity are functions of position, with the strongest variation being in the focal region. These velocities are everywhere parallel to each other, and their product is constant in space. For a coherent monochromatic electromagnetic beam, the energy t

Marat M. Rvachev

Here a viable and never before investigated mechanism of propagation of spikes along neurons is proposed. In the following, velocity of propagation of small-amplitude pressure waves through the cytoplasmic interior of myelinated and unmyelinated axons of different diameters is theoretically estimated, and is found to generally agree with the action potential

S. R. Klein, R. Vogt

We study the effect of spatially homogeneous and inhomogeneous shadowing on $J/ψ$ production in deuterium-nucleus collisions. We discuss how the shadowing and its spatial dependence may be measured by comparing central and peripheral $dA$ collisions. These event classes may be selected by using gray protons from heavy ion breakup and events where the proton

Paul Sutcliffe, Arthur Winfree

Through extensive numerical simulations we investigate the evolution of knotted and linked vortices in the FitzHugh-Nagumo model. On medium time scales, of the order of a hundred times the vortex rotation period, knots simultaneously translate and precess with very little change of shape. However, on long time scales we find that knots evolve in a more compl

Bennett Chow, David Glickenstein, Peng Lu

We study sequences of 3-dimensional solutions to the Ricci flow with almost nonnegative sectional curvatures and diameters tending to infinity. Such sequences may arise from the limits of dilations about singularities of Type IIb. In particular, we study the case when the sequence collapses, which may occur when dilating about infinite time singularities. In

Vadim E. Levit, Eugen Mandrescu

If for any k the k-th coefficient of a polynomial I(G;x)is equal to the number of stable sets of cardinality k in graph G, then it is called the independence polynomial of G (Gutman and Harary, 1983). A graph G is very well-covered (Favaron, 1982) if it has no isolated vertices, its order equals 2*alpha(G), where alpha(G) is the size of a maximum stable set,

Jochen Koenigsmann

Let X be a smooth projective curve of genus >1 over a field K which is finitely generated over the rationals. The section conjecture in Grothendieck&#39;s anabelian geometry says that the sections of the canonical projection from the arithmetic fundamental group of X onto the absolute Galois group of K are (up to conjugation) in one-to-one correspondence wit

Cord Erdenberger

The moduli space of (1,p)-polarized abelian surfaces is a quasi-projective variety. In the case when p is a prime, we study its Kodaira dimension. We show that it is of general type for p > 71 and some smaller values of p. This improves an earlier result of G. K. Sankaran.

Francesc Rossello

We compute explicitly several abstract metrics for RNA secondary structures defined by Reidys and Stadler.

William Graham

Let V be a rank N vector bundle on a d-dimensional complex projective scheme X; assume that V is equipped with a skew-symmetric bilinear form with values in a line bundle L and that Λ^2 V^* \otimes L is ample. Suppose that the maximum rank of the form at any point of X is r, where r>0 is even. The main result of this paper is that if d>2(N-r), then the locus

Alberto Berretti, Guido Gentile

The behavior of the critical function for the breakdown of the homotopically non-trivial invariant (KAM) curves for the standard map, as the rotation number tends to a rational number, is investigated using a version of Greene&#39;s residue criterion. The results are compared to the analogous ones for the radius of convergence of the Lindstedt series, in whi

Frederic Helein

We consider harmonic maps into pseudo-Riemannian manifolds. We show the removability of isolated singularities for continuous maps, i.e. that any continuous map from an open subset of R^m into a pseudo-Riemannian manifold which is two times continuously differentiable and harmonic everywhere outside an isolated point is actually smooth harmonic everywhere.

Edward Frenkel

This is the text of the Hermann Weyl Prize lecture given by the author at the XXIV Colloquium on Group Theoretical Methods in Physics, Paris, July 2002 (to appear in the Proceedings of the Colloquium).

Diane Maclagan, Gregory G. Smith

We give an effective uniform bound on the multigraded regularity of a subscheme of a smooth projective toric variety X with a given multigraded Hilbert polynomial. To establish this bound, we introduce a new combinatorial tool, called a Stanley filtration, for studying monomial ideals in the homogeneous coordinate ring of X. As a special case, we obtain a ne

Diane Maclagan, Gregory G. Smith

We develop a multigraded variant of Castelnuovo-Mumford regularity. Motivated by toric geometry, we work with modules over a polynomial ring graded by a finitely generated abelian group. As in the standard graded case, our definition of multigraded regularity involves the vanishing of graded components of local cohomology. We establish the key properties of

Nguyen Tien Zung

We prove the following result, conjectured by Alan Weinstein: every smooth proper Lie groupoid near a fixed point is locally linearizable, i.e. it is locally isomorphic to the associated groupoid of a linear action of a compact Lie group. In combination with a slice theorem of Weinstein, our result implies the smooth linearizability of a proper Lie groupoid

Hermann Boos, Vladimir Korepin, Feodor Smirnov

This paper is continuation of our previous papers hep-th/0209246 and hep-th/0304077 . We discuss in more detail a new form of solution to the quantum Knizhnik-Zamolodchikov equation [qKZ] on level -4 obtained in the paper hep-th/0304077 for the Heisenberg XXX spin chain. The main advantage of this form is it&#39;s explicit reducibility to one-dimensional int

A. A. Slavnov, K. V. Stepanyantz

A manifestly invariant renormalization scheme of N=1 nonabelian supersymmetric gauge theories is proposed.

Clovis Wotzasek

We shall discuss issues of duality and topological mass generation in diverse dimensions. Particular emphasis will be given to the mass generation mechanism from interference between self and anti self-dual components, as disclosed by the soldering formalism. This is a gauge embedding procedure derived from an old algorithm of second-class constraint convers

Kazuki Ohmori

We study the level-expansion structure of the NS string field theory actions, mainly focusing on the modified (i.e. 0-picture in the NS sector) cubic superstring field theory. This theory has a non-trivial structure already at the quadratic level due to presence of the picture-changing operator. It is explicitly shown how the usual Maxwell and tachyon action

Bert Schroer

After recalling episodes from Pascual Jordan&#39;s biography including his pivotal role in the shaping of quantum field theory and his much criticized conduct during the NS regime, I draw attention to his presentation of the first phase of development of quantum field theory in a talk presented at the 1929 Kharkov conference. He starts by giving a comprehens

W. S. Bae, Y. M. Cho

We present finite energy analytic monopole and dyon solutions whose size is fixed by the electroweak scale. We discuss two types of solutions. The first type is obtained by regularizing the recent solutions of Cho and Maison by modifying the coupling strength of the quartic self-interaction of $W$-boson in Weinberg-Salam model. The second is obtained by enla

P. F. Harrison, W. G. Scott, T. J. Weiler

We write the probabilities for neutrino oscillations in uniform-density matter exactly in terms of convention-independent vacuum neutrino oscillation parameters and the matter density. This extends earlier results formulating neutrino oscillations in terms of matter-, phase-, and trace-invariant quantities.

Yu Jia

Heavy hadron production in $e^+e^-$ annihilation is studied in the framework of heavy-quark recombination mechanism. This mechanism predicts a new type of 3-jet event such as $b\bar{b}q$ or $b\bar{b}\bar{q}$, which is power-suppressed relative to the standard $b\bar{b}g$ event. Furthermore, heavy quark fragmentation function also receives a contribution from

A. Donnachie, P. V. Landshoff

At present there is no correct theory of evolution of F_2(x,Q^2) at small x. It is a mixture of hard and soft pomeron exchange and perturbative QCD very successfully describes the evolution of the hard-pomeron component. This allows the gluon density to be calculated. It is somewhat different from what is conventionally supposed, but it leads to a clean PQCD

Alejandro Ayala

The behavior of the pion dispersion relation in a pion medium is strongly modified by the introduction of a finite chemical potential associated to the finite pion number density. Such behavior is particularly important during the hadronic phase of a relativistic heavy-ion collision, between chemical and thermal freeze-out, where the pion number changing pro

V. Antonelli, F. Caravaglios, R. Ferrari, M. Picariello

By using a model independent Monte Carlo approach, we study the possible structure of charged and neutral lepton mass matrices, under the assumption of an U(2) horizontal symmetry (additional to the usual Standard Model ones) involving the light fermion generations. We assume the most general Majorana mass matrix for neutrinos. We update the results of our p

Noriyuki Oshimo

Assuming grand unified theory (GUT) and supersymmetry, we propose a simple model which can consistently accommodate the masses and mixings for quarks and leptons. The grand unified group is SO(10), and $\bf 10$, $\bf 120$, and $\bar {\bf 126}$ representations are introduced for the Higgs superfields which give masses to the quarks and leptons. The difference

A. M. Cooper-Sarkar, R. C. E. Devenish

A short personal account is given of the impact of HERA data and the influence of Jan Kwiecinski on low x physics

Elvira Gamiz, Joaquim Prades, Ignazio Scimemi

We update the CP-violating asymmetries in K^+ -> 3 pi. In particular we study Delta g_C and Delta g_N -the asymmetries in the slope g. We emphasize its complementarity to the direct CP-violation parameter epsilon_K&#39; and the large sensitivity to the size of the imaginary part of the octet coupling Im G_8 at lowest order in CHPT. We also give the prospects

Giulia Zanderighi

We present an innovative method to resum infrared and collinear logarithms appearing in distributions of jet observables in QCD. The method, based on a general master formula with applicability conditions, allows resummations at next-to-leading logarithmic accuracy in an automated way. As a sample application we present resummed results in hadronic dijet eve

J R Forshaw

We discuss two novel possibilities in Higgs physics. The first is that, by adding a real Higgs triplet to the Standard Model, it is possible for the lightest Higgs boson to be as heavy as 500 GeV without any fine tuning. The second, somewhat orthogonal, possibility concerns the MSSM with explicit CP violation. This model is known to permit a light Higgs boso

Jianwei Qiu

The extension of the factorization theorems of perturbative QCD to power corrections associated with re-scattering in nuclear collisions is reviewed. The importance of hadron-nucleus collisions is discussed.

Paramita Adhya, D. Rai Chaudhuri

Late-time entropy production from scalar decay arises in scenarios like thermal inflation, proposed to dilute long-lived, massive fields like the gravitino and the moduli. The scalar decay may continue into Mev-scale temperatures and affect BB nucleosynthesis. The effect of such entropy production on electron neutrino decoupling is studied. A lower bound of

H. T. Diehl

We report new top quark and electroweak results from the DZero Experiment, which is accumulating luminosity from pbar-p collisions at center-of-mass energy 1.86 TeV (Run II).

G. Vuagnin

In this paper the studies of three different B decays to hadronic states are presented. These results are based on 1999-2003 dataset collected by the BaBar experiment at the PEP-II e+e- storage ring at the Stanford Linear Accelerator Center. The measurements are the hadronic branching fraction of B+ -> J/psi p Lambda-bar, B0 -> J/psi p p-bar, B0 -> D*+D-, an

Pamela Ferrari

The results of the Higgs boson searches performed by the four LEP experiments at centre-of-mass energies between 189 GeV and 209 GeV corresponding to an integrated luminosity of 2461 pb$^{-1}$ are presented here. Searches have been performed for Higgs in the Standard Model (SM), in 2 Higgs Doublet Models (2HDM&#39;s), for doubly charged, fermiophobic and inv

FOCUS collaboration, J. M. Link

Using data collected by the fixed target Fermilab experiment FOCUS, we measure the branching ratios of the Cabibbo favored decays $Ξ_c^+ \to Σ^+K^-π^+$, $Ξ_c^+ \to Σ^+ \bar{K}^{*}(892)^0$, and $Ξ_c^+ \to Λ^0K^-π^+π^+$ relative to $Ξ_c^+ \to Ξ^-π^+π^+$ to be $0.91\pm0.11\pm0.04$, $0.78\pm0.16\pm0.06$, and $0.28\pm0.06\pm0.06$, respectively. We report the firs

A. Limosani

Results on two inclusive Vub measurements at Belle are presented. We also present a new measurement of the branching fraction for Ds->phi pi. A data sample of 78.1fb^-1 accumulated using the Belle detector at the KEKB asymmetric e^+e^- collider operating at the Upsilon(4S) resonance is used. All results are preliminary.

The KLOE Collaboration

We have measured the ratio R=Gamma(K_L -> gamma gamma)/ Γ(K_L -> 3 pi^0) using the KLOE detector. From a sample of ~ 10^9 phi-mesons produced at DAFNE, the Frascati phi-factory, we select ~ 1.6 10^8 K_L-mesons tagged by observing K_S -> pi^+ pi^- following the reaction e^+ e^- -> phi -> K_L K_S. From this sample we select 27,375 K_L -> gamma gamma events and

T. Nakadaira

We present an improved measurement of CP-violating asymmetries in B0 -> pi+ pi- decays based on a 78/fb data sample collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We reconstruct one neutral B meson as a B0 -> pi+ pi- CP eigenstate and identify the flavor of the accompanying B meson from its decay product

Neeti Parashar

The \d0 (DZERO) Detector at Fermilab is currently collecting data since March 1, 2001, called Run 2. The detector has undergone an extensive upgrade to participate in the Run 2 data taking. The design of the detector meets the requirements of the high luminosity environment provided by the accelerator. This paper describes the upgraded detector subsystems an

Yvonne Choquet-Bruhat

I prove the existence of vacuum $S^{1}$ symmetric Einsteinian, unpolarized, space times which are complete in the direction of the expansion, for small initial data, without supposing that the $S^{1}$ orbits are orthogonal to the 3-manifolds, as was done in previous work in collaboration with V. Moncrief.

S. B. Tchapnda, A. D. Rendall

The behaviour of expanding cosmological models with collisionless matter and a positive cosmological constant is analysed. It is shown that under the assumption of plane or hyperbolic symmetry the area radius goes to infinity, the spacetimes are future geodesically complete, and the expansion becomes isotropic and exponential at late times. This proves a for