August 1998 arXiv papers — page 2

Andrew Lesniewski, Mary Beth Ruskai

We use the relative modular operator to define a generalized relative entropy for any convex operator function g on the positive real line satisfying g(1) = 0. We show that these convex operator functions can be partitioned into convex subsets each of which defines a unique symmetrized relative entropy, a unique family (parameterized by density matrices) of

Bjorn Poonen

In "Mordell-Lang plus Bogomolov", we formulated a conjecture combining the Mordell-Lang conjecture (now proven) and the Bogomolov conjecture, and proved the Mordellic part when A is almost split (i.e., isogenous to the product of an abelian variety and a torus). Here we prove that the full conjecture would follow from the Bogomolov conjecture and an

Bjorn Poonen

We formulate a conjecture for semiabelian varieties A over number fields that includes both the Mordell-Lang conjecture (now proven) and the Bogomolov conjecture. We prove the "Mordellic" (finitely generated) part of the conjecture when A is isogenous to the product of an abelian variety and a torus. The proof makes use of the Mordell-Lang conjecture

Steven Corley

We solve the Dirichlet boundary value problem for the massless gravitino on $AdS_{d+1}$ space and compute the two-point function of the dual CFT supersymmetry currents using the $AdS$/CFT correspondence principle. We find analogously to the spinor case that the boundary data for the massless $(d+1)$ dimensional bulk gravitino field consists of only a $(d-1)$

Seungjoon Hyun, Youngjai Kiem, Hyeonjoon Shin

The effective action for the membrane dynamics on the background geometry of the $N$-sector DLCQ $M$ theory compactified on a two-torus is computed via supergravity. We compare it to the effective action obtained from the matrix theory, i.e., the (2+1)-dimensional supersymmetric Yang-Mills (SYM) theory, including the one-loop perturbative and full non-pertur

Patrick B. Greene, Lev Kofman, Alexei A. Starobinsky

We consider the instability of fluctuations in an oscillating scalar field which obeys the Sine-Gordon equation. We present simple closed-form analytic solutions describing the parametric resonance in the Sine-Gordon model. The structure of the resonance differs from that obtained with the Mathieu equation which is usually derived with the small angle approx

Georg Raffelt, Guenter Sigl

We develop a simple model for the evolution of a nucleon spin in a hot and dense nuclear medium. A given nucleon is limited to one-dimensional motion in a distribution of external, spin-dependent scattering potentials. We calculate the nucleon spin autocorrelation function numerically for a variety of potential densities and distributions which are meant to

Michael Rueter

Using the Model of the Stochastic Vacuum many diffractive processes have been calculated by investigating the dipole-dipole scattering at a cm-energy of 20 GeV. In this work we extend the calculation to larger energies and small dipoles. We assume that there are two pomerons, the hard- and the soft-pomeron, which cause the different energy dependence for pro

Vipul Periwal

Bialek, Callan and Strong have recently given a solution of the problem of determining a continuous probability distribution from a finite set of experimental measurements by formulating it as a one-dimensional quantum field theory. This report applies an extension of their formalism to the inference of functional parton distributions from scattering data.

Martin Zach, Manfried Faber, Alexandra Müller, Peter Skala

Abelian gauge theories formulated on a space-time lattice can be used as a prototype for investigating the confinement mechanism. In U(1) lattice gauge theory it is possible to perform a dual transformation of the path integral. Simulating the obtained dual theory (which corresponds to a certain limit of a dual Higgs model) including external sources, we per

The OPAL Collaboration, G. Abbiendi et al

In the process e+e- to hadrons, one of the effects of gluon emission is to modify the 1+cos(theta)**2 form of the angular distribution of the thrust axis, an effect which may be quantified by the longitudinal cross-section. Using the OPAL detector at LEP, we have determined the longitudinal to total cross-section ratio to be 0.0127+-0.0016+-0.0013 at the par

Richard J. Epp

Carlip has shown that the entropy of the three-dimensional black hole has its origin in the statistical mechanics of microscopic states living at the horizon. Beginning with a certain orthonormal frame action, and applying similar methods, I show that an analogous result extends to the (Euclidean) black hole in any spacetime dimension. However, this approach

S. Aubry, S. Flach, K. Kladko, E. Olbrich

We analyze the classical and quantum properties of the integrable dimer problem. The classical version exhibits exactly one bifurcation in phase space, which gives birth to permutational symmetry broken trajectories and a separatrix. The quantum analysis yields all tunneling rates (splittings) in leading order of perturbation. In the semiclassical regime the

Judith G. Cohen, David W. Hogg, Roger Blandford, Michael A. Pahre

We discuss the very red objects found in the first field of the Caltech Faint Galaxy Redshift Survey, for which the observations and analysis are now complete. In this field, which is 15 arcmin$^2$ and at J005325+1234 there are 195 objects with $K_s < 20$ mag, of which 84% have redshifts. The sample includes 24 spectroscopically confirmed Galactic stars, 136

Shude Mao, H. J. Mo

It has been suggested recently that the rate of gamma-ray bursts (GRBs) is proportional to the star formation rate in the universe. In this paper, we study the nature of GRB hosts expected in this scenario. We improve upon previous studies by incorporating a luminosity function for the GRBs, as required by observations. This model provides a good match to th

E. Penev, P. Kratzer, M. Scheffler

Three different clusters, Si_9H_12, Si_15H_16, and Si_21H_20, are used in density-functional theory calculations in conjunction with ab initio pseudopotentials to study how the energetics of H_2 dissociativ e adsorption on and associative desorption from Si(001) depends on the cluster size. The results are compared to five-layer slab calculations using the s

Andreas Karch, Tatsuo Kobayashi, Jisuke Kubo, George Zoupanos

Applying the recently obtained results on the renormalization of soft supersymmetry-breaking parameters, we investigate the infrared behaviour of the softly broken supersymmetric QCD as well as its dual theory in the conformal window. Under general assumptions on $β$-functions, it is shown that the soft supersymmetry-breaking parameters asymptotically vanish

George Triantaphyllou

The gap equation for fermions in a version of thermal QED in three dimensions is studied numerically in the Schwinger-Dyson formalism. The interest in this theory has been recently revived since it has been proposed as a model of high-temperature superconductors. We include wave-function renormalization in our equations and use a non-bare vertex. We then hav

B. Abbott

We have studied tbar-t production using multijet final states in pbar-p collisions at a center-of-mass energy of 1.8 TeV, with an integrated luminosity of 110.3 pb(-1). Each of the top quarks with these final states decays exclusively to a bottom quark and a W boson, with the W bosons decaying into quark-antiquark pairs. The analysis has been optimized using

R. Movshovich, A. Yatskar, M. F. Hundley, P. C. Canfield

In order to elucidate the nature of the ground state in the heavy-electron system PrInAg_2, we measured its specific heat for temperatures between 60 mK and 2 K in magnetic fields up to 9 T. The peak maximum of the low temperature anomaly in the specific heat (interpreted as Kondo anomaly) shifts from 0.42 K at zero field to 0.45 K at 6 T, and to 0.5 K at 9

Joel David Hamkins, W. Hugh Woodin

After small forcing, almost every strongness embedding is the lift of a strongness embedding in the ground model. Consequently, small forcing creates neither strong nor Woodin cardinals.

Edward S. Letzter, Martin Lorenz

We show that group algebras kG of polycyclic-by-finite groups G, where k is a field, are catenary: Given prime ideals P and P&#39; of kG, with P contained in P&#39;, all saturated chains of primes between P and P&#39; have the same length.

P. A. Zizzi

We perform a foliation of a four dimensional Riemannian space-time with respect to a discrete time which is an integer multiple of the Planck time. We find that the quantum fluctuations of the metric have a discrete energy spectrum. The metric field is expanded in stationary eigenstates, and this leads to the description of a de Sitter-like universe. At the

Andrea Cappelli, Guillermo R. Zemba

The W-infinity minimal models are conformal field theories which can describe the edge excitations of the hierarchical plateaus in the quantum Hall effect. In this paper, these models are described in very explicit terms by using a bosonic Fock space with constraints, or, equivalently, with a non-trivial Hamiltonian. The Fock space is that of the multi-compo

Andrew Chamblin, Roberto Emparan, Clifford V. Johnson, Robert C. Myers

Recent results in the literature concerning holography indicate that the thermodynamics of quantum gravity (at least with a negative cosmological constant) can be modeled by the large N thermodynamics of quantum field theory. We emphasize that this suggests a completely unitary evolution of processes in quantum gravity, including black hole formation and dec

Sandip Pakvasa

The theory and phenomenology of CP violation in hyperon decays is summarized.

Hiroko Ichie, Hideo Suganuma

We study monopoles and gluon fields in QCD in the maximally abelian (MA) gauge in the context of the dual superconductor picture for confinement. In the abelian gauge, unit-charge magnetic monopoles appear, but multi-charge monopoles do not in general cases. The appearance of the monopole is studied using the gauge-connection formalism in relation to the SU(

Nir Friedman, Joseph Y. Halpern

We introduce a new approach to modeling uncertainty based on plausibility measures. This approach is easily seen to generalize other approaches to modeling uncertainty, such as probability measures, belief functions, and possibility measures. We focus on one application of plausibility measures in this paper: default reasoning. In recent years, a number of d

Enzo Granato

The scaling behavior of the current-voltage characteristics of chiral and gauge glass models of disordered superconductors, are studied numerically, in two dimensions. For both models, the linear resistance is nonzero at finite temperatures and the scaling analysis of the nonlinear resistivity is consistent with a phase transition at T=0 temperature characte

Seung-Pyo Hong, Hyeonjin Doh, Sung-Ho Suck Salk

Considering interacting (antiferromagnetically correlated) electrons, we derive a generalized Harper&#39;s equation for the square lattice of infinite size. We obtain an analytic expression for the density of states from the newly derived Harper&#39;s equation. We present a predicted phase diagram of staggered magnetization in the plane of temperature vs dop

Nobuyoshi Makino, Katsuaki Asano

We study density cusps in the center of clusters of galaxies to reconcile X-ray mass estimates with gravitational lensing masses. For various mass density models with cusps we compute X-ray surface brightness distribution, and fit them to observations to measure the range of parameters in the density models. The Einstein radii estimated from these density mo

Ming Sun, Zhen-ru Wang, Yang Chen

Based on the data from the observation of the SNR G327.1-1.1 by ASCA and ROSAT, we find that G327.1-1.1 is a composite remnant with both a nonthermal emission component and a diffuse thermal emission component. The nonthermal component is well fitted by a power-law model with photon index about 2.2. This component is attributed to the emission from the synch

Takashi Hamana

We rederive a relation between gravitational lensing magnification relative to the standard Friedmann distance and one relative to the Dyer-Roeder distance by investigating the null geodesic deviation equation. We show that the relation comes from a natural consequence of the definition of the lensing magnification matrices and is not based on the averaging

Frank J. Masci, Rachel L. Webster, Paul J. Francis

We describe an algorithm that measures self-consistently the relative galaxy contribution in a sample of radio-quasars from their optical spectra alone. This is based on a spectral fitting method which uses the size of the characteristic 4000Å~ feature of elliptical galaxy SEDs. We apply this method to the Parkes Half-Jansky Flat Spectrum sample of Drinkwate

Ali Kinkhabwala, Marc Kamionkowski

We calculate the large-angle cross-correlation between the cosmic-microwave-background (CMB) temperature and the x-ray-background (XRB) intensity expected in an open Universe with cold dark matter (CDM) and a nearly scale-invariant spectrum of adiabatic density perturbations. Results are presented as a function of the nonrelativistic-matter density $Ω_0$ (in

C. P. Burgess

These notes review the effective lagrangian treatment of Goldstone and pseudo-Goldstone bosons, taking examples from high-energy/nuclear and condensed-matter physics. The contents are: 1. Goldstone Bosons 2. Pions: A Relativistic Application 3. Magnons: Nonrelativistic Applications 4. SO(5) Invariance and Superconductors 5. Bibliography

Sheldon L. Glashow, Peter J. Kernan, Lawrence M. Krauss

Recent evidence for oscillations of atmospheric neutrinos at Super-Kamiokande suggest, in the simplest see-saw interpretation, neutrino masses such that `just so&#39; vacuum oscillations can explain the solar neutrino deficit. Super-K solar neutrino data provide preliminary support for this interpretation. We describe how the just-so signal---an energy depen

John D. Anderson, Philip A. Laing, Eunice L. Lau, Anthony S. Liu

Radio metric data from the Pioneer 10/11, Galileo, and Ulysses spacecraft indicate an apparent anomalous, constant, acceleration acting on the spacecraft with a magnitude $\sim 8.5\times 10^{-8}$ cm/s$^2$, directed towards the Sun. Two independent codes and physical strategies have been used to analyze the data. A number of potential causes have been ruled o

D. Rainwater, D. Zeppenfeld, K. Hagiwara

Weak boson fusion is a copious source of intermediate mass Higgs bosons at the LHC. The additional very energetic forward jets in these events provide for powerful background suppression tools. We analyze the $H \to ττ$ decay mode for the Standard Model Higgs boson. A parton level analysis of the dominant physics backgrounds (mainly $Z \to ττ$ and Drell-Yan

Oleg Yakovlev

We calculate the cross section of the process e^+e^- \to t\bar t near threshold by resumming Coulomb-like terms with next-to-next-to-leading (NNLO) accuracy. The nonrelativistic Green function formalism and the method of ``direct matching&#39;&#39; are used. The NNLO correction turns out to be large, of the same size as the NLO correction. It changes the pos

E. Z. Kuchinskii, M. V. Sadovskii

We analyze a number of ``nearly exactly&#39;&#39; solvable models of electronic spectrum of two-dimensional systems with well-developed fluctuations of short range order of ``dielectric&#39;&#39; (e.g. antiferromagnetic) or ``superconducting&#39;&#39; type, which lead to the formation of anisotropic pseudogap state on certain parts of the Fermi surface. We f

Tomohiro Ogawa, Hiroshi Nagaoka

A lower bound on the probability of decoding error of quantum communication channel is presented. The strong converse to the quantum channel coding theorem is shown immediately from the lower bound. It is the same as Arimoto&#39;s method exept for the difficulty due to non-commutativity.

Subhendra Mohanty, D. P. Roy, Utpal Sarkar

We propose a simple texture of the neutrino mass matrix with one sterile neutrino along with the three standard ones. It gives maximal mixing angles for $ν_e \to ν_S$ and $ν_μ\to ν_τ$ oscillations or vice versa. Thus with only four parameters, this mass matrix can explain the solar neutrino anomaly, atmospheric neutrino anomaly, LSND result and the hot dark

S. Ravy, J. Jegoudez, A. Revcolevschi

We present an X-ray diffuse scattering study of the pretransitional structural fluctuations of the magneto-elastic transition in alpha&#39;-NaV2O5. This transition is characterized by the appearance below Tsp~35K of satellite reflections at the reduced wave vector (1/2,1/2,1/4). A large regime of structural fluctuations is measured up to 90 K. These fluctuat

W. de Boer

An overview of hints for new physics outside the Standard Model and the status of sparticle and Higgs searches is given. The present limits on Higgs bosons of about 90 GeV as well as the $\bsg$ rate and cosmological constraints severely restrict the available parameter space of the MSSM.

Sheng Li, Yishi Duan

The topological structure of the electric topological current of the locally gauge invariant Maxwell-Chern-Simons Model and its bifurcation is studied. The electric topological charge is quantized in term of winding number. The Hopf indices and Brouwer degree labeled the local topological structure of the electric topological current. Using $Φ$-mapping metho

Joseph Y. Halpern

The standard approach to logic in the literature in philosophy and mathematics, which has also been adopted in computer science, is to define a language (the syntax), an appropriate class of models together with an interpretation of formulas in the language (the semantics), a collection of axioms and rules of inference characterizing reasoning (the proof the

Jon Links, Angela Foerster, Michael Karowski

A quantum algebra invariant integrable closed spin 1 chain is introduced and analysed in detail. The Bethe ansatz equations as well as the energy eigenvalues of the model are obtained. The highest weight property of the Bethe vectors with respect to U_q(sl(2)) is proved.

D. F. Mundarain, P. A. Maia Neto

We consider the electromagnetic vacuum field inside a perfect plane cavity with moving mirrors, in the nonrelativistic approximation. We show that low frequency photons are generated in pairs that satisfy simple properties associated to the plane geometry. We calculate the photon generation rates for each polarization as functions of the mechanical frequency

Kalvis M. Jansons, G. D. Lythe

Classical Stokes&#39; drift is the small time-averaged drift velocity of suspended non-diffusing particles in a fluid due to the presence of a wave. We consider the effect of adding diffusion to the motion of the particles, and show in particular that a non-zero time-averaged drift velocity exists in general even when the classical Stokes&#39; drift is zero.

V. A. Gani, V. M. Weinberg

Recurrence relations of perturbation theory for hydrogen ground state are obtained. With their aid polarizabilities in constant perpendicular electric and magnetic fields are computed up to 80th order. The high orders asymptotic is compared with its quasiclassical estimate. For the case of arbitrary mutual orientation of external fields a general sixth order

Hartmut Ruhl, Peter Mulser, Steffen Hain, Fulvio Cornolti

The interaction of intense fs laser pulses with thin foils that have an imposed deformation is compared with thick targets that develop bow shocks. Both target types yield good absorption. Up to 80% absorption is obtained for a $0.2μm$ thick, 15 times over-dense foil at $4 \cdot 10^{18} W/cm^2$. A value of 50% is obtained for a $4 μm$ thick, 2 times over-den

Asish K. Dhara, Sailajananda Bhattacharya, Kewal Krishan Variable Energy Cyclotron Centre, Calcutta

Asymptotic expansion of the Fokker-Planck equation in terms of the strength of the fluctuation has been carried out. The mean and the variance of the total kinetic energies of the fission fragments have been calculated and compared with the experimental values.

A. K. Chaudhuri

We investigate the chemical equilibration of the parton distributions in collisions of two heavy nuclei, assuming the partonic fluid to be ideal as well as viscous. The initial conditions are taken from HIJING calculations for Au+Au collisions at RHIC and LHC energies. It was seen that when the viscous drag is taken into account in the fluid flow, the life t

M. X Shao, Z. Y Zhu

Via K$\ddot{a}$hker polarization we geometrically quantize free fields in the spaces of motions, namely the space of solutions of equations of motion. We obtain the correct results just as that given by the canonical quantization. Since we follow the method of covariant symplectic current proposed by Crnkovic, Witten and Zuckerman et al, the canonical commut

Mark C. Wilson

Let $H$ be a finite-dimensional Hopf algebra. We study the behaviou r of primitive and maximal ideals in certain types of ring extensions determined by $H$. The main focus is on the class of faithfully flat Galois extensions, which includes includes smash and crossed products. It is shown how analogous results can be obtained for the larger class of extensio

Pavel Etingof, David Kazhdan

This paper is a continuation of &#34;Quantization of Lie bialgebras I-IV&#34;. The goal of this paper is to define and study the notion of a quantum vertex operator algebra in the setting of the formal deformation theory and give interesting examples of such algebras. In particular, we construct a quantum vertex operator algebra from a rational, trigonometri

Andras Nemethi

The main message of the paper is that for Gorenstein singularities, whose (real) link is rational homology sphere, the Artin--Laufer program can be continued. Here we give the complete answer in the case of elliptic singularities. The main result of the paper says that in the case of an elliptic Gorenstein singularity whose link is rational homology sphere,

Christian Krattenthaler

We derive several identities that feature irreducible characters of the general linear, the symplectic, the orthogonal, and the special orthogonal groups. All the identities feature characters that are indexed by shapes that are &#34;nearly&#34; rectangular, by which we mean that the shapes are rectangles except for one row or column that might be shorter th

Karen Guenzl

Let E be a simple finite dimensional representation of a semisimple Lie algebra with extremal weight nu and choose nonzero e in E_{nu}. Let M(tau) be the Verma module with highest weight tau and v_{tau} in M(tau)_{tau} its canonical generator. We investigate the projection of e \otimes v_{tau} in E \otimes M(tau) on the central character chi(tau + nu). This

David M. Bressoud

Elementary proofs are given for sums of Schur functions over partitions into at most n parts each less than or equal to m for which i) all parts are even, ii) all parts of the conjugate partition are even. Also, an elementary proof of a recent result of Ishikawa and Wakayama is given.

Ronald Evans, Henk Hollmann, Christian Krattenthaler, Qing Xiang

We study quadratic residue difference sets, GMW difference sets, and difference sets arising from monomial hyperovals, all of which are $(2^d-1, 2^{d-1}-1, 2^{d-2}-1)$ cyclic difference sets in the multiplicative group of the finite field $F_{2^d}$ of $2^d$ elements, with $d \geq 2$. We show that, except for a few cases with small $d$, these difference sets

Pavel Etingof, David Kazhdan

This paper is a continuation of &#34;Quantization of Lie bialgebras, III&#34; (q-alg/9610030, revised version). In QLB-III, we introduced the Hopf algebra F(R)_\z associated to a quantum R-matrix R(z) with a spectral parameter, and a set of points \z=(z_1,...,z_n). This algebra is generated by entries of a matrix power series T_i(u), i=1,...,n,subject to Fad

Sergei Gukov, Anton Kapustin

We consider M-theory on (T^2\times R^2)/Z_n with M5 branes wrapped on R^2. One can probe this background with M5 branes wrapped on T^2. The theories on the probes provide many new examples of N=2 field theories without Lagrangian description. All these theories have Coulomb branches, and we find the corresponding Seiberg-Witten curves. The exact solution is

M. G. Negrao, A. Penna-Firme, J. A. Helayel-Neto

The equivalence between rank-2 anti-symmetric tensor fields, considered as gauge potentials, and torsionless non-linear $σ$-models suggests us to study the possibility of coupling tensorial matter with Yang-Mills fields, through the gauging of the isometries of the target space. We show that this coupling is actually possible; however, the matter appears no

M. Blagojevic, D. S. Popovic, B. Sazdovic

Starting from the Kac--Moody structure of the WZNW model for SL(2,R) and using the general canonical formalism, we formulate a gauge theory invariant under local SL(2,R) x SL(2,R) and diffeomorphisms. This theory represents a gauge extension of the WZNW system, defined by a difference of two simple WZNW actions. By performing a partial gauge fixing and integ

John Ellis, N. E. Mavromatos

We present a Liouville-string approach to confinement in four-dimensional gauge theories, which extends previous approaches to include non-conformal theories. We consider Liouville field theory on world sheets whose boundaries are the Wilson loops of gauge theory, which exhibit vortex and spike defects. We show that world-sheet vortex condensation occurs whe

Maxim Zabzine

We consider evidence for the existence of gauge configurations with fractional charge in pure N=1 supersymmetric Yang-Mills theory . We argue that these field configurations are singular and have to be treated as distributions. It is shown that the path integral representation of constant Green&#39;s functions can be reduced to a finite dimensional integral.

T. Fugleberg, I. Halperin, A. Zhitnitsky

We suggest an anomalous effective Lagrangian which reproduces the anomalous conformal and chiral Ward identities and topological charge quantization in QCD. It is shown that the large N_c Di Vecchia-Veneziano-Witten effective chiral Lagrangian is locally recovered from our results, along with 1/N_c corrections, after integrating out the heavy &#34;glueball&#

L. Apanasevich, C. Balazs, C. Bromberg, J. Huston

We discuss the phenomenology of initial-state parton-kt broadening in direct-photon production and related processes in hadron collisions. After a brief summary of the theoretical basis for a Gaussian-smearing approach, we present a systematic study of recent results on fixed-target and collider direct-photon production, using complementary data on diphoton

J. -J. Cao, T. Han, X. -M. Zhang, G. -R. Lu

We study the possible signature for lepton-flavor violation processes in the scalar-lepton sector of the minimal supersymmetric model at future electron-photon colliders. We find that an $\egm$ collider can provide a good opportunity to probe the mass differences and flavor mixing angles between the sleptons of the first generation and the other two generati

Pran Nath, R. Arnowitt

A review of baryon and lepton conservation in supersymmetric grand unified theories is given. Proton stability is discussed in the minimal SU(5) supergravity grand unification and in several non-minimal extensions such as the $SU(3)^3$, SO(10) and some string based models. Effects of dark matter on proton stability are also discussed and it is shown that the

S. Kretzer

In charged current deep inelastic scattering charm is dominantly produced in scattering events on strange quarks, thereby allowing for an experimental determination of the nucleon&#39;s strange sea density. A measurement of the energy spectrum of final state charm fragments (D-mesons) determines the charm fragmentation function at spacelike scales considerab

Stefano Forte, Guido Altarelli, Giovanni Ridolfi

We show that the naive positivity conditions on polarized parton distributions which follow from their probabilistic interpretation in the naive parton model are reproduced in perturbative QCD at the leading log level if the quark and gluon distribution are defined in terms of physical processes. We show how these conditions are modified at the next-to-leadi

C. X. Chen, G. Papini, N. Mobed, G. Lambiase

The maximal acceleration corrections to the Lamb shift of muonic hydrogen are calculated by using the relativistic Dirac wave functions. The correction for the $2S-2P$ transition is $\sim 0.38$ meV and is higher than the accuracy of present QED calculations and of the expected accuracy of experiments in preparation.

G. Lambiase, G. Papini, G. Scarpetta

Caianiello&#39;s quantum geometrical model with maximal acceleration places the upper limit $μ\leq 719.5$ GeV on the mass of the Higgs boson. The model also provides an equation linking the mass of the W boson to the Higgs mass $μ$ and independent symmetry breaking and mass generating mechanisms. These may further restrict the value of $μ$.

A. Bottino, F. Donato, N. Fornengo, S. Scopel

Recent results of the DAMA/NaI experiment for WIMP direct detection point to a possible annual modulation effect in the detection rate. We show that these results, when interpreted in terms of a relic neutralino, are compatible with supergravity models. Together with the universal SUGRA scheme, we also consider SUGRA models where the unification condition in

Z. Chacko, R. N. Mohapatra

We present a new approach to realizing the Dimopoulos-Wiczek mechanism for doublet-triplet splitting in supersymmetric SO(10). The method can be used to achieve strong suppression of proton decay in a straightforward manner and is relatively economical; in particular the particle spectrum required for its implementation is consistent with the constraints fro

K. A. Milton, I. L. Solovtsov, O. P. Solovtsova

A technique called analytic perturbation theory, which respects the required analytic properties, consistent with causality, is applied to the definition of the running coupling in the timelike region, to the description of inclusive $τ$-decay, to deep-inelastic scattering sum rules, and to the investigation of the renormalization scheme ambiguity. It is sho

A. Bottino, F. Donato, N. Fornengo, S. Scopel

We demonstrate that the further indication of a possible annual modulation effect, singled out by the DAMA/NaI experiment for WIMP direct detection, is widely compatible with an interpretation in terms of a relic neutralino as the major component of dark matter in the Universe. We discuss the supersymmetric features of this neutralino in the Minimal Supersym

D. Yu. Ivanov, M. Wusthoff

We propose to test perturbative QCD in the Regge limit by means of diffractive photon scattering $γp \to γX$ at large $t$ and very high energies $W^2\gg |t|\gg Λ^2_{QCD}$. The helicity amplitudes of this process were calculated using the Lipatov solution of the BFKL equation for $t\neq 0$. We found that the perturbatively calculated cross section for this pr

W. Buchmuller, T. Gehrmann, A. Hebecker

In the semiclassical approach, inclusive and diffractive quark and gluon distributions are expressed in terms of correlation functions of Wilson loops. Each Wilson loop integrates the colour field strength in the area between the trajectories of two fast partons penetrating the proton. We introduce a specific model for averaging over the relevant colour fiel

W. Bernreuther

The salient features of CP-violating interactions in the standard electroweak theory and in a few of its popular extensions are discussed. Moreover a brief overview is given on the status and prospects of searches for CP non-conservation effects in low and high energy experiments.

Richard F. Lebed

Explicit quark-hadron duality in the limit of heavy quark mass is studied using the &#39;t Hooft model, where both partonic and hadronic amplitudes may be computed exactly. Results for weak decays of heavy mesons are presented for both standard spectator decays, where the duality limit is convincingly approached, and annihilation decays of the valence quark-

O. Ramirez del Prado

We present a calculation for the diffractive structure functions $x_{\rm p} F_{\rm T}^{D(3)}$ and $x_{\rm p} F_{\rm L}^{D(3)}$ at low values of $Q^2$ using an eikonal approximation. The non-perturbative model of the stochastic QCD vacuum is used to evaluate the interactions between the quarks (antiquarks) and the color field. The diffractive final state cont

L. L. Frankfurt, M. V. Polyakov, M. Strikman

We evaluate the amplitude of Bethe-Heitler process: γ^* p -> γΔ^+ -electron bremsstrahlung of photon accompanied by the excitation of Δ$ isobar. We show that this background is suppressed at small momentum transfer squared t to a proton relative to that for γ^* p -> γp and γ^* p\to -> Δ^+ - DVCS processes. From experimental point of view, this means that N -

Nils A. Tornqvist

This paper is removed because it used an approximation, which alters some of the conclusions. Another paper will be written in the near future.

I. Royen

I show that a lowest-order pQCD calculation of elastic vector-meson production does reproduce all the features of experimental measurements at HERA, for all Q^2 and all mesons, at fixed energy.

A. Hart, R. W. Haymaker, Y. Sasai

Making use of an Ehrenfest-Maxwell relation we show that in Abelian projected SU(2), in the maximal Abelian gauge, the dynamical electric charge density generated by the coset fields, gauge fixing and ghosts shows antiscreening as in the case of the non-Abelian charge.

Balint Joo, UKQCD Collaboration

We present results from our study of the Parallel Tempering algorithm. We examine the swapping acceptance rate of a twin subensemble PT system. We use action matching technology in an attempt to maximise the swap acceptance rate. We model the autocorrelation times within Parallel Tempering ensembles in terms of autocorrelation times from Hybrid Monte Carlo.

A. Hart, R. W. Haymaker, Y. Sasai

We show in the maximal Abelian gauge the dynamical electric charge density generated by the coset fields, gauge fixing and ghosts shows antiscreening as in the case of the non-Abelian charge. We verify that with the completion of the ghost term all contributions to flux are accounted for in an exact lattice Ehrenfest relation.

A. Hart, J. D. Stack, M. Teper

We apply smoothing to SU(2) lattice field configurations in 3+1 dimensions before fixing to the maximally Abelian gauge. The Abelian projected string tension is shown to be stable under this, whilst the monopole string tension declines by O(30%). Blocking of the SU(2) fields reduces this effect, but the use of extended monopole definitions does not. We discu

J. Cox, J. Jersak, H. Pfeiffer, T. Neuhaus

We continue numerical studies of the spectrum of the pure U(1) lattice gauge theory in the confinement phase, initiated in our previous work. Using the extended Wilson action $ S = -\sum_P [β\cos(Θ_P) + γ\cos(2Θ_P)] $ we address the question of universality of the phase transition line in the ($β,γ$) plane between the confinement and the Coulomb phases. Our

A. Agodi, G. Andronico

The Constrained Effective Potential (CEP) is known to be equivalent to the usual Effective Potential (EP) in the infinite volume limit. We have carried out MonteCarlo calculations based on the two different definitions to get informations on finite size effects. We also compared these calculations with those based on an Improved CEP (ICEP) which takes into a

Robert E. Lanou

A review is presented of several projects under development which aim to be &#34;third generation&#34; solar neutrino detectors.

O. Smirnova, B. Lorstad, R. Muresan

Studies of implementation of the simulation of the Bose-Einstein correlation effects in the JETSET particle generator are performed. Analysis of dependance of the one-dimensional correlation function parameters on the presumed boson source size reveals appearance of the effective new length scale, which limits applicability of the simple momentum-shifting me

The OPAL Collaboration, G. Abbiendi et al

The correlated production of Lambda and Lambdabar baryons has been studied using 4.3 million multihadronic Zo decays recorded with the OPAL detector at LEP. Di-lambda pairs were investigated in the full data sample and for the first time also in 2-jet and 3-jet events selected with the k_t algorithm. The distributions of rapidity differences from correlated

Pierluigi Fortini, Enrico Montanari, Antonello Ortolan, Gerhard Schaefer

The interaction, in the long--wavelength approximation, of normal and superconducting electromagnetic circuits with gravitational waves is investigated. We show that such interaction takes place by modifying the physical parameters R, L, C of the electromagnetic devices. Exploiting this peculiarity of the gravitational field we find that a circuit with two p

Nazeem Mustapha, Charles Hellaby, G. F. R. Ellis

We reconsider the issue of proving large scale spatial homogeneity of the universe, given isotropic observations about us and the possibility of source evolution both in numbers and luminosities. Two theorems make precise the freedom available in constructing cosmological models that will fit the observations. They make quite clear that homogeneity cannot be

Nir Friedman, Joseph Y. Halpern, Daphne Koller

Conditional logics play an important role in recent attempts to formulate theories of default reasoning. This paper investigates first-order conditional logic. We show that, as for first-order probabilistic logic, it is important not to confound statistical conditionals over the domain (such as ``most birds fly&#39;&#39;), and subjective conditionals over po