Defining a most economical parametrization of time-dependent $B\to {\rho }^{\pm }{\pi }^{\mp }$ decays, including a measurable phase ${\alpha }_{\mathrm{e}\mathrm{f}\mathrm{f}}$ which equals the weak phase $\alpha$ in the limit of vanishing penguin amplitudes, we propose two ways for determining $\alpha$ in this processes. We explain the limitation of one method, assuming only that two relevant tree amplitudes factorize and that their relative strong phase ${\delta }_t$ is negligible. The other method, based on broken flavor SU(3), permits a determination of $\alpha$ in $B^0\to {\rho }^{\pm }{\pi }^{\mp }$ in an overconstrained system using also rate measurements of $B^{0,+}\to K^{*}\pi$ and $B^{0,+}\to \rho K$. Current data are shown to restrict two ratios of penguin and tree amplitudes $r_{\pm }$ to a narrow range around 0.2 and to imply an upper bound $|{\alpha }_{\mathrm{e}\mathrm{f}\mathrm{f}}-\alpha |<15°$. Assuming that ${\delta }_t$ is much smaller than 90°, we find $\alpha =(93\pm 16)°$ and $(102\pm 20)°$ using BABAR and BELLE results for $B(t)\to {\rho }^{\pm }{\pi }^{\mp }$. Avoiding this assumption for completeness, we demonstrate the reduction of discrete ambiguities in $\alpha$ with increased statistics and show that SU(3) breaking effects are effectively second order in $r_{\pm }$.

We analyze the physics potential of long-baseline neutrino oscillation experiments planned for the coming ten years, where the main focus is the sensitivity limit to the small mixing angle ${\theta }_{13}$. The discussed experiments include the conventional beam experiments MINOS, ICARUS, and OPERA, which are under construction, the planned superbeam experiments J-PARC to Super-Kamiokande and NuMI off-axis, as well as new reactor experiments with near and far detectors, represented by the Double-Chooz project. We perform a complete numerical simulation including systematics, correlations, and degeneracies on an equal footing for all experiments using the GLoBES software. After discussing the improvement of our knowledge on the atmospheric parameters ${\theta }_{23}$ and $\Delta m_{31}^2$ by these experiments, we investigate the potential to determine ${\theta }_{13}$ within the next ten years in detail. Furthermore, we show that under optimistic assumptions and for ${\theta }_{13}$ close to the current bound, even the next generation of experiments might provide some information on the Dirac CP phase and the type of the neutrino mass hierarchy.

The process $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{\pi }^0\gamma$ has been studied at a center-of-mass energy near the ${\rm Y}(4S)$ resonance using a $89.3{\mathrm{f}\mathrm{b}}^{-1}$ data sample collected with the BABAR detector at the PEP-II collider. From the measured $3\pi$ mass spectrum we have obtained the products of branching fractions for the $\omega$ and $\varphi$ mesons, $\mathcal{B}(\omega \to e^{+}{e}^{-})\mathcal{B}(\omega \to 3\pi )=(6.70\pm 0.06\pm 0.27)\times {10}^{-5}$ and $\mathcal{B}(\varphi \to e^{+}{e}^{-})\mathcal{B}(\varphi \to 3\pi )=(4.30\pm 0.08\pm 0.21)\times {10}^{-5}$ and evaluated the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{\pi }^0$ cross section for the $e^{+}{e}^{-}$ center-of-mass energy range 1.05 to 3.00 GeV. About 900 $e^{+}{e}^{-}\to J/\psi \gamma \to {\pi }^{+}{\pi }^{-}{\pi }^0\gamma$ events have been selected and the branching fraction $\mathcal{B}(J/\psi \to {\pi }^{+}{\pi }^{-}{\pi }^0)=(2.18\pm 0.19)\%$ has been measured.

We construct a time-dependent solution in vacuum string field theory and investigate whether the solution can be regarded as a rolling tachyon solution. First, compactifying one space direction on a circle of radius $R$, we construct a space-dependent solution given as an infinite number of $*$ products of a string field with center-of-mass momentum dependence of the form $e^{-b{p}^2/4}$. Our time-dependent solution is obtained by an inverse-Wick rotation of the compactified space direction. We focus on one particular component field of the solution, which takes the form of the partition function of a Coulomb system on a circle with temperature $R^2$. Analyzing this component field both analytically and numerically using Monte Carlo simulation, we find that the parameter $b$ in the solution must be set equal to zero for the solution to approach a finite value in the large time limit $x^0\to \infty$. We also explore the possibility that the self-dual radius $R=\sqrt{{\alpha }^{\prime }}$ is a phase transition point of our Coulomb system.

We look for and analyze in some details some exact solutions of Einstein-Maxwell-dilaton gravity with one or two Liouville-type dilaton potential(s) in an arbitrary dimension. Such a theory could be obtained by dimensionally reducing Einstein-Maxwell theory with a cosmological constant to a lower dimension. These (neutral/magnetic/electric charged) solutions can have a (two) black hole horizon(s), cosmological horizon, or a naked singularity. Black hole horizon or cosmological horizon of these solutions can be a hypersurface of positive, zero or negative constant curvature. These exact solutions are neither asymptotically flat, nor asymptotically AdS/dS. But some of them can be uplifted to a higher dimension, and those higher dimensional solutions are either asymptotically flat, or asymptotically AdS/dS with/without a compact constant curvature space. This observation is useful to better understand holographic properties of these nonasymptotically AdS/dS solutions.

We investigate the thermal relic density of cold dark matter in the context of brane world cosmology. Since the expansion law in a high energy regime is modified from the one in the standard cosmology, if the dark matter decouples in such a high energy regime its relic number density is affected by this modified expansion law. We derive analytic formulas for the number density of dark matter. It is found that the resultant relic density is characterized by the “transition temperature” at which the modified expansion law in brane world cosmology is connecting with the standard one, and can be considerably enhanced compared to that in the standard cosmology, if the transition temperature is low enough.

We use the halo model formalism to provide expressions for cluster abundances and bias, as well as estimates for the correlation matrix between these observables. Off-diagonal elements due to scatter in the mass-tracer scaling with mass are included, as are observational effects such as biases/scatter in the data, detection rates (completeness), and false detections (purity). We apply the formalism to a hypothetical volume limited optical survey where the cluster mass-tracer is chosen to be the number of satellite galaxies assigned to a cluster. Such a survey can strongly constrain ${\sigma }_8$ ($\Delta {\sigma }_8\approx 0.05$), the power law index $\alpha$ where $⟨N_{gal}|m⟩=(m/M_1{)}^{\alpha }$ ($\Delta \alpha \approx 0.03$), and perhaps even the Hubble parameter ($\Delta h\approx 0.07$). We find cluster abundances and bias are not well suited for constraining ${\Omega }_m$ or the amplitude $M_1$. We also find that without bias information ${\sigma }_8$ and $\alpha$ are degenerate, implying constraints on the former are strongly dependent on priors used for the latter and vice-versa. The degeneracy stems from an intrinsic scaling relation of the halo mass function, and hence it should be present regardless of the mass-tracer used in the survey.

We discuss the consequences of Lorentz violation (as expressed within the Lorentz-violating extension of the standard model) for the hydrogen molecule, which represents a generic model of a molecular binding. Lorentz-violating shifts of electronic, vibrational and rotational energy levels, and of the internuclear distance are calculated. This offers the possibility of obtaining improved bounds on Lorentz invariance by experiments using molecules.

We study the asymptotic behavior of the $B$ meson wave function in the framework of $k_T$ factorization theorem. We first construct a definition of the $k_T$-dependent $B$ meson wave function, which is free of light-cone divergences. Next-to-leading-order corrections are then calculated based on this definition. The treatment of different types of logarithms in the above corrections, including the Sudakov logarithms, and those depending on a renormalization scale and on an infrared regulator, is summarized. The criticism raised in the literature on our resummation formalism and Sudakov effect is responded. We show that the $B$ meson wave function remains normalizable after taking into account renormalization-group evolution effects, contrary to the observation derived in the collinear factorization theorem.

The dynamics of a bounded gravitational collapsing configuration emitting gravitational waves is studied. The exterior spacetime is described by Robinson-Trautman geometries and have the Schwarzschild black hole as its final gravitational configuration, when the gravitational wave emission ceases. The nonlinear regime is examined by using the Galerkin method that allows us to reduce the equations governing the dynamics to a finite-dimensional dynamical system, after a proper truncation procedure. Gravitational wave emission patterns from given initial configurations are exhibited for several phases of the collapse and the mass-loss ratio that characterizes the amount of mass extracted by the gravitational wave emission is evaluated. We obtain that the smaller initial mass $M_{\mathrm{i}\mathrm{n}\mathrm{i}\mathrm{t}}$ of the configuration, the more rapidly the Schwarzschild solution is attained and a larger fraction of $M_{\mathrm{i}\mathrm{n}\mathrm{i}\mathrm{t}}$ is lost in the process of gravitational wave emission. Within all our numerical experiments, the distribution of the mass fraction extracted by gravitational wave emission is shown to satisfy the distribution law of nonextensive statistics and this result is independent of the initial configurations considered.

The inflaton necessary to implement the mechanism of inflationary cosmology has natural candidates in quiver gauge theory. We discuss the dimensionless coefficients of quartic couplings and enumerate scalars which are singlet under the low-energy gauge group. The inflaton mass is generally predicted to be in the TeV region, close to 4 TeV for one specific unified model. A quartic inflaton potential, and a mutated hybrid inflation, are discussed. They can give adequate inflation and appropriate fluctuations but different spectral indices.

We consider the response of an Unruh detector to scalar fields in an expanding spacetime. When combining transition elements of the scalar field Hamiltonian with the interaction operator of detector and field, one finds at second order in time-dependent perturbation theory a transition amplitude, which actually dominates in the ultraviolet over the first order contribution. In particular, the detector response faithfully reproduces the particle number implied by the stress energy of a minimally coupled scalar field, which is inversely proportional to the energy of a scalar mode. This finding disagrees with the contention that in de Sitter space, the response of the detector drops exponentially with particle energy and therefore indicates a thermal spectrum.

We calculate the two-loop partition function of QCD on the lattice, using the Wilson formulation for gluons and the overlap-Dirac operator for fermions. Direct by-products of our result are the two-loop free energy and average plaquette. Our calculation serves also as a prototype for further higher-loop calculations in the overlap formalism. We present our results as a function of a free parameter $M_0$ entering the overlap action; the dependence on the number of colors $N$ and fermionic flavors $N_f$ is shown explicitly.

We investigate supergravity models in which the lightest supersymmetric particle (LSP) is a stable gravitino. We assume that the next-lightest supersymmetric particle (NLSP) freezes out with its thermal relic density before decaying to the gravitino at time $t\sim {10}^4-{10}^8\mathrm{s}$. In contrast to studies that assume a fixed gravitino relic density, the thermal relic density assumption implies upper, not lower, bounds on superpartner masses, with important implications for particle colliders. We consider slepton, sneutrino, and neutralino NLSPs, and determine what superpartner masses are viable in all of these cases, applying cosmic microwave background (CMB) and electromagnetic and hadronic big bang nucleosynthesis (BBN) constraints to the leading two- and three-body NLSP decays. Hadronic constraints have been neglected previously, but we find that they provide the most stringent constraints in much of the natural parameter space. We then discuss the collider phenomenology of supergravity with a gravitino LSP. We find that colliders may provide important insights to clarify BBN and the thermal history of the Universe below temperatures around 10 GeV and may even provide precise measurements of the gravitino’s mass and couplings.

If the fundamental Planck scale is near a TeV, then we should expect to see TeV scale black holes at the CERN LHC. Similarly, if the scale of supersymmetry (SUSY) breaking is sufficiently low, then we might expect to see light supersymmetric particles in the next generation of colliders. If the mass of the supersymmetric particle is of order a TeV and is comparable to the temperature of a typical TeV scale black hole, then such sparticles will be copiously produced via Hawking radiation: The black hole will act as a resonance for sparticles, among other things. In this paper we compare various signatures for SUSY production at LHC, and we contrast the situation where the sparticles are produced directly via parton fusion processes with the situation where they are produced indirectly through black hole resonances. We found that black hole resonances provide a larger source for heavy mass SUSY (squark and gluino) production than the direct perturbative QCD-SUSY production via parton fusion processes depending on the values of the Planck mass and black hole mass. Hence black hole production at LHC may indirectly act as a dominant channel for SUSY production. We also found that the differential cross section $d\sigma /d{p}_t$ for SUSY production increases as a function of the $p_t$ (up to $p_t$ equal to about 1 TeV or more) of the SUSY particles (squarks and gluinos), which is in sharp contrast with the pQCD predictions where the differential cross section $d\sigma /d{p}_t$ decreases as $p_t$ increases for high $p_t$ about 1 TeV or higher. This is a feature for any particle emission from a TeV scale black hole as long as the temperature of the black hole is very high ($\sim \mathrm{T}\mathrm{e}\mathrm{V}$). Hence the measurement of increase of $d\sigma /d{p}_t$ with $p_t$ for $p_t$ up to about 1 TeV or higher for final state particles might be a useful signature for black hole production at LHC.

We compute finite-volume corrections to nucleon matrix elements of the axial-vector current. We show that knowledge of this finite-volume dependence—as well as that of the nucleon mass—obtained using lattice QCD may allow a clean determination of the chiral-limit values of the nucleon and $\Delta$-resonance axial-vector couplings.

We present a new analysis of double charmonium production in $e^{+}{e}^{-}$ annihilation. The observation of the processes $e^{+}{e}^{-}\to J/\psi {\eta }_c$, $J/\psi {\chi }_{c0}$, and $J/\psi {\eta }_c(2S)$ is confirmed using a data set more than 3 times larger than that of Belle’s previous report, and no evidence for the process $e^{+}{e}^{-}\to J/\psi J/\psi$ is found. We perform an angular analysis for $J/\psi {\eta }_c$ production and set an upper limit on the production of $J/\psi J/\psi$. Processes of the type $e^{+}{e}^{-}\to \psi (2S)(c\overline{c}{)}_{\mathrm{r}\mathrm{e}\mathrm{s}}$ have been observed for the first time; their rates are found to be comparable to those of $e^{+}{e}^{-}\to J/\psi (c\overline{c}{)}_{\mathrm{r}\mathrm{e}\mathrm{s}}$ processes.

We model the transition of a system of quarks and gluons at high energies to a system of quarks and mesons at low energies in a consistent renormalization group approach. Flow equations interpolate between the physics of the high-temperature degrees of freedom and the low-temperature dynamics at a scale of 1  GeV. We also discuss the dependence of the equation of state on baryon density and compare our results with recent lattice gauge simulations.

Using the methods of loop quantum gravity, we derive a framework for describing an inflationary, homogeneous universe in a purely quantum theory. The classical model is formulated in terms of the Ashtekar-Sen connection variables for a general subclass of Bianchi class A spacetimes. This formulation then provides a means to develop a corresponding quantum theory. An exact solution is derived for the classical Bianchi type I model and the corresponding semiclassical quantum state is found to also be an exact solution to the quantum theory. The development of a normalizable quantum state from this exact solution is presented and the implications for the normalizability of the Kodama state discussed. We briefly consider some consequences of such a quantum cosmological framework and show that the quantum scale factor of the universe has a continuous spectrum in this model. This result may suggest further modifications that are required to build a more accurate theory. We close this study by suggesting a variety of directions in which to take the results presented.