The constraints on the anomalous quartic $WW\gamma \gamma$ and $ZZ\gamma \gamma$ gauge boson couplings are investigated through the processes $e\gamma \to W^{-}\gamma {\nu }_e$ and $e\gamma \to Z\gamma e$. Considering the longitudinal and transverse polarization states of the final $W$ or $Z$ boson and incoming beam polarizations we find 95% confidence level limits on the anomalous coupling parameters $a_0$ and $a_c$ with an integrated luminosity of $500{\mathrm{fb}}^{-1}$ and $\sqrt{s}=0.5$, 1 TeV energies. Assuming the $W^{+}{W}^{-}\gamma \gamma$ couplings are independent of the $ZZ\gamma \gamma$ couplings we show that the longitudinal polarization state of the final gauge boson improves the sensitivity to anomalous couplings by a factor of 2-3 depending on energy and coupling. An extra enhancement in sensitivity by a factor of 1.3 comes from a set of initial beam polarizations.

We report on a study of exclusive radiative decays of the ${\rm Y}(1S)$ resonance into the final states $\gamma {\pi }^0{\pi }^0$, $\gamma \eta \eta$ and $\gamma {\pi }^0\eta$, using $1.13{\mathrm{fb}}^{-1}$ of ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ annihilation data collected at $\sqrt{s}=9.46\mathrm{GeV}$ with the CLEO III detector operating at the Cornell Electron Storage Ring. In the channel $\gamma {\pi }^0{\pi }^0$, we measure the branching ratio for the decay mode ${\rm Y}(1S)\to \gamma f_2(1270)$ to be $(10.5\pm 1.6(\mathrm{stat}{)}_{-1.8}^{+1.9}(\mathrm{syst}))\times {10}^{-5}$. We place upper limits on the product branching ratios for the isoscalar resonances $f_0(1500)$ and $f_0(1710)$ for the ${\pi }^0{\pi }^0$ and $\eta \eta$ decay channels. We also set an upper limit on the ${\rm Y}(1S)$ radiative decay into ${\pi }^0\eta$.

We construct quasiequilibrium sequences of black hole-neutron star binaries in general relativity. We solve Einstein’s constraint equations in the conformal thin-sandwich formalism, subject to black hole boundary conditions imposed on the surface of an excised sphere, together with the relativistic equations of hydrostatic equilibrium. In contrast to our previous calculations we adopt a flat spatial background geometry and do not assume extreme mass ratios. We adopt a $\Gamma =2$ polytropic equation of state and focus on irrotational neutron star configurations as well as approximately nonspinning black holes. We present numerical results for ratios of the black hole’s irreducible mass to the neutron star’s ADM mass in isolation of $M_{\mathrm{irr}}^{\mathrm{BH}}/M_{\mathrm{ADM},0}^{\mathrm{NS}}=1$, 2, 3, 5, and 10. We consider neutron stars of baryon rest mass $M_{\mathrm{B}}^{\mathrm{NS}}/M_{\mathrm{B}}^{\max }=83\%$ and 56%, where $M_{\mathrm{B}}^{\max }$ is the maximum allowed rest mass of a spherical star in isolation for our equation of state. For these sequences, we locate the onset of tidal disruption and, in cases with sufficiently large mass ratios and neutron star compactions, the innermost stable circular orbit. We compare with previous results for black hole-neutron star binaries and find excellent agreement with third-order post-Newtonian results, especially for large binary separations. We also use our results to estimate the energy spectrum of the outgoing gravitational radiation emitted during the inspiral phase for these binaries.

We investigate the late-time behavior of the massive vector field in the background of the Schwarzschild and Schwarzschild–de Sitter black holes. For Schwarzschild black hole, at intermediately late times the massive vector field is represented by three functions with different decay law ${\Psi }_0\sim t^{-(\ell +3/2)}\sin mt$, ${\Psi }_1\sim t^{-(\ell +5/2)}\sin mt$, ${\Psi }_2\sim t^{-(\ell +1/2)}\sin mt$, while at asymptotically late times the decay law $\Psi \sim t^{-5/6}\sin (mt)$ is universal and does not depend on the multipole number $\ell$. Together with a previous study of massive scalar and Dirac fields where the same asymptotically late-time decay law was found, it means that the asymptotically late-time decay law $\sim t^{-5/6}\sin (mt)$ does not depend also on the spin of the field under consideration. For Schwarzschild–de Sitter black holes it is observed in two different regimes in the late-time decay of perturbations: nonoscillatory exponential damping for small values of $m$ and oscillatory quasinormal mode decay for high enough $m$. Numerical and analytical results are found for these quasinormal frequencies.

A study on the possibility of distinguishing new heavy Majorana neutrino models at LHC energies is presented. The experimental confirmation of standard neutrinos with nonzero mass and the theoretical possibility of lepton number violation find a natural explanation when new heavy Majorana neutrinos exist. These new neutrinos appear in models with new right-handed singlets, in new doublets of some grand unified theories and left-right symmetrical models. It is expected that signals of new particles can be found at the CERN high-energy hadron collider (LHC). We present signatures and distributions that can indicate the theoretical origin of these new particles. The single and pair production of heavy Majorana neutrinos are calculated and the model dependence is discussed. Same-sign dileptons in the final state provide a clear signal for the Majorana nature of heavy neutrinos, since there is lepton number violation. Mass bounds on heavy Majorana neutrinos allowing model discrimination are estimated for three different LHC luminosities.

Using a sample of $3\times {10}^6$ $\psi (2S)$ decays collected by the CLEO III and CLEO-c detector configurations, we present results of a study of ${\chi }_{c0}$ and ${\chi }_{c2}$ decays into $\eta \eta$, $\eta {\eta }^{\prime }$, and ${\eta }^{\prime }{\eta }^{\prime }$ final states. We find $B({\chi }_{c0}\to \eta \eta )=(0.31\pm 0.05\pm 0.04\pm 0.02)\%$, $B({\chi }_{c0}\to \eta {\eta }^{\prime })<0.05\%$ at the 90% confidence level, and $B({\chi }_{c0}\to {\eta }^{\prime }{\eta }^{\prime })=(0.17\pm 0.04\pm 0.02\pm 0.01)\%$. We also present upper limits for the decays of ${\chi }_{c2}$ into these final states. These results give information on the decay mechanism of ${\chi }_c$ states into pseudoscalars.

It is shown that the differential form of Friedmann equation of a FRW universe can be rewritten as the first law of thermodynamics $dE=TdS+WdV$ at apparent horizon, where $E=\rho V$ is the total energy of matter inside the apparent horizon, $V$ is the volume inside the apparent horizon, $W=(\rho -P)/2$ is the work density, $\rho$ and $P$ are energy density and pressure of matter in the universe, respectively. From the thermodynamic identity one can derive that the apparent horizon ${\tilde{r}}_A$ has associated entropy $S=A/4G$ and temperature $T=\kappa /2\pi$ in Einstein general relativity, where $A$ is the area of apparent horizon and $\kappa$ is the surface gravity at apparent horizon of FRW universe. We extend our procedure to the Gauss-Bonnet gravity and more general Lovelock gravity and show that the differential form of Friedmann equations in these gravities can also be written as $dE=TdS+WdV$ at the apparent horizon of FRW universe with entropy $S$ being given by expression previously known via black hole thermodynamics.

We consider the evolution of a bulk scalar field in anti-de Sitter (AdS) spacetime linearly coupled to a scalar field on a de Sitter boundary brane. We present results of a spectral analysis of the system, and find that the model can exhibit both bound and continuum resonant modes. We find that zero, one, or two bound states may exist, depending upon the masses of the brane and bulk fields relative to the Hubble length and the AdS curvature scale and the coupling strength. In all cases, we find a critical coupling above which there exists a tachyonic bound state. We show how the 5-dimensional spectral results can be interpreted in terms of a 4-dimensional effective theory for the bound states. We find excellent agreement between our analytic results and the results of a new numerical code developed to model the evolution of bulk fields coupled to degrees of freedom on a moving brane. This code can be used to model the behavior of brane-world cosmological perturbations in scenarios for which no analytic results are known.

We discuss light curves and the spectral broadening of the radiation emitted during a finite interval of time from the surface of a spherically symmetric collapsing object. We study a simplified model of monochromatic radiations. We discuss how one can obtain information about the physical parameters of the collapsing body, such as its mass and radius, from the light curves and spectral broadenings.

The large-$N_c$ orientifold planar equivalence between $\mathcal{N}=1$ supersymmetric Yang-Mills theory and ordinary 1-flavor QCD suggests that low-energy quark-gluon dynamics in QCD should be constrained by the supersymmetry of the parent theory. One supersymmetry relic expected from orientifold equivalence is the approximate degeneracy of the scalar and pseudoscalar mesons in 1-flavor QCD. Here we study the role of the $q\overline{q}$ annihilation (hairpin) contributions to the meson correlators. These annihilation terms induce mass shifts of opposite sign in the scalar and pseudoscalar channels, making degeneracy plausible. Calculations of valence and hairpin correlators in quenched lattice QCD are consistent with approximate degeneracy, although the errors on the scalar hairpin are large. We also study the role of $q\overline{q}$ annihilation in the 1- and 2-flavor Nambu-Jona Lasinio model, where annihilation terms arise from the chiral field determinant representing the axial $U(1)$ anomaly. Scalar-pseudoscalar degeneracy for the 1-flavor case reduces to a constraint on the relative size of the anomalous and nonanomalous 4-fermion couplings.

We use techniques of quantum information theory to analyze the quantum causal histories approach to quantum gravity. While it is consistent to introduce closed timelike curves (CTCs), they cannot generically carry independent degrees of freedom. Moreover, if the effective dynamics of the chronology-respecting part of the system is linear, it should be completely decoupled from the CTCs. In the absence of a CTC, not all causal structures admit the introduction of quantum mechanics. It is possible for those and only those causal structures that can be represented as quantum computational networks. Dynamics of the subsystems should not be unitary or even completely positive. However, we show that other commonly made assumptions ensure the complete positivity of the reduced dynamics.

We discuss the lower bound to the lightest Higgs boson $H_1$ in the minimal supersymmetric extension of the standard model with explicit $CP$ violation, and the phenomenology of the lightest relic neutralino in the same scenario. In particular, adopting the CPX benchmark scenario, we find that the combination of experimental constraints coming from LEP, thallium electric dipole moment measurements, quarkonium decays, and $B_s\to \mu \mu$ decay favors a region of the parameter space where the mass of $H_1$ is in the range $7\mathrm{GeV}\lesssim M_{H_1}\lesssim 10\mathrm{GeV}$, while $3\lesssim \tan \beta \lesssim 5$. Assuming a departure from the usual grand unified theory relation among gaugino masses ($|M_1|\ll |M_2|$), we find that through resonant annihilation to $H_1$ a neutralino as light as 2.9 GeV can be a viable dark matter candidate in this scenario. We call this the CPX light neutralino scenario and discuss its phenomenology showing that indirect dark matter searches are compatible with the present experimental constraints, as long as $m_{\chi }\lesssim M_{H_1}/2$. On the other hand, part of the range $m_{\chi }\gtrsim M_{H_1}/2$ which is allowed by cosmology is excluded by antiproton fluxes.

The causality and/or the energy-momentum conservation constraints on the amplitudes of high energy processes are generalized to QCD. The constraints imply that the energetic parton may experience at most one inelastic collision (an arbitrary number of elastic collisions) and that the number of the constituents in the light cone wave function of the projectile is increasing with the collision energy and the atomic number.

In this paper we compute the one-loop chiral logarithmic corrections to the $S$ and $T$ parameters in a highly deconstructed Higgsless model with only three sites. In addition to the electroweak gauge bosons, this model contains a single extra triplet of vector states (which we denote ${\rho }^{\pm }$ and ${\rho }^0$), rather than an infinite tower of Kaluza-Klein modes. We compute the corrections to $S$ and $T$ in ’t Hooft-Feynman gauge, including the ghost, unphysical Goldstone-boson, and appropriate pinch contributions required to obtain gauge-invariant results for the one-loop self-energy functions. We demonstrate that the chiral-logarithmic corrections naturally separate into two parts, a model-independent part arising from scaling below the $\rho$ mass, which has the same form as the large Higgs-mass dependence of the $S$ or $T$ parameter in the standard model, and a second model-dependent contribution arising from scaling between the $\rho$ mass and the cutoff of the model. The form of the universal part of the one-loop result allows us to correctly interpret the phenomenologically derived limits on the $S$ and $T$ parameters (which depend on a reference Higgs-boson mass) in this three-site Higgsless model. Higgsless models may be viewed as dual to models of dynamical symmetry breaking akin to “walking technicolor,” and in these terms our calculation is the first to compute the subleading $1/N$ corrections to the $S$ and $T$ parameters. We also discuss the reduction of the model to the “two-site” model, which is the usual electroweak chiral Lagrangian, noting the “nondecoupling” contributions present in the limit $M_{\rho }\to \infty$.

We conduct a detailed analysis of the phenomenology of two predictive seesaw scenarios leading to quark-lepton complementarity. In both cases we discuss the neutrino mixing observables and their correlations, neutrinoless double beta decay and lepton flavor violating decays such as $\mu \to e\gamma$. We also comment on leptogenesis. The first scenario is disfavored on the level of one to two standard deviations, in particular, due to its prediction for $|U_{e3}|$. There can be resonant leptogenesis with quasidegenerate heavy and light neutrinos, which would imply sizable cancellations in neutrinoless double beta decay. The decays $\mu \to e\gamma$ and $\tau \to \mu \gamma$ are typically observable unless the SUSY masses approach the TeV scale. In the second scenario leptogenesis is impossible. It is, however, in perfect agreement with all oscillation data. The prediction for $\mu \to e\gamma$ is in general too large, unless the SUSY masses are in the range of several TeV. In this case $\tau \to e\gamma$ and $\tau \to \mu \gamma$ are unobservable.

I present a calculation of soft-gluon corrections to single top-quark production in $pp$ collisions at the LHC via the standard model partonic processes in the $t$ and $s$ channels and associated top quark and $W$ boson production. Higher-order soft-gluon corrections through next-to-next-to-next-to-leading order (NNNLO) are calculated at next-to-leading logarithmic (NLL) accuracy. The soft-gluon corrections in the $s$ channel and in $tW$ production are large and dominant, while in the $t$ channel they are not a good approximation of the complete QCD corrections.

The previous Comment contains a valid criticism of the numerical precision of the results reported in a recent paper of ours, as well as fresh ideas on how to characterize a quantum cosmological singularity. However, we argue that, contrary to what is suggested in the Comment, the quantum cosmological models we studied show hardly any sign of singular behavior.

The quantization of the Friedmann-Robertson-Walker spacetime in the presence of a negative cosmological constant was used in a recent paper to conclude that there are solutions that avoid singularities (big bang–big crunch) at the quantum level. We show that a proper study of their model does not indicate that it prevents the occurrence of singularities at the quantum level, in fact the quantum probability of such event is larger than the classical one. Our numerical simulations based on the powerful variational sinc collocation method (VSCM) also show that the precision of the results of that paper is much lower than the 20 significant digits reported by the authors.

After reviewing the existing results we give an extensive analysis of the critical points of the potentials of the gauged $\mathcal{N}=2$ Yang-Mills/Einstein supergravity theories coupled to tensor multiplets and hypermultiplets. Our analysis includes all the possible gaugings of all $\mathcal{N}=2$ Maxwell-Einstein supergravity theories whose scalar manifolds are symmetric spaces. In general, the scalar potential gets contributions from $R$-symmetry gauging, tensor couplings, and hypercouplings. We show that the coupling of a hypermultiplet into a theory whose potential has a nonzero value at its critical point, and gauging a compact subgroup of the hyperscalar isometry group will only rescale the value of the potential at the critical point by a positive factor, and therefore will not change the nature of an existing critical point. However this is not the case for noncompact $SO(1,1)$ gaugings. An $SO(1,1)$ gauging of the hyperisometry will generally lead to de Sitter vacua, which is analogous to the ground states found by simultaneously gauging $SO(1,1)$ symmetry of the real scalar manifold with $U(1{)}_R$ in earlier literature. $SO(m,1)$ gaugings with $m>1$, which give contributions to the scalar potential only in the magical Jordan family theories, on the other hand, do not lead to de Sitter vacua. Anti-de Sitter vacua are generically obtained when the $U(1{)}_R$ symmetry is gauged. We also show that it is possible to embed certain generic Jordan family theories into the magical Jordan family preserving the nature of the ground states. However the magical Jordan family theories have additional ground states which are not found in the generic Jordan family theories.

We consider $\mathcal{N}=1$ supersymmetric QCD with the gauge group $\mathrm{U}(N)$ and $N_f=N$ quark flavors. To get rid of flat directions we add a meson superfield. The theory has no adjoint fields and, therefore, no ’t Hooft-Polyakov monopoles in the quasiclassical limit. We observe a non-Abelian Meissner effect: condensation of color charges (squarks) gives rise to confined monopoles. The very fact of their existence in $\mathcal{N}=1$ supersymmetric QCD without adjoint scalars was not known previously. Our analysis is analytic and is based on the fact that the $\mathcal{N}=1$ theory under consideration can be obtained starting from $\mathcal{N}=2$ SQCD in which the ’t Hooft-Polyakov monopoles do exist, through a certain limiting procedure allowing us to track the status of these monopoles at various stages. Monopoles are confined by Bogomol’nyi-Prasad-Sommerfield (BPS) non-Abelian strings (flux tubes). Dynamics of string orientational zero modes are described by a supersymmetric $CP(N-1)$ sigma model on the string world sheet. If a dual of $\mathcal{N}=1$ SQCD with the gauge group $\mathrm{U}(N)$ and $N_f=N$ quark flavors could be identified, in this dual theory our demonstration would be equivalent to the proof of the non-Abelian dual Meissner effect.