June 2004 arXiv papers — page 10

Giancarlo Ferrera, Barbara Mele

In the Minimal Supersymmetric Standard Model (MSSM), we study the light Higgs-boson radiation off a light-chargino pair in the process e+e- -> h chi^+ chi^- at linear colliders with \sqs=500 GeV. We analyze cross sections in the regions of the MSSM parameter space where the process can not proceed via on-shell production and subsequent decay of either heavie

Batool Safarzadeh

We consider ${\cal N}=2$ supersymmetric U(1) gauge theory in a nonanticommutative ${\cal N}=2$ harmonic superspace with the singlet deformation. We generalize analytic superfield and gauge parameter to the nonanticommutative theory so that gauge transformations act on the component fields in a canonical form (Seiberg-Witten map). This superfield, upon a fiel

B. Mookerjea, C. Kramer, M. Nielbock, L. -A. Nyman

We have mapped the dust continuum emission from the molecular cloud covering a region of 28pcx94pc associated with the well-known HII region RCW 106 at 1.2 mm using SIMBA on SEST. The observations, having an HPBW of 24" (0.4 pc), reveal 95 clumps. Owing to the higher sensitivity to colder dust and higher angular resolution the present observations identi

G. Laveissiere

We have made the first measurements of the virtual Compton scattering process via the e p -> e p gamma exclusive reaction at Q**2 = 1 GeV**2 in the nucleon resonance region. The cross section is obtained at center of mass (CM) backward angle, theta_gamma_gamma*, in a range of total (gamma* p) CM energy W from the proton mass up to W = 1.91 GeV. The data show

M. Beccaria, H. Eberl, F. M. Renard, C. Verzegnassi

We consider the production of neutralino, chargino, and charged Higgs boson pairs in the MSSM framework at future $e^+e^-$ colliders. We show that, for c.m. energies in the one TeV range and in a ``moderately'' light SUSY scenario, a combined analysis of the slopes of these production cross sections could lead to a strong consistency test involving t

Benjamin A. Burrington, James T. Liu, Leopoldo A. Pando Zayas, Diana Vaman

We construct backreacted D3/D7 supergravity backgrounds which are dual to four-dimensional N=1 and N=2 supersymmetric Yang-Mills at large N_c with flavor quarks in the fundamental representation of SU(N_c). We take into account the backreaction of D7-branes on either AdS(5) x S(5) or AdS(5) x T^{1,1}, or more generically on backgrounds where the space transv

Bodo Geyer, Peter Lavrov

The study of recently introduced Fedosov supermanifolds is continued. Using normal coordinates, properties of even and odd symplectic supermanifolds endowed with a symmetric connection respecting given sympletic structure are studied.

Ya. S. Greenberg, I. L. Novikov, V. Schultze, H. -G. Meyer

A theory for the voltage-current characteristic in high TC DC SQUIDs, which accounts for a second harmonic in the junction current-phase relation, is developed. The comparison with experiment is performed. It is shown that if the second harmonic is prevailed, the theory can explain the large deviations of the experimental voltage modulation from theoretical

Christian Beck, Michael C. Mackey

The experimentally measured spectral density of current noise in Josephson junctions provides direct evidence for the existence of zero-point fluctuations. Assuming that the total vacuum energy associated with these fluctuations cannot exceed the presently measured dark energy of the universe, we predict an upper cutoff frequency of nu_c=(1.69 +- 0.05) x 10^

D. Gwion Evans

Given a row-finite $k$-graph $\Lambda$ with no sources we investigate the $K$-theory of the higher rank graph $C^*$-algebra, $C^*(\Lambda)$. When $k=2$ we are able to give explicit formulae to calculate the $K$-groups of $C^*(\Lambda)$. The $K$-groups of $C^*(\Lambda)$ for $k>2$ can be calculated under certain circumstances and we consider the case $k=3$. We

Antonino Di Piazza, Giorgio Calucci

We present the calculation of the probability production of an electron-positron pair in the presence of a strong magnetic field with time-varying strength. The calculation takes into account the presence of a strong, constant and uniform gravitational field in the same direction of the magnetic field. The results show that the presence of the gravitational

Michael Mayer, Wolfgang J. Duschl

We present stationary models of protostellar population III (Pop III, for short) accretion discs, compare them to Pop I discs, and investigate the influence of the different chemical compositions on the occurence of gravitational, thermal and thermal-viscous instabilities in the discs. In particular in the cooler regions, we find major differences between Po

Krzysztof Redlich

We compare the statistical thermodynamics of hadron resonance gas with recent LGT results at finite chemical potential. We argue that for $T\leq T_c$ the equation of state derived from Monte--Carlo simulations of two quark--flavor QCD at finite chemical potential is consistent with that of a hadron resonance gas when applying the same set of approximations a

Vladimir M. Lipunov

Recently estimation of merger rate of double neutron stars from the observations of PSR J0737-3039 by Burgay is discussed under real astrophysical background.

B. Cessac, J. A. Sepulchre

We apply the linear response theory developed in \cite{Ruelle} to analyze how a periodic signal of weak amplitude, superimposed upon a chaotic background, is transmitted in a network of non linearly interacting units. We numerically compute the complex susceptibility and show the existence of specific poles (stable resonances) corresponding to the response t

R. Mathieu, D. Akahoshi, A. Asamitsu, Y. Tomioka

The magnetic and electrical properties of high quality single crystals of $A$-site disordered (solid solution) Ln$_{0.5}$Ba$_{0.5}$MnO$_3$ are investigated near the phase boundary between the spin glass insulator and colossal-magnetoresistive ferromagnetic metal, locating near Ln = Sm. The temperature dependence of the ac-susceptibility and the x-ray diffuse

Volodymyr M. Gorkavenko, Alexander V. Viznyuk

We consider the backreaction of the vacuum polarization effect for a massive charged scalar field in the presence of a singular magnetic massless string on the background metric. Using semiclassical approach, we find the first-order (in $\hbar$ units) metric modifications and the corresponding gravitational potential and deficit angle. It is shown that, in c

Bradley Efron, Trevor Hastie, Iain Johnstone, Robert Tibshirani

The purpose of model selection algorithms such as All Subsets, Forward Selection and Backward Elimination is to choose a linear model on the basis of the same set of data to which the model will be applied. Typically we have available a large collection of possible covariates from which we hope to select a parsimonious set for the efficient prediction of a r

M. Sasaki, P. E. Jönsson, H. Takayama, H. Mamiya

Many dense magnetic nanoparticle systems exhibit slow dynamics which is qualitatively indistinguishable from that observed in atomic spin glasses and its origin is attributed to dipole interactions among particle moments (or superspins). However, even in dilute nanoparticle systems where the dipole interactions are vanishingly small, slow dynamics is observe

R. W. Spekkens

An operational definition of contextuality is introduced which generalizes the standard notion in three ways: (1) it applies to arbitrary operational theories rather than just quantum theory, (2) it applies to arbitrary experimental procedures, rather than just sharp measurements, and (3) it applies to a broad class of ontological models of quantum theory, r

Yong-Geun OH

The author previously defined the spectral invariants, denoted by $ρ(H;a)$, of a Hamiltonian function $H$ as the mini-max value of the action functional $Å_H$ over the Novikov Floer cycles in the Floer homology class dual to the quantum cohomology class $a$. The spectrality axiom of the invariant $ρ(H;a)$ states that the mini-max value is a critical value of

Svante Janson, Elchanan Mossel

Consider a Markov chain on an infinite tree T=(V,E) rooted at ρ. In such a chain, once the initial root state σ(ρ) is chosen, each vertex iteratively chooses its state from the one of its parent by an application of a Markov transition rule (and all such applications are independent). Let μ_j denote the resulting measure for σ(ρ)=j. The resulting measure μ_j

Stefan Boettcher, Paolo Sibani

Using a non-thermal local search, called Extremal Optimization (EO), in conjunction with a recently developed scheme for classifying the valley structure of complex systems, we analyze a short-range spin glass. In comparison with earlier studies using a thermal algorithm with detailed balance, we determine which features of the landscape are algorithm depend

Lan Yin, Ping Ao

In this paper, we study the properties of a phase slip in a superfluid Fermi gas near a Feshbach resonance. The phase slip can be generated by the phase imprinting method. Below the superfluid transition temperature, it appears as a dip in the density profile, and becomes more pronounced when the temperature is lowered. Therefore the phase slip can provide a

Michael P. Ryan,, Alexander V. Turbiner

In quantum mechanics the kinetic energy term for a single particle is usually written in the form of the Laplace-Beltrami operator. This operator is a factor ordering of the classical kinetic energy. We investigate other relatively simple factor orderings and show that the {\it only} other solution for a conformally flat metric is the conformally invariant L

L. Kaplan, Kh. Kh. Shakov, A. Chalastaras, M. Maggio

We examine time ordering effects in strongly, suddenly perturbed two-state quantum systems (kicked qubits) by comparing results with time ordering to results without time ordering. Simple analytic expressions are given for state occupation amplitudes and probabilities for singly and multiply kicked qubits. We investigate the limit of no time ordering, which

L. Praxmeyer, B. -G. Englert, K. Wodkiewicz

We construct a wide class of bounded continuous variables observables that lead to violations of Bell inequalities for the EPR state and give an intuitive Wigner function explanation how to predetermine which operators won't ever exceed the bounds given by local theories.

Qing-yu Cai

In this comment, we want to emphasize that when the state of the two qubit is $|0>_{B}|1>_{A}$ or $|1>_{A}|0>_{B}$, Bob's Bell basis measurement outcome can not be $|ϕ^{\pm}>$. Also, when the product state is $|0> |0>$ or $|1> |1>$, Bob's measurement outcome can not be $|ψ^{\pm}>$.

Chirag Dhara, N. D. Hari Dass

Purification of mixed states in Quantum Mechanics, by which we mean the transformation into pure states, has been viewed as an {\it Operation} in the sense of Kraus et al and explicit {\it Kraus Operators} \cite{kra1,kra2,kra3} have been constructed for two seperate purification protocols. The first one, initially due to Schrodinger \cite{sch} and subsequent

Chirag Dhara, N. D. Hari Dass

When an optimal measurement is made on a qubit and what we call an Unbiased Mixture of the resulting ensembles is taken, then the post measurement density matrix is shown to be related to the pre-measurement density matrix through a simple and linear relation. It is shown that such a relation holds only when the measurements are made in Mutually Unbiased Bas

David Fattal, Toby S. Cubitt, Yoshihisa Yamamoto, Sergey Bravyi

We define a multi-partite entanglement measure for stabilizer states, which can be computed efficiently from a set of generators of the stabilizer group. Our measure applies to qubits, qudits and continuous variables.

Jianming Wen, Morton H. Rubin

We examine the possibility of storing and retrieving a single photon using electromagnetically induced transparency (EIT). We consider the theory of a proof of principle two-photon interference experiment, in which an atomic vapor cell is placed in one arm of a two-photon interferometer. Since the two-photon state is entangled, we can examine the degree to w

P. Štelmachovič, V. Bužek

We present detailed analytical calculations for an 1D Ising ring of arbitrary number of spin-1/2 particles, in order to reveal entanglement properties of the stationary states. We show that the ground state and specific eigenstates of the Ising Hamiltonian posses remarkable entanglement properties that can reveal new insight into quantum correlations present

Abel Camacho

A model describing the relationship between the ortho--positronium lifetime and the volume of a void, located in a synthetic zeolite, is analyzed. Our idea, which allows us to take into account the effects of temperature, comprises the introduction of a non--hermitian term in the Hamiltonian, which accounts for the annihilation of the ortho--positronium. The

Daniel J. Farrell, J. Dunning-Davies

New varying speed of light (VSL) theories as alternatives to the inflationary model of the universe are discussed and evidence for a varying speed of light reviewed. Work linked with VSL but primarily concerned with deriving Planck's black body energy distribution for a gas-like aether using Maxwell statistics is considered also. Doubly Special Relativit

Oleg A. Kobelev, Alexandr V. Kobelev

The closed integral equations for the interfacial tension as a function of external polarization at the liquid metal - ionic melt interface are derived. The version of Popel'-Pavlov isotherm is applied to the analysis of electrocapillary curves (ecc), i.e. the dependences of interfacial tension on electrode potential. The interaction between adsorbed par

David H. Foster, Jens U. Nockel

We develop and demonstrate two numerical methods for solving the class of open cavity problems which involve a curved, cylindrically symmetric conducting mirror facing a planar dielectric stack. Such dome-shaped cavities are useful due to their tight focusing of light onto the flat surface. The first method uses the Bessel wave basis. From this method evolve

D. E. Kahana, S. H. Kahana

Great interest has attached to recent D+Au, s^(1/2) = 200 A GeV data at RHIC, obtained with the BRAHMS detector. Between pseudorapidity eta=0 and eta=3.2 the appropriately defined ratio R[DAu/PP], comparing transverse momentum spectra of D+Au to P+P exhibits a steady decrease with eta. This diminuition is examined within a two-stage simulation, the last stag

C. B. Das, S. Das Gupta, B. K. Jennings

The grand canonical ensemble has been used to make predictions for composite yields using simple models for nuclear fragmentation. While this gives correct model prediction for high energy collisions, it can give very inaccurate results at intermediate energy.

N. Soic, M. Freer, L. Donadille, N. M. Clarke

Studies of the 16O(9Be,alpha7Be)14C and 7Li(9Be,alpha7Li)5He reactions at E{beam}=70 MeV have been performed using resonant particle spectroscopy techniques. The 11C excited states decaying into alpha+7Be(gs) are observed at 8.65, 9.85, 10.7 and 12.1 MeV as well as possible states at 12.6 and 13.4 MeV. This result is the first observation of alpha-decay for

L. Kaplan

A phase-space semiclassical approximation valid to $O(\hbar)$ at short times is used to compare semiclassical accuracy for long-time and stationary observables in chaotic, stable, and mixed systems. Given the same level of semiclassical accuracy for the short time behavior, the squared semiclassical error in the chaotic system grows linearly in time, in cont

R. Lopez-Ruiz, Y. Moreno, S. Boccaletti, D. -U. Hwang

A network with local dynamics of logistic type is considered. We implement a mean-field multiplicative coupling among first-neighbor nodes. When the coupling parameter is small the dynamics is dissipated and there is no activity: the network is {\it turned off}. For a critical value of the coupling a non-null stable synchronized state, which represents a {\i

L. A. Khodarinova, I. A. Prikhodsky

Algebraic integrability of the elliptic Calogero-Moser quantum problem related to the deformed root systems A_2(2) is proved. Explicit formulae for integrals are found.

G. Gaeta, P. Morando

We give a geometrical characterization of $λ$-prolongations of vector fields, and hence of $λ$-symmetries of ODEs. This allows an extension to the case of PDEs and systems of PDEs; in this context the central object is a horizontal one-form $μ$, and we speak of $μ$-prolongations of vector fields and $μ$-symmetries of PDEs. We show that these are as good as s

L. A. Khodarinova, I. A. Prikhodsky

Explicit algebraic relations between the quantum integrals of the elliptic Calogero-Moser quantum problems related to the root systems A_2 and B_2 are found.

Hari Bercovici

We show that the monotonic independence introduced by Muraki can also be used to define a multiplicative convolution. We also find a method for the calculation of this convolution based on an appropriate form of the Cauchy transform. We discuss infinite divisibility in the multiplicative monotonic context as well.

Christian Haase, Ilarion V. Melnikov

The reflexive dimension refldim(P) of a lattice polytope P is the minimal d so that P is the face of some d-dimensional reflexive polytope. We show that refldim(P) is finite for every P, and give bounds for refldim(kP) in terms of refldim(P) and k.

K. T. -R. McLaughlin, P. D. Miller

We develop a new asymptotic method for the analysis of matrix Riemann-Hilbert problems. Our method is a generalization of the steepest descent method first proposed by Deift and Zhou; however our method systematically handles jump matrices that need not be analytic. The essential technique is to introduce nonanalytic extensions of certain functions appearing

J. F. Jardine

The usual notion of a site fibred over a stack is expanded to a definition of a site C/A fibred over a presheaf of categories A. Presheaves of simplicial sets on the site fibred over a presheaf of categories A are contravariant enriched diagrams defined on A, taking values in simplicial sets. The standard model structure for presheaves of simplicial sets ind

Saharon Shelah

We strengthen the revised GCH theorem by showing, e.g., that for lambda=cf(lambda)>beth_omega, for all but finitely many regular kappa<beth_omega, lambda is accessible on cofinality kappa in a weak version of it holds. In particular, lambda=2^mu=mu^+>beth_omega implies the diamond on lambda is restricted to cofinality kappa for all but finitely many kappa in

Tapani Hyttinen, Olivier Lessmann, Saharon Shelah

This paper is concerned with extensions of geometric stability theory to some nonelementary classes. We prove the following theorem: Theorem: Let C be a large homogeneous model of a stable diagram D. Let p, q in S_D(A), where p is quasiminimal and q unbounded. Let P=p(C) and Q=q(C). Suppose that there exists an integer n<omega such that dim(a_1...a_n/A cup C

Valentin Ferenczi, Eloi Medina Galego

We construct a continuum of mutually non-isomorphic separable Banach spaces which are complemented in each other. Consequently, the Schroeder-Bernstein Index of any of these spaces is $2^{\aleph_0}$. Our construction is based on a Banach space introduced by W. T. Gowers and B. Maurey in 1997. We also use classical descriptive set theory methods, as in some w

Patrice Philippon, Martin Sombra

We present an explicit expression for the normalized height of a projective toric variety. This expression decomposes as a sum of local contributions, each term being the integral of a certain function, concave and piecewise linear-affine. More generally, we obtain an explicit expression for the normalized multiheight of a torus with respect to several monom

Josep Elgueta

We give a concrete description of a strict totally coordinatized version of Kapranov and Voevodsky&#39;s 2-category of finite dimensional 2-vector spaces. In particular, we give explicit formulas for composition of 1-morphisms and the two compositions between 2-morphisms

Bradley Efron, Trevor Hastie, Iain Johnstone, Robert Tibshirani

Rejoinder to ``Least angle regression&#39;&#39; by Efron et al. [math.ST/0406456]

Sanford Weisberg

Discussion of ``Least angle regression&#39;&#39; by Efron et al. [math.ST/0406456]

Berwin A. Turlach

Discussion of ``Least angle regression&#39;&#39; by Efron et al. [math.ST/0406456]

Robert A. Stine

Discussion of ``Least angle regression&#39;&#39; by Efron et al. [math.ST/0406456]

Saharon Rosset, Ji Zhu

Discussion of ``Least angle regression&#39;&#39; by Efron et al. [math.ST/0406456]

David Madigan, Greg Ridgeway

Discussion of ``Least angle regression&#39;&#39; by Efron et al. [math.ST/0406456]

Jean-Michel Loubes, Pascal Massart

Discussion of ``Least angle regression&#39;&#39; by Efron et al. [math.ST/0406456]

Keith Knight

Discussion of ``Least angle regression&#39;&#39; by Efron et al. [math.ST/0406456]

Jianqing Fan, Heng Peng

A class of variable selection procedures for parametric models via nonconcave penalized likelihood was proposed by Fan and Li to simultaneously estimate parameters and select important variables. They demonstrated that this class of procedures has an oracle property when the number of parameters is finite. However, in most model selection problems the number

Florentina Bunea

This paper presents a model selection technique of estimation in semiparametric regression models of the type Y_i=β^{\prime}\underbarX_i+f(T_i)+W_i, i=1,...,n. The parametric and nonparametric components are estimated simultaneously by this procedure. Estimation is based on a collection of finite-dimensional models, using a penalized least squares criterion

Maria Maddalena Barbieri, James O. Berger

Often the goal of model selection is to choose a model for future prediction, and it is natural to measure the accuracy of a future prediction by squared error loss. Under the Bayesian approach, it is commonly perceived that the optimal predictive model is the model with highest posterior probability, but this is not necessarily the case. In this paper we sh

Hemant Ishwaran

Discussion of ``Least angle regression&#39;&#39; by Efron et al. [math.ST/0406456]

Peter C. B. Phillips, Katsumi Shimotsu

Asymptotic properties of the local Whittle estimator in the nonstationary case (d>{1/2}) are explored. For {1/2}<d\leq 1, the estimator is shown to be consistent, and its limit distribution and the rate of convergence depend on the value of d. For d=1, the limit distribution is mixed normal. For d>1 and when the process has a polynomial trend of order α>{1/2

James O. Berger, Luis R. Pericchi

Central to several objective approaches to Bayesian model selection is the use of training samples (subsets of the data), so as to allow utilization of improper objective priors. The most common prescription for choosing training samples is to choose them to be as small as possible, subject to yielding proper posteriors; these are called minimal training sam

V. M. Buchstaber, S. Yu. Shorina

In this paper we construct a family of commuting multidimensional differential operators of order 3, which is closely related to the KdV hierarchy. We find a common eigenfunction of this family and an algebraic relation between these operators. Using these operators we associate a hyperelliptic curve to any solution of the stationary KdV equation. A basic ge

Kalyan Das, Jiming Jiang, J. N. K. Rao

The term ``empirical predictor&#39;&#39; refers to a two-stage predictor of a linear combination of fixed and random effects. In the first stage, a predictor is obtained but it involves unknown parameters; thus, in the second stage, the unknown parameters are replaced by their estimators. In this paper, we consider mean squared errors (MSE) of empirical pred

Galin L. Jones, James P. Hobert

We consider Gibbs and block Gibbs samplers for a Bayesian hierarchical version of the one-way random effects model. Drift and minorization conditions are established for the underlying Markov chains. The drift and minorization are used in conjunction with results from J. S. Rosenthal [J. Amer. Statist. Assoc. 90 (1995) 558-566] and G. O. Roberts and R. L. Tw

Jae Kwang Kim

Finite sample properties of multiple imputation estimators under the linear regression model are studied. The exact bias of the multiple imputation variance estimator is presented. A method of reducing the bias is presented and simulation is used to make comparisons. We also show that the suggested method can be used for a general class of linear estimators.

Bin Nan, Mary J. Emond, Jon A. Wellner

We derive information bounds for the regression parameters in Cox models when data are missing at random. These calculations are of interest for understanding the behavior of efficient estimation in case-cohort designs, a type of two-phase design often used in cohort studies. The derivations make use of key lemmas appearing in Robins, Rotnitzky and Zhao [J.

Guobing Lu, John B. Copas

This paper provides further insight into the key concept of missing at random (MAR) in incomplete data analysis. Following the usual selection modelling approach we envisage two models with separable parameters: a model for the response of interest and a model for the missing data mechanism (MDM). If the response model is given by a complete density family,

Sever Silvestru Dragomir

Some additive reverses of the generalised triangle inequality in normed linear spaces are given. Applications for complex numbers are provided as well.

Elchanan Mossel

Consider a tree network T, where each edge acts as an independent copy of a given channel M, and information is propagated from the root. For which T and M does the configuration obtained at level n of T typically contain significant information on the root variable? This model appeared independently in biology, information theory, and statistical physics. I

Luc Miller

We make two remarks about the null-controllability of the heat equation with Dirichlet condition in unbounded domains. Firstly, we give a geometric necessary condition (for interior null-controllability in the Euclidean setting)which implies that one can not go infinitely far away from the control region without tending to the boundary (if any), but also app

Wen-Ching Winnie Li, Ling Long, Zifeng Yang

In this paper we exhibit a noncongruence subgroup $\G$ whose space of weight 3 cusp forms $S_3(\G)$ admits a basis satisfying the Atkin-Swinnerton-Dyer congruence relations with two weight 3 newforms for certain congruence subgroups. This gives a modularity interpretation of the motive attached to $S_3(\G)$ by A. Scholl and also verifies the Atkin-Swinnerton

Richard W. Kenyon, David B. Wilson

We study the phase transition in the honeycomb dimer model (equivalently, monotone non-intersecting lattice path model). At the critical point the system has a strong long-range dependence; in particular, periodic boundary conditions give rise to a ``resonance&#39;&#39; phenomenon, where the partition function and other properties of the system depend sensit

Jan de Boer, Vishnu Jejjala, Djordje Minic

Field theory in de Sitter space admits a one-parameter family of vacua determined by a superselection parameter alpha. Of these vacua, the Euclidean vacuum uniquely extrapolates to the vacuum of flat Minkowski space. States which resemble the alpha-vacua can be constructed as excitations above the Euclidean vacuum. Such states have modes alpha(k) which decay

Gerald V. Dunne

I present a pedagogical review of Heisenberg-Euler effective Lagrangians, beginning with the original work of Heisenberg and Euler, and Weisskopf, for the one loop effective action of quantum electrodynamics in a constant electromagnetic background field, and then summarizing some of the important applications and generalizations to inhomogeneous background

Aram A. Saharian

Vacuum expectation value of the surface energy-momentum tensor is evaluated for a massive scalar field with general curvature coupling parameter subject to Robin boundary conditions on two parallel branes located on (D+1)-dimensional AdS bulk. The general case of different Robin coefficients on separate branes is considered. As an regularization procedure th

Yves Brihaye, Theodora Ioannidou

Spherically symmetric solutions of the SU(5) Einstein-Yang-Mills-Higgs system are constructed using the harmonic map ansatz \cite{IS}. This way the problem reduces to solving a set of ordinary differential equations for the appropriate profile functions.

Stefan Forste, Hans Peter Nilles, Patrick K. S. Vaudrevange, Akin Wingerter

Orbifold compactification of heterotic E8 x E8 string theory is a source for promising grand unified model building. It can accommodate the successful aspects of grand unification while avoiding problems like doublet-triplet splitting in the Higgs sector. Many of the phenomenological properties of the 4-dimensional effective theory find an explanation throug

Martin Lüscher, Peter Weisz

In the presence of a static quark--antiquark pair, the spectrum of the low-lying states in SU($N$) gauge theories is discrete and likely to be described, at large quark separations $r$, by an effective string theory. The expansion of the excitation energies in powers of $1/r$, which derives from the latter, involves an increasing number of unknown couplings

Gilad Lifschytz

We develop the quasi-particle picture for Schwarzchild and far from extremal black holes. We show that the thermalization equations of the black hole is recovered from the model of branes and anti-branes. This can also be viewed as a field theory explanation of the relationship between area and entropy for these black holes. As a by product the annihilation

Stephon Alexander, Manasse Mbonye, John Moffat

A mechanism for suppressing the cosmological constant is developed, based on an analogy with a superconducting phaseshift in which free fermions coupled perturbatively to a weak gravitational field are in an unstable false vacuum state. The coupling of the fermions to the gravitational field generates fermion condensates with zero momentum and a phase transi

Bodo Geyer, Peter Lavrov, Armen Nersessian

We equip the whole space of fields of the triplectic formalism of Lagrangian quantization with an even supersymplectic structure and clarify its geometric meaning. We also discuss its relation to a closed two-form arising naturally in the superfield approach to the triplectic formalism.

Alex Buchel

Using gauge theory /string theory correspondence certain universal aspects of the strongly coupled four dimensional gauge theory hydrodynamics were established in hep-th/0311175. The analysis were performed in the framework of ``membrane paradigm&#39;&#39; approach to the fluctuations on the black brane stretched horizon. We confirm the universal result for

D. Delepine, S. Khalil

We analyse the top flavour violating decays in general supersymmetric model using the mass insertion approximation. In particular, we discuss the impact of a light right-handed top-squark and large mixing between the first or second and third generation of up-squarks on processes as t -> q gamma,g . We also take into account the relevant experimental constra

Muriel Pivk, Francois R. Le Diberder

The Standard Model constraints on alpha which can be derived from the B-> pipi decays are revisited in some depth. As experimental inputs, the three branching ratios, the two CP parameters Spipi and Cpipi and/or the value of alpha as determined by the global CKM fit are used. The constraints discussed here are model independent in the sense that they rely on

Patricia Ball, Roman Zwicky

We present an improved calculation of all B -> light pseudoscalar formfactors from light-cone sum rules, including one-loop radiative corrections to twist-2 and twist-3 contributions, and leading order twist-4 corrections. The total theoretical uncertainty of our results at zero momentum transfer is 10 to 13%. The dependence of the formfactors on the momentu

Itzhak Goldman, Shmuel Nussinov

Models in which the &#34;dark&#34; halo particles have mutual and potentially also appreciable nuclear interactions have been considered by various authors. In this note we briefly point out strategies for a most sensitive search for these particles. We show that a particular matter/anti-matter symmetric variant due to Farrar et al. is excluded by combining

Alan Kostelecky, Matthew Mewes

A general discussion is given of signals for broken Lorentz symmetry in short-baseline neutrino experiments. Among the effects that Lorentz violation can introduce are a dependence on energy differing from that of the usual massive-neutrino solution and a dependence on the direction of neutrino propagation. Using the results of the LSND experiment, explicit

Bernd A. Kniehl, Jan H. Piclum, Matthias Steinhauser

We calculate the O(alpha alpha_s) corrections to the relationships between the MS-bar Yukawa couplings and the pole masses of the first five quark flavours in the standard model. We also present the corresponding relationships between the MS-bar and pole masses, which emerge as by-products of our main analysis. The occurring self-energies are evaluated using

Borexino collaboration, H. O. Back

The Pauli exclusion principle (PEP) has been tested for nucleons ($n,p$) in $^{12}C$ and $^{16}O$ nuclei, using the results of background measurements with the prototype of the Borexino detector, the Counting Test Facility (CTF). The approach consisted of a search for $γ$, $n$, $p$ and/or $α$&#39;s emitted in a non-Paulian transition of 1$P$- shell nucleons

Michael C. Birse, Boris Krippa, Judith A. McGovern, Niels R. Walet

We study the application of the exact renormalisation group to a many-fermion system with a short-range attractive force. We introduce a boson field to describe pairing effects, and take a simple ansatz for the effective action. We derive a set of approximate flow equations for the effective coupling including boson and fermionic fluctuations. The initial co

L. Pandola

The final data of the Gallex and GNO radiochemical experiments have been searched for possible time modulations of the solar neutrino capture rate using the Lomb-Scargle periodogram and the maximum likelihood methods. Both analyses, performed using the raw data, do not support the presence of a time variability with characteristic periods resembling those of

Zenro Hioki

We performed an analysis on possible anomalous top-quark couplings generated by SU(2) x U(1) gauge-invariant dimension-6 effective operators, applying the optimal-observable procedure to the final lepton/b-quark momentum distribution in gamma gamma --> t tbar --> l X/b X. We studied how many such anomalous coupling constants could be determined altogether th

O. Kaczmarek, F. Karsch, P. Petreczky, F. Zantow

We analyze the free energy of a static quark anti-quark pair in quenched QCD at short and large distances. From this we deduce running couplings, g^2(r,T), and determine the length scale that separates at high temperature the short distance perturbative regime from the large distance non-perturbative regime in the QCD plasma phase. Ambiguities in the definit