We examine classical configurations of $SU(3)$ Yang-Mills theory as they can exist on the lattice at finite temperature. Employing the cooling method, a set of classical fields is generated from a confining Monte-Carlo ensemble. Various operators are used to describe this set with respect to its topological properties. We find pseudoparticle fields, so-called caloron solutions, possessing the remarkable features of (superpositions of) Kraan-van Baal solutions, i.e. extensions of Harrington-Shepard calorons to generic values of the holonomy.

We study spin $\frac{1}{2}$ hadronic states in quenched lattice QCD to search for a possible $S=+1$ pentaquark resonance. Simulations are carried out on $8^3\times 24$, ${10}^3\times 24$, ${12}^3\times 24$, and ${16}^3\times 24$ lattices at $\beta =5.7$ at the quenched level with the standard plaquette gauge action and the Wilson quark action. We adopt a Dirichlet boundary condition in the time direction for the quark to circumvent the possible contaminations due to the (anti)periodic boundary condition for the quark field, which are peculiar to the pentaquark. By diagonalizing the $2\times 2$ correlation matrices constructed from two independent operators with the quantum numbers $(I,J)=(0,\frac{1}{2})$, we successfully obtain the energies of the lowest state and the 2nd-lowest state in this channel. The analysis of the volume dependence of the energies and spectral weight factors indicates that a resonance state is likely to exist slightly above the nucleon-Kaon ($NK$) threshold in $(I,J^P)=(0,{\frac{1}{2}}^{-})$ channel.

We investigate effects resulting from the use of different discretizations for the valence and the sea quarks in lattice QCD, considering Wilson and/or Ginsparg-Wilson fermions. We assume that such effects appear through scaling violations that can be studied using effective Lagrangian techniques. We show that a double pole is present in flavor-neutral Goldstone-meson propagators, even if the charged Goldstone mesons made out of valence quarks and those made out of sea quarks have equal masses. We then consider some observables known to be anomalously sensitive to the presence of a double pole. For these observables, we find that the double-pole enhanced scaling violations may turn out to be rather small in practice.

A simple three-flavor neutrino-oscillation model is discussed which has both nonzero mass differences and timelike Fermi-point splittings, together with a combined bi-maximal and trimaximal mixing pattern. One possible consequence would be new effects in ${\nu }_{\mu }\to {\nu }_e$ oscillations, characterized by an energy-dependent effective mixing angle ${\Theta }_{13}$. Future experiments such as T2K and NO$\nu$A, and perhaps even the current MINOS experiment, could look for these effects.

We present measurements of the branching fractions for $J/\psi \to e^{+}{e}^{-}$ and ${\mu }^{+}{\mu }^{-}$ using 3M $\psi (2S)$ decays collected with the CLEO detector operating at the CESR $e^{+}{e}^{-}$ collider. We obtain $\mathcal{B}(J/\psi \to e^{+}{e}^{-})=(5.945\pm 0.067\pm 0.042)\%$ and $\mathcal{B}(J/\psi \to {\mu }^{+}{\mu }^{-})=(5.960\pm 0.065\pm 0.050)\%$, leading to an average of $\mathcal{B}(J/\psi \to {\ell }^{+}{\ell }^{-})=(5.953\pm 0.056\pm 0.042)\%$ and a ratio of $\mathcal{B}(J/\psi \to e^{+}{e}^{-})/\mathcal{B}(J/\psi \to {\mu }^{+}{\mu }^{-})=(99.7\pm 1.2\pm 0.6)\%$, all consistent with, but more precise than, previous measurements.

In classical general relativity, the generic approach to the initial singularity is usually understood in terms of the Belinskii-Khalatnikov-Lifschitz scenario. In this scenario, along with the Bianchi IX model, the exact, singular, Kasner solution of the vacuum Bianchi I model also plays a pivotal role. Using an effective classical Hamiltonian obtained from loop quantization of the vacuum Bianchi I model, an exact solution is obtained which is nonsingular due to a discreteness parameter. The solution is parametrized in exactly the same manner as the usual Kasner solution and reduces to the Kasner solution as the discreteness parameter is taken to zero. At the effective Hamiltonian level, the avoidance of Kasner singularity uses a mechanism distinct from the “inverse volume” modifications characteristic of loop quantum cosmology.

We consider the equivalence of covariant and light front quantum electrodynamics at one loop level. We show that the one loop expressions for fermion self-energy, vacuum polarization, and vertex correction in the covariant perturbation theory can be reduced to a sum of propagating and instantaneous diagrams of light front time-ordered perturbation theory by performing $k^{-}$ integration. We show that the third term in the doubly transverse gauge propagator is necessary to generate the diagrams involving instantaneous photon exchange both in the case of fermion self-energy as well as the vertex correction. We also show that the correspondence between the covariant and light front diagrams cannot be established if one removes the $k^{+}=0$ modes by an infrared cutoff before performing $k^{-}$ integration.

We obtain plane fronted gravitational waves (PFGWs) in arbitrary dimension in Lovelock gravity, to any order in the Riemann tensor. We exhibit pure gravity as well as Lovelock-Yang-Mills PFGWs. Lovelock-Maxwell and $pp$ waves arise as particular cases. The electrovac solutions trivially satisfy the Lovelock-Born-Infeld field equations. The peculiarities that arise in degenerate Lovelock theories are also analyzed.

We consider a model in which dark matter consists of a large self-interacting component (SIDM particles) and a small component with strong interactions with baryons (SIMPs). We show that the DAMA annual modulation signal can be caused by SIDM particles interacting with SIMPs trapped in iodine nuclei in the DAMA/NaI detector.

In the scenarios with heavy top squarks, mass parameters of the Higgs field must be fine-tuned due to a large logarithmic correction to the soft scalar mass. We consider a new possibility that the top-Yukawa coupling is small above TeV scale. The large top mass is induced from strong Yukawa interaction of the Higgs with another gauge sector, in which supersymmetry breaking parameters are given to be small. Then it is found that the logarithmic correction to the Higgs soft scalar mass is suppressed in spite of the strong coupling, and the fine-tuning is ameliorated. We propose an explicit model coupled to a superconformal gauge theory which realizes the above situation.

We explore the unitarity violation of the Cabibbo-Kobayashi-Maskawa (CKM) matrix in the model where the third generation fermions are subjected to the separate $SU(2{)}_L$ gauge interaction. With the recent LEP and SLAC linear collider (SLC) data at $Z$-pole and low-energy neutral current interaction data, the analysis on the parameter space of the model is updated, and the unitary violation is predicted under the constraint.

As a probe of the Yang-Mills vacuum, we study numerically the eigenmode spectrum of the covariant lattice Laplacian operator. We find that the eigenmodes at the low and high ends of the spectrum are localized in finite regions whose volume is insensitive to the lattice volume. We also find that the vacuum is seen very differently by localized modes of the covariant Laplacian in different representations of the gauge group. In the fundamental representation, the data suggests that the localization volume is finite in physical units set by the string tension, and localization disappears when center vortices are removed. In the adjoint and $j=3/2$ representations the low and high-lying modes are far more localized, and the localization volume appears to scale to zero, in physical units, in the continuum limit. The adjoint Laplacian is insensitive to vortex removal, but we find that exponential localization is absent for adjoint eigenmodes in the Higgs phase of a gauge-Higgs theory. Localization is also absent in the spectrum of the Coulomb gauge Faddeev-Popov operator, as required in Coulomb gauge confinement scenarios.

We investigate a possible nuclear correction to the NuTeV measurement of the weak-mixing angle ${sin}^2{\theta }_W$. In particular, a nuclear modification difference between $u_v$ and $d_v$ distributions contributes to the NuTeV measurement with the iron target. First, the modification difference is determined by a ${\chi }^2$ analysis so as to reproduce nuclear data on the structure function $F_2$ and Drell-Yan processes. Then, taking the NuTeV kinematics into account, we calculate a contribution to the ${sin}^2{\theta }_W$ determination. In addition, its uncertainty is estimated by the Hessian method. Although the uncertainty becomes comparable to the NuTeV deviation, the effect is not large enough to explain the whole NuTeV ${sin}^2{\theta }_W$ anomaly at this stage. However, it is difficult to determine such a nuclear modification difference, so that we need further investigations on the difference and its effect on the NuTeV anomaly.

We present a measurement of the time-dependent $CP$-violating asymmetries in decays of neutral $B$ mesons to the final states $D^{*\mp }{\pi }^{\pm }$, using approximately $232\times {10}^6$ $B\overline{B}$ events recorded by the BABAR experiment at the PEP-II $e^{+}{e}^{-}$ storage ring. Events containing these decays are selected with a partial reconstruction technique, in which only the high-momentum ${\pi }^{\pm }$ from the $B$ decay and the low-momentum ${\pi }^{\mp }$ from the $D^{*\mp }$ decay are used. We measure the parameters related to $2\beta +\gamma$ to be $a_{D^{*}\pi }=-0.034\pm 0.014\pm 0.009$ and $c_{D^{*}\pi }^{\ell }=-0.019\pm 0.022\pm 0.013$. With some theoretical assumptions, we interpret our results in terms of the lower limits $|\sin (2\beta +\gamma )|>0.62(0.35)$ at 68% (90%) confidence level.

LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own Galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. Our approach relies on entirely analytic expressions of the LISA time-delay interferometric responses to the gravitational radiation emitted by such systems, which allows us to implement a computationally efficient and accurate simulation of the background in the LISA data. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. This suggests that, during this time period, LISA could search for other gravitational wave signals incoming from directions that are away from the galactic plane. Since the galactic white-dwarf background will be observed by LISA not as a stationary but rather as a cyclostationary random process with a period of 1 yr, we summarize the theory of cyclostationary random processes, present the corresponding generalized spectral method needed to characterize such process, and make a comparison between our analytic results and those obtained by applying our method to the simulated data. We find that, by measuring the generalized spectral components of the white-dwarf background, LISA will be able to infer properties of the distribution of the white-dwarf binary systems present in our Galaxy.

The final results of the EDELWEISS-I dark matter search using cryogenic heat-and-ionization Ge detectors are presented. The final data sample corresponds to an increase by a factor 5 in exposure relative to the previously published results. A recoil energy threshold of 13 keV or better was achieved with three 320 g detectors working simultaneously over four months of stable operation. Limits on the spin-independent cross section for the scattering of a weakly interacting massive particle on a nucleon are derived from an accumulated fiducial exposure of $62\mathrm{kg}\mathrm{d}$.

In this work a generic set of boundary conditions for $\mathcal{N}=1$ supergravity is proposed. These conditions define that Hamiltonian charges equal Noether ones, including supercharge.

The new generalization of the gauge interaction for the bosonic strings is found. We consider some quasiequivariant maps from the space of metrics on the worldsheet to the space of $n$-tuples of one- and two-dimensional loops. The two-dimensional case is based on the cylinders interacted with a path space connection. The special 2-gauge string model is formulated using two 1-connections, non-Abelian background symmetric tensor field and non-Abelian 2-form. The branched non-Abelian space-time is the result of our construction.

We study the quantum-mechanical generation of gravitational waves during inflation on a brane embedded in a five-dimensional anti de Sitter bulk. To make the problem well posed, we consider the setup in which both initial and final phases are given by a de Sitter brane with different values of the Hubble expansion rate. Assuming that the quantum state is in a de Sitter invariant vacuum in the initial de Sitter phase, we numerically evaluate the amplitude of quantum fluctuations of the growing solution of the zero mode in the final de Sitter phase. We find that the vacuum fluctuations of the initial Kaluza-Klein gravitons as well as of the zero mode gravitons contribute to the final amplitude of the zero mode on small scales, and the power spectrum is quite well approximated by what we call the rescaled spectrum, which is obtained by rescaling the standard four-dimensional calculation following a simple mapping rule. Our results confirm the speculation raised in Ref. [T. Kobayashi, H. Kudoh, and T. Tanaka, Phys. Rev. D 68, 044025 (2003).] before.

We point out that Kaluza-Klein (KK) dark matter physics is drastically affected by second KK particles. In this work various interesting phenomena caused by the second KK modes are discussed. In particular, we reevaluate the annihilation cross section relevant to the thermal relic density of KK dark matter in universal extra dimension models. In these models, the first KK mode of a $B$ boson is a viable dark matter candidate by virtue of KK parity. We demonstrate that the KK dark matter annihilation cross section can be enhanced, compared with the tree-level cross section mediated only by first KK particles. The mass of the first KK mode of the $B$ boson consistent with the Wilkinson Microwave Anisotropy Probe observation is increased.