The quantitative aspects of the model used, together with kinematic reflections to explain the $K^{+}n$ spectrum in $K^{+}{K}^{-}$ photoproduction on deuterium, were recently criticized. Here we respond to these criticisms.

The $\mathrm{SU}(3{)}_L\otimes \mathrm{U}(1{)}_N$ electroweak model predicts new Higgs bosons beyond the one of the standard model. In this work we investigate the signature and production of neutral $\mathrm{SU}(3{)}_L\otimes \mathrm{U}(1{)}_N$ Higgs bosons in the $e^{-}{e}^{+}$ Next Linear Collider and in the CERN Linear Collider . We compute the branching ratios of two of the $\mathrm{SU}(3{)}_L\otimes \mathrm{U}(1{)}_N$ neutral Higgs bosons and study the possibility to detect them and the $Z^{\prime }$ extra neutral boson of the model.

We present a top-condensation model in which the $CP$ symmetry is spontaneously broken at the electroweak scale due to the condensation of two composite Higgs doublets. In particular the $CP$-violating phase of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix is generated. A simpler model where only one quark family is included is also discussed. In this case, for a general four-fermion interaction ($G_{tb}\ne 0$), the particle spectrum is the one of the one Higgs doublet model.

The inclusion of electromagnetic effects in unquenched QCD can be accomplished using ensembles generated in dynamical simulations with pure QCD provided the change in the quark determinant induced by a weak electromagnetic field can be efficiently computed. A stochastic technique for achieving this in the case of dynamical domain wall calculations is described.

We systematically investigate general forms of mass matrices for three-generation up and down quarks, including asymmetrical ones in generation space. Viable zero matrix elements are explored which are compatible with the current observation of masses and mixing angles, and also with the recent measurement of $CP$ violation in the $B$-meson system. The simplest form with the maximal number of vanishing matrix elements is found to be almost consistent with the experimental data, but has an unsatisfactory point that one of the mixing angles is slightly large. At the next-to-minimal level, it is found with help of leptonic generation mixing that only six patterns of mass matrices well describe the experimental data. These sets of mass textures predict all the properties of quarks, including the $CP$ violation, as well as the large (charged) lepton mixing, which may be appropriate for the atmospheric neutrino in the grand unification scheme.

We calculate magnetic transition moments in the chiral quark-soliton model, with explicit SU(3)-symmetry breaking taken into account. The dynamical model parameters are fixed by experimental data for the magnetic moments of the baryon octet and from the recent measurements of ${\Theta }^{+}$ mass. Known magnetic transition moments ${\mu }_{\Lambda \Sigma }$, ${\mu }_{N\Delta }$ are reproduced and predictions for other octet-decuplet and octet-antidecuplet transitions are given. In particular ${\mu }_{\Sigma {\Sigma }^{*}}$ recently constrained by SELEX is shown to be below $0.82{\mu }_N$. The recent GRAAL data on $\eta$ photoproduction off the nucleon are explained in terms of a new narrow antidecuplet neutronlike resonance.

A coherent study of the production of $f_0^i$ [$i=1$, 2, 3 corresponding to $f_0(1710)$, $f_0(1500)$, and $f_0(1370)$] in $J/\psi \to V{f}_0\to VPP$ is reported based on a previously proposed glueball and $Q\overline{Q}$ nonet mixing scheme, and a factorization for the decay of $J/\psi \to V{f}_0^i$, where $V$ denotes the isoscalar vector mesons $\varphi$ and $\omega$, and $P$ denotes pseudoscalar mesons. The results show that the $J/\psi$ decays are very sensitive to the structure of those scalar mesons, and suggest a glueball in the 1.5–1.7 GeV region, in line with lattice QCD. The presence of significant glueball mixings in the scalar wave functions produces peculiar patterns in the branching ratios for $J/\psi \to V{f}_0^i\to VPP$, which are in good agreement with the recently published experimental data from the BES Collaboration.

The three-flavor mixing matrix can be parameterized by the rephasing invariants ${\Gamma }_{ijk}=V_{1i}{V}_{2j}{V}_{3k}$. This formulation brings out the inherent symmetry of the problem and has some appealing features. Examples illustrating the parametrization and applications to quark mixing are presented.

This paper investigates the physics reach of the IceCube neutrino detector when it will have collected a data set of order one million atmospheric neutrinos with energies in the $0.1\sim {10}^4\mathrm{TeV}$ range. The paper consists of three parts. We first demonstrate how to simulate the detector performance using relatively simple analytic methods. Because of the high energies of the neutrinos, their oscillations, propagation in the Earth and regeneration due to $\tau$ decay must be treated in a coherent way. We set up the formalism to do this and discuss the implications. In a final section we apply the methods developed to evaluate the potential of IceCube to study new physics beyond neutrino oscillations. Not surprisingly, because of the increased energy and statistics over present experiments, existing bounds on violations of the equivalence principle and of Lorentz invariance can be improved by over 2 orders of magnitude. The methods developed can be readily applied to other nonconventional physics associated with neutrinos.

In brane world string models with large extra dimensions, there are processes where fermion and antifermion (or two gluons) can annihilate producing a light particle (e.g. gluon) carrying transverse momentum and a Kaluza-Klein graviton or an excited closed string that propagates in the extra dimensions. In high energy colliders, this process gives a missing-momentum signature. We compute the total cross section for this process within the context of type II superstring theory in the presence of a D-brane. This includes all missing-energy sources for this string-theory model up to $s=8M_s^2$, and it can be used to put new limits on the string scale $M_s$.

It has recently been suggested that the acceleration of the Universe can be explained as the backreaction effect of superhorizon perturbations using second order perturbation theory. If this mechanism is correct, it should also apply to a hypothetical, gedanken universe in which the subhorizon perturbations are absent. In such a gedanken universe it is possible to compute the deceleration parameter $q_0$ measured by comoving observers using local covariant Taylor expansions rather than using second order perturbation theory. The result indicates that second order corrections to $q_0$ are present, but shows that if $q_0$ is negative then its magnitude is constrained to be less than or of the order of the square of the peculiar velocity on Hubble scales today. We argue that, since this quantity is constrained by observations to be small compared to unity, superhorizon perturbations cannot be responsible for the acceleration of the Universe.

We present a complete set of generators for the rank 5 special unitary group, SU(6), to unify strong, weak and electromagnetic interactions. The unification is realized through the breaking pattern of $\mathrm{SU}(6)\to \mathrm{SU}(3{)}_C\otimes \mathrm{SU}(3{)}_H\otimes \mathrm{U}(1{)}_C$ followed by $\mathrm{SU}(3{)}_H\to \mathrm{SU}(2{)}_L\otimes \mathrm{U}(1{)}_B$. All known elementary particles and its quantum numbers are well accommodated in its $\{6\}$ and $\{15\}$ multiplets. These multiplets require a new neutral fermion which should be assigned as the heavy Majorana neutrino to realize the seesaw mechanism naturally.

The Pomeron, which dominates high energy elastic and diffractive hadronic processes, must be largely gluonic in nature. We use a recent picture of a scalar glueball/sigma system with coupling of the sigma to glue determined from experiment to predict strong peripheral sigma production in the $\mathrm{pp}{\pi }^0{\pi }^0$ and double-sigma production in the $\mathrm{pp}{\pi }^0{\pi }^0{\pi }^0{\pi }^0$ channels.

We show that the gravitating static soliton in the $2+1$ dimensional $O(3)$ $\sigma$ model does not exist in the presence of a negative cosmological constant, contrary to the claim made by Kim and Moon in [Phys. Rev. D 58, 105013 (1998).].

We construct new semirealistic type IIB flux vacua on $Z_2\times Z_2$ orientifolds with three- and four-standard model families and up to three units of quantized flux. The open string sector is comprised of magnetized D-branes and is T-dual to supersymmetric intersecting D6-brane constructions. The standard model sector contains magnetized D9-branes with negative D3-brane charge contribution. There are large classes of such models and we present explicit constructions for representative ones. In addition to models with one and two units of quantized flux, we also construct the first three- and four-family standard-like models with supersymmetric fluxes, i.e. comprising three units of quantized flux. Supergravity fluxes are due to the self-dual Neveu-Schwarz-Neveu-Schwarz and Ramond-Ramond three-form field strength and they fix the toroidal complex structure moduli and the dilaton. The supersymmetry conditions for the D-brane sector fix in some models all three toroidal Kähler moduli. We also provide examples where toroidal Kähler moduli are fixed by strong gauge dynamics on the “hidden sector” D7-brane. Most of the models possess Higgs doublet pairs with Yukawa couplings that can generate masses for quarks and leptons. The models have (mainly right-) chiral exotics.

A modified self-consistent Hartree-Fock approximation to the $\lambda {\varphi }^4$ theory with spontaneously broken $O(N)$ symmetry is proposed. It preserves all the desirable features, like conservation laws and thermodynamic consistency, of the self-consistent Schwinger-Dyson scheme generated from a 2PI functional, also known as the $\Phi$-derivable scheme, while simultaneously respecting the Nambu-Goldstone theorem in the chiral-symmetry broken phase. Various approximate resummation schemes are discussed.

We present convergent gravitational waveforms extracted from three-dimensional, numerical simulations in the wave zone and with causally disconnected boundaries. These waveforms last for multiple periods and are very accurate, showing a peak error to peak amplitude ratio of 2% or better. Our approach includes defining the Weyl scalar ${\Psi }_4$ in terms of a three-plus-one decomposition of the Einstein equations; applying, for the first time, a novel algorithm due to Misner for computing spherical harmonic components of our wave data; and using fixed mesh refinement to focus resolution on nonlinear sources while simultaneously resolving the wave zone and maintaining a causally disconnected computational boundary. We apply our techniques to a (linear) Teukolsky wave, and then to an equal-mass, head-on collision of two black holes. We argue both for the quality of our results and for the value of these problems as standard test cases for wave extraction techniques.

We analyze the excision strategy for simulating black holes. The problem is modeled by the propagation of quasilinear waves in a 1-dimensional spatial region with timelike outer boundary, spacelike inner boundary and a horizon in between. Proofs of well-posed evolution and boundary algorithms for a second differential order treatment of the system are given for the separate pieces underlying the finite-difference problem. These are implemented in a numerical code which gives accurate long term simulations of the quasilinear excision problem. Excitation of long wavelength exponential modes, which are latent in the problem, are suppressed using conservation laws for the discretized system. The techniques are designed to apply directly to recent codes for the Einstein equations based upon the harmonic formulation.

One of the best motivated hypotheses in cosmology states that most of the matter in the universe is in the form of weakly-interacting massive particles that decoupled early in the history of the universe and cooled adiabatically to an extremely low temperature. Nevertheless, the finite temperature and horizon scales at which these particles decoupled imprint generic signatures on their small-scale density fluctuations. We show that the previously recognized cut-off in the fluctuation power-spectrum due to free-streaming of particles at the thermal speed of decoupling, is supplemented by acoustic oscillations owing to the initial coupling between the cold dark matter (CDM) and the radiation field. The power-spectrum oscillations appear on the scale of the horizon at kinematic decoupling which corresponds to a mass scale of $\sim {10}^{-4}(T_{\mathrm{d}}/10\mathrm{MeV}{)}^{-3}{M}_{\odot }$ for a CDM decoupling temperature $T_{\mathrm{d}}$. The suppression of the power-spectrum on smaller scales by the acoustic oscillations is physically independent from the free-streaming effect, although the two cut-off scales are coincidentally comparable for $T_{\mathrm{d}}\sim 10\mathrm{MeV}$ and a particle mass of $M\sim 100\mathrm{GeV}$. The initial conditions for recent numerical simulations of the earliest and smallest objects to have formed in the universe, need to be modified accordingly. The smallest dark-matter clumps may be detectable through $\gamma$-ray production from particle annihilation, through fluctuations in the event rate of direct detection experiments, or through their tidal gravitational effect on wide orbits of objects near the outer edge of the solar system.