The angular distributions of the decay products in the successive decays ${\chi }_c({\chi }_b)\to \mathrm{J}/\psi ({\rm Y})\gamma$ and $\mathrm{J}/\psi ({\rm Y})\to {\ell }^{+}{\ell }^{-}$ are calculated as a function of the angular momentum composition of the decaying $\chi$ meson and of the multipole structure of the photon radiation, using a formalism independent of production mechanisms and polarization frames. The polarizations of the $\chi$ states produced in high-energy collisions can be derived from the dilepton decay distributions of the daughter $\mathrm{J}/\psi$ or ${\rm Y}$ mesons, with a reduced dependence on the details of the photon reconstruction or simulation. Moreover, this method eliminates the dependence of the polarization measurement on the actual details of the multipole structure of the radiative transition. Problematic points in previous calculations of the ${\chi }_c$ decay angular distributions are identified and clarified.

We study a softly broken supersymmetric model whose gauge symmetry is that of the standard model gauge group times an extra Abelian symmetry $U(1{)}^{\prime }$. We call this gauge-extended model the $U(1{)}^{\prime }$ model, and we study a $U(1{)}^{\prime }$ model with a secluded sector such that neutrinos acquire Dirac masses via higher-dimensional terms allowed by the $U(1{)}^{\prime }$ invariance. In this model the $\mu$ term of the minimal supersymmetric model (MSSM) is dynamically induced by the vacuum expectation value of a singlet scalar. In addition, the model contains exotic particles necessary for anomaly cancellation, and extra singlet bosons for achieving correct $Z^{\prime }/Z$ mass hierarchy. The neutrinos are charged under $U(1{)}^{\prime }$, and thus, their production and decay channels differ from those in the MSSM in strength and topology. We implement the model into standard packages and perform a detailed analysis of sneutrino production and decay at the Large Hadron Collider, for various mass scenarios, concentrating on three types of signals: (1) $0\ell +\mathrm{MET}$, (2) $2\ell +\mathrm{MET}$, and (3) $4\ell +\mathrm{MET}$. We compare the results with those of the MSSM whenever possible, and analyze the standard model background for each signal. The sneutrino production and decays provide clear signatures enabling distinction of the $U(1{)}^{\prime }$ model from the MSSM at the LHC.

We estimate the relative branching ratio of $\sigma$ to $2\pi$ for the decay of the ${\Psi }^{\prime }(2S)$, which we have found to be a mixed charm and hybrid charmonium meson. The external field method and correlators from a previous calculation are used to estimate these decays. We find the $\sigma$ to $2\pi$ branching ratio for ${\Psi }^{\prime }(2S)$ to the $J/\Psi (1S)$ decay to be 0.98, in agreement with an experiment at IHEP-BES.

We present the complete next-to-leading order (NLO) QCD predictions for the $t\gamma$ associated production induced by model-independent $tq\gamma$ and $tqg$ flavor-changing neutral-current (FCNC) couplings at hadron colliders, respectively. We also consider the mixing effects between the $tq\gamma$ and $tqg$ FCNC couplings for this process. Our results show that, for the $tq\gamma$ couplings, the NLO QCD corrections can enhance the total cross sections by about 50% and 40% at the Tevatron and LHC, respectively. Including the contributions from the $tq\gamma$, $tqg$ FCNC couplings and their mixing effects, the NLO QCD corrections can enhance the total cross sections by about 50% for the $tu\gamma$ and $tug$ FCNC couplings, and by about 80% for the $tc\gamma$ and $tcg$ FCNC couplings at the LHC, respectively. Moreover, the NLO corrections reduce the dependence of the total cross section on the renormalization and factorization scale significantly. We also evaluate the NLO corrections for several important kinematic distributions.

Photons carrying nonzero orbital angular momentum (twisted photons) are well-known in optics. Recently, using Compton backscattering to boost optical twisted photons to high energies was suggested. Twisted electrons in the intermediate energy range have also been produced recently. Thus, collisions involving energetic twisted particles seem to be feasible and represent a new tool in high-energy physics. Here we discuss some generic features of scattering processes involving twisted particles in the initial and/or final state. In order to avoid additional complications arising from nontrivial polarization states, we focus here on scalar fields only. We show that processes involving twisted particles allow one to perform a Fourier analysis of the plane-wave cross section with respect to the azimuthal angles of the initial particles. In addition, using twisted states, one can probe the autocorrelation function of the amplitude, which is inaccessible in the plane-wave collisions. Finally, we discuss prospects for experimental study of these effects.

This Erratum corrects some mistakes in this paper.

Proofs of two statements are provided in this paper. First, the authors prove that the formalism of the pseudo-Hermitian quantum mechanics allows for describing the Dirac particles motion in arbitrary stationary gravitational fields. Second, it is proved that using the Parker weight operator and the subsequent transition to the $\eta$ representation gives the transformation of the Schrödinger equation for the nonstationary metric, when the evolution operator becomes self-conjugate. The scalar products in the $\eta$ representation are flat, which makes possible the use of a standard apparatus for the Hermitian quantum mechanics. Based on the results of this paper the authors draw a conclusion about solution of the problem of uniqueness and self-conjugacy of Dirac Hamiltonians in arbitrary gravitational fields including those dependent on time. The general approach is illustrated by the example of Dirac Hamiltonians for several stationary metrics, as well as for the cosmologically flat and the open Friedmann models.

In previous work by M. A. L. Capri, A. J. Gomez, M. S. Guimaraes, V. E. R. Lemes, S. P. Sorella, and D. G. Tedesco [Phys. Rev. D 82, 105019 (2010)], we have shown that the soft breaking of the Becchi-Rouet-Stora-Tyutin (BRST) symmetry arising within the Gribov-Zwanziger framework can be converted into a linear breaking, while preserving the nilpotency of the BRST operator. Because of its compatibility with the quantum action principle, the linearly broken BRST symmetry directly translates into a set of Slavnov-Taylor identities. We show that these identities guarantee the multiplicative renormalizability of both Gribov-Zwanziger and refined Gribov-Zwanziger theories to all orders. The known property that only two renormalization factors are needed is recovered. The nonrenormalization theorem of the gluon-ghost-antighost vertex, as well as the renormalization factor of the Gribov parameter, are derived within the linearly broken formulation.

We apply the nonstandard loop quantum cosmology method to quantize a flat Friedmann-Robertson-Walker cosmological model with a free scalar field and the cosmological constant $\Lambda >0$. Modification of the Hamiltonian in terms of loop geometry parametrized by a length $\lambda$ introduces a scale dependence of the model. The spectrum of the volume operator is discrete and depends on $\Lambda$. Relating quantum of the volume with an elementary lattice cell leads to an explicit dependence of $\Lambda$ on $\lambda$. Based on this assumption, we investigate the possibility of interpreting $\Lambda$ as a running constant.

We study two large classes of alternative theories, modifying the action through algebraic, quadratic curvature invariants coupled to scalar fields. We find one class that admits solutions that solve the vacuum Einstein equations and another that does not. In the latter, we find a deformation to the Schwarzschild metric that solves the modified field equations in the small-coupling approximation. We calculate the event horizon shift, the innermost stable circular orbit shift, and corrections to gravitational waves, mapping them to the parametrized post-Einsteinian framework.

We study the AdS rotating black hole solution for the Bergshoeff-Hohm-Townsend massive gravity in three dimensions. The field equations of the asymptotically AdS black hole of the static metric can be expressed as the first law of thermodynamics, i.e. $dE=TdS-PdV$. The corrected Hawking-like temperature and entropy of the asymptotically AdS rotating black hole are calculated using the Cardy formula and the tunneling method. Comparison of these methods will help identify the unknown leading correction parameter ${\beta }_1$ in the tunneling method.

We analyze the magnitude-redshift data of type Ia supernovae included in the Union and Union2 compilations in the framework of an anisotropic Bianchi type I cosmological model and in the presence of a dark-energy fluid with anisotropic equation of state. We find that the amount of deviation from isotropy of the equation of state of dark energy, the skewness $\delta$, and the present level of anisotropy of the large-scale geometry of the Universe, the actual shear ${\Sigma }_0$, are constrained in the ranges $-0.16\lesssim \delta \lesssim 0.12$ and $-0.012\lesssim {\Sigma }_0\lesssim 0.012$ ($1\sigma$ C.L.) by Union2 data. Supernova data are then compatible with a standard isotropic universe ($\delta ={\Sigma }_0=0$), but a large level of anisotropy, both in the geometry of the Universe and in the equation of state of dark energy, is allowed.

Bursts of particle production during inflation provide a well-motivated mechanism for creating bumplike features in the primordial power spectrum. Current data constrain these features to be less than about 5% the size of the featureless primordial power spectrum at wave numbers of about $0.1h{\mathrm{Mpc}}^{-1}$. We forecast that the Planck cosmic microwave background experiment will be able to strengthen this constraint to the 0.5% level. We also predict that adding data from a square kilometer array galaxy redshift survey would improve the constraint to about the 0.1% level. For features at larger wave numbers, Planck will be limited by Silk damping and foregrounds, while the square kilometer array will be limited by nonlinear effects. We forecast, for a cosmic inflation probe galaxy redshift survey, that similar constraints can be achieved up to about a wave number of $1.0h{\mathrm{Mpc}}^{-1}$.

We examine how a parametrization of neutrino mixing matrix reflecting quark-lepton complementarity can be probed by considering phase-averaged oscillation probabilities, flavor composition of neutrino fluxes coming from atmospheric and astrophysical neutrinos and lepton flavor violating radiative decays. We discuss some distinct features of the parametrization by comparing the triminimal parametrization of perturbations to the tribimaximal neutrino mixing matrix.

An updated heavy quark-antiquark potential is constructed by matching the short-distance perturbative part to long-distance lattice QCD results at an intermediate $r$ scale. The static potential and the order $1/m$ potential are both analyzed in this way. Effects of order $1/m$ in charmonium and bottomonium spectra are discussed in comparison. Charm and bottom quark masses are deduced from the spectra and related to the quark masses of other schemes.

The $k_{\perp }$ moment of a quark’s Sivers function is known to be related to the corresponding twist-three quark-gluon correlation function $T_{q,F}(x,x)$. The two functions have been extracted from data for single-spin asymmetries in semi-inclusive deep-inelastic scattering and in single-inclusive hadron production in $pp$ collisions, respectively. Performing a consistent comparison of the extracted functions, we find that they show a “sign mismatch”: while the magnitude of the functions is roughly consistent, the $k_{\perp }$ moment of the Sivers function has opposite sign from that of $T_{q,F}(x,x)$, both for up and for down quarks. Barring any inconsistencies in our theoretical understanding of the Sivers functions and their process dependence, the implication of this mismatch is that either the Sivers effect is not dominantly responsible for the observed single-spin asymmetries in $pp$ collisions or the current semi-inclusive lepton scattering data do not sufficiently constrain the $k_{\perp }$ moment of the quark Sivers functions. Both possibilities strengthen the case for further experimental investigations of single-spin asymmetries in high-energy $pp$ and $ep$ scattering.

Recently, the possibility was pointed out by one of the present authors and his collaborators that an effective naked singularity referred to as “a visible border of spacetime” is generated by high-energy particle collision in the context of large extra dimensions or TeV-scale gravity. In this paper, we investigate the particle creation by a naked singularity in general dimensions, while adopting a model in which a marginally naked singularity forms in the collapse of a homothetic lightlike pressureless fluid. We find that the spectrum deviates from that of Hawking radiation due to scattering near the singularity but can be recast in quasithermal form. The temperature is always higher than that of Hawking radiation of a same-mass black hole, and can be arbitrarily high depending on a parameter in the model. This implies that, in principle, the naked singularity may be distinguished from a black hole in collider experiments.

The detection of gravitational waves from compact binaries relies on a computationally burdensome processing of gravitational-wave detector data. The parameter space of compact-binary-coalescence gravitational waves is large and optimal detection strategies often require nearly redundant calculations. Previously, it has been shown that singular value decomposition of search filters removes redundancy. Here we will demonstrate the use of singular value decomposition for a composite detection statistic. This can greatly improve the prospects for a computationally feasible rapid detection scheme across a large compact binary parameter space.

Noticeable deviations from the prediction of the fiducial lambda cold dark matter cosmology are found in the angular power spectrum of the cosmic microwave background. Besides large-angle anomalies, the WMAP first year data revealed a dip in the power spectrum at $l\sim 200$, which seemed to disappear in the third year and subsequent angular power spectra. Using the WMAP single first, third, and fifth year data as well as the total 5 yr coadded data, we study the intensity and spatial distribution of this feature in order to unveil its origin and its implications for the cosmological parameters. We show that in the 5 yr coadded WMAP data release there is a suppression of the first Doppler peak in a region near the north ecliptic pole at a significance level between 99% and 96% depending on the weighting scheme that is considered.

This is a general work on gravitational lensing. We present new expressions for the optical scalars and the deflection angle in terms of the energy-momentum tensor components of matter distributions. Our work generalizes standard references in the literature where normally stringent assumptions are made on the sources. The new expressions are manifestly gauge invariant, since they are presented in terms of curvature components. We also present a method of approximation for solving the lens equations, that can be applied to any order.