Conformal totally symmetric arbitrary spin currents and shadow fields in flat space-time of dimension greater than or equal to four are studied. A gauge invariant formulation for such currents and shadow fields is developed. Gauge symmetries are realized by involving the Stueckelberg fields. A realization of global conformal boost symmetries is obtained. Gauge invariant differential constraints for currents and shadow fields are obtained. AdS/CFT correspondence for currents and shadow fields and the respective normalizable and non-normalizable solutions of massless totally symmetric arbitrary spin AdS fields are studied. The bulk fields are considered in a modified de Donder gauge that leads to decoupled equations of motion. We demonstrate that leftover on shell gauge symmetries of bulk fields correspond to gauge symmetries of boundary currents and shadow fields, while the modified de Donder gauge conditions for bulk fields correspond to differential constraints for boundary conformal currents and shadow fields. Breaking conformal symmetries, we find interrelations between the gauge invariant formulation of the currents and shadow fields, and the gauge invariant formulation of massive fields.

Basing on the Cornwall-Jackiw-Tomboulis effective action approach we formulate a theoretical formalism for studying kaon condensation in the linear sigma model at finite density and temperature. We derive the renormalized effective potential in the Hartree-Fock approximation, which preserves the Goldstone theorem. This quantity is then used to consider physical properties of kaon matter.

Expressions for the gravitational-wave (GW) energy flux and center-of-mass energy of a compact binary are integral building blocks of post-Newtonian (PN) waveforms. In this paper, we compute the GW energy flux and GW frequency derivative from a highly accurate numerical simulation of an equal-mass, nonspinning black-hole binary. We also estimate the (derivative of the) center-of-mass energy from the simulation by assuming energy balance. We compare these quantities with the predictions of various PN approximants [adiabatic Taylor and Padé models; nonadiabatic effective-one-body (EOB) models]. We find that Padé summation of the energy flux does not accelerate the convergence of the flux series; nevertheless, the Padé flux is markedly closer to the numerical result for the whole range of the simulation (about 30 GW cycles). Taylor and Padé models overestimate the increase in flux and frequency derivative close to merger, whereas EOB models reproduce more faithfully the shape of and are closer to the numerical flux, frequency derivative, and derivative of energy. We also compare the GW phase of the numerical simulation with Padé and EOB models. Matching numerical and untuned 3.5 PN order waveforms, we find that the phase difference accumulated until $M\omega =0.1$ is $-0.12$ radians for Padé approximants, and 0.50 (0.45) radians for an EOB approximant with Keplerian (non-Keplerian) flux. We fit free parameters within the EOB models to minimize the phase difference, and confirm the presence of degeneracies among these parameters. By tuning the pseudo 4PN order coefficients in the radial potential or in the flux, or, if present, the location of the pole in the flux, we find that the accumulated phase difference at $M\omega =0.1$ can be reduced—if desired—to much less than the estimated numerical phase error (0.02 radians).

Bekenstein’s tensor-vector-scalar (TeVeS) theory has had considerable success in explaining various phenomena without the need for dark matter. However, it is difficult to observationally discern the differences between TeVeS and predictions made within the $\Lambda$-cold dark matter concordance model. This implies that alternative tests are required that independently verify which theory is correct. For this we turn to the strong-field regime of TeVeS. In particular, we solve the spherically symmetric equations of hydrostatic equilibrium for a perfect fluid with a realistic equation of state to build models of neutron stars in TeVeS. We show that causality within the neutron star is only maintained for certain cosmological values of the scalar field, which allows us to put constraints on this value independently of cosmological observations. We also discuss in detail the internal structure of neutron stars and how each of the free parameters in the theory affects the overall size and mass of the neutron stars. In particular, the radii of neutron stars in TeVeS can significantly differ from those in general relativity for certain values of the vector field coupling, which allows us to also place extra constraints on this parameter. Finally, we discuss future observations of neutron stars using both the electromagnetic and gravitational wave spectrums that will allow for tests of the appropriate theory of gravity.

In Einstein’s gravity, the entropy of horizons is proportional to their area. Several arguments given in the literature suggest that, in this context, both area and entropy should be quantized with an equally-spaced spectrum for large quantum numbers. But in more general theories (like, for example, in the black hole solutions of Gauss-Bonnet or Lanczos-Lovelock gravity) the horizon entropy is not proportional to area and the question arises as to which of the two (if at all) will have this property. We give a general argument that in all Lanczos-Lovelock theories of gravity, it is the entropy that has an equally-spaced spectrum. In the case of Gauss-Bonnet gravity, we use the asymptotic form of quasinormal mode frequencies to explicitly demonstrate this result. Hence, the concept of a quantum of area in Einstein-Hilbert gravity needs to be replaced by a concept of quantum of entropy in a more general context.

We investigate stability of the $D$-dimensional Reissner-Nordström-anti-de Sitter metrics as solutions of the Einstein-Maxwell equations. We have shown that asymptotically anti-de Sitter (AdS) black holes are dynamically stable for all values of charge and anti-de Sitter radius in $D=5,6\dots 11$ dimensional space-times. This does not contradict dynamical instability of RNAdS black holes found by Gubser in $\mathcal{N}=8$ gauged supergravity, because the latter instability comes from the tachyon mode of the scalar field, coupled to the system. Asymptotically AdS black holes are known to be thermodynamically unstable for some region of parameters, yet, as we have shown here, they are stable against gravitational perturbations.

One of the first orders of business for LHC experiments after beam turn-on will be to calibrate the detectors using well-understood standard model (SM) processes such as $W$ and $Z$ production and $t\overline{t}$ production. These familiar SM processes can be used to calibrate the electromagnetic and hadronic calorimeters, and also to calibrate the associated missing transverse energy signal. However, the presence of new physics may already affect the results coming from these standard benchmark processes. We show that the presence of relatively low mass supersymmetry (SUSY) particles may give rise to significant deviations from SM predictions of $Z+\mathrm{\text{jets}}$ and $W+\mathrm{\text{jets}}$ events for jet multiplicity $\ge 4$ or $\ge 5$, respectively. Furthermore, the presence of low mass SUSY may cause nonstandard deviations to appear in top quark invariant and transverse mass distributions. Thus, effects that might be construed as detector malperformance could in fact be the presence of new physics. We advocate several methods to check when new physics might be present within SM calibration data.

We study the QCD phase structure in a three-flavor random matrix model with symmetries of QCD formulated at finite temperature and nonzero chemical potentials of baryon number, isospin, and strangeness. We numerically investigate the phase diagram in the chemical potential plane at zero temperature with finite quark masses. We find a rich phase structure separated by both first and second order phase transition lines, which qualitatively agrees with the predictions of effective chiral models and Nambu-Jona-Lasinio models. The phases are characterized by the chiral condensates of three flavors, pion and kaon condensates.

We perform a time-dependent and time-integrated angular analysis of the decays $B^0\to \phi K^{*}(892{)}^0$, $\phi K_2^{*}(1430{)}^0$, and $\phi (K\pi {)}_0^{*0}$ with the final sample of about $465\times {10}^6$ $B\overline{B}$ pairs recorded with the BABAR detector. Twenty-four parameters are investigated, including the branching fractions, $CP$-violation parameters, and parameters sensitive to final-state interactions. We use the dependence on the $K\pi$ invariant mass of the interference between the scalar and vector or tensor components to resolve discrete ambiguities of the strong and weak phases. We use the time evolution of the $B\to \phi K_S^0{\pi }^0$ channel to extract the $CP$-violation phase difference $\Delta {\varphi }_{00}=0.28\pm 0.42\pm 0.04$ between the $B$ and $\overline{B}$ decay amplitudes. When the $B\to \phi K^{\pm }{\pi }^{\mp }$ channel is included, the fractions of longitudinal polarization $f_L$ of the vector-vector and vector-tensor decay modes are measured to be $0.494\pm 0.034\pm 0.013$ and ${0.901}_{-0.058}^{+0.046}\pm 0.037$, respectively. This polarization pattern requires the presence of a positive-helicity amplitude in the vector-vector decay from a currently unknown source.

Using a data sample of $24.5\times {10}^6$ $\psi (2S)$ the reactions $\psi (2S)\to \gamma {\chi }_{cJ}$, ${\chi }_{cJ}\to \gamma \gamma$ have been studied for the first time to determine the two-photon widths of the ${\chi }_{cJ}$ states of charmonium in their decay into two photons. The measured quantities are $\mathcal{B}(\psi (2S)\to \gamma {\chi }_{c0})\times \mathcal{B}({\chi }_{c0}\to \gamma \gamma )=(2.17\pm 0.32\pm 0.10)\times {10}^{-5}$ and $\mathcal{B}(\psi (2S)\to \gamma {\chi }_{c2})\times \mathcal{B}({\chi }_{c2}\to \gamma \gamma )=(2.68\pm 0.28\pm 0.15)\times {10}^{-5}$. Using values for $\mathcal{B}(\psi (2S)\to \gamma {\chi }_{c0,c2})$ and $\Gamma ({\chi }_{c0,c2})$ from the literature the two-photon widths are derived to be ${\Gamma }_{\gamma \gamma }({\chi }_{c0})=(2.36\pm 0.35\pm 0.22)\mathrm{keV}$, ${\Gamma }_{\gamma \gamma }({\chi }_{c2})=(0.66\pm 0.07\pm 0.06)\mathrm{keV}$, and $\mathcal{R}\equiv {\Gamma }_{\gamma \gamma }({\chi }_{c2})/{\Gamma }_{\gamma \gamma }({\chi }_{c0})=0.278\pm 0.050\pm 0.036$. The importance of the measurement of $\mathcal{R}$ is emphasized. For the forbidden transition, ${\chi }_{c1}\to \gamma \gamma$, an upper limit of ${\Gamma }_{\gamma \gamma }({\chi }_{c1})<0.03\mathrm{keV}$ is established.

Shibata, Uryū and Friedman recently suggested a new decomposition of Einstein’s equations that is useful for constructing initial data. In contrast to previous decompositions, the conformal metric is no longer treated as a freely specifiable variable, but rather is determined as a solution to the field equations. The new set of freely specifiable variables includes only time derivatives of metric quantities, which makes this decomposition very attractive for the construction of quasiequilibrium solutions. To date, this new formalism has only been used for binary neutron stars. Applications involving black holes require new boundary conditions for the conformal metric on the domain boundaries. In this paper we demonstrate how these boundary conditions follow naturally from the conformal geometry of the boundary surfaces and the inherent gauge freedom of the conformal metric.

We study Schwinger pair production in scalar QED from a uniform electric field in $d{S}_2$ with scalar curvature $R_{\mathrm{dS}}=2H^2$ and in $Ad{S}_2$ with $R_{\mathrm{AdS}}=-2K^2$. With suitable boundary conditions, we find that the pair-production rate is the same analytic function of the scalar curvature in both cases.

The static, i.e., linear momentum independent, part of the next-to-leading order (NLO) gravitational spin(1)-spin(1) interaction Hamiltonian within the post-Newtonian (PN) approximation is calculated from a three-dimensional covariant ansatz for the Hamilton constraint. All coefficients in this ansatz can be uniquely fixed for black holes. The resulting Hamiltonian fits into the canonical formalism of Arnowitt, Deser, and Misner (ADM) and is given in their transverse-traceless (ADMTT) gauge. This completes the recent result for the momentum dependent part of the NLO spin(1)-spin(1) ADM Hamiltonian for binary black holes (BBH). Thus, all PN NLO effects up to quadratic order in spin for BBH are now given in Hamiltonian form in the ADMTT gauge. The equations of motion resulting from this Hamiltonian are an important step toward more accurate calculations of templates for gravitational waves.

We analyze deep inelastic scattering at small Bjorken $x$, using the approximate conformal invariance of QCD at high energies. Hard Pomeron exchanges are resummed eikonally, restoring unitarity at large values of the phase shift in the dual anti-de Sitter (AdS) geometry. At weak coupling this phase is imaginary, corresponding to a black disk in AdS space. In this saturated regime, cross sections exhibit geometric scaling and have a simple universal form, which we test against available experimental data for the proton structure function $F_2(x,Q^2)$. We predict, in particular, the dependence of the cross section on the scaling variable $(Q/Q_{\mathrm{s}}{)}^2$ in the deeply saturated region, where $Q_{\mathrm{s}}$ is the usual saturation scale. We find agreement with current data on $F_2$ in the kinematical region $0.5<Q^2<10{\mathrm{GeV}}^2$, $x<{10}^{-2}$, with an average 6% accuracy. We conclude by discussing the relation of our approach with the commonly used dipole formalism.

We study the production of the heavy $W^{\prime }$ and $Z^{\prime }$ bosons in the three-site Higgsless model at the LHC. We focus on the $s$-channel production mode to estimate the prospects for measuring their suppressed couplings to standard model fermions.

Gluinos and neutralinos, supersymmetric partners of gluons and neutral electroweak gauge and Higgs bosons, are Majorana particles in the minimal supersymmetric standard model (MSSM). Decays of such self-conjugate particles generate charge symmetric ensembles of final states. Moreover, production channels of supersymmetric particles at colliders are characteristically affected by the Majorana nature of particles exchanged in the production processes. The sensitivity to the Majorana character of the particles can be quantified by comparing the predictions with Dirac exchange mechanisms. A consistent framework for introducing gluino and neutralino Dirac fields can be designed by extending the $N=1$ supersymmetry of the MSSM to $N=2$ in the gauge sector. We examine to which extent like-sign dilepton production in the processes $qq\to \tilde{q}\tilde{q}$ and $e^{-}{e}^{-}\to {\tilde{e}}^{-}{\tilde{e}}^{-}$ is affected by the exchange of either Majorana or Dirac gluinos and neutralinos, respectively, at the Large Hadron Collider (LHC) and in the prospective $e^{-}{e}^{-}$ mode of a lepton linear collider.

We calculate the next-to-next-to-leading-order $\mathcal{O}({\alpha }_s^4)$ one-loop squared corrections to the production of heavy-quark pairs in the gluon-gluon fusion process. Together with the previously derived results on the $q\overline{q}$ production channel, the results of this paper complete the calculation of the one-loop squared contributions of the next-to-next-to-leading-order $\mathcal{O}({\alpha }_s^4)$ radiative QCD corrections to the hadroproduction of heavy flavors. Our results, with the full mass dependence retained, are presented in a closed and very compact form, in dimensional regularization.

It is shown that in reaction $\gamma \gamma \to {\ell }^{+}{\ell }^{-}+\nu$’s at $\sqrt{s}>200\mathrm{GeV}$ with polarized photons, large and well observable differences arise in the distribution of positive and negative charged leptons ($\ell ={\mu }^{\pm }$, $e^{\pm }$) (charge asymmetry). The modification due to the contribution of the cascade processes with intermediate $\tau$ lepton in $\gamma \gamma \to W^{\pm }{\ell }^{\mp }+\nu$’s reaction is taken into account. This charge asymmetry is potentially sensitive to effects of physics beyond the standard model at the anticipated luminosity of the photon collider mode of the future international linear collider.

We analyze several aspects of the recent construction of three-dimensional conformal gauge theories by Aharony et al. in various regimes. We pay special attention to understanding how the M-theory geometry and interpretation can be extracted from the analysis of the field theory. We revisit the calculations of the moduli space of vacua and the complete characterization of chiral ring operators by analyzing the field theory compactified on a 2-sphere. We show that many of the states dual to these operators can be interpreted as D-brane states in the weak-coupling limit. Also, various features of the dual AdS geometry can be obtained by performing a strong coupling expansion around moduli space configurations, even though one is not taking the planar expansion. In particular, we show that at strong coupling the corresponding weak-coupling D-brane states of the chiral ring localize on particular submanifolds of the dual geometry that match the M-theory interpretation. We also study the massive spectrum of fields in the moduli space. We use this to investigate the dispersion relation of giant magnons from the field theory point of view. Our analysis predicts the exact functional form of the dispersion relation as a function of the world sheet momentum, independently of integrability assumptions, but not the exact form with respect to the ’t Hooft coupling. We also get the dispersion relation of bound states of giant magnons from first principles, providing evidence for the full integrability of the corresponding spin chain model at strong ’t Hooft coupling.