The detection of the gravitational waves (GWs) emitted by precessing binaries of spinning compact objects is complicated by the large number of parameters (such as the magnitudes and initial directions of the spins, and the position and orientation of the binary with respect to the detector) that are required to model accurately the precession-induced modulations of the GW signal. In this paper we describe a fast matched-filtering search scheme for precessing binaries, and we adopt the physical template family proposed by Buonanno, Chen, and Vallisneri [Phys. Rev. D 67, 104025 (2003)] for ground-based interferometers. This family provides essentially exact waveforms, written directly in terms of the physical parameters, for binaries with a single significant spin, and for which the observed GW signal is emitted during the phase of adiabatic inspiral (for LIGO-I and VIRGO, this corresponds to a total mass $M\lesssim {15M}_{\odot }).\mathrm{}$ We show how the detection statistic can be maximized automatically over all the parameters (including the position and orientation of the binary with respect to the detector), except four (the two masses, the magnitude of the single spin, and the opening angle between the spin and the orbital angular momentum), so the template bank used in the search is only four-dimensional; this technique is relevant also to the searches for GW from extreme-mass-ratio inspirals and supermassive black hole inspirals to be performed using the space-borne detector LISA. Using the LIGO-I design sensitivity, we compute the detection threshold $\left(\sim 10\right)$ required for a false-alarm probability of ${10}^{-3}/\mathrm{yr}$ and the number of templates $\left(\sim 76000\right)$ required for a minimum match of 0.97 for the mass range ${(m}_1{,m}_2)=[7,12]M_{\odot }\times [1,3]M_{\odot }.$

We consider the curvaton scenario in the context of supersymmetry (SUSY) with gravity-mediated SUSY breaking. In the case of a large initial curvaton amplitude during inflation and a negative order $H^2$ correction to the mass squared term after inflation, the curvaton will be close to the minimum of its potential at the end of inflation. In this case the curvaton amplitude fluctuations will be damped due to oscillations around the effective minimum of the curvaton potential, requiring a large expansion rate during inflation in order to account for the observed energy density perturbations, in conflict with cosmic microwave background constraints. Here we introduce a new curvaton scenario, the phase-induced curvaton scenario, in which de Sitter fluctuations of the phase of a complex SUSY curvaton field induce an amplitude fluctuation that is unsuppressed even in the presence of a negative order $H^2$ correction and large initial curvaton amplitude. This scenario is closely related to the Affleck-Dine mechanism and a curvaton asymmetry is naturally generated in conjunction with the energy density perturbations. Cosmological energy density perturbations can be explained with an expansion rate $H\approx {10}^{12}\mathrm{GeV}$ during inflation.

The effect of perturbative QCD interactions on the high-energy scattering of electroweak vector bosons, when the exchanged channel has pion quantum numbers, is considered. The chiral anomaly is shown to appear in the couplings of particular transverse momentum diagrams, producing an enhancement of the scattering amplitude by a power of the energy. At $O\left({\alpha }_s\right)$ a single large transverse momentum gluon is involved and, within the transverse momentum diagram framework, there is no cancellation. In higher orders, soft gluons, carrying both normal and anomalous color parity, are also present. The manipulation of a transverse momentum cutoff to replace the ultraviolet anomaly divergence by infrared divergences that can lead to confinement and chiral symmetry breaking is briefly discussed. The possible implications for electroweak symmetry breaking are noted.

A new evaluation of the charged Higgs boson decay $H^{+}\to W^{+}\gamma$ is presented in the context of the general two-Higgs doublet model. A nonlinear $R_{\xi }$ gauge which considerably simplifies the calculation is introduced and simple expressions are obtained for the fermionic and bosonic contributions. The $H^{+}\to W^{+}\gamma$ branching ratio is analyzed for several values of the parameters of the model. Although this decay can have a branching fraction as large as ${10}^{-4}$ in a certain region of the parameter space, it is found that such a region is disfavored by the most recent constraints on $\overrightarrow{b}s\gamma ,$ $g-2$ of the muon, $\overrightarrow{Z}b\overline{b},$ and the $\rho$ parameter, along with the exclusions from direct searches at the CERN $e^{-}{e}^{+}$ LEP collider. The possibility of detecting this decay at future colliders is discussed.

In a physical renormalization scheme, gauge couplings are defined directly in terms of physical observables. Such effective charges are analytic functions of physical scales, and thus mass thresholds are treated with their correct analytic dependence. In particular, particles will contribute to physical predictions even at energies below their threshold. This is in contrast with unphysical renormalization schemes such as $\overline{\mathrm{MS}}$ where mass thresholds are treated as step functions. In this paper we analyze supersymmetric grand unification in the context of physical renormalization schemes and find a number of qualitative differences and improvements in precision over conventional approaches. The effective charge formalism presented here provides a template for calculating all mass threshold effects for any given grand unified theory. These new threshold corrections may be important in making the measured values of the gauge couplings consistent with unification.

We comment on the reweighting method for the study of finite density lattice QCD. We discuss the applicable parameter range of the reweighting method for models that have more than one simulation parameter. The applicability range is determined by the fluctuations of the modification factor of the Boltzmann weight. In some models having a first order phase transition, the fluctuations are minimized along the phase transition line if we assume that the pressure in the hot and the cold phases is balanced at the first order phase transition point. This suggests that the reweighting method with two parameters is applicable in a wide range for the purpose of tracing out the phase transition line in the parameter space. To confirm the usefulness of the reweighting method for two-flavor QCD, the fluctuations of the reweighting factor are measured by numerical simulations for the cases of reweighting in the quark mass and chemical potential directions. The relation to the phase transition line is discussed. Moreover, the sign problem caused by the complex phase fluctuations is studied.

Employing the standard hard-scattering approach and the running coupling method we calculate a class of power-suppressed corrections $\sim {1/Q}^{2n},n=1,2,3,\dots$ to the electromagnetic ${\pi }^0\gamma$ transition form factor (FF) $Q^2{F}_{\pi \gamma }{(Q}^2)$ arising from the end-point $\overrightarrow{x}0,1$ integration regions. In the investigation we use a hard-scattering amplitude of the subprocess $\gamma +{\gamma }^{*}\to q+\overline{q},$ symmetrized under the exchange ${\mu }_R^2\leftrightarrow {\overline{\mu }}_R^2$ important for exclusive processes containing two external photons. In the computations the pion model distribution amplitudes (DA’s) with one and two nonasymptotic terms are employed. The obtained predictions are compared with the CLEO data and constraints on the DA parameters $b_2\left({\mu }_0^2\right)$ and $b_4\left({\mu }_0^2\right)$ at the normalization point ${\mu }_0^2=1\mathrm{}{\mathrm{GeV}}^2$ are extracted. Further restrictions on the pion DA’s are deduced from the experimental data on the electromagnetic FF $F_{\pi }{(Q}^2).\mathrm{}$

We study the group structure of a baryon antidecuplet containing ${\Theta }^{+}.$ We derive the SU(3) mass relations among the pentaquark baryons in the antidecuplet, when there is either no mixing or ideal mixing with the pentaquark octet, as advocated by Jaffe and Wilczek. This constitutes the Gell-Mann–Okubo mass formula for the pentaquark baryons. We also derive the SU(3) symmetric Lagrangian for the interactions of the baryons in the antidecuplet with the meson octet and the baryon octet. Our analysis for the decay widths of the antidecuplet states suggests that $N\left(1710\right)\mathrm{}$ is ruled out as a pure antidecuplet state, but it may have an antidecuplet component in its wave function if the multiplet is mixed with the pentaquark octet.

We compute the rapidity distributions of W and Z bosons produced at the Fermilab Tevatron and the CERN LHC through next-to-next-to leading order in QCD. Our results demonstrate remarkable stability with respect to variations of the factorization and renormalization scales for all values of rapidity accessible in current and future experiments. These processes are therefore “gold-plated”: current theoretical knowledge yields QCD predictions accurate to better than 1%. These results strengthen the proposal to use W and Z production to determine parton-parton luminosities and constrain parton distribution functions at the LHC. For example, LHC data should easily be able to distinguish the central parton distribution fit obtained by MRST from that obtained by Alekhin.

The static electromagnetic properties of the W boson, $\Delta \kappa$ and $\Delta Q,$ are calculated in the ${\mathrm{SU}}_L\mathrm{}\left(3\right)\mathrm{}\times U_X\mathrm{}\left(1\right)\mathrm{}$ model with right-handed neutrinos. The new contributions from this model arise from the gauge and scalar sectors. In the gauge sector there is a new contribution from a complex neutral gauge boson $Y^0$ and a singly charged gauge boson $Y^{\pm }.$ The mass of these gauge bosons, called bileptons, is expected to be in the range of a few hundred GeV according to the current bounds from experimental data. If the bilepton masses are of the order of 200 GeV, the size of their contribution is similar to that obtained in other weakly coupled theories. However, the contributions to both $\Delta Q$ and $\Delta \kappa$ are negligible for very heavy or degenerate bileptons. As for the scalar sector, a scenario is examined in which the contribution to the W form factors is identical to that of a two-Higgs-doublet model. It is found that this sector would not give large corrections to $\Delta \kappa$ and $\Delta Q.\mathrm{}$

The processes $\psi \mathrm{}\left(2S\right)\mathrm{}\to \gamma {\chi }_{\mathrm{cJ}},$ ${\chi }_{\mathrm{cJ}}\to p\overline{p}$ $\mathrm{}(J=0,1,2\mathrm{})\mathrm{}$ are studied using a sample of $14\times {10}^6$ $\psi \mathrm{}\left(2S\right)\mathrm{}$ decays collected with the Beijing Spectrometer at the Beijing Electron-Positron Collider. Very clear ${\chi }_{c0\mathrm{}},$ ${\chi }_{c1\mathrm{}}$ and ${\chi }_{c2\mathrm{}}$ signals are observed, and the branching fractions $\mathcal{B}({\chi }_{\mathrm{cJ}}\to p\overline{p})$ $\mathrm{}(J=0,1,2\mathrm{})\mathrm{}$ are determined to be ${(27.1\mathrm{}}_{-3.9}^{+4.3\mathrm{}}\pm 4.7)\times {10}^{-5},$ ${(5.7\mathrm{}}_{-1.5}^{+1.7\mathrm{}}\pm 0.9)\times {10}^{-5},$ and ${(6.5\mathrm{}}_{-2.1}^{+2.4\mathrm{}}\pm 1.0)\times {10}^{-5},$ respectively, where the first errors are statistical and the second are systematic.

We present a numerical code designed to study astrophysical phenomena involving dynamical spacetimes containing black holes in the presence of relativistic hydrodynamic matter. We present evolutions of the collapse of a fluid star from the onset of collapse to the settling of the resulting black hole to a final stationary state. In order to evolve stably after the black hole forms, we excise a region inside the hole before a singularity is encountered. This excision region is introduced after the appearance of an apparent horizon, but while a significant amount of matter remains outside the hole. We test our code by evolving accurately a vacuum Schwarzschild black hole, a relativistic Bondi accretion flow onto a black hole, Oppenheimer-Snyder dust collapse, and the collapse of nonrotating and rotating stars. These systems are tracked reliably for hundreds of M following excision, where M is the mass of the black hole. We perform these tests both in axisymmetry and in full 3+1 dimensions. We then apply our code to study the effect of the stellar spin parameter ${J/M}^2$ on the final outcome of gravitational collapse of rapidly rotating $n=1\mathrm{}$ polytropes. We find that a black hole forms only if ${J/M}^2<1,$ in agreement with previous simulations. When ${J/M}^2>1,$ the collapsing star forms a torus which fragments into nonaxisymmetric clumps, capable of generating appreciable “splash” gravitational radiation.

The renormalization issue in the reparametrization invariance in heavy quark effective theory and NRQCD is investigated. I argue that the renormalization of the transformation of the heavy quark field under the variation of the velocity parameter V is attributed to the renormalization of the small component field in the proposed transformation. I derive the matching conditions for determining the renormalized small component field by imposing an infinitesimal transformation of V on the relations between the Green’s functions in QCD full theory and those in the effective theory. As an application, I determine the renormalized transformation to order ${1/m}^2$ using the matching conditions. The obtained result is in disagreement with that determined by the indirect method.

Triplet-mediated proton decay in grand unified theories (GUTs) is usually suppressed by arranging a large triplet mass. Here we explore instead a mechanism for suppressing the couplings of the triplets to the first and second generations compared to the Yukawa couplings, so that the triplets can be light. This mechanism is based on a “triplet symmetry” in the context of product-group GUTs. We study two possibilities. The first possibility, which requires the top Yukawa coupling to arise from a nonrenormalizable operator at the GUT scale, is that all triplet couplings to matter are negligible, so that the triplets can be at the weak scale, giving new evidence for grand unification. The second possibility is that some triplet couplings, and in particular Ttb and $T\overline{t}\overline{l},$ are equal to the corresponding Yukawa couplings. This would give a distinct signature of grand unification if the triplets were sufficiently light. However, we derive a model-independent bound on the triplet mass in this case, which is at least ${10}^6\mathrm{GeV}.$ Finally, we construct an explicit viable GUT model based on Yukawa splitting, with the triplets at ${10}^{14}\mathrm{GeV},$ as required for coupling unification to work. This model requires no additional thresholds below the GUT scale.

We analyze the potential of the CERN Large Hadron Collider to study anomalous quartic vector-boson interactions $\mathrm{ZZ}\gamma \gamma ,$ $\mathrm{ZZZ}\gamma ,$ $W^{+}{W}^{-}\gamma \gamma ,$ and $W^{+}{W}^{-}Z\gamma$ through the weak boson fusion processes $q\overrightarrow{q}\mathrm{qq}\gamma \gamma$ and $q\overrightarrow{q}\mathrm{qq}\gamma Z(\to {\mathcal{l}}^{+}{\mathcal{l}}^{-})$ with $\mathcal{l}=e$ or $\mu .$ After a careful study of the backgrounds and how to extract them from the data, we show that the process $p\overrightarrow{p}\mathrm{jj}\gamma {\mathcal{l}}^{+}{\mathcal{l}}^{-}$ is potentially the most sensitive to deviations from the standard model, improving the sensitivity to anomalous couplings by up to a factor of ${10}^4{(10\mathrm{}}^2)$ with respect to the present direct (indirect) limits.

We determine the energies of the excited states of a heavy-light meson $Q\overline{q},$ with a static heavy quark and light quark with mass approximately that of the strange quark from both quenched lattices and with dynamical fermions. We are able to explore the energies of orbital excitations up to $L=3,$ the spin-orbit splitting up to $L=2\mathrm{}$ and the first radial excitation. These $b\overline{s}$ mesons will be very narrow if their mass is less than 5775 MeV—the BK threshold. We investigate this in detail and present evidence that the scalar meson $\mathrm{}(L=1\mathrm{})\mathrm{}$ will be very narrow and that altogether 6 $b\overline{s}$ excited states will have energies close to the BK threshold and all will be relatively narrow.

We discuss the effect of the choice of an Abelian projection on the dual superconductor mechanism of confinement in SU(2) gluodynamics. Using qualitative arguments we show that the dual superconductor Lagrangian corresponding to the Abelian Polyakov gauge has a different structure compared to the dual Lagrangian in the maximal Abelian gauge. The difference between these Lagrangians reflects the fact that in the continuum limit the monopoles should be static in the Abelian Polyakov gauge and therefore these monopoles cannot give rise to the confinement of static quarks. Using the Abelian Polyakov gauge as an example, we show that (i) the dual superconductor scenario of confinement may depend on the Abelian projection, and (ii) the condensation of the Abelian monopoles—which may be realized in any Abelian projection—is a necessary but not sufficient condition for confinement. These results do not exclude the existence of a class of Abelian gauges (including the Maximal Abelian gauge) in which the dual superconductor scenario works well.

We investigate the adjoint SU(2) lattice gauge theory in $3+1$ dimensions with the Wilson plaquette action modified by a $Z_2$ monopole suppression term. For the zero-twist sector we report on indications for the existence of a finite temperature transition decoupled from the unphysical bulk transitions.

We study the difficulties associated with detecting chiral singularities predicted by chiral perturbation theory (ChPT) in lattice QCD. We focus on the physics of the remnant O(2) chiral symmetry of staggered fermions in the strong coupling limit using the recently discovered directed path algorithm. Since it is easier to look for powerlike singularities as compared to logarithmic ones, our calculations are performed at a fixed finite temperature in the chirally broken phase. We show that the behavior of the chiral condensate, the pion mass, and the pion decay constant are all consistent with the predictions of ChPT for small masses. However, in order to demonstrate this we need quark masses that are much smaller (in lattice units) than those typically used in dynamical QCD simulations. We also need to use higher order terms in the chiral expansion to fit our data.