We discuss universal statistical patterns in the chaotic dynamics of closed inflationary cosmologies, associated with the presence of a saddle-center critical point in the phase space of the models. We extend and complete the analysis made in a previous paper [H. P. de Oliveira, S. L. Sautu, I. Damião Soares, and E. V. Tonini, Phys. Rev. D 60, 121301 (1999)], including also other inflationary models. The statistical distribution connected to orbits that visit a neighborhood of the saddle center is shown to be in the realm of Tsallis nonextensive statistics that generalizes the Boltzmann-Gibbs statistics for systems in which long-range interactions are present. The value of the entropic index q of the distribution function determines the dimension of the fractal basin boundaries in the ensemble of initial conditions, with respect to the code recollapse/escape into inflation. In a regime of high nonintegrability, this distribution is universal in the sense that it is scale invariant, independent of the parameters of the model and independent of the particular system where the saddle-center is present. Also it does not depend on the specific model where the saddle-center is present. The consequences for the physics of the early stages of inflation are discussed.

We show that by combining measurements of the temperature and polarization anisotropies of the cosmic microwave background (CMB), future experiments will tightly constrain the expansion rate of the universe during recombination. A change in the expansion rate modifies the way in which the recombination of hydrogen proceeds, altering the shape of the acoustic peaks and the level of CMB polarization. The proposed test is similar in spirit to the examination of abundances of light elements produced during big bang nucleosynthesis and it constitutes a way to study possible departures from standard recombination. For simplicity we parametrize the change in the Friedmann equation by changing the gravitational constant G. The main effect on the temperature power spectrum is a change in the degree of damping of the acoustic peaks on small angular scales. The effect can be compensated by a change in the shape of the primordial power spectrum. We show that this degeneracy between the expansion rate and the primordial spectrum can be broken by measuring CMB polarization. In particular we show that the MAP satellite could obtain a constraint for the expansion rate H during recombination of $\delta H/H\simeq 0.09$ or $\delta G/G\simeq 0.18$ after observing for four years, whereas Planck could obtain $\delta H/H<~0.014$ or $\delta G/G<~0.028$ within two years, even after allowing for further freedom in the shape of the power spectrum of primordial fluctuations.

At high center of mass energies, hadroproduction of heavy quarks can be expressed in terms of the same color dipole cross section as low Bjorken-x deep inelastic scattering. We show analytically that, at leading order, the dipole formulation is equivalent to the gluon-gluon fusion mechanism of the conventional parton model. In phenomenological application, we employ a parametrization of the dipole cross section which also includes higher order and saturation effects, thereby going beyond the parton model. Numerical calculations in the dipole approach agree well with experimental data on open charm production over a wide range of energy. The dipole approach and the next to leading order parton model yield similar values for open charm production, but for open bottom production, the dipole approach tends to predict somewhat higher cross sections than the parton model.

We calculate the exclusive cross sections for $e^{+}{e}^{-}$ annihilation into two charmonium states through a virtual photon. Purely electromagnetic contributions are surprisingly large, changing the cross sections by as much as 21%. The predicted cross section for $J/\psi +{\eta }_c$ is about an order of magnitude smaller than a recent measurement by the BELLE Collaboration, although part of the discrepancy can be attributed to large relativistic corrections. The cross sections for S-wave + P-wave, P-wave + P-wave, and S-wave + D-wave charmonium states are also calculated. It may be possible to discover the D-wave state ${\eta }_{c2\mathrm{}}\mathrm{}\left(1D\right)\mathrm{}$ at the B factories through the mode $J/\psi +{\eta }_{c2\mathrm{}},$ whose cross section is predicted to be about a factor of 10 smaller than $J/\psi +{\eta }_c.$

We report a precise determination of the $B^0-B^0$ mixing parameter $\Delta m_d$ based on the time evolution of same-sign and opposite-sign dilepton yields in ${\rm Y}\mathrm{}\left(4S\right)\mathrm{}$ decays. Data were collected with the Belle detector at KEKB. Using data samples of 29.4 ${\mathrm{fb}}^{\mathrm{-}1}$ recorded at the ${\rm Y}\mathrm{}\left(4S\right)\mathrm{}$ resonance and 3.0 ${\mathrm{fb}}^{\mathrm{-}1}$ recorded at an energy 60 MeV below the resonance, we measure $\Delta m_d=[0.503\pm 0.008(\mathrm{stat})\pm 0.010(\mathrm{syst}\left)\right]{\mathrm{ps}}^{-1}.$ From the same analysis, we also measure the ratio of charged and neutral B meson production at the ${\rm Y}\mathrm{}\left(4S\right),$ $f_{+}{/f}_0=1.01\mathrm{}\pm 0.03\left(\mathrm{stat}\right)\pm 0.09\left(\mathrm{syst}\right),$ and CPT violation parameters in $B^0-B^0$ mixing, $\mathfrak{R}\left(\cos \theta \right)=0.00\mathrm{}\pm 0.12\left(\mathrm{stat}\right)\pm 0.01\left(\mathrm{syst}\right)$ and $\mathfrak{I}\left(\cos \theta \right)=0.03\mathrm{}\pm 0.01\left(\mathrm{stat}\right)\pm 0.03\left(\mathrm{syst}\right).\mathrm{}$

We consider a generalized connection in three dimensions and show that it emerges in Chern-Simons-Maxwell theories when one studies the disorder instanton operator. We generalize this construction to non-Abelian theories and find that the disorder operator (the ’t Hooft operator) is equivalent to a generalized Wilson loop in a representation that depends on the Chern-Simons term. We speculate about the effective action of the disorder operator and its applications to the possible phases of the theory in the infrared. We also show that fractional statistics can emerge in gauge theories without a Chern-Simons term if the generalized connection rather than the ordinary connection is used to couple charged particles.

We detail the global structure of the five-dimensional bulk for the cosmological evolution of Dvali-Gabadadze-Porrati brane worlds. The picture articulated here provides a framework and intuition for understanding how metric perturbations leave (and possibly reenter) the brane universe. A bulk observer sees the brane world as a relativistically expanding bubble, viewed either from the interior (in the case of the Friedmann-Lemaître-Robertson-Walker phase) or the exterior (the self-accelerating phase). Shortcuts through the bulk in the first phase can lead to an apparent brane causality violation and provide an opportunity for the evasion of the horizon problem found in conventional four-dimensional cosmologies. Features of the global geometry in the latter phase anticipate a depletion of power for linear metric perturbations on large scales.

The scattering of the temperature anisotropy quadrupole by free electrons in galaxy clusters leads to a now well-known polarization signal in the cosmic microwave background fluctuations. Using multifrequency polarization data, one can extract the temperature quadrupole and separate it from the contaminant polarization associated with the kinematic quadrupole due to the transverse motion of clusters. At low redshifts, the temperature quadrupole contains a significant contribution from the integrated Sachs-Wolfe effect (ISW) associated with the growth of density fluctuations. Using polarization data from a sample of clusters over a wide range in redshift, one can statistically establish the presence of the ISW effect and determine the redshift dependence of the ISW contribution to the rms quadrupole. Given the strong dependence of the ISW effect on the background cosmology, the cluster polarization can eventually be used as a probe of the dark energy.

Cosmic microwave background (CMB) experiments generally infer a temperature fluctuation from a measured intensity fluctuation through the first term in the Taylor expansion of the Planck function, the relation between the intensity in a given frequency and the temperature. However, with the forthcoming Planck satellite, and perhaps even with the Microwave Anisotropy Probe, the CMB-dipole amplitude will be large enough to warrant inclusion of the next higher order term. To quadratic order in the dipole amplitude, there is an intensity quadrupole induced by the dipole with a frequency dependence given by the second derivative of the Planck function. The Planck satellite should be able to detect this dipole-induced intensity quadrupole and distinguish it through its frequency dependence from the intrinsic CMB temperature and foreground quadrupoles. This higher-order effect provides a robust pre-determined target that may provide tests of Planck’s and MAP’s large-angle-fluctuation measurements and of their techniques for multifrequency foreground subtraction.

Using the CLEO II detector at CESR, we measure the ${\eta }^{\prime }$ energy spectra in ${\rm Y}\mathrm{}\left(1S\right)\mathrm{}$ decays that we compare with models of the ${\eta }^{\prime }{g}^{*}g$ form factor. This form factor, especially at large ${\eta }^{\prime }$ energies, may provide an explanation of the large rate for $\overrightarrow{B}{X}_s{\eta }^{\prime }.$ Our data do not support a large anomalous coupling at higher $q^2$ and thus the large ${\eta }^{\prime }$ rate remains a mystery, possibly requiring a non-standard-model explanation.

We reconsider supersymmetric five dimensional rotating charged black holes and their description in terms of D-branes. By wrapping some of the branes on $K3,$ we are able to explore the role of the enhançon mechanism in this system. We verify that enhançon loci protect the black hole from violations of the second law of thermodynamics which would have been achieved by the addition of certain D-brane charges. The same charges can potentially result in the formation of closed timelike curves by adding them to holes initially free of them, and so the enhançon mechanism forbids this as well. Although this latter observation is encouraging, it is noted that this mechanism alone does not eliminate closed timelike curves from these systems, but is in accord with earlier suggestions that they may not be manufactured, in this context, by physical processes.

We illustrate a basic framework for analytic computations of Feynman graphs using the Moyal star formulation of string field theory. We present efficient methods of computation based on (a) the monoid algebra in noncommutative space and (b) the conventional Feynman rules in Fourier space. The methods apply equally well to perturbative string states or nonperturbative string states involving D-branes. The ghost sector is formulated using Moyal products with fermionic (b,c) ghosts. We also provide a short account on how the purely cubic theory and/or vaccum string field theory proposals may receive some clarification of their midpoint structures in our regularized framework.

In a previous paper, we presented a solution to the Slavnov-Taylor identity for the QCD effective action, and argued that the action terms containing (anti)ghost fields are unique. These terms have the same form as those in the classical action, but the gluon and (anti)ghost effective fields are convoluted with gluon and ghost dressing functions $G_A$ and $G_c,$ the latter containing perturbative and nonperturbative effects (but not including the solitonlike vacuum effects). In the present work we show how perturbative QCD (PQCD) can be incorporated into the framework of this action, and we present explicit one-loop PQCD expressions for $G_A$ and $G_c.$ We then go on to check the consistency of the results obtained by considering an antighost Dyson-Schwinger equation (DSE). By solving the relations that result from the Legendre transformation leading to the effective action, we obtain the effective fields as power expansions of sources. We check explicitly that the aforementioned one-loop functions $G_A$ and $G_c$ satisfy the antighost DSE at the linear source level. We further explicitly check that these one-loop $G_A$ and $G_c$ have a regularization scale and momentum dependence consistent with the antighost DSE at the quadratic source level. These checks suggest that the effective action with dressing functions represents a consistent framework for treating QCD, at least at the one-loop level.

We present a way to solve Slavnov-Taylor identities in a general nonsupersymmetric theory. The solution can be parametrized by a limited number of functions of spacetime coordinates, so that all the effective fields are dressed by these functions via integral convolution. The solution restricts the ghost part of the effective action and gives predictions for the physical part of the effective action.

We present a detailed study of cosmological effects of homogeneous tachyon matter coexisting with nonrelativistic matter and radiation, concentrating on the inverse square potential and the exponential potential for the tachyonic scalar field. A distinguishing feature of these models (compared to other cosmological models) is that the matter density parameter and the density parameter for tachyons remain comparable even in the matter dominated phase. For the exponential potential, the solutions have an accelerating phase, followed by a phase with $a\left(t\right)\mathrm{}\propto t^{2/3}$ as $\overrightarrow{t}\infty .$ This eliminates the future event horizon present in cold dark matter models with a cosmological constant $\left(\Lambda \mathrm{CDM}\right)$ and is an attractive feature from the string theory perspective. A comparison with supernova type Ia data shows that for both the potentials there exists a range of models in which the universe undergoes an accelerated expansion at low redshifts which are also consistent with the requirements of structure formation. They do require fine-tuning of parameters but not any more than in the case of $\Lambda \mathrm{CDM}$ models or quintessence models.

We study relativistic massive vector condensation due to a nonzero chemical potential associated with some of the globally conserved charges of the theory. We show that the phase structure is very rich. More specifically, there are three distinct phases depending on the value of one of the zero chemical potential vector self-interaction terms. We also develop a formalism which enables us to investigate the vacuum structure and dispersion relations in the spontaneously broken phase of the theory. We show that, in a certain limit of the couplings and for a large chemical potential, the theory is not stable. This limit, interestingly, corresponds to a gauge-type limit often employed to economically describe the ordinary vector mesons self-interactions in QCD. We finally indicate for which physical systems our analysis is relevant.

We present a calculation for single-inclusive large-$p_T$ pion production in longitudinally polarized $\mathrm{pp}$ collisions in next-to-leading order QCD. We choose an approach where fully analytical expressions for the underlying partonic hard-scattering cross sections are obtained. We simultaneously rederive the corresponding corrections to unpolarized scattering and confirm the results existing in the literature. Our results allow to calculate the double-spin asymmetry $A_{\mathrm{LL}}^{\pi }$ for this process at next-to-leading order, which will soon be used at the BNL Relativistic Heavy Ion Collider to measure the polarization of gluons in the nucleon.

We calculate the next-to-leading order (NLO) QCD corrections to the spin-dependent cross section for single-inclusive-hadron production in hadronic collisions. This process will be soon studied experimentally at the BNL Relativistic Heavy Ion Collider, providing a tool to unveil the polarized gluon distribution $\Delta g.\mathrm{}$ We observe a considerable improvement in the perturbative stability for both unpolarized and polarized cross sections. The NLO corrections are found to be nontrivial, resulting in a reduction of the asymmetry.

We report measurements of branching fractions for $\psi \mathrm{}\left(2S\right)\mathrm{}$ decays into $\omega {\pi }^{+}{\pi }^{-},$ $b_1\pi ,$ $\omega f_2\mathrm{}\left(1270\right),$ $\omega K^{+}{K}^{-},$ $\omega p\overline{p},$ $\phi {\pi }^{+}{\pi }^{-},$ $\phi f_0\mathrm{}\left(980\right),$ $\phi K^{+}{K}^{-},$ and an upper limit for $\phi p\overline{p}$ final states based on a data sample of $(4.02\mathrm{}\pm 0.22)\times {10}^6\psi \mathrm{}\left(2S\right)\mathrm{}$ events collected with the BESI detector at the Beijing Electron-Positron Collider. The branching fractions for $b_1\pi$ and $\omega f_2\mathrm{}\left(1270\right)\mathrm{}$ update previous BES results, while those for other decay modes are first measurements. The ratios of $\psi \mathrm{}\left(2S\right)\mathrm{}$ and $J/\psi$ branching fractions are smaller than what is expected from the $12\%$ rule by a factor of 5 for $\omega f_2\mathrm{}\left(1270\right)\mathrm{}$ and by a factor of 2 for $\omega {\pi }^{+}{\pi }^{-},$ $\omega p\overline{p},$ and $\phi K^{+}{K}^{-},$ while for other studied channels the ratios are consistent with expectations within errors.