We consider a five-dimensional action which is composed of a gravitational sector and a sector of matter, where the gravitational sector is given by a Einstein-Chern-Simons gravity action instead of the Einstein-Hilbert action. We obtain the Einstein-Chern-Simons (EChS) field equations together with their spherically symmetric solution, which lead, in certain limit, to the standard five-dimensional solution of the Einstein-Cartan field equations. The conditions are found under which the EChS field equations admit black hole type solutions. The maximal extension and conformal compactification are also studied.

We consider a complex scalar ${\Phi }^4$ theory with spontaneously broken global U(1) symmetry, minimally coupling to perturbatively quantized Einstein gravity which is treated as an effective theory at the energy well below the Planck scale. Both the lowest order pure real scalar correction and the gravitational correction to the renormalizations of the Higgs sector in this model have been investigated. Our results show that the gravitational correction renders the renormalization of the Higgs sector in this model inconsistent while the pure real scalar correction to it leads to a compatible renormalization.

We study the stability of ($4+1$)-dimensional charged Gauss-Bonnet black holes and solitons. We observe an instability related to the condensation of a scalar field and construct explicit “hairy” black hole and soliton solutions of the full system of coupled field equations. We investigate the cases of a massless scalar field as well as that of a tachyonic scalar field. The solitons with scalar hair exist for a particular range of the charge and the gauge coupling. This range is such that for intermediate values of the gauge coupling a “forbidden band” of charges for the hairy solitons exists. We also discuss the behavior of the black holes with scalar hair when changing the horizon radius and/or the gauge coupling and find that various scenarios at the approach of a limiting solution appear. One observation is that hairy Gauss-Bonnet black holes never tend to a regular soliton solution in the limit of vanishing horizon radius. We also prove that extremal Gauss-Bonnet black holes can not carry massless or tachyonic scalar hair and show that our solutions tend to their planar counterparts for large charges.

One of the most common assumptions in the study of neutron star models and their oscillations is that the pressure is isotopic, however, there are arguments that this may not be correct. Thus in the present paper we make a first step towards studying the nonradial oscillations of neutron stars with an anisotropic pressure. We adopt the so-called Cowling approximation where the spacetime metric is kept fixed and the oscillation spectrum for the first few fluid modes is obtained. The effect of the anisotropy on the frequencies is apparent, although with the present results it might be hard to distinguish it from the changes in the frequencies caused by different equations of state.

We present dynamic wormhole solutions in the framework of Lovelock gravity with compact extra dimensions. Calculations are done in $D=7$, although they can be extended to an arbitrary number of extra dimensions. It is shown that as the wormhole inflates with the three-dimensional space, the extra dimensions deflate to very small, yet nonvanishing scales. The weak energy condition is shown to hold for certain ranges of the free parameters, everywhere, down to the throat of the wormhole.

In any realistic particle physics model of inflation, the inflaton can be expected to couple to other fields. We consider a model with a dilatonlike coupling between a $U(1)$ gauge field and a scalar inflaton. We show that this coupling can result in observable non-Gaussianity, even in the conventional regime where inflation is supported by a single scalar slowly rolling on a smooth potential: the time-dependent inflaton condensate leads to amplification of the large-scale gauge field fluctuations, which can feed back into the scalar/tensor cosmological perturbations. In the squeezed limit, the resulting bispectrum is close to the local one, but it shows a sizable and characteristic quadrupolar dependence on the angle between the shorter and the larger modes in the correlation. Observable non-Gaussianity is obtained in a regime where perturbation theory is under control. If the gauge field is identified with the electromagnetic field, the model that we study is a realization of the magnetogenesis idea originally proposed by Ratra, and widely studied. This identification (which is not necessary for the non-Gaussianity production) is however problematic in light of a strong coupling problem already noted in the literature.

The BESS-Polar collaboration has recently performed a precise measurement of the local antiproton flux which is consistent with a pure secondary production of antiprotons. We constrain a possible primary component originating from dark matter pair-annihilations. We derive limits on the annihilation cross section which are stronger than or comparable to those from the PAMELA satellite experiment for dark matter masses up to 200 GeV. Especially, we exclude thermal WIMPs with masses in the range 3–20 GeV if they annihilate dominantly into quark pairs unless their cross section is velocity suppressed.

Cosmological data have provided new constraints on the number of neutrino species and the neutrino mass. However, these constraints depend on assumptions related to the underlying cosmology. Since a correlation is expected between the number of effective neutrinos $N_{\mathrm{eff}}$, the neutrino mass $\sum _{}^{}{m}_{\nu }$, and the curvature of the universe ${\Omega }_k$, it is useful to investigate the current constraints in the framework of a nonflat universe. In this paper we update the constraints on neutrino parameters by making use of the latest cosmic microwave background data from the Atacama Cosmology Telescope and South Pole Telescope experiments and consider the possibility of a universe with nonzero curvature. We first place new constraints on $N_{\mathrm{eff}}$ and ${\Omega }_k$, with $N_{\mathrm{eff}}=4.03\pm 0.45$ and ${10}^3{\Omega }_k=-4.46\pm 5.24$. Thus, even when ${\Omega }_k$ is allowed to vary, $N_{\mathrm{eff}}=3$ is still disfavored with 95% confidence. We then investigate the correlation between neutrino mass and curvature that shifts the 95% upper limit of $\sum _{}^{}{m}_{\nu }<0.45\mathrm{eV}$ to $\sum _{}^{}{m}_{\nu }<0.95\mathrm{eV}$. Thus, the impact of assuming flatness in neutrino cosmology is significant and an essential consideration with future experiments.

We investigate cosmological scenarios in the theory of gravity with the scalar field possessing a nonminimal kinetic coupling to the curvature. It is shown that the kinetic coupling provides an essentially new inflationary mechanism. Namely, at early cosmological times the domination of coupling terms in the field equations guarantees the quasi–de Sitter behavior of the scale factor: $a(t)\propto e^{H_{\kappa }t}$ with $H_{\kappa }=1/\sqrt{9\kappa }$, where $\kappa \simeq {10}^{-74}{\sec }^2$ is the coupling parameter. The primary inflationary epoch driven by nonminimal kinetic coupling comes to the end at $t_f\simeq {10}^{-35}\sec$. Later on, the matter terms are dominating, and the Universe enters into the matter-dominated epoch which lasts approximately $0.5H_0^{-1}\sim 0.5\times {10}^{18}\sec$. Then, the cosmological term comes into play, and the Universe enters into the secondary inflationary epoch with $a(t)\propto e^{H_{\Lambda }t}$, where $H_{\Lambda }=\sqrt{\Lambda /3}$. Thus, the cosmological model with nonminimal kinetic coupling represents the realistic cosmological scenario which successfully describes basic cosmological epochs and provides the natural mechanism of epoch change without any fine-tuned potential.

Galactic nuclei are densely populated by stellar mass compact objects such as black holes and neutron stars. Bound, highly eccentric binaries form as a result of gravitational wave (GW) losses during close flybys between these objects. We study the evolution of these systems using 2.5 and 3.5 order post-Newtonian (PN) equations of motion. The GW signal consists of many thousand repeated bursts (RB) for minutes to days (depending on the impact parameter and masses), followed by a powerful GW chirp and an eccentric merger. We show that a significant signal-to-noise ratio accumulates already in the RB phase, corresponding to a detection limit around 200–300 Mpc and 300–600 Mpc for advanced LIGO for an average orientation black hole/neutron star or black hole/black hole binary, respectively. The theoretical errors introduced by the inaccuracy of the PN templates are typically much less severe for the RB phase than in the following eccentric merger. The GW signal in the RB phase is broadband; we show that encounters involving intermediate mass black holes are detectable in multiple frequency bands coincidentally using LIGO and LISA.

The first flavor-tagged amplitude analysis of the decay $D^0$ to the self-conjugate final state $K^{+}{K}^{-}{\pi }^{+}{\pi }^{-}$ is presented. Approximately 3000 signal decays are selected from data acquired by the CLEO II.V, CLEO III, and CLEO-c detectors. The three most significant amplitudes, which contribute to the model that best fits the data, are $\varphi {\rho }^0$, $K_1(1270{)}^{\pm }{K}^{\mp }$, and nonresonant $K^{+}{K}^{-}{\pi }^{+}{\pi }^{-}$. Separate amplitude analyses of $D^0$ and ${\overline{D}}^0$ candidates indicate no $CP$ violation among the amplitudes at the level of 5% to 30% depending on the mode. In addition, the sensitivity to the $CP$-violating parameter $\gamma /{\varphi }_3$ from a sample of 2000 $B^{+}\to {\tilde{D}}^0(K^{+}{K}^{-}{\pi }^{+}{\pi }^{-})K^{+}$ decays, where $\tilde{D}$ is a $D^0$ or ${\overline{D}}^0$, collected at LHCb or a future flavor facility, is estimated to be $(11.3\pm 0.3)°$ using the favored model.

In this letter we describe an infinite family of new $\mathcal{N}=1$ ${\mathrm{AdS}}_5/{\mathrm{CFT}}_4$ dual pairs which arise from M5-branes wrapping Riemann surfaces in Calabi-Yau threefolds. We use the relevant brane constructions to compute the central charges of the infrared fixed points from the M5-brane anomaly polynomial. We then present ${\mathrm{AdS}}_5\times M_6$ solutions of 11-dimensional supergravity which are dual to these conformal field theories (CFTs) at large $N$. Finally, we provide a purely four-dimensional field theory construction which flows to a special class of these fixed points. These theories are further elaborated upon in a companion paper [I. Bah, C. Beem, N. Bobev, and B. Wecht, arXiv:1203.0303.].

A pair of a domain wall and an antidomain wall is unstable to decay. We show that when a vortex string is stretched between the walls, there remains a knot soliton (Hopfion) after the pair annihilation.

The masses of experimentally known highly excited baryons of negative parity supposed to belong to the $[\mathbf{70},{\ell }^{-}]$ multiplets ($\ell =1$, 2, 3) of the $N=3$ band are calculated in the $1/N_c$ expansion method to order $1/N_c$ by using a procedure which allows to considerably reduce the number of linearly independent operators entering the mass formula. The numerical fits to present data show that the coefficients encoding the QCD dynamics have large, comparable values, for the flavor and spin operators. It implies that these operators contribute dominantly to the flavor-spin SU(6) symmetry breaking, like for the $[\mathbf{70},1^{-}]$ multiplet of the $N=1$ band.

We study the lightest $CP$-even Higgs boson mass in five kinds of testable flipped $SU(5)\times U(1{)}_X$ models from $F$-theory. Two kinds of models have vectorlike particles around the TeV scale, while the other three kinds also have the vectorlike particles at the intermediate scale that can be considered as messenger fields in gauge-mediated supersymmetry breaking. We require that the Yukawa couplings for the TeV-scale vectorlike particles and the third family of the Standard Model (SM) fermions are smaller than three from the electroweak scale to the $SU(3{)}_C\times SU(2{)}_L$ unification scale. With the two-loop renormalization group equation running for the gauge couplings and Yukawa couplings, we obtain the maximal Yukawa couplings between the TeV-scale vectorlike particles and Higgs fields. To calculate the lightest $CP$-even Higgs boson mass upper bounds, we employ the renormalization group improved effective Higgs potential approach, and consider the two-loop leading contributions in the supersymmetric SM and one-loop contributions from the TeV-scale vectorlike particles. We assume maximal mixings between the stops and between the TeV-scale vectorlike scalars. The numerical results for these five kinds of models are roughly the same. In particular, we show that the lightest $CP$-even Higgs boson can have mass up to 146 GeV naturally, which is the current upper bound from the CMS and ATLAS collaborations.

We study radiative corrections to the electroweak parameters in the Higgs model with the $Y=1$ triplet field, which is introduced in the scenario of generating neutrino masses based on the so-called type II seesaw mechanism. In this model, the rho parameter deviates from unity at the tree level. Consequently, the electroweak sector of the model is described by the four input parameters such as ${\alpha }_{\mathrm{em}}$, $G_F$, $m_Z$ and ${sin}^2{\theta }_W$. We calculate the one-loop contribution to the $W$ boson mass as well as to the rho parameter in order to clarify the possible mass spectrum of the extra Higgs bosons under the constraint from the electroweak precision data. We find that the hierarchical mass spectrum among $H^{\pm \pm }$, $H^{\pm }$ and $A$ (or $H$) is favored by the precision data especially for the case of $m_A(\simeq m_H)>m_{H^{+}}>m_{H^{++}}$, where $H^{\pm \pm }$, $H^{\pm }$, $A$ and $H$ are the doubly-charged, singly-charged, $CP$-odd and $CP$-even Higgs bosons mainly originated from the triplet field. We also discuss phenomenological consequences of such a mass spectrum with relatively large mass splitting. The decay rate of the Higgs boson decay into two photons is evaluated under the constraint from the electroweak precision data, regarding the recent Higgs boson searches at the CERN LHC.

In the framework of the RSII-$n$ model with $n$ compact and one infinite extra dimensions, we study the production of $Z$-bosons and photons, which escape into the bulk, in association with a jet in $pp$ collisions at the LHC energies. This would show up as the process $pp\to \mathrm{\text{jet}}+{\mathrm{E̸}}_T$. We calculate the distributions in the jet transverse momentum and rapidity and compare them with the standard model background $pp\to \mathrm{\text{jet}}+\nu \overline{\nu }$. We find that the models with $n\ge 4$ can be probed at the collision energy 14 TeV, while searches at 7 TeV are sensitive to models with $n\ge 6$ only.

We report on the first extraction of interference fragmentation functions from the semi-inclusive production of two hadron pairs in back-to-back jets in $e^{+}{e}^{-}$ annihilation. A nonzero asymmetry in the correlation of azimuthal orientations of opposite ${\pi }^{+}{\pi }^{-}$ pairs is related to the transverse polarization of fragmenting quarks through a significant polarized dihadron fragmentation function. Extraction of the latter requires the knowledge of its unpolarized counterpart, the probability density for a quark to fragment in a ${\pi }^{+}{\pi }^{-}$ pair. Since data for the unpolarized cross section are missing, we extract the unpolarized dihadron fragmentation function from a Monte Carlo simulation of the cross section.

We have developed a Monte Carlo event generator for nonresonant diphoton ($\gamma \gamma$) production at hadron collisions in the framework of GR@PPA, which consistently includes additional one-jet production. The jet-matching method developed for initial-state jet production has been extended to the final state in order to regularize the final-state QED divergence in the $qg\to \gamma \gamma +q$ process. A QCD/QED-mixed parton shower (PS) has been developed to complete the matching. The PS has the capability of enforcing hard-photon radiation, and small-$Q^2$ photon radiations that are not covered by the PS are supplemented by using a fragmentation function. The generated events can be passed to general-purpose event generators in order to perform the simulations down to the hadron level. Thus, we can simulate the isolation requirements that must be applied in experiments at the hadron level. The simulation results are in reasonable agreement with the predictions from RESBOS and DIPHOX. The simulated hadron-level events can be further fed to detector simulations in order to investigate the detailed performance of experiments.

We present a comprehensive study of inclusive hadron production in deep inelastic scattering (DIS) at low $x$. Properties of the hadron spectrum are different in different kinematic regions formed by three relevant momentum scales: photon virtuality $Q^2$, hadron transverse momentum $k_T$ and the saturation momentum $Q_s(x)$. We investigate each kinematic region and derive the corresponding asymptotic formulas for the cross section at the leading logarithmic order. We also analyze the next-to-leading-order corrections to the Balitskiĭ-Fadin-Kuraev-Lipatov kernel that are responsible for the momentum conservation. In particular, we establish the asymptotic behavior of the forward elastic dipole-nucleus scattering amplitude at high energies deeply in the saturation regime and a modification of the pomeron intercept. We study the nuclear effect on the inclusive cross section using the nuclear modification factor and its logarithmic derivative. We argue that the later is proportional to the difference between the anomalous dimension of the gluon distribution in nucleus and in proton and thus is a direct measure of the coherence effects. To augment our arguments and present quantitative results we performed numerical calculations in the kinematic region that may be accessible by the future DIS experiments.