May 1997 arXiv papers — page 8

Yuval Grossman, Helen R. Quinn

We discuss methods to resolve the ambiguities in CP violating phase angles $ϕ$ that are left when a measurement of $\sin 2 ϕ$ is made. We show what knowledge of hadronic quantities will be needed to fully resolve all such ambiguities.

J. J. M. Verbaarschot

According to the Banks-Casher formula the chiral order parameter is directly related to the spectrum of the Dirac operator. In this lecture, we will argue that some properties of the Dirac spectrum are universal and can be obtained from a random matrix theory with the global symmetries of the QCD partition function. In particular, this is true for the spectr

Bogdan Mihaila, John F. Dawson, Fred Cooper

We solve numerically to order 1/N the time evolution of a quantum dynamical system of N oscillators of mass m coupled quadratically to a massless dynamic variable. We use Schwinger's closed time path (CTP) formalism to derive the equations. We compare two methods which differ by terms of order 1/N^2. The first method is a direct perturbation theory in 1/

Rahul Basu

In this talk I review the low x QCD experimental results from HERA and their theoretical underpinnings. In particular, I discuss the structure function $F_2$, large rapidity gap events, pomeron structure functions and $J/ψ$ production.

Kim Maltman, Michael C. Birse

We revisit the QCD sum-rule treatment of the isospin-breaking axial correlator in light of the recent claim that a previous treatment produced results incompatible with known chiral constraints. The source of the error in the previous analysis is identified, and a corrected version of the sum-rule treatment obtained. It is then shown that, using input from c

S. Esposito, N. Tancredi

We study Pontecorvo neutrino-antineutrino oscillations both in vacuum and in matter within a field theoretic approach, showing that this phenomenon can occur only if neutrinos have a Dirac-Majorana mass term. We find that matter effects suppress these oscillations and cannot explain the solar neutrino problem. On the contrary, a vacuum neutrino-antineutrino

G. V. Dass, K. V. L. Sarma

Extraction of the mass difference $Δm$ from $B^0\bar B^0$ oscillations involves tagging of bottom flavour at production and at decay. We show that the asymmetry between the unmixed and mixed events factorizes into two parts, one depending on the production-tag and the other on the decay-tag.

A. Yu. Ignatiev, G. C. Joshi

We address the problem of string arbitrariness in the quantum field theory of Dirac magnetic monopoles. Different prescriptions are shown to yield different physical results. The constraints due to the discrete symmetries (C and P) are derived for the process of electron- positron annihilation into the monopole-antimonopole pair. In the case of the annihilat

Savas Dimopoulos, Gia Dvali, Riccardo Rattazzi

We show that simple strongly coupled supersymmetric gauge theories with quantum moduli spaces can naturally lead to hybrid inflation. These theories contain no input dimensionful or small parameters. The effective superpotential is linear in the inflaton field; this ensures that supergravity corrections do not spoil the slow roll conditions for inflation. We

Patrick Greene, Lev Kofman, Andrei Linde, Alexei Starobinsky

We consider preheating in the theory $1/4 λϕ^4 + 1/2 g^2ϕ^2χ^2 $, where the classical oscillating inflaton field $ϕ$ decays into $χ$-particles and $ϕ$-particles. The parametric resonance which leads to particle production in this conformally invariant theory is described by the Lame equation. It significantly differs from the resonance in the theory with a q

P. N. Burrows

A pedagogical review is given of precise tests of QCD in electron-positron annihilation. Emphasis is placed on measurements that have served to establish QCD as the correct theory of strong interactions, as well as measurements of the coupling parameter alpha-s. An outlook is given for future important tests at a high energy e+e- collider.

V. A. De Lorenci, R. De Paola, N. F. Svaiter

The spontaneous loss of angular momentum of a spinning cosmic string due to particle emission is discussed. The rate of particle production between two assymptotic spacetimes: the spinning cosmic string spacetime in the infinite past and a non-spinning cosmic string spacetime in the infinite future is calculated.

John D Barrow, Andrew R Liddle

Despite its central role in modern cosmology, doubts are often expressed as to whether cosmological inflation is really a falsifiable theory. We distinguish two facets of inflation, one as a theory of initial conditions for the hot big bang and the other as a model for the origin of structure in the Universe. We argue that the latter can readily be excluded

Ichiro Oda

We study some quantum mechanical aspects of dynamical black holes where the Vaidya metric is used as a model representing evaporating black holes. It is shown that in this model the Wheeler-DeWitt equation is solvable in whole region of spacetime, provided that one considers the ingoing (or outgoing) Vaidya metric and selects a suitable coordinate frame. Thi

P. A. Rikvold, M. A. Novotny, M. Kolesik, H. L. Richards

A nucleation picture of magnetization switching in single-domain ferromagnetic nanoparticles with high local anisotropy is discussed. Relevant aspects of nucleation theory are presented, stressing the effects of the particle size on the switching dynamics. The theory is illustrated by Monte Carlo simulations and compared with experiments on single particles.

O. G. Balev, P. Vasilopoulos

A self-consistent treatment of exchange and correlation interactions in a quantum wire (QW) subject to a strong perpendicular magnetic field is presented using a modified local-density approximation (MLDA). The influence of many-body interactions on the spin-splitting between the two lowest Landau levels (LLs) is calculated within the screened Hartree-Fock a

P. W. Brouwer, P. G. Silvestrov, C. W. J. Beenakker

We present an analytical solution of the delocalization transition that is induced by an imaginary vector potential in a disordered chain [N. Hatano and D. R. Nelson, Phys. Rev. Lett. 77, 570 (1996), cond-mat/9603165]. We compute the relation between the real and imaginary parts of the energy in the thermodynamic limit, as well as finite-size effects. The re

Greg Watson, Geoff Canright, Frank L. Somer

It has recently been shown that the third law of thermodynamics is violated by an entire class of classical Hamiltonians in one dimension, over a finite volume of coupling-constant space, assuming only that certain elementary symmetries are exact, and that the interactions are finite-ranged. However, until now, only the existence of such Hamiltonians was kno

Pep Español

We formulate the stochastic differential equations for non-linear hydrodynamic fluctuations. The equations incorporate the random forces through a random stress tensor and random heat flux as in the Landau and Lifshitz theory. However, the equations are non-linear and the random forces are non-Gaussian. We provide explicit expressions for these random quanti

G. Lattanzi, G. Nardulli, G. Pasquariello, S. Stramaglia

We consider a neural network with adapting synapses whose dynamics can be analitically computed. The model is made of $N$ neurons and each of them is connected to $K$ input neurons chosen at random in the network. The synapses are $n$-states variables which evolve in time according to Stochastic Learning rules; a parallel stochastic dynamics is assumed for n

Peter D. Olmsted, C. -Y. D. Lu

We demonstrate how to construct dynamic phase diagrams for complex fluids that undergo transitions under flow, in which the conserved composition variable and the broken-symmetry order parameter (nematic, smectic, crystalline, etc.) are coupled to shear rate. Our construction relies on a selection criterion, the existence of a steady interface connecting two

Atsuhiro Kitazawa, Kiyohide Nomura

The phase diagram of the spin-1 bond-alternating XXZ chain is studied numerically. This model is appropriate to study the VBS picture and the hidden Z_2\times Z_2 symmetry concerning to the Haldane gap problem. The possible phases are the ferromagnetic, the XY, the Haldane, the dimer, and the Néel ones. The critical properties of this model can be interprete

Ugo Bastolla, Peter Grassberger

We study numerically a lattice model of semiflexible homopolymers with nearest neighbor attraction and energetic preference for straight joints between bonded monomers. For this we use a new algorithm, the "Pruned-Enriched Rosenbluth Method" (PERM). It is very efficient both for relatively open configurations at high temperatures and for compact and

A. Freund

In this paper, we propose an extension of the Smolin-model of a galactic disc in isolated, flocculent SC-type galaxies. This model supplies the necessary mechanism to suppress spatial inhomogeneities on short distance scales not present in the model proposed by Smolin.

Edward C. Moran, David J. Helfand

We present a high-quality X-ray spectrum in the 3--53 keV rest-frame band of the radio-loud quasar 1508+5714, by far the brightest known X-ray source at z > 4. A simple power-law model with an absorption column density equal to the Galactic value in the direction of the source provides an excellent and fully adequate fit to the data; the measured power-law p

M. S. Sahu, J. Chris Blades

Archival Goddard High Resolution Spectrograph low-resolution spectra of NGC 1705, with wavelength ranges 1170.3 to 1461.7 A and 1453.5 to 1740.1 A and a velocity resolution of about 100 km\s, have been used to derive the velocity structure and equivalent widths of the absorption lines of Si II 1190.42, 1260.42, 1304.37 and 1526.71 A, S II 1253 , Al II 1670.7

Ana Campos

In this paper the counts and colors of the faint galaxies observed in the Hubble Deep Field are fitted by means of simple luminosity evolution models which incorporate a numerous population of fading dwarfs. The observed color distribution of the very faint galaxies allows now to put constrains on the star formation history in dwarfs. It is shown that the st

Tema Fridman, David Merritt

The orbital structure of triaxial models with weak central density cusps, $ρ\propto r^{-γ}, gamma < 1$, is investigated. The stability of the $x$- (long-) axis orbit -- and hence the existence of box orbits -- depends sensitively on $γ$; the range of model shapes for which the $x$-axis orbit is stable becomes progressively smaller as $γ$ approaches one. The

Cheongho Han, Seunghun Lee

We determine the microlensing event rate distribution, $Γ(t_{E})$, that is properly normalized by the first year MACHO group observations (Alcock et al. 1997). By comparing the determined $Γ(t_{E})$ with various MF models of lens populations to the observed distribution, we find that stars and WDs explain just $\sim 49%$ of the total event rate and $\sim 37%

George F. Smoot

This paper reports a summary of the contents contents of six hours of lectures on the CMB anisotropy experiments given at the Strasbourg NATO school on the CMB and cosmology. (Its companion paper, astro-ph/9705101 reports the lectures on the CMB spectrum.) A context is set as a bridge from the theoretical CMB anisotropy lectures and the experimental situatio

O. Bergman, M. R. Gaberdiel, G. Lifschytz

The potential of a configuration of two Dirichlet branes for which the number of ND-directions is eight is determined. Depending on whether one of the branes is an anti-brane or a brane, the potential vanishes or is twice as large as the dilaton-gravitational potential. This is shown to be related to the fact that a fundamental string is created when two suc

Chia-Hung V. Chang, Guey-Lin Lin, York-Peng Yao

The short distance QCD corrections to $b\to sγγ$ are calculated in the leading logarithmic approximation. The equivalence of operator basis reduction for S-matrix elements by using the equations of motion or by proving a low energy theorem is discussed. We apply the above results to the exclusive $B_s\to γγ$ decay. The branching ratio of this decay is found

Maya Paczuski, Stefan Boettcher

We numerically study avalanches in the two dimensional Abelian sandpile model in terms of a sequence of waves of toppling events. Priezzhev et al [PRL 76, 2093 (1996)] have recently proposed exact results for the critical exponents in this model based on the existence of a proposed scaling relation for the difference in sizes of subsequent waves, $Δs =s_{k}-

Harry Buhrman, Richard Cleve, Wim van Dam

We consider a variation of the multi-party communication complexity scenario where the parties are supplied with an extra resource: particles in an entangled quantum state. We show that, although a prior quantum entanglement cannot be used to simulate a communication channel, it can reduce the communication complexity of functions in some cases. Specifically

V. D. Lyakhovsky, V. I. Tkach

The quantum double for the quantized BRST superalgebra is studied. The corresponding R-matrix is explicitly constucted. The Hopf algebras of the double form an analytical variety with coordinates described by the canonical deformation parameters. This provides the possibility to construct the nontrivial quantization of the proper time supergroup cotangent bu

Muneyuki Ishida, Shin Ishida, Masuho Oda

The spectra and form factors of exclusive semi-leptonic decays of B-meson are analyzed, taking account of confined effects of quarks by the Covariant Oscillator Quark Model. The predicted B --> (D*,D)l nubar_l spectra with the conventional value of V_cb are fit well to the high-precision experiment. It is also shown the values of V_cb and V_ub obtained throu

Efrat Shimshoni

It is shown that the Coulomb drag between two identical layers in the Anderson insulting state indicates a striking difference between the Mott and Efros-Shklovskii (ES) insulators. In the former, the trans-resistance $ρ_t$ is monotonically increasing with the localization length $ξ$; in the latter, the presence of a Coulomb gap leads to an opposite result:

Pierre Collet, Jean-Pierre Eckmann

Using, and extending, striking inequalities by V.V. Ivanov on the down-crossings of monotone functions and ergodic sums, we give universal bounds on the probability of finding oscillations of observables in 1-dimensional lattice gases in infinite volume. In particular, we study the finite volume average of the occupation number as one runs through an increas

The SLAC E154 Collaboration, K. Abe

We present a Next-to-Leading order perturbative QCD analysis of world data on the spin dependent structure functions $g_1^p, g_1^n$, and $g_1^d$, including the new experimental information on the $Q^2$ dependence of $g_1^n$. Careful attention is paid to the experimental and theoretical uncertainties. The data constrain the first moments of the polarized vale

Pavlos M. Vranas

Domain Wall Fermions utilize an extra space time dimension to provide a method for restoring the regularization induced chiral symmetry breaking in lattice vector gauge theories even at finite lattice spacing. The breaking is restored at an exponential rate as the size of the extra dimension increases. Before this method can be used in dynamical simulations

Jordi Comellas

The connection between the anomalous dimension and some invariance properties of the fixed point actions within exact RG is explored. As an application, Polchinski equation at next-to-leading order in the derivative expansion is studied. For the Wilson fixed point of the one-component scalar theory in three dimensions we obtain the critical exponents η=0.042

F. Bagnoli, N. Boccara, P. Palmerini

We study the phase diagram and the critical behavior of a one-dimensional radius-1 two-state totalistic probabilistic cellular automaton having two absorbing states. This system exhibits a first-order phase transition between the fully occupied state and the empty state, two second-order phase transitions between a partially occupied state and either the ful

V. V. Flambaum, G. F. Gribakin, O. P. Sushkov

The paper in its present form has been withdrawn.

Jin Min Yang, Bing-Lin Young, X. Zhang

The flavor changing top quark decays t -> cV (V=Z,photon,gluon) induced by R-parity-violating couplings in the minimal supersymmetric standard model (MSSM) are evaluated. We find that the decays t -> cV can be significantly enhanced relative to those in the R-parity conserving SUSY model. Our results show that the top quark FCNC decay can be as large as Br(t

Renat Zhdanov, Ihor Revenko, Wilhelm Fushchych

Using the Lie&#39;s infinitesimal method we establish that the Dirac equation in one variable is integrable by quadratures if the potential V(x) is a solution of one of the equations of the stationary mKdV hierarchy.

Renat Zhdanov

Using the S.Lie&#39;s infinitesimal approach we establish the connection between integrability of a one-parameter family of the Riccati equations and the stationary KdV hierarchy.

Federico Finkel, Niky Kamran

We find exact solutions of the time-dependent Schrödinger equation for a family of quasi-exactly solvable time-dependent potentials by means of non-unitary gauge transformations.

M. Fukuma, H. Kawai, Y. Kitazawa, A. Tsuchiya

We derive Schwinger-Dyson equations for the Wilson loops of a type IIB matrix model. Superstring coordinates are introduced through the construction of the loop space. We show that the continuum limit of the loop equation reproduces the light-cone superstring field theory of type IIB superstring in the large-N limit. We find that the interacting string theor

L. Baulieu, H. Kanno, I. M. Singer

We construct nearly topological Yang-Mills theories on eight dimensional manifolds with a special holonomy group. These manifolds are the Joyce manifold with $Spin(7)$ holonomy and the Calabi-Yau manifold with SU(4) holonomy. An invariant closed four form $T_{μνρσ}$ on the manifold allows us to define an analogue of the instanton equation, which serves as a

W. L. van Neerven

We present the higher order QCD corrections to the fragmentation functions and the corresponding cross sections.

V. Gogohia, B. Lukács, M. Prisznyák

By using an Ansatz for the pressure (measured in terms of the bag constant) of the hadronic gas in equilibrium, we have formulated a new bag-type model for the phase transition, i. e. the extended bag model. This allows one to take into account the nonperturbative vacuum effects from both sides of the equilibrium condition. We have explicitly shown that our

Herbert Neuberger

The main construction of the paper in the title [hep-lat/9612017] is summarized using more standard particle physics language. Also, a flaw is pointed out and several objections to the more general thoughts expressed by Creutz et. al. are raised.

The SLAC E154 Collaboration, K. Abe

We report on a precision measurement of the neutron spin structure function $g^n_1$ using deep inelastic scattering of polarized electrons by polarized ^3He. For the kinematic range 0.014<x<0.7 and 1 (GeV/c)^2< Q^2< 17 (GeV/c)^2, we obtain $\int^{0.7}_{0.014} g^n_1(x)dx = -0.036 \pm 0.004 (stat) \pm 0.005 (syst)$ at an average $Q^2=5 (GeV/c)^2$. We find rela

U. Kasper, M. Rainer, A. Zhuk

We consider anisotropic cosmological models with an universe of dimension 4 or more, factorized into n>1 Ricci-flat spaces, containing an m-component perfect fluid of m non-interacting homogeneous minimally coupled scalar fields under special conditions. We describe the dynamics of the universe: It has a Kasner-like behaviour near the singularity and isotrop

Luis P. Chimento, Alejandro S. Jakubi, Vicenç Méndez

The Einstein&#39;s field equations of FRW universes filled with a dissipative fluid described by full theory of causal transport equations are analyzed. New exact solutions are found using a non-local transformations on the nonlinear differential equation for the Hubble factor. The stability of the de Sitter and asymptotically friedmannian solutions are anal

Ana Canas da Silva, Yael Karshon, Susan Tolman

We prove several versions of &#34;quantization commutes with reduction&#34; for circle actions on manifolds that are not symplectic. Instead, these manifolds possess a weaker structure, such as a spin^c structure. Our theorems work whenever the quantization data and the reduction data are compatible; this condition always holds if we start from a presymplect

Oded Agam, Igor L. Aleiner

Recent experiment on the tunneling spectra of ultrasmall superconducting grains revealed an unusual structure of the lowest differential conductance peak for grains in the odd charging states. We explain this behavior by nonequilibrium ``gapless&#39;&#39; excitations associated with different energy levels occupied by the unpaired electron. These excitations

F. C. Alcaraz, S. Dasmahapatra, V. Rittenberg

Stationary probability distributions for stochastic processes on linear chains with closed or open ends are obtained using the matrix product Ansatz. The matrices are representations of some quadratic algebras. The algebras and the types of representations considered depend on the boundary conditions. In the language of quantum chains we obtain the ground st

Chung-Yu Mou, J. W. P. Hsu

We examine the applicability of the continuum model to describe the surface morphology of a hetero-growth system: compositionally-graded, relaxed GeSi films on (001) Si substrates. Surface roughness versus lateral dimension was analyzed for samples what were grown under different conditions. We find that all samples belong to the same growth class, in which

Pavel Kroupa

Since the major review by Scalo (1986), significant progress has been achieved in constraining the mass function (MF) of low-mass stars. The break-throughs which today allow a much better understanding of the stellar luminosity function (LF) and the underlying MF are documented here and the resulting MF for Galactic field stars is confronted with microlensin

Peter Hoeflich, J. Craig Wheeler

We examine the current status of the spectral analysis of SN1987A during its early stages. Issues of the shock breakout and UV flash, the density and chemical structure, and masses of different layers are discussed. A decade later, several aspects need a fresh look and interpretation. We summarize what questions have been answered and where some results disa

Tom Abel, Peter Anninos, Michael L. Norman, Yu Zhang

We investigate the possibility of very early formation of primordial star clusters from high-σperturbations in cold dark matter dominated structure formation scenarios. For this we have developed a powerful 2-level hierarchical cosmological code with a realistic and robust treatment of multi-species primordial gas chemistry, paying special attention to the f

James B. Dove, Jorn Wilms, Michael Maisack, Mitchell C. Begelman

We apply our self-consistent accretion disk corona (ADC) model, with two different geometries, to the broad-band X-ray spectrum of the black hole candidate Cygnus X-1. As shown in a companion paper (Dove, Wilms, and Begelman), models where the Comptonizing medium is a slab surrounding the cold accretion disk cannot have a temperature higher than about 120 ke

John P. Blakeslee, John L. Tonry, Mark R. Metzger

We study the globular cluster (GC) populations of 21 giant elliptical galaxies in 19 Abell clusters. This method, applied here primarily in the R band, is based on the surface brightness fluctuations technique of extragalactic distance measurement. The sample galaxies range in redshift from 5000 to 10,000 \kms, and were selected primarily from the Lauer & Po

Rahul Pandharipande

A geometric construction of Getzler&#39;s cohomological relation in the moduli space of 4 pointed elliptic curves is given by a push-forward of a natural rational equivalence in a space of admissible covers. In particular, Getzler&#39;s relation is shown to be a rational equivalence. The recursion for the elliptic Gromov-Witten invariants of P^2 predicted by

C. Fosco, G. L. Rossini, F. A. Schaposnik

We compute the exact induced parity-breaking part of the effective action for 2+1 massive fermions in $QED_3$ at finite temperature by calculating the fermion determinant in a particular background. The result confirms that gauge invariance of the effective action is respected even when large gauge transformations are considered.

John Preskill

I assess the potential of quantum computation. Broad and important applications must be found to justify construction of a quantum computer; I review some of the known quantum algorithms and consider the prospects for finding new ones. Quantum computers are notoriously susceptible to making errors; I discuss recently developed fault-tolerant procedures that

John Preskill

The new field of quantum error correction has developed spectacularly since its origin less than two years ago. Encoded quantum information can be protected from errors that arise due to uncontrolled interactions with the environment. Recovery from errors can work effectively even if occasional mistakes occur during the recovery procedure. Furthermore, encod

A. S. Cattaneo, P. Cotta-Ramusino, F. Fucito, M. Martellini

The classical action for pure Yang--Mills gauge theory can be formulated as a deformation of the topological $BF$ theory where, beside the two-form field $B$, one has to add one extra-field $η$ given by a one-form which transforms as the difference of two connections. The ensuing action functional gives a theory that is both classically and quantistically eq

Michael Spira

Higgs boson production at the LHC within the Standard Model and its minimal supersymmetric extension is reviewed. The predictions for decay rates and production cross sections are updated by choosing the present value of the top quark mass and recent parton density sets. Moreover, all relevant higher order corrections, some of which have been obtained only r

M. K. Volkov, D. Ebert, M. Nagy

A chiral SU(2) x SU(2) Lagrangian containing, besides the usual meson fields, their first radial excitations is considered. The Lagrangian is derived by bosonization of the Nambu-Jona-Lasinio quark model with separable non-local interactions, with form factors corresponding to 3-dimensional ground and excited state wave functions. The spontaneous breaking of

S. E. Hjelmeland, U. Lindström

This is the written version of a series of lectures reviewing the basics of duality as applied to p-forms and sigma-models. The ideas are introduced by way of worked examples, often quite detailed. Our approach is very pedestrian and the presentation is aimed at non-specialists, such as e.g. graduate students.

Masato Hisakado

We study the unitary matrix model with a topological term. We call the topological term the theta term. In the symmetric model there is the phase transition between the strong and weak coupling regime at $λ_{c}=2$. If the Wilson term is bigger than the theta term, there is the strong-weak coupling phase transition at the same $λ_{c}$. On the other hand, if t

L. V. Bogdanov, B. G. Konopelchenko

Analytic-bilinear approach for construction and study of integrable hierarchies is discussed. Generalized multicomponent KP and 2D Toda lattice hierarchies are considered. This approach allows to represent generalized hierarchies of integrable equations in a condensed form of finite functional equations. Generalized hierarchy incorporates basic hierarchy, mo

Masanao Ozawa

This paper gives new foundations of quantum state reduction without appealing to the projection postulate for the probe measurement. For this purpose, the quantum Bayes principle is formulated as the most fundamental principle for determining the state of a quantum system, and the joint probability distribution for the outcomes of local successive measuremen

J. Avan, L. Frappat, M. Rossi, P. Sorba

It is shown that the elliptic algebra A_{p,q}(sl(2)_c) has a non trivial center at the critical level $c=-2$, generalizing the result of Reshetikhin and Semenov-Tian-Shansky for trigonometric algebras. A family of Poisson structures indexed by a non-negative integer $k$ is constructed on this center.

Stephane Focant, Thierry Gallay

We study a one-dimensional reaction-diffusion system which describes an isothermal autocatalytic chemical reaction involving both a quadratic (A + B -> 2B) and a cubic (A + 2B -> 3B) autocatalysis. The parameters of this system are the ratio D = D_B/D_A of the diffusion constants of the reactant A and the autocatalyst B, and the relative activity k of the cu

Fl. Stancu, S. Pepin, L. Ya. Glozman

We study the short-range nucleon-nucleon interaction in a chiral constituent quark model by diagonalizing a Hamiltonian comprising a linear confinement and a Goldstone boson exchange interaction between quarks. The six-quark harmonic oscillator basis contains up to two excitation quanta. We show that the highly dominant configuration is $\mid s^4p^2[42]_O [5

Bernhard Koeck

Let G be a finite group and K a number field. We show that the &#34;k-th Adams operation&#34; defined by Cassou-Nogues and Taylor on the locally free class group Cl(Z_K G) is a symmetric power operation, if k is coprime to the order of G. Using the equivariant Adams-Riemann-Roch theorem, we furthermore give a geometric interpretation of a formula established

Cameron McA. Gordon, Ying-Qing Wu

Suppose $M$ is a hyperbolic 3-manifold which admits two Dehn fillings $M(r_1)$ and $M(r_2)$ such that $M(r_1)$ contains an essential torus and $M(r_2)$ contains an essential annulus. It is known that $Δ= Δ(r_1, r_2) \leq 5$. We will show that if $Δ= 5$ then $M$ is the Whitehead sister link exterior, and if $Δ= 4$ then $M$ is the exterior of either the Whiteh

Miklós Bóna

Using earlier results we prove a formula for the number $W_{(n,k)}$ of 2-stack sortable permutations of length $n$ with $k$ runs, or in other words, $k-1$ descents. This formula will yield the suprising fact that there are as many 2-stack sortable permutations with $k-1$ descents as with $k-1$ ascents. We also prove that $W_{(n,k)}$ is unimodal in $k$, for a

Vladimir Shpilrain

Combinatorial methods (or methods of elementary transformations) came to group theory from low-dimensional topology in the beginning of the century. Soon after that, combinatorial group theory became an independent area with its own powerful techniques. On the other hand, combinatorial commutative algebra emerged in the sixties, after Buchberger introduced w

Djordje Minic

Matrix String Theory of Banks, Fischler, Shenker and Susskind can be understood as a generalized quantum theory (provisionally named &#34;quansical&#34; theory) which differs from Adler&#39;s generalized trace quantum dynamics. The effective Matrix String Theory Hamiltonian is constructed in a particular fermionic realization of Matrix String Theory treated

Djordje Minic

The planar Yang-Mills theory in three spatial dimensions is examined in a particular representation which explicitly embodies factorization. The effective planar Yang-Mills theory Hamiltonian is constructed in this representation.

D. Boyanovsky, Will Loinaz, R. S. Willey

We study a simplified version of the Standard Electroweak Model and introduce the concept of the physical gauge invariant effective potential in terms of matrix elements of the Hamiltonian in physical states. This procedure allows an unambiguous identification of the symmetry breaking order parameter and the resulting effective potential as the energy in a c

Naoya Hata, Paul Langacker

We present an updated analysis of astrophysical solutions, two-flavor MSW solutions, and vacuum oscillation solutions to the solar neutrino anomaly. The recent results of each of the five solar neutrino experiments are incorporated, including both the zenith angle (day-night) and spectral information from the Kamiokande experiment, and the preliminary Super-

S. I. Bityukov, N. V. Krasnikov

We investigate the possibility to look for new physics by the measurement of the 4-jet cross section at LHC and FNAL. In particular, we consider the model with scalar colour octet and the supersymmetric model with R-parity violation. In both models pair produced new particles decay into 2 jets thus leading to 4-jet events. Therefore, the measurement of the d

T. Gehrmann

The results of a recent calculation of the QCD corrections to the polarized Drell-Yan process are summarized. Some implications for the production of vector bosons at RHIC are discussed.

D. Delepine, J. -M. Gerard, R. Gonzalez Felipe, J. Weyers

A dynamical scheme where the third generation of quarks plays a distinctive role is implemented. New interactions with a $θ$ term induce the breaking of the electroweak symmetry and the top-bottom mass splitting. A large CP-violating phase naturally follows from the latter.

G. Montagna, M. Moretti, O. Nicrosini, F. Piccinini

The production of an intermediate-mass Higgs boson in processes of the kind $e^+ e^- \to 6$ fermions at the energies of future linear colliders is studied. The recently developed and fully automatic algorithm/code ALPHA is used to compute the tree-level scattering amplitudes for the reactions $e^+ e^- \to μ^+ μ^- τ^- \barν_τ u \bar d, μ^+ μ^- e^- \barν_{e} u

R. S. Bhalerao, S. K. Gupta, P. Shukla

We recently presented a method of analyzing invariant-mass spectra of kaon pairs resulting from decay of $ϕ$ mesons produced in high-energy heavy-ion collisions. It can be used to extract the shifts in the mass and the width ($ΔM$ and $ΔΓ$) of the $ϕ$ mesons when they are inside the dense matter formed in these collisions. We have now performed a Monte-Carlo

A. Ardekani, A. G. Williams

We study Monte Carlo calculations of the effective potential for a scalar field theory using three techniques. One of these is a new method proposed and tested for the first time. In each case we extract the renormalised quantities of the theory. The system studied in our calculations is a one component $ϕ^4$ model in two dimensions. We apply these methods t

L. I. Glazman, A. I. Larkin

We examine the phase diagram of an ordered one-dimensional Josephson array of small grains. The average grain charge in such a system can be tuned by means of gate voltage. At small grain-to-grain conductance, this system is strongly correlated because of the charge discreteness constraint (Coulomb blockade). At the gate voltages in the vicinity of the charg

E. E. Narimanov, A. Douglas Stone

The anomalously strong scarring of wavefunctions found in numerical studies of quantum wells in a tilted magnetic field is shown to be due to special properties of the classical dynamics of this system. A certain subset of periodic orbits are identified which are nearly stable over a very large interval of variation of the classical dynamics; only this subse

Jan R. Engelbrecht, Alexander Nazarenko, Mohit Randeria, Elbio Dagotto

We study the anomalous normal state properties of a simple two-dimensional model whose ground state is a d-wave superconductor. Using a self-consistent, conserving formulation, we show that pairing correlations above T_c lead to the appearance of a highly anisotropic pseudogap in the electronic spectral function and the destruction of the Fermi surface. We d

J. V. Alvarez, J. Gonzalez, F. Guinea, M. A. H. Vozmediano

We apply a renormalization group approach to the determination of the phase diagram of the t-t&#39; Hubbard model at the Van Hove filling, as function of t&#39;/t, for small values of U/t. The model presents ferromagnetic, antiferromagnetic and d-wave superconducting phases. Antiferromagnetism and d-wave superconductivity arise from the same interactions, an

O. Derzhko, J. Richter

The paper presents exact calculations of thermodynamic quantities for the spin-1/2 isotropic XY chain with random lorentzian intersite interaction and transverse field that depends linearly on the surrounding intersite interactions.

N. B. Ivanov, J. Richter

We consider a class of one-dimensional Heisenberg spin models (plaquette chains) related to the recently found 1/5-depleted square-lattice Heisenberg system $CaV_4O_9$. A number of exact and exact-numerical results concerning the properties of the competing dimer and resonating plaquette phases are presented.

Maurizio Serva

The model considered is a d=2 layered random Ising system on a square lattice with nearest neighbours interaction. It is assumed that all the vertical couplings are equal and take the positive value J while the horizontal couplings are quenched random variables which are equal in the same row but can take the two possible values J and J-K in different rows.

D. A. Johnston, P. Plechac

In a series of papers we have found identical behaviour for various spin models on thin random graphs - Feynman diagrams - and the corresponding Bethe lattices. In this note we observe that in all cases the ratios of various saddle point equations in the random graph approach are identical in form to the fixed point(s) of the recursion relations which are us