November 2001 arXiv papers — page 3

C. Grimaldi

It is shown how the resonant states induced by a single spinless impurity in a d-wave superconductor evolve under the effect of an applied Zeeman magnetic field. Moreover, it is demonstrated that the spin-orbit coupling to the impurity potential can have important and characteristic effects on the resonant states and their response to the Zeeman field, espec

Makoto Ambai, Yoshiaki Kobayashi, Satoshi Iikubo, Masatoshi Sato

Transport and Cu-NQR studies have been carried out for the T*-type high temperature superconducting Cu oxide Nd1.6-xCexSr0.4CuO4 with single layered CuO2 planes formed by CuO5 pyramids. No anomaly related to the static or quasi static "stripe" order has been observed in the temperature T and x dependence of the thermoelectric powers S. We have not fo

Benjamin Grinstein, Zoltan Ligeti

We calculate heavy quark symmetry breaking in the slopes and curvatures of the $B\to D^{(*)}\ell\barν$ spectra at zero recoil, including the order $α_s^2β_0$ corrections. We point out that the theoretical uncertainties in the differences between $B\to D$ and $B\to D^*$ slopes and curvatures are smaller than in the deviations of the slopes and curvatures them

Stanley J. Brodsky, Victor S. Fadin, Victor T. Kim, Lev N. Lipatov

The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order (NLO) in QCD, is presented. The NLO BFKL predictions, improved by the BLM optimal scale setting, are in excellent agreement with recent OPAL and L3 data at CERN LEP2.

Andras Nemethi, Liviu I Nicolaescu

We formulate a very general conjecture relating the analytical invariants of a normal surface singularity to the Seiberg-Witten invariants of its link provided that the link is a rational homology sphere. As supporting evidence, we establish its validity for a large class of singularities: some rational and minimally elliptic (including the cyclic quotient a

G. A. Luna-Acosta, J. A. Méndez-Bermúdez, F. M. Izrailev

We investigate the classical-quantum correspondence for particle motion in a superlattice in the form of a 2D channel with periodic modulated boundaries. Its classical dynamics undergoes the generic transition to chaos of Hamiltonian systems as the amplitude of the modulation is increased. We show that for strong chaotic motion, the classical counterpart of

D. H. Hughes, I. Aretxaga, E. L. Chapin, E. Gaztanaga

Future extragalactic sub-millimetre and millimetre surveys have the potential to provide a sensitive census of the level of obscured star formation in galaxies at all redshifts. While in general there is good agreement between the source counts from existing SCUBA (850um) and MAMBO (1.25mm) surveys of different depths and areas, it remains difficult to deter

A. Yu. Khrennikov, Ya. I. Volovich

We consider a classical analogue of the well known quantum two-slit experiment. Charged particles are scattered on flat screen with two slits and hit the second screen. We show that the probability distribution on the second screen when both slits are open is not given by the sum of distributions for each slit separately, but has an extra interference term t

Christof Wunderlich

Internal states of different ions in an electrodynamic trap are coupled when a static magnetic field is applied -- analogous to spin-spin coupling in molecules used for NMR. This spin-spin interaction can be used, for example, to implement quantum logic operations in ion traps using NMR methods. The collection of trapped ions can be viewed as a $N$-qubit mol

S. J. van Enk, Christopher A. Fuchs

Optical implementations of quantum communication protocols typically involve laser fields. However, the standard description of the quantum state of a laser field is surprisingly insufficient to understand the quantum nature of such implementations. In this paper, we give a quantum information-theoretic description of a propagating continuous-wave laser fiel

Adam J. Makowski, Michal Frackowiak

The simplest non-trivial model of chaotic Bohmian dynamics is identified. We argue that its most important features can be observed in more complex models, above all, the presumable mechanism of the appearance of chaos in the Bohmian-type dynamical systems.

Philippe Grangier

In a previous preprint (quant-ph/0012122) we introduced a ``contextual objectivity" formulation of quantum mechanics (QM). A central feature of this approach is to define the quantum state in physical rather than in mathematical terms, in such a way that it may be given an "objective reality". Here we use some ideas about the system dimensionalit

A. Drago, A. Argan, M. Serio

Transverse feedback systems for controlling the vertical coupled-bunch instabilities in the positron and electron main rings are installed at DAFNE. They started to be operative respectively from June and September 2000. For the horizontal plane, similar systems have been installed in summer 2001 with less kicker power. Design specifications and the basic sy

M. C. Rodriguez

Foi com base neste estudo que fizemos a construção da versão supersimétrica dos modelos de simetria $SU(3)_{C} \otimes SU(3)_{L} \otimes U(1)_{N}$ \cite{susy331}, apresentado no final da minha tese de doutorado \cite{mcr1}. Bem como dos estudos fenomenológicos subsequente \cite{mcr}.

A. Eriksson, B. Haubold, B. Mehlig

Random models of evolution are instrumental in extracting rates of microscopic evolutionary mechanisms from empirical observations on genetic variation in genome sequences. In this context it is necessary to know the statistical properties of empirical observables (such as the local homozygosity for instance). Previous work relies on numerical results or ass

Marcelo O. Magnasco

The tuning curve of the cochlea measures how large an input is required to elicit a given output level as a function of the frequency. It is a fundamental object of auditory theory, for it summarizes how to infer what a sound was on the basis of the cochlear output. A simple model is presented showing that only two elements are sufficient for establishing th

J. Morris, T. D'Ottavio

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven has completed nearly two years of successful commissioning and operation. The control system is briefly reviewed and its contribution to the RHIC effort is analyzed, with emphasis on special challenges and innovative design: continuing efforts are also discussed.

P. K. Panda, F. L. Braghin

We derive the equation of state of nuclear matter including vacuum polarization effects arising from the nucleons and the sigma mesons in the quark-meson coupling model which incorporates explicitly quark degrees of freedom with quark coupled to the scalar and vector mesons. This leads to a softer equation of state for nuclear matter giving a lower value of

A. S. Rinat, M. F. Taragin

We exploit a relationship between the Structure Functions of nucleons, the physical deuteron and of a deuteron, composed of point-nucleons to compute angular distributions of inclusive cross sections of 4.05 GeV electrons. We report general agreement with data and interpret the remaining discrepancies. We discuss the potential of the data for information on

S. Muroya, A. Nakamura, C. Nonaka

We investigate high density state of SU(2) QCD by using Lattice QCD simulation with Wilson fermions. The ratio of fermion determinants is evaluated at each step of the Metropol is link update by Woodbury formula. At $β=0.7$, and $κ= 0.150$, we calculate the baryon number density, the Polyakov lines, and the energy density of gluon sector with chemical potent

TRIUMF Munoic Hydrogen Collaboration, M. C. Fujiwara, A. Adamczak, J. M. Bailey

Resonant scattering of muonic hydrogen atoms via back decay of molecular complex, a key process in the understanding of epithermal muonic molecular formation, is analyzed. The limitations of the effective rate approximation are discussed and the importance of the explicit treatment of the back decay is stressed. An expression of the energy distribution for t

G. Boffetta, A. Celani, S. Musacchio, M. Vergassola

We study the statistics of the vorticity field in two-dimensional Navier-Stokes turbulence with a linear Ekman friction. We show that the small-scale vorticity fluctuations are intermittent, as conjectured by Nam et al. [Phys. Rev. Lett. vol.84 (2000) 5134]. The small-scale statistics of vorticity fluctuations coincides with the one of a passive scalar with

Debabrata Biswas

We propose a method of measuring approximate quantum eigenfunctions in polygonalized billiard geometries, based on a quasiclassical evolution operator having a (smoothened) Perron-Frobenius kernel modulated by a phase arising from quantum considerations. We show that quasiclassical evolution differs from semiclassical (or quantum) evolution but the operators

M. Disertori, H. Pinson, T. Spencer

By applying the supersymmetric approach we rigorously prove smoothness of the averaged density of states for a three dimensional random band matrix ensemble, in the limit of infinite volume and fixed band width. We also prove that the resulting expression for the density of states coincides with the Wigner semicircle with a precision $1/W^2$, for $W$ large b

Steven Kleiman, Ragni Piene

We enumerate the singular algebraic curves in a complete linear system on a smooth projective surface. The system must be suitably ample in a rather precise sense. The curves may have up to eight nodes, or a triple point of a given type and up to three nodes. The curves must also pass through appropriately many general points. The number of curves is given b

Howard Kleiman

We use admissible permutations and a variant of the Floyd-Warshall algorithm to obtain an optimal solution to the Assignment Problem. Using another variant of the F-W algorithm, we obtain an approximate solution to the Traveling Salesman Problem. We also give a sufficient condition for the approximate solution to be an optimal solution.

C. Briot, E. Ragoucy

Starting with the superYangian Y(M|N) based on gl(M|N), we define twisted superYangians Y^+(M|N) and Y^-(M|N). Only Y^+(M|2n) and Y^-(2m|N) can be defined, and appear to be isomorphic one with each other. We study their finite-dimensional irreducible highest weight representations.

I. Yu. Fedorov

Divisors with minimal discrepancy over cA points are classified

Jonathan Brundan, Alexander Kleshchev

We compute the determinant of the Gram matrix of the Shapovalov form on weight spaces of the basic representation of an affine Kac-Moody algebra of ADE type (possibly twisted). As a consequence, we obtain explicit formulae for the determinants of the Cartan matrices of $p$-blocks of the symmetric group and its double cover, and of the associated Hecke algebr

Massimo Campanino, Dimitri Petritis

Simple random walks on various types of partially horizontally oriented regular lattices are considered. The horizontal orientations of the lattices can be of various types (deterministic or random) and depending on the nature of the orientation the asymptotic behaviour of the random walk is shown to be recurrent or transient. In particular, for randomly hor

S. A. Kudryavtsev

The first examples of exceptional terminal singularities are constructed.

Patricia Hersh, Isabella Novik

We verify the Upper Bound Conjecture (UBC) for a class of odd-dimensional simplicial complexes that in particular includes all Eulerian simplicial complexes with isolated singularities. The proof relies on a new invariant of simplicial complexes -- a short simplicial h-vector.

Juergen Eichhorn

The set of Clifford bundles of bounded geometry over open manifolds can be endowed with a metrizable uniform structure. For one fixed bundle $E$ we define the generalized component $\gencomp (E)$ as the set of Clifford bundles $E'$ which have finite distance to $E$. If $D$, $D'$ are the associated generalized Dirac operators, we prove for the pair $(

Nguyen Van Chau

We present a list of all polynomial dominanting maps of the complex plane with branched value curve isomorphic to the complex line, up to polynomial automorphisms.

S. Kleiman, R. Piene

We continue the development of methods for enumerating nodal curves on smooth complex surfaces, stressing the range of validity. We illustrate the new methods in three important examples. First, for up to eight nodes, we confirm Göttsche's conjecture about plane curves of low degree. Second, we justify Vainsencher's enumeration of irreducible six-nod

Andrew Mathas

We compute the generic degrees of the Ariki--Koike algebras by first constructing a basis of matrix units in the semisimple case. As a consequence, we also obtain an explicit isomorphism from any semisimple Ariki--Koike algebra to the group algebra of the corresponding complex reflection group.

Tomasz Maszczyk, Andrzej Weber

Let $g$ be a reductive Lie algebra over a field of characteristic zero. Suppose $g$ acts on a complex of vector spaces $M$ by $i_λ$ and $L_λ$, which satisfy the identities as contraction and Lie derivative do for smooth differential forms. Out of this data one defines cohomology of the invariants and equivariant cohomology of $M$. We establish Koszul duality

Alexandru Dimca, Morihiko Saito

We show that for a polynomial map, the size of the Jordan blocks for the eigenvalue 1 of the monodromy at infinity is bounded by the multiplicity of the reduced divisor at infinity of a good compactification of a general fiber. The existence of such Jordan blocks is related to global invariant cycles of the graded pieces of the weight filtration. These imply

Leonardo Rastelli, Ashoke Sen, Barton Zwiebach

The spectrum of the infinite dimensional Neumann matrices M^{11}, M^{12} and M^{21} in the oscillator construction of the three-string vertex determines key properties of the star product and of wedge and sliver states. We study the spectrum of eigenvalues and eigenvectors of these matrices using the derivation K_1 = L_1 + L_{-1} of the star algebra, which d

Nick E. Mavromatos

`Old' String Theory is a theory of one-dimensional extended objects, whose vibrations correspond to excitations of various target-space field modes including gravity. In these lectures I will give an introduction to low-energy Effective Target-Space Actions derived from conformal invariance conditions of the underlying sigma models in string theory, disc

C. P. Constantinidis, F. Gieres, O. Piguet, M. S. Sarandy

The perturbative finiteness of various topological models (e.g. BF models) has its origin in an extra symmetry of the gauge-fixed action, the so-called vector supersymmetry. Since an invariance of this type also exists for gravity and since gravity is closely related to certain BF models, vector supersymmetry should also be useful for tackling various aspect

N. Emmenegger

In the present work the gauge invariance of causal Yang-Mills theory will be proven with the aid of the gauge-factor group. For that purpose it must be shown, that the operator valued distributions T_n and D_n(ret) occurring in the causal S-matrix construction can be written, after applying the gauge variation d_Q, as a divergence. Since merely local terms l

Vyacheslav A. Soroka

In this report I wish to recall how the basic concepts and ingredients of supergravity were formulated by Dmitrij V. Volkov and the present author in 1973-74 under the first investigation of the super-Higgs effect .

Oleg Yu. Shvedov

Correspondence between BRST-BFV, Dirac and refined algebraic (group averaging, projection operator) approaches to quantize constrained systems is analyzed. For the closed-algebra case, it is shown that the component of the BFV wave function with maximal (minimal) number of ghosts and antighosts in the Schrodinger representation may be viewed as a wave functi

I. Antoniadis, E. Kiritsis, T. Tomaras

The minimal embedding of the Standard Model in type I string theory is described. The SU(3) color and SU(2) weak interactions arise from two different collections of branes. The correct prediction of the weak angle is obtained for a string scale of 6-8 TeV. Two Higgs doublets are necessary and proton stability is guaranteed. It predicts two massive vector bo

V. Bozza, M. Gasperini, G. Veneziano

We derive and solve the full set of scalar perturbation equations for a class of five-dimensional brane--world solutions, with a dilaton scalar field coupled to the bulk cosmological constant and to a 3-brane. The spectrum contains one localized massless scalar mode, to be interpreted as an effective dilaton on the brane, inducing long--range scalar interact

Jane H. MacGibbon, Ubi F. Wichoski

The intrinsic tau neutrino flux from cosmological and astrophysical sources has usually been considered negligible in comparison to the electron and muon neutrino fluxes. However, the inclusion of the tau neutrino component coming from hadronic decay at the source can significantly modify the tau neutrino spectrum expected at Earth. We report our results on

S. D. Ellis, J. Huston, M. Toennesmann

We discuss recent progress in understanding the issues essential to the development of better cone jet algorithms.

Bodo Geyer, Markus Lazar, Dieter Robaschik

The decomposition of nonlocal operators (and of their matrix elements) into an (infinite) series w.r.t. geometric twist is used to introduce (new) parton distributions, generalized parton distributions and hadron wave functions of definite twist. Their comparision with the conventional distributions (of definite dynamical twist) leads to Wandzura-Wilczek lik

A. Freitas, D. J. Miller

Accurate theoretical calculations of slepton pair production processes at threshold are necessary for an accurate determination of slepton masses. We discuss the gauge invariant calculation of these processes for selectron and smuon pairs, including finite width effects and Coulomb corrections. Energy cuts to reduce irreducible supersymmetric backgrounds are

SÉRGIO RAMOS

The J/$ψ$ production in 158 A GeV Pb-Pb interactions is studied, in the dimuon decay channel, as a function of centrality, as measured with the electromagnetic or with the very forward calorimeters. After a first sharp variation at mid centrality, both patterns continue to fall down and exhibit a curvature change at high centrality values. This trend exclude

K. Fialkowski, R. Wit

Recent results on modelling Bose-Einstein effect in Monte Carlo generators for a source with no spherical symmetry (as seen in the data on $Z^0$ hadronic decays) are reported. Modifications of the weight method necessary for $W^+W^-$ decays are presented and some preliminary results concerning the "inter-$W$" interference effects are discussed.

J. L. Nagle

Strangeness production has long been proposed as a diagnostic tool for understanding the dynamics of relativistic heavy ion collisions. In this presentation we review the traditional picture of strangeness enhancement as a signature for quark-gluon plasma formation. We then review, in order, some experimental data on strange particle production in $e^{+}e^{-

Bo Andersson

I will use this opportunity on the one hand to comment upon some of the many interesting results that have been presented at this meeting, on the other hand to discuss some new features that we have recently learned on the structure and properties of the Lund Model both with respect to the fragmentation of multigluon string states and the partonic cascades b

V. Friese

We present recent results of the SPS experiment NA49 on production of strange particles and event-by-event fluctuations of mean $p_t$ and of charged particle ratios in central Pb+Pb collisions at various beam energies (40, 80, 158 AGeV) as well as in different collisions at 158 AGeV, going from p+p over light-ion collisions to peripheral and central Pb+Pb.

G. Marchesini

I recall some points on the present status of QCD results in the short distance regions and illustrate the case of event shape in QCD radiation

Kenneth N. Barish

I report on results from the PHENIX collaboration for the first RHIC run, where gold ions were collided at $\sqrt{s_{NN}}=130 GeV$. In order to study initial conditions, PHENIX has measured the ratio between anti-protons and protons, the transverse energy, and charged multiplicity as a function of collision centrality. These measurements allows us to extract

Georgios D. Stavropoulos

The study of QCD processes at the LHC will serve two main goals. First the predictions of QCD will be tested and precision measurements will be performed. Second QCD processes represent a major part of the background to other Standard Model processes and signals of new physics at the LHC and thus need to be understood precisely in the new kinematic region av

Einan Gardi, Johan Rathsman

Event-shape distributions in $e^+e^-$ annihilation offer a unique lab oratory for understanding perturbative and non-perturbative aspects of QCD. Dressed Gluon Exponentiation is a resummation method designed to evaluate differ ential cross sections close to a kinematic threshold and provide the basis for parametrization of power corrections. The method and i

Jes Madsen

Three topics with relation to color superconductivity in strange quark matter are discussed. 1) The r-mode instability in strange stars, which is consistent with the existence of ``ordinary'' strange quark matter stars but inconsistent with strange stars in a pure color-flavor locked state. 2) Color-flavor locked strangelets, which are more bound tha

A. Del Fabbro

The double parton collisions become increasingly important at high energies. The scale factors are the dimensional parameters which characterize these interactions and are the physical observables that can provide a first quantitative information on the correlations in the hadron structure.

C. B. Yang, Rudolph C. Hwa

The proton and neutron inclusive distributions in the projectile fragmentation region of $pA$ collisions are studied in the valon model. Momentum degradation and flavor changes due to the nuclear medium are described at the valon level using two parameters. Particle production is treated by means of the recombination subprocess. Pion inclusive distributions

G. Calucci, E. Cattaruzza

In the study of multiple scattering of partons in hadron-hadron collisions the possibility of a hard inelastic process at the parton level is included in its simplest possible way, $i.e.$ including the $2 \to 3$ transition. The specific physical process to which the treatment is applied is the inelastic collision of a nucleon with a heavy nucleus

Thomas Nunnemann

Quantum Chromodynamics has been studied extensively at Fermilab's Tevatron collider. Between 1992 and 1996 the DØand CDF experiments, each accumulated approximately $100 \mathrm{pb}^{-1}$ of proton-antiproton collisions at a center-of-mass energy $\sqrt{s}=1800 \mathrm{GeV}$ and $\sim 0.5 \mathrm{pb}^{-1}$ at $\sqrt{s}=630 \mathrm{GeV}$. In this paper, w

Valeria Tano

We describe a study of the underlying event in jet and minimum bias events using data from the CDF detector. The underlying event contribution to the jet energy has been calculated in jet events and compared to the results of two Monte Carlo programs: Herwig and Pythia. The analysis has been carried out at two different center of mass energies: $\sqrt{s}=$18

V. A. Khoze

We quantify the rate and the signal-to-background ratio for Higgs $\to b\bar{b}$ detection in double-diffractive events at the Tevatron and the LHC. The signal is predicted to be very small at the Tevatron, but observable at the LHC. We exemplify the diagnostic power of hadronic antenna pattern by considering the topology of hadronic flow corresponding to Hi

J. Manjavidze, A. Sissakian

The possibility to suppress the nonperturbative effects choosing the vary high multiplicity final state is discussed. The theoretical uncertainties and the experimental observable consequence of this choice are discussed.

A. Rostovtsev

HERA data on soft hadron production are discussed. The measured inclusive and exclusive hadron cross sections show a simple scaling behaviour.

B. Buschbeck, F. Mandl

Using the full statistics of the DELPHI experiment at $\sqrt{s}=91 GeV$ 3-jet events are selected and gluon respectively quark jet enriched subsamples are defined. The leading systems of the two kinds of jets are determined using rapidity gaps. The sum of charges of the leading systems is studied. It is found that for gluon-jets there is a significant excess

Li Shi-yuan, Shao Feng-lan, Xie Qu-bing

By selecting two-jet like events and employing sensitive observable, we find that two kinds of colour connections at the hard-soft interface lead to significantly differences in hadron states.

U. Flagmeyer

Data from electron positron annihilations at different center of mass energies are collected by the four LEP experiments. Direct tests of hard QCD are performed by measuring and analysing event shape observables.

O. Behnke

Recent results of open charm and beauty production in electron proton scattering at HERA are presented. In photoproduction, the measured cross sections for charm exceed fixed order NLO QCD calculations. Experimental evidence supports the hypothesis that a significant fraction of photoproduction events with charm can be described by resolved photon processes,

Xin-Nian Wang

Particle production mechanisms in high-energy heavy-ion collisions are reviewed in connection with recent experimental data from RHIC. Implications on mini-jet production, parton saturation and jet quenching are discussed.

Liang Zuo-tang

Spin effects in high energy fragmentation processes can provide us with important information on hadronization mechanisms and spin structure of hadrons. It can in particular give new tests to the hadronization models. In this talk, we make a brief introduction to the different topics studied in this connection and a short summary of the available data. After

Nicolas Borghini, Phuong Mai Dinh, Jean-Yves Ollitrault

We discuss signatures of thermalisation in heavy ion collisions based on elliptic flow. We then propose a new method to analyse elliptic flow, based on multiparticle azimuthal correlations. This method allows one to test quantitatively the collective behaviour of the interacting system.

Denes Molnar

Differential elliptic flow and particle spectra are calculated from covariant Boltzmann transport theory taking into account the finite transport opacity of the gluon plasma produced in Au+Au at $E_{cm}\sim 130$ $A$ GeV at RHIC. The solutions are shown to depend mainly on the transport opacity, $χ=\int dz σ_tρ_g$. The elliptic flow saturation pattern reporte

Edmond Iancu

At very high energies, the relevant component of the hadron wavefunction can be described as a Color Glass Condensate, i.e., a state of high density gluonic matter whose distribution is random, but frozen over the relevant time scales. The weight function for this distribution obeys a renormalization group equation in the form of a functional Fokker-Planck e

B. Golli, P. Alberto, M. Fiolhais

We study the contribution of glueball and sigma-meson degrees of freedom to nucleon excited states in the framework of a chiral version of the chromodielectric model. We have found that these degrees of freedom considerably lower the energy of the Roper and may substantially weaken the electroexcitation amplitudes for the N(1440) and in particular for the N(

L. L. Jenkovszky, V. K. Magas

By using the concept of duality between direct channel resonances and Regge exchanges we relate the small- and large-$x$ behavior of the structure functions. We show that even a single resonance exhibits Bjorken scaling at large $Q^2$.

Ph. Gavillet

Inclusive production of two $(K\bar Kπ)^0$ states in the mass region 1.22--1.56 GeV in $Z$ decay at LEP I has been observed by the DELPHI Collaboration. The measured masses and widths are $1274\pm4$ and $29\pm12$ MeV for the first peak and $1426\pm4$ and $51\pm14$ MeV for the second. A partial-wave analysis has been performed on the $(K\bar Kπ)^0$ spectrum i

P. Abreu

The preliminary results on the search of colour reconnection effects (CR) from the four experiments at LEP, Aleph, Delphi, L3 and Opal, are reviewed. Extreme models are excluded by studies of standard variables, and on going studies of a method first suggested by L3, the particle flow method, are yet inconclusive.

Sonja Kabana

We address the question of how to identify the QCD phase transition using measured light (u,d,s-structured) hadrons, without invoking comparison to the QCD $ε_c$ predictions, and extract $ε_c$ from the data. We analyse several particle and nuclear collisions and extract their chemical freeze-out temperature $T$ at zero baryochemical potential ($μ_B$). We fin

Giuseppina Anzivino

The NA48 experiment at the CERN SPS aims to search for direct CP violation in the $K^0$ system through the measurement of ${\rm Re}(ε'/ ε)$ with high accuracy. In 1999 the NA48 collaboration has published its first measuremen based on 1997 data. A new result, based on 1998 and 1999 data, is presented in this article. The result, combined with 1997 data,

Thomas Besmer, Christoph Greub, Tobias Hurth

Using the example of the rare decay $B \to X_s γ$, we analyse the importance of interference effects for the bounds on the parameters in the squark mass matrices within the unconstrained MSSM. In former model-independent analyses no correlations between the different sources of flavour violation were taken into account. In our new analysis we include the con

Martina Brisudova

With the current state of similarity renormalisation group approach to light-front QCD, it is possible to address with a degree of generality the issue of light-cone zero modes. We find, contrary to earlier results in a less general framework, that infrared divergences associated with the zero modes do not cancel out in a color singlet heavy quark-antiquark

Jonathan Osborne

I present an introduction to the field of Quantum Chromodynamics (QCD) with emphasis on nucleon spin structure and perturbative methods. After a somewhat comprehensive overview of perturbative QCD, including the systematics of renormalization, I introduce deeply-inelastic scattering and deeply-virtual Compton scattering along with the nonperturbative distrib

F. Karsch, Ch. Schmidt, S. Stickan

In the presented study we investigated the second order endpoints of the lines of first order phase transitions which emerge for the QCD in the heavy and light quark mass regime and for the three-dimensional three state Potts model with an external field. We located the endpoints with Binder cumulants and constructed the energy-like and ordering field like o

G. Bonvicini, CLEO Collaboration

We search and find no evidence for CP violation in tau decays into the K pi nu final state. We provide confidence limits on the imaginary part of the coupling constant Lambda, describing a relative contribution of the CP violating processes with respect to the Standard Model, to be -0.155 < Im(Lambda) < 0.047 at 90% C.L.

G. Chiodini, J. A. Appel, G. Cardoso, D. C. Christian

In future experiments the readout electronics for pixel detectors is required to be resistant to a very high radiation level. In this paper we report on irradiation tests performed on several preFPIX2 prototype pixel readout chips for the BTeV experiment exposed to a 200 MeV proton beam. The prototype chips have been implemented in commercial 0.25 um CMOS pr

V. M. Biryukov, Yu. A. Chesnokov, V. I. Kotov, D. Trbojevic

In the framework of the project to design and test a collimation system prototype using bent channeling crystal for cleaning of the RHIC heavy ion beam halo, we have studied the optimal length and bending angle of a silicon (110) single crystal proposed to be a primary element situated upstream of the traditional heavy amorphous collimator. Besides the matte

E. Scapparone, MACRO Collaboration

An estimate of the energy of neutrino-induced muons in MACRO is provided by a multiple Coulomb scattering measurement. The MACRO original upward-muon data sample has been subdivided according to the reconstructed muon energy. The results are interpreted in terms of neutrino oscillation.

Aharon Davidson, David Karasik, Yoav Lederer

Dark energy/matter unification is first demonstrated within the framework of a simplified model. Geodetic evolution of a cosmological constant dominated bubble Universe, free of genuine matter, is translated into a specific FRW cosmology whose effectively induced dark component highly resembles the cold dark matter ansatz. The realistic extension constitutes

S. Capozziello, S. Carloni, G. Lambiase, C. Stornaiolo

The issues of quintessence and cosmic acceleration can be discussed in the framework of higher order curvature and torsion theories of gravity. We can define effective pressure and energy density directly connected to the curvature or to the torsion fields and then ask for the conditions to get an accelerated expansion. Exact accelerated expanding solutions

Serge Reynaud, Brahim Lamine, Astrid Lambrecht, Paulo Maia Neto

We study the decoherence process associated with the scattering of stochastic gravitational waves. We discuss the case of macroscopic systems, such as the planetary motion of the Moon around the Earth, for which gravitational scattering is found to dominate decoherence though it has a negligible influence on damping. This contrast is due to the very high eff

G. S. Khadekar, Shilpa Samdurkar

A new class of non-static higher dimensional vacuum solutions in space-time -mass (STM) theory of gravity is found. This solution represent expanding universe without big bang singularity and the higher dimension of these models shrinks as they expands.

T. Loftus, C. A. Regal, C. Ticknor, J. L. Bohn

We have loaded an ultracold gas of fermionic atoms into a far off resonance optical dipole trap and precisely controlled the spin composition of the trapped gas. We have measured a magnetic-field Feshbach resonance between atoms in the two lowest energy spin-states, |9/2, -9/2> and |9/2, -7/2>. The resonance peaks at a magnetic field of 201.5 plus or minus 1

Priya Mahadevan, Alex Zunger

CdGeP2 chalcopyrites doped with Mn have been recently found to exhibit room temperature ferromagnetism. Isovalent substitution of the Cd site is expected, however, to create antiferromagnetism, in analogy with the well-known CdTe:Mn (d^5) case. However, chalcopyrite semiconductors exhibit low-energy intrinsic defects. We show theoretically how ferromagnetism

Priya Mahadevan, K. Terakura, D. D. Sarma

Using first principle band structure calculations, we critically examine results of resonant x-ray scattering experiments which is believed to directly probe charge and orbital ordering. Considering the specific case of La0.5Sr1.5MnO4, we show that this technique actually probes most directly and sensitively small structural distortions in the system. Such d

Z. Pluhar, H. A. Weidenmueller

We extend the recent study of the k-body embedded Gaussian ensembles by Benet et al. (Phys. Rev. Lett. 87 (2001) 101601-1 and Ann. Phys. 292 (2001) 67) and by Asaga et al. (cond-mat/0107363 and cond-mat/ 0107364). We show that central results of these papers can be derived directly from the symmetry properties of both, the many-particle states and the random

Vladimir L. Safonov

A tensor form of phenomenological damping is derived for small magnetization motions. This form reflects basic physical relaxation processes for a general uniformly magnetized particle or film. Scalar Landau-Lifshitz damping is found to occur only for two special cases of system symmetry.