December 2000 arXiv papers — page 13

Elisabete M. de Gouveia Dal Pino

It has been recently discovered that spatially separated Herbig-Haro objects, once considered unrelated, are linked within a chain that may extend for parsecs in either direction of the embedded protostar forming a "giant Herbig-Haro jet". Presently, several dozen of these giant flows have been detected and the best documented example, the HH~34 syst

Kenji Bekki

The central bulge of M31 is observed to have two distinct brightness peaks with the separation of $\sim$ 2 pc. Tremaine (1995) recently proposed a new idea that the M31's nucleus is actually a single thick eccentric disk surrounding the central super-massive black hole. In order to explore the origin of the proposed eccentric disk, we numerically investi

Kenji Bekki, Yasuhiro Shioya, Warrick J. Couch

The formation and evolution of the ``E+A'' (also named ``k+a'' and ``a+k'' types by Dressler et al. 1999) galaxies found in significant numbers in the cores of intermediate redshift clusters has been extensively discussed by many authors. In this paper, we model the spectral, dynamical and morphological evolution of a prime candidate

Kenji Bekki, Yasuhiro Shioya

By performing N-body simulations of chemodynamical evolution of galaxies with dusty starbursts, we investigate photometric evolution of gas-rich major mergers in order to explore the nature of ultraluminous infrared galaxies (ULIRGs) with the total infrared luminosity ($L_{\rm IR}$ for $8\sim 1000$ $μ$m) of $\sim$ $10^{12}$ $L_{\odot}$. Main results are the

Andrei Gruzinov

Linear eigenmodes of a spherically symmetrical ultra-relativistic blast wave (the Blandford-McKee, BMK, solution) are calculated. The BMK solution is shown to be stable and strongly non-universal. It is stable because all the eigenmodes decay. Non-universality of the BMK solution (BMK is not an intermediate asymptotic) is a consequence of causality. In terms

Kenji Bekki

We numerically investigate stellar and gaseous dynamical evolution of mergers between five identical late-type disk galaxies with the special emphasis on star formation history and chemical evolution of multiple galaxy mergers. We found that multiple encounter and merging can trigger repetitive massive starbursts (typically $\sim$ 100 $M_{\odot}$ ${\rm yr}^{

Eric B. Ford, Marketa Havlickova, Frederic A. Rasio

Instabilities and strong dynamical interactions between several giant planets have been proposed as a possible explanation for the surprising orbital properties of extrasolar planetary systems. In particular, dynamical instabilities would seem to provide a natural mechanism for producing the highly eccentric orbits seen in many systems. Here we present resul

N. S. Deger, A. Kaya, E. Sezgin, P. Sundell

We examine the boundary behaviour of the gauged N=(2,0) supergravity in D=3 coupled to an arbitrary number of scalar supermultiplets which parametrize a Kahler manifold. In addition to the gravitational coupling constant, the model depends on two parameters, namely the cosmological constant and the size of the Kahler manifold. It is shown that regular and ir

Ying-Jer Kao, G. S. Grest, K. Levin, J. Brooke

In this paper we investigate the relationship between glassy and ferromagnetic phases in disordered Ising ferromagnets in the presence of transverse magnetic fields, $Γ$. Iterative mean field simulations probe the free energy landscape and suggest the existence of a glass transition as a function of $Γ$ which is distinct from the Curie temperature. New exper

Simonetta Frittelli, Carlos Kozameh, Ezra T. Newman

We first show how, from the general 3rd order ODE of the form z'''=F(z,z',z'',s), one can construct a natural Lorentzian conformal metric on the four-dimensional space (z,z',z'',s). When the function F(z,z',z'',s) satisfies a special differential condition of the form, U[F]=0, the conformal metric possesses a c

A. Braverman, D. Gaitsgory, M. Finkelberg, I. Mirković

Let $X$ be a smooth complete curve, $G$ be a reductive group and $P\subset G$ a parabolic. Following Drinfeld, one defines a compactification $\widetilde{\on{Bun}}_P$ of the moduli stack of $P$-bundles on $X$. The present paper is concerned with the explicit description of the Intersection Cohomology sheaf of $\widetilde{\on{Bun}}_P$. The description is give

G. Barenboim, F. J. Botella, O. Vives

Tree-level Flavor-Changing Neutral Currents (FCNC) are characteristic of models with extra vector-like quarks. These new couplings can strongly modify the B^0 CP asymmetries without conflicting with low--energy constraints. In the light of a low CP asymmetry in B --> J/ψK_{S}, we discuss the implications of these contributions. We find that even these low va

R. Mulet, A. Pagnani, G. Parisi

We study the temperature structure of the naive TAP equations by mean of a recursion algorithm. The problem of the chaos in temperature is addressed using the notion of the temperature evolution of equilibrium states. The lowest free energy states show relevant correlations with the ground state, and a careful finite size analysis indicates that these correl

Montserrat Guilleumas, Robert Graham

We consider non centered vortices and their arrays in a cylindrically trapped Bose-Einstein condensate at zero temperature. We study the kinetic energy and the angular momentum per particle in the Thomas Fermi regime and their dependence on the distance of the vortices from the center of the trap. Using a perturbative approach with respect to the velocity-fi

W. A. Rodrigues, Dario S. Thober, Ademir L. Xavier

In this paper we present a theoretical analysis of an experiment by Mugnai and collaborators where superluminal behavior was observed in the propagation of microwaves. We suggest that what was observed can be well approximated by the motion of a superluminal X wave. Furthermore the experimental results are also explained by the so called scissor effect which

E. Arrigoni, A. P. Harju, W. Hanke, B. Brendel

We study the competition between long- and short-range interactions among charge carriers in strongly-correlated electronic systems employing a new method which combines the density-matrix renormalization-group technique with a self-consistent treatment of the long-range interactions. We apply the method to an extended t-J model which exhibits ``stripe'&

Michael J. Pfenning, Eric Poisson

We calculate the self-force experienced by a point scalar charge, a point electric charge, and a point mass moving in a weakly curved spacetime characterized by a time-independent Newtonian potential. The self-forces are calculated by first computing the retarded Green's functions for scalar, electromagnetic, and (linearized) gravitational fields in the

Yan Levin, Paulo S. Kuhn, Marcia C. Barbosa

A model of polar fluid is studied theoretically. The interaction potential, in addition to dipole-dipole term, possesses a dispersion contribution of the van der Waals-London form. It is found that when the dispersion force is comparable to dipole-dipole interaction, the fluid separates into coexisting liquid and gas phases. The calculated critical parameter

Yolanda Lozano

The analysis of the worldvolume effective actions of the M-theory Kaluza-Klein monopole and 9-brane suggests that it should be possible to describe non-abelian configurations of M2-branes or M5-branes if the M2-branes are transverse to the eleventh direction and the M5-branes are wrapped on it. This is determined by the fact that the Kaluza-Klein monopole an

A. Huebsch, J. Richter, C. Waidacher, K. W. Becker

We investigate the electron-energy loss spectrum of one-dimensional undoped CuO$_{3}$ chains within an extended multi-band Hubbard model and an extended one-band Hubbard model, using the standard Lanczos algorithm. Short-range intersite Coulomb interactions are explicitly included in these models, and long-range interactions are treated in random-phase appro

James P. Gregory, Simon F. Ross

A primary goal in holographic theories of gravity is to study the causal structure of spacetime from the field theory point of view. This is a particularly difficult problem when the spacetime has a non-trivial causal structure, such as a black hole. We attempt to study causality through the UV/IR relation between field theory and spacetime quantities, which

F. Szalma, W. Selke, S. Fischer

In the framework of SOS models, the dynamics of isolated and pairs of surface steps of monoatomic height is studied, for step--edge diffusion and for evaporation kinetics, using Monte Carlo techniques. In particular, various interesting crossover phenomena are identified. Simulational results are compared, especially, to those of continuum theories and rando

Etienne Blanchard

Given a Hausdorff compact space X, we study the C^*-(semi)-norms on the algebraic tensor product $A\otimes_{alg,C(X)} B$ of two C(X)-algebras A and B over C(X). In particular, if one of the two C(X)-algebras defines a continuous field of C^*-algebras over X, there exist minimal and maximal C^*-norms on $A\otimes_{alg,C(X)} B$ but there does not exist any C^*

P. Bialas, A. Morel, B. Petersson, K. Petrov

We present a numerical study of an SU(3) gauged 2D model for adjoint scalar fields, defined by dimensional reduction of pure gauge QCD in (2+1)D at high temperature. In the symmetric phase of its global Z_2 symmetry, two colourless boundstates, even and odd under Z_2, are identified. Their respective contributions (poles) in correlation functions of local co

T. Opatrny, D. -G. Welsch

We propose an optical double-cavity resonator whose response to a signal is similar to that of an Electromagnetically Induced Transparency (EIT) medium. A combination of such a device with a four-level EIT medium can serve for achieving large cross-Kerr modulation of a probe field by a signal field. This would offer the possibility of building a quantum logi

A. A. Penckwitt, R. J. Ballagh

We present a systematic classification of the elementary excitations of Bose-Einstein condensates in cylindrical traps in terms of their shapes. The classification generalizes the concept of families of excitations first identified by Hutchinson and Zaremba (1998) Phys. Rev. A 57 1280 by introducing a second classification number that allows all possible mod

Christos G. Tsagas

The vector nature of magnetic fields and the geometrical interpretation of gravity introduced by general relativity, guarantee a special coupling between magnetism and spacetime curvature. This magneto-geometrical interaction effectively transfers the tension properties of the field into the spacetime fabric, triggering a variety of effects with profound imp

C. Figueira de Morisson Faria, M. L. Du

Using a high-frequency field superposed to a linearly polarized bichromatic laser field composed by a wave with frequency $ω$ and a wave with frequency $2ω$, we show it is possible to enhance the intensity of a group of high harmonics in orders of magnitude. These harmonics have frequencies about 30% higher than the monochromatic-cutoff frequency, and, withi

Elias C. Vagenas

In the standard methodology for evaluating the Hawking radiation emanating from a black hole, the background geometry is fixed. Trying to be more realistic we consider a dynamical geometry for a two-dimensional charged black hole and we evaluate the Hawking radiation as tunneling process. This modification to the geometry gives rise to a nonthermal part in t

Cenalo Vaz, Louis Witten, T. P. Singh

LeMa\^ıtre-Tolman-Bondi models of spherical dust collapse have been used and continue to be used extensively to study various stellar collapse scenarios. It is by now well-known that these models lead to the formation of black holes and naked singularities from regular initial data. The final outcome of the collapse, particularly in the event of naked singul

A. K. Chaudhuri

In a hydrodynamic model, we have analysed the direct photon data obtained by the WA98 collaboration in 158 A GeV Pb+Pb collisions at CERN SPS. The transverse expansion of the system was taken into account. Two scenarios (i) formation of quark-gluon plasma and (ii) formation of hot hadronic gas were considered. Equally well description to the data were obtain

Jian-Xin Zhu, C. S. Ting

The local quasiparticle density of states around a unitary impurity with a Kondo-like magnetic moment induced at its nearest neighbors in a d-wave superconductor is studied within the slave-boson mean-field approach. The Hamiltonian is exactly diagonalized and the results are obtained self-consistently. We show that the interference between the strong impuri

Nicos Pelavas, Nicholas Neary, Kayll Lake

This paper explores properties of the instantaneous ergo surface of a Kerr black hole. The surface area is evaluated in closed form. In terms of the mass ($m$) and angular velocity ($a$), to second order in $a$, the area of the ergo surface is given by $16 πm^2 + 4 πa^2$ (compared to the familiar $16 πm^2 - 4 πa^2$ for the event horizon). Whereas the total c

Edmond L. Berger, B. W. Harris, Z. Sullivan

We study the s-channel production of a single top squark in hadron collisions through an R-parity-violating mechanism, examining in detail the case in which the squark decays through an R-parity-conserving process into a bottom quark, a lepton, and missing energy. We show that the top squark can be discovered if its mass is less than 400 GeV, or that the cur

Stephen E. Vance

The microscopic origin of the strangeness enhancements observed in PbPb collisions at the SPS is studied by testing the effects of three mechanisms. First, the junction processes found in the HIJING/BBbar event generator are reviewed showing that they can account for only part of the observed hyperon enhancements. Second, the efficient final state chemical c

Massimo Ricotti, Nickolay Y. Gnedin, J. Michael Shull

We use one-dimensional radiative transfer simulations to study the evolution of H_2 gas-phase (H^- catalyzed) formation and photo-dissociation regions in the primordial universe. We find a new positive feedback mechanism capable of producing shells of H_2 in the intergalactic medium, which are optically thick in some Lyman-Werner bands. While these shells ex

John R. Klauder

Reparametrization invariant theories have a vanishing Hamiltonian and enforce their dynamics through a constraint. We specifically choose the Dirac procedure of quantization before the introduction of constraints. Consequently, for field theories, and prior to the introduction of any constraints, it is argued that the original field operator representation s

S. N. Molotkov, S. S. Nazin

The relativistic quantum protocols realizing the bit commitment and distant coin tossing schemes are proposed. The protocols are based on the fact that the non-stationary orthogonal extended quantum states cannot be reliably distinguished if they are not fully accessible for the measurement. As the states propagate from the domain controlled by one of the us

Koenraad Audenaert, Frank Verstraete, Tijl De Bie, Bart De Moor

We consider two measures of entanglement of mixed bipartite states of dimension 2X2: concurrence and negativity. We first prove the conjecture of Eisert and Plenio that concurrence can never be smaller than negativity. We then characterise all states for which concurrence equals negativity and also those states for which the difference between concurrence an

D. A. Trifonov

Characteristic uncertainty relations and their related squeezed states are briefly reviewed and compared in accordance with the generalizations of three equivalent definitions of the canonical coherent states. The standard SU(1,1) coherent states are shown to be the unique states that minimize the Schroedinger uncertainty relation for every pair of the three

E. L. Afraimovich, O. S. Lesyuta, I. I. Ushakov

We have investigated a dependence of the relative density of phase slips in the GPS navigation system on the disturbance level of the Earth's magnetosphere. The study is based on using Internet-available selected data from the global GPS network, with the simultaneously handled number of receiving stations ranging from 160 to 323. The analysis used four

Martin J. Savage, Barry R. Holstein

The Electromagnetic and Hadronic Physics sub-community of nuclear physics held a town hall meeting at Jefferson Lab during November 30 to December 4 of 2000. This is is our combined contribution to the white paper that will result from this meeting.

T. Siiskonen, M. Hjorth-Jensen, J. Suhonen

The renormalization of the weak charge-changing hadronic current as a function of the reaction energy release is studied at the nucleonic level. We have calculated the average quenching factors for each type of current (vector, axial vector and induced pseudoscalar). The obtained quenching in the axial vector part is, at zero momentum transfer, 19% for the s

C. A. Bertulani

The lowest-order correction of the density dependence of in-medium nucleon-nucleon cross sections is obtained from geometrical considerations of Pauli-blocking effects. As a by-product, it is shown that the medium corrections imply an 1/E energy dependence of the density-dependent term.

WA98 Collaboration, M. M. Aggarwal, A. Agnihotri, Z. Ahammed

First results on the measurement of localized fluctuations in the multiplicity of charged particles and photons produced in central 158 A GeV Pb+Pb collisions are presented. The charged versus neutral correlations in common phase space regions of varying azimuthal size are analyzed by two different methods. The measured results are compared to those from sim

C. Quesne

We consider the problem of bosonizing supersymmetric quantum mechanics (SSQM) and some of its variants, i.e., of realizing them in terms of only boson-like operators without fermion-like ones. In the SSQM case, this is realized in terms of the generators of the Calogero-Vasiliev algebra (also termed deformed Heisenberg algebra with reflection). In that of th

Diego L. Rapoport

We integrate in closed implicit form the Navier-Stokes equations for an incompressible fluid and the kinematical dynamo equation, in smooth manifolds and Euclidean space. This integration is carried out by applying Stochastic Differential Geometry, i.e. the gauge-theoretical formulation of Brownian motions. Non-Riemannian geometries with torsion of the trace

Etienne Blanchard

We extend in this paper the characterisation of a separable nuclear \cst-algebra given by Kirchberg proving that given a unital separable continuous field of nuclear C*-algebras A over a compact metrizable space X, the C(X)-algebra A is isomorphic to a unital C(X)-subalgebra of the trivial continuous field C(X;O_2), image of C(X;O_2) by a norm one projection

Etienne Blanchard

We extend in this paper several results of E. Kirchberg, S. Wassermann and the author dealing with continuous fields of C*--algebras to the semi-continuous case. We provide a new characterisation of separable lower semi-continuity C*--bundles and we present exactness criteria for C(X)-algebras and unital bisimplifiable Hopf \cst-algebras.

Ilse Fischer

Consider the probability that an arbitrary chosen lozenge tiling of the hexagon with side lengths a, b, c, a, b, c contains the horizontal lozenge with lowest vertex (x,y) as if it described the distribution of mass in the plane. We compute the horizontal and the vertical moments of inertia with respect to this distribution. This solves a problem by Propp [1

R. Dehy, R. Yu

Using polytopes defined in an earlier paper, we show in this paper the existence of degenerations of a large class of Schubert varieties of SL_n to toric varieties by extending the method used by Gonciulea and Lakshmibai for a minuscule G/P to Schubert varieties in SL_n

Hubert Flenner, Mikhail Zaidenberg

For a normal subvariety $V$ of ${\bf C}^n$ with a good ${\bf C}^*$-action we give a simple characterization for when it has only log canonical, log terminal or rational singularities. Moreover we are able to give formulas for the plurigenera of isolated singular points of such varieties and of the logarithmic Kodaira dimension of $V\backslash \{0\}$. For thi

Ivelina Bobtcheva

Given a semisimple stable autonomous tensor category over a field $K$, to any group presentation with finite number of generators we associate an element $Q(P)\in K$ invariant under the Andrews-Curtis moves. We show that in fact, this is the same invariant as the one produced by the algorithm of Frank Quinn. The new definition allows us to present a relative

Jan Adriaenssens, Raf Bocklandt, Geert Van de Weyer

Semisimple representations of the free product Z_p*Z_q determine θ-semistable representations of a specific quiver Q_pq. The dimension vectors of θ-stable representations of this quiver were classified by Le Bruyn and Adriaenssens. In this paper we classify the moduli spaces M_α^ss(Q_pq,θ) which are smooth projective varieties.

Birge Huisgen-Zimmermann, Manuel Saorin

The two main theorems proved here are as follows: If $A$ is a finite dimensional algebra over an algebraically closed field, the identity component of the algebraic group of outer automorphisms of $A$ is invariant under derived equivalence. This invariance is obtained as a consequence of the following generalization of a result of Voigt. Namely, given an app

Franco Ferrari

On plane algebraic curves the so-called Weierstrass kernel plays the same role of the Cauchy kernel on the complex plane. A straightforward prescription to construct the Weierstrass kernel is known since one century. How can it be extended to the case of more general curves obtained from the intersection of hypersurfaces in a $n$ dimensional complex space? T

A. Dimca

We describe a new relation between the topology of hypersurface complements, Milnor fibers and degree of gradient mappings. The main tools are polar curves and the affine Lefschetz theory developped by H. Hamm and A. Némethi. In the special case of the hyperplane arrangements, we strengthen some results due to Orlik and Terao (see Math. Ann. 301(1995)) and o

Troels Harmark

This is a short review of the newly discovered ODp-theories that are non-gravitational six-dimensional theories defined as the decoupling limit of NS5-branes in the presence of a near-critical (p+1)-form RR fields. We discuss the motivation for these new theories, their definitions and properties, and their relation to NCOS theory, OM theory and Little Strin

M. M. Deminov, A. A. Slavnov

It is shown that a simple modification of the dimensional regularization allows to compute in a consistent and gauge invariant way any diagram with less than four loops in the SO(10) unified model. The method applies also to the Standard Model generated by the symmetry breaking $SO(10) \to SU(3)\times SU(2)\times U(1)$. A gauge invariant regularization for a

S. Sinha, C. Vafa

We study the large N limit of SO(N) and Sp(N) Chern-Simons gauge theory on S^3 and identify its closed string dual as topological strings on an orientifold of the small resolution of the conifold. Applications to large N dualities for N=1 supersymmetric gauge systems in 4 dimensions are also discussed.

L. K. Hoevenaars, P. H. M. Kersten, R. Martini

An associative algebra of holomorphic differential forms is constructed associated with pure N=2 Super-Yang-Mills theory for the Lie algebra F4. Existence and associativity of this algebra, combined with the general arguments in the work of Marshakov, Mironov and Morozov, proves that the prepotential of this theory satisfies the generalized WDVV system.

Hideo Kodama

In this paper we present a gauge-invariant formalism for perturbations of the brane-world model developed by the author, A. Ishibashi and O. Seto recently, and analyze the behavior of cosmological perturbations in a spatially flat expanding universe realized as a boundary 3-brane in AdS$^5$ in terms of this formalism. For simplicity we restrict arguments to

C. Bagnuls, C. Bervillier

The obtention (up to five or six loop orders) of nonasymptotic critical behavior, above and below Tc, from the field theoretical framework is presented and discussed.

Detlev Buchholz, Jens Mund, Stephen J. Summers

A novel method of transplanting algebras of observables from de Sitter space to a large class of Robertson-Walker space-times is exhibited. It allows one to establish the existence of an abundance of local nets on these spaces which comply with a recently proposed condition of geometric modular action. The corresponding modular symmetry groups appearing in t

Matthias Neubert

These notes provide a pedagogical introduction to the theory of non-leptonic heavy-meson decays recently proposed by Beneke, Buchalla, Sachrajda and myself. We provide a rigorous basis for factorization for a large class of non-leptonic two-body B-meson decays in the heavy-quark limit. The resulting factorization formula incorporates elements of the naive fa

S. Khalil, E. Torrente-Lujan

We present a review of the present status of the problem of neutrino masses and mixing including a survey of theoretical motivations and models, experimental searches and implications of recently appeared solar and atmospheric neutrino data, which strongly indicate nonzero neutrino masses and mixing angles.

Heather E. Logan

We study the prospects for distinguishing the CP-even Higgs boson of the minimal supersymmetric extension of the Standard Model (MSSM) from the Standard Model (SM) Higgs boson by measuring its branching ratios at an e+e- linear collider. The regions of the M_A - tan beta plane in which an MSSM Higgs boson can be distinguished from the SM Higgs boson depend s

Lynne H. Orr, W. J. Stirling

Virtual photon scattering in $e^+e^-$ collisions can result in events with the electron-positron pair at large rapidity separation with hadronic activity in between. The BFKL equation resums large logarithms that dominate the cross section for this process. We report here on a Monte Carlo method for solving the BFKL equation that allows kinematic constraints

Cosmin Macesanu, Lynne H. Orr

We present the results of an exact calculation of gluon radiation in top production and decay at high energy electron-positron colliders. We include all spin correlations and interferences, the bottom quark mass, and finite top width effects in the matrix element calculation. We study properties of the radiated gluons and implications for top mass measuremen

John F. Gunion

The manner in which the parameters of a two-Higgs-doublet model can be chosen so that no Higgs boson is discovered at a $\sqrt{s}\leq 800\gev$ $\epem$ collider, while maintaining consistency with current precision electroweak measurements, is described. The importance of a Giga-$Z$ factory and higher collider energies for such a scenario is emphasized.

Lynne H. Orr, W. J. Stirling

Virtual photon scattering in $e^+e^-$ collisions can result in events with the electron-positron pair produced at large rapidity separation in association with hadrons. The BFKL equation resums large logarithms that dominate the cross section for this process. After a brief overview of analytic BFKL resummation and its experimental status, we report on a Mon

Michael Melles

At energies much larger than the mass of the weak gauge bosons, electroweak radiative corrections can lead to significant corrections. At 1 TeV the one loop corrections can be of ${\cal O} (20 %)$ due to large contributions of the Sudakov type. We summarize recent progress in the evaluation and resummation of the double and single logarithmic corrections to

Michael Melles

For a Higgs boson below the $W^\pm$ threshold, the $γγ$ collider option of a future linear $e^+ e^-$ machine is compelling. In this case one can measure the ``gold-plated'' loop induced $Γ(H \longrightarrow γγ)$ partial width to high precision, testing various extensions of the Standard Model. With recent progress in the expected $γγ$ luminosity at T

Silvano Simula

We comment on the papers "Nucleon elastic form factors and local duality" [Phys. Rev. {\bf D62}, 073008 (2000)] and "Experimental verification of quark-hadron duality" [Phys. Rev. Lett. {\bf 85}, 1186 (2000)]. Our main comment is that the reconstruction of the proton magnetic form factor, claimed to be obtained from the inelastic scaling curv

S. Ambrosanio, B. Mele, A. Nisati, S. Petrarca

We draw a possible scenario for the observation of massive long-lived charged particles at the LHC detector ATLAS. The required flexibility of the detector triggers and of the identification and reconstruction systems are discussed. As an example, we focus on the measurement of the mass and lifetime of long-lived charged sleptons predicted in the framework o

T. Binoth, J. Ph. Guillet, E. Pilon, M. Werlen

We discuss effects induced by beyond leading order contributions to photon pair production. We point out that next to leading order contributions to the fragmentation component of the signal lead to a change in the shape of distributions. This is already mildly visible in present Tevatron data though stringent isolation criteria tend to suppress the fragment

Francesca Rosati

The issue of Supersymmetry breaking in the context of Supergravity models of Quintessence is discussed.

J. Fleischer, M. Tentyukov

New developments concerning the extension of the recently introduced Feynman diagram analyser DIANA are presented.

Torbjörn Sjöstrand

Recent improvements in the PYTHIA event generator are summarized: new hard subprocesses, gamma*-gamma* physics, QCD final-state showers, and more.

Torbjörn Sjöstrand

An algorithm for an improved description of final-state QCD radiation is introduced. It is matched to the first-order matrix elements for gluon emission in a host of decays, for processes within the Standard Model and the Minimal Supersymmetric extension thereof.

Tatsu Takeuchi, Lay Nam Chang, Oleg Lebedev, Will Loinaz

We consider a model with extra compact dimensions in which only gravity exists in the 4+n dimensional bulk. If the gravitational connection is not assumed to be symmetric, that is, unless torsion is artificially set to zero, then a universal contact interaction among the fermions on the 4-dimensional wall is induced. Using a global fit to Z-pole observables,

Torbjörn Sjöstrand

A `complete' framework for gamma-gamma / gamma*-gamma / gamma*-gamma* interactions is presented. The emphasis is on providing a model for gamma-gamma physics at all photon virtualities, including the difficult transition region around the rho meson mass.

Yi Jiang, Wen-Gan Ma, Liang Han, Hong-Sheng Hou

The CP-violating effects to the subprocess $gg\to H^+H^-$ is studied in the mSUGRA scenario at the CERN LHC, by taking into account the experimental bounds of electron and neutron EDM's. The CP violation effects in this process are related to the complex phases of $μ$ and $A_{f}$ in the mSUGRA scenario. In our calculation we consider small CP phases of $

Hiroshi Igarashi, Kiyoshi Okuyama, Hiroshi Suzuki

We correct some intermediate expressions and arguments in hep-lat/0002009 (Nucl. Phys. B 585 (2000) 471--513). The main results do not change. We also mention some additional observations, including a constraint on a coefficient of the possible nontrivial anomaly which was not given in the paper.

D. J. Mangeol

The charged-particle multiplicity distribution and its moments have been measured, for all hadronic as well as for light-quark and b-quark events in e+e- collisions at the Z mass. The Hq moments derived from the charged-particle multiplicity distribution are known to exhibit quasi-oscillations when plotted versus the order of the moment. This behavior is pre

D. V. Bandourin, V. F. Konoplianikov, N. B. Skachkov

In this paper the study of &#34;photon+Jet&#34; events is continued, aimed at jet energy scale setting and hadron calorimeter calibration at LHC energies. The event number distribution over Pt and pseudorapidity eta in the barrel region of the photon is presented. The features of &#34;photon+Jet&#34; events in CMS detector |eta|<1.4 are exposed. Pt structure

Jose M. Martin-Garcia, Carsten Gundlach

In Paper I in this series we constructed evolution equations for the complete gauge-invariant linear perturbations of a time-dependent spherically symmetric perfect fluid spacetime. A key application of this formalism is the interior of a collapsing star. Here we derive boundary conditions at the surface of the star, matching the interior perturbations to th

J. Makela, P. Repo, M. Luomajoki, J. Piilonen

We consider a Hamiltonian quantum theory of stationary spacetimes containing a Kerr-Newman black hole. The physical phase space of such spacetimes is just six-dimensional, and it is spanned by the mass $M$, the electric charge $Q$ and angular momentum $J$ of the hole, together with the corresponding canonical momenta. In this six-dimensional phase space we p

N. Straumann

There are documents which show that Wolfgang Pauli developed in 1953 the first consistent generalization of the five-dimensional theory of Kaluza, Klein, Fock and others to a higher dimensional internal space. Because he saw no way to give masses to the gauge bosons, he refrained from publishing his results formally.

P. Fiziev

We consider: minimal scalar-tensor model of gravity with Brans-Dicke factor $ω(Φ)\equiv 0$ and cosmological factor $Π(Φ)$; restrictions on it from gravitational experiments; qualitative analysis of new approach to cosmological constant problem based on the huge amount of action in Universe; determination of $Π(Φ)$ using time evolution of scale factor of Univ

Krzysztof R. Apt

Constraint propagation algorithms form an important part of most of the constraint programming systems. We provide here a simple, yet very general framework that allows us to explain several constraint propagation algorithms in a systematic way. In this framework we proceed in two steps. First, we introduce a generic iteration algorithm on partial orderings

V. L. Pokrovsky, N. A. Sinitsyn

During the adiabatic time evolution levels crossing violates the adiabaticity and makes transitions between levels possible. Conventionally only two energy levels cross simultaneously. The transition probabilities for this case were found by Landau and Zener. However, the multilevel crossing happens systematically rather than occasionally if the Hamiltonian

Alejandro D. Sanchez, Jorge A. Revelli, Horacio S. Wio

We present a simple one-dimensional trapping model prompted by the problem of ion current across biological membranes. The trap is modeled mimicking the ionic channel membrane behaviour. Such voltage-sensitive channels are open or closed depending on the value taken by a potential. Here we have assumed that the external potential has two contributions: a det

Steve Allen

In this thesis, I present a non-perturbative approach to the single-band attractive Hubard model which is an extension of previous work by Vilk and Tremblay on the repulsive model. Exact results are derived in the general context of functional derivative approaches to many-body theories. The first step of the approximation is based on a local field type ansa

Daniel R. Spiegel, Alexis L. Thompson, Wesley C. Campbell

We have employed forced Rayleigh scattering (FRS) to study the diffusion of an azo tracer molecule (methyl red) through a nematic liquid crystal (5CB). This system was first investigated in an important study by Hara et al. (Japan. J. Appl. Phys. 23, 1420 [1984]). Since that time, it has become clear that the presence of complementary ground-state and photop

Konstantin Yu. Guslienko, Konstantin L. Metlov

The energy of a displaced magnetic vortex in a cylindrical particle made of isotropic ferromagnetic material (magnetic dot) is calculated taking into account the magnetic dipolar and the exchange interactions. Under the simplifying assumption of small dot thickness the closed-form expressions for the dot energy is written in a non-perturbative way as a funct

Wei Bao, A H Lacerda, J D Thompson, J M Honig

The effect of a magnetic field on the two long-range-ordered magnetic phases, the collinear insulating antiferromagnetic (AFI) and the incommensurate metallic transverse spin density wave (SDW), is investigated for the vanadium sesquioxide system. A field of 18 T has little effect on the AFI phase of a nominal V2O3 sample. The transverse SDW phase of V1.96O3

Cristian Micheletti, Flavio Seno, Jayanth Banavar, Amos Maritan

The prediction of the three-dimensional structures of the native state of proteins from the sequences of their amino acids is one of the most important challenges in molecular biology. An essential ingredient to solve this problem within coarse-grained models is the task of deducing effective interaction potentials between the amino acids. Over the years sev

J. S. Brooks, L. Balicas, K. Storr, B. H. Ward

Two organic conducting materials, where unusual aspects of their composition play important roles, are explored: beta&#39;&#39;-(BEDT-TTF)2SF5XSO3 which exhibits superconductivity, or a metal-insulator transition (for X=CH2CF2 or CHF respectively), and tau-(P-S, S -DMEDT-TTF)2 (AuBr2) (AuBr2)y which exhibits a large, hysteretic, negative magnetoresistance. D

Daniel S. Fisher, Pierre Le Doussal, Cecile Monthus

Non-equilibrium dynamics of classical random Ising spin chains are studied using asymptotically exact real space renormalization group. Specifically the random field Ising model with and without an applied field (and the Ising spin glass (SG) in a field), in the universal regime of a large Imry Ma length so that coarsening of domains after a quench occurs ov