The Goldberger-Wise mechanism enables one to stabilize the length of the warped extra dimension employed in Randall-Sundrum models. In this work we generalize this mechanism to models with multiple warped throats sharing a common ultraviolet brane. For independent throats this generalization is straightforward. If the throats possess a discrete interchange symmetry like $Z_n$, the stabilizing dynamics may respect the symmetry, resulting in equal throat lengths, or they may break it. In the latter case the ground state of an initially symmetric configuration is a stabilized asymmetric configuration in which the throat lengths differ. We focus on two- (three-) throat setups with a $Z_2$ ($Z_3$) interchange symmetry and present stabilization dynamics suitable for either breaking or maintaining the symmetry. Though admitting more general application, our results are relevant for existing models in the literature, including the two-throat model with Kaluza-Klein parity, and the three-throat model of flavor with a broken $Z_3$ symmetry.

We establish the evolution equations of the set of independent variables characterizing the 2PN rigorous conservative dynamics of a spinning compact binary, with the inclusion of the leading order spin-orbit, spin-spin, and mass quadrupole-mass monopole effects, for generic (noncircular, nonspherical) orbits. More specifically, we give a closed system of first order ordinary differential equations for the orbital elements of the osculating ellipse and for the angles characterizing the spin orientations with respect to the osculating orbit. We also prove that (i) the relative angle of the spins stays constant for equal mass black holes, irrespective of their orientation, and (ii) the special configuration of equal mass black holes with equal, but antialigned spins, both laying in the plane of motion (leading to the largest recoil found in numerical simulations) is preserved at 2PN level of accuracy, with leading order spin-orbit, spin-spin, and mass quadrupolar contributions included.

The unparticle effects on the $B_s\mathrm{\text{−}}{\overline{B}}_s$ mixing is revisited. Taking into account the unitarity constraints on the unparticle operators, we find that the contribution of the vector unparticle is very suppressed compared to that of the scalar unparticle. This is due to the fact that the lower bound of the scaling dimension of the vector-unparticle operator is larger. It is also shown that the mixing phase from the scalar unparticle is negative, and unparticles can produce a large mixing phase.

We calculate the effects of velocity-dependent dark matter annihilation cross sections on the intensity of the extragalactic gamma-ray background. Our formalism does not assume a locally thermal distribution of dark matter particles in phase space, and is valid for arbitrary velocity-dependent annihilation. Although the model of the dark matter distribution we use is simple and may not describe nature precisely, it is sufficient for quantifying the effects of velocity-dependent annihilations: different halo models would be expected to produce the same general features. As concrete examples, we calculate the effects of p-wave annihilation (with the $v$-weighted cross section of $\sigma v=a+b{v}^2$) on the mean intensity of extragalactic gamma rays produced in cosmological dark matter halos. This velocity variation makes the shape of the energy spectrum harder, but this change in the shape is too small to see unless $b/a\gtrsim {10}^6$. While we find no such models in the parameter space of the minimal supersymmetric standard model, we show that it is possible to find $b/a\gtrsim {10}^6$ in the extension $\mathrm{MSSM}\otimes U(1{)}_{B-L}$. However, we find that the most dominant effect of the p-wave annihilation is the suppression of the amplitude of the gamma-ray background. A nonzero $b$ at the dark matter freeze-out epoch requires a smaller value of $a$ in order for the relic density constraint to be satisfied, suppressing the amplitude by a factor as low as ${10}^{-6}$ for a thermal relic. Nonthermal relics will have weaker amplitude suppression. As another velocity-dependent effect, we calculate the spectrum for s-wave annihilation into fermions enhanced by the attractive Sommerfeld effect. Resonances associated with this effect result in significantly enhanced intensities, with a slightly softer energy spectrum.

In a previous paper, Crater and Van Alstine applied the two-body Dirac equations of constraint dynamics to quark-antiquark bound states using a relativistic extention of the Adler-Piran potential and compared their spectral results to those from other approaches which also considered meson spectroscopy as a whole and not in parts. In this paper, we explore in more detail the differences and similarities in an important subset of those approaches, the quasipotential approach. In the earlier paper, the transformation properties of the quark-antiquark potentials were limited to a scalar and an electromagnetic-like four-vector, with the former accounting for the confining aspects of the overall potential, and the latter the short range portion. The static Adler-Piran potential was first given an invariant form and then apportioned between those two different types of potentials. Here, we make a change in this apportionment that leads to a substantial improvement in the resultant spectroscopy by including a timelike confining vector potential over and above the scalar confining one and the electromagnetic-like vector potential. Our fit includes 19 more mesons than the earlier results and we modify the scalar portion of the potential in such a way that allows this formalism to account for the isoscalar mesons $\eta$ and ${\eta }^{\prime }$ not included in the previous work. Continuing the comparisons of formalisms and spectral results made in the previous paper with other approaches to meson spectroscopy, we examine in this paper the quasipotential approach of Ebert, Faustov, and Galkin.

An ultralarge liquid argon time projection chamber based neutrino detector will have the uncommon ability to detect atmospheric ${\nu }_{\tau }/{\overline{\nu }}_{\tau }$ events. This paper discusses the most promising modes for identifying charged current ${\nu }_{\tau }/{\overline{\nu }}_{\tau }$, and shows that, with simple kinematic cuts, $\sim 30{\nu }_{\tau }+{\overline{\nu }}_{\tau }$ interactions can be isolated in a $100\mathrm{kt}·\mathrm{yr}$ exposure, with greater than $4\sigma$ significance. This sample is sufficient to perform flux-averaged total cross-section and cross-section shape parametrization measurements—the first steps toward using ${\nu }_{\tau }/{\overline{\nu }}_{\tau }$ to search for physics beyond the standard model.

The main goal of the IceCube Deep Core array is to search for neutrinos of astrophysical origins. Atmospheric neutrinos are commonly considered as a background for these searches. We show that the very high statistics atmospheric neutrino data can be used to obtain precise measurements of the main oscillation parameters.

We investigate the lattice Weinberg-Salam model without fermions numerically for the realistic choice of coupling constants correspondent to the value of the Weinberg angle ${\theta }_W\sim 30°$, and bare fine structure constant around $\alpha \sim \frac{1}{150}$. We consider the values of the scalar self-coupling corresponding to Higgs mass $M_H\sim 100$, 150, 270 GeV. It has been found that nonperturbative effects become important while approaching continuum physics within the lattice model. When the ultraviolet cutoff $\Lambda =\frac{\pi }{a}$ (where $a$ is the lattice spacing) is increased and achieves the value around 1 TeV, one encounters the fluctuational region (on the phase diagram of the lattice model), where the fluctuations of the scalar field become strong. The classical Nambu monopole can be considered as an embryo of the unphysical symmetric phase within the physical phase. In the fluctuational region quantum Nambu monopoles are dense, and therefore, the use of the perturbation expansion around the trivial vacuum in this region is limited. Further increase of the cutoff is accompanied by a transition to the region of the phase diagram, where the scalar field is not condensed (this happens at the value of $\Lambda$ around 1.4 TeV for the considered lattice sizes). Within this region further increase of the cutoff is possible, although we do not observe this in detail due to the strong fluctuations of the gauge boson correlator. Both above mentioned regions look unphysical. Therefore we come to the conclusion that the maximal value of the cutoff admitted within lattice electroweak theory cannot exceed the value of the order of 1 TeV.

This paper is an addendum to earlier work where we computed the Pomeron contribution to $pp$ and $p\overline{p}$ scattering in AdS/QCD. Our model for $pp$ scattering in the Regge regime depends on four parameters: the slope and intercept of the Pomeron trajectory ${\alpha }_c^{\prime }$, ${\alpha }_c(0)$, a mass scale $M_d$, which determines a form factor entering into matrix elements of the energy-momentum tensor, and a coupling ${\lambda }_{\mathcal{P}}$ between the lightest spin-two glueball and the proton, which sets the overall scale of the total cross section. Here we perform a more detailed computation of ${\lambda }_{\mathcal{P}}$ in the Sakai-Sugimoto model by using the construction of nucleons as instantons of the dual 5D gauge theory and an effective 5D fermion description of these nucleons which has been successfully used to compute a variety of nucleon-meson couplings. We find ${\lambda }_{\mathcal{P},\mathrm{SS}}\simeq 6.38{\mathrm{GeV}}^{-1}$, which is in reasonable agreement with the value ${\lambda }_{\mathcal{P},\mathrm{fit}}=8.28{\mathrm{GeV}}^{-1}$ determined by fitting single Pomeron exchange to data.

We study the invariance under duality transformations in massless and massive $p$-form field theories and obtain the Noether generators of the infinitesimal transformations that correspond to this symmetry. These generators can be realized in geometrical representations that generalize the loop representation of the Maxwell field, allowing for a geometrical interpretation which is studied.

We construct a class of quantum critical points with non-mean-field critical exponents via holography. Our approach is phenomenological. Beginning with the D3/D5 system at nonzero density and magnetic field which has a chiral phase transition, we simulate the addition of a third control parameter. We then identify a line of quantum critical points in the phase diagram of this theory, provided that the simulated control parameter has dimension less than two. This line smoothly interpolates between a second-order transition with mean-field exponents at zero magnetic field to a holographic Berezinskii-Kosterlitz-Thouless transition at larger magnetic fields. The critical exponents of these transitions only depend upon the parameters of an emergent infrared theory. Moreover, the non-mean-field scaling is destroyed at any nonzero temperature. We discuss how generic these transitions are.

We study, by separately calculating the contributions of vacuum fluctuations and radiation reaction to the atomic energy level shift, the Lamb shift of a static two-level atom interacting with real massless scalar fields in the Boulware, Unruh, and Hartle-Hawking vacuums outside a Schwarzschild black hole. We find that in the Boulware vacuum, the Lamb shift gets a correction arising as a result of the backscattering of vacuum field modes off the space-time curvature, which is reminiscent of the correction to the Lamb shift induced by the presence of cavities. However, when the Unruh and Hartle-Hawking vacua are concerned, our results show that the Lamb shift behaves as if the atom were irradiated by a thermal radiation or immersed in a thermal bath at the Hawking temperature, depending on whether the scalar field is in the Unruh or the Hartle-Hawking vacuum. Remarkably, the thermal radiation is always backscattered by the space-time geometry.

We consider a two-dimensional Maxwell system defined on the Rindler space with metric $d{s}^2=\exp (2a\xi )·(d{\eta }^2-d{\xi }^2)$ with the goal to study the dynamics of the ghosts. We find an extra contribution to the vacuum energy in comparison with Minkowski space-time with metric $d{s}^2=d{t}^2-d{x}^2$. This extra contribution can be traced to the unphysical degrees of freedom (in Minkowski space). The technical reason for this effect to occur is the property of Bogolubov’s coefficients which mix the positive- and negative-frequency modes. The corresponding mixture cannot be avoided because the projections to positive-frequency modes with respect to Minkowski time $t$ and positive-frequency modes with respect to the Rindler observer’s proper time $\eta$ are not equivalent. The exact cancellation of unphysical degrees of freedom which is maintained in Minkowski space cannot hold in the Rindler space. In the Becchi-Rouet-Stora-Tyutin (BRST) approach this effect manifests itself as the presence of BRST charge density in $L$ and $R$ parts. An inertial observer in Minkowski vacuum $|0⟩$ observes a universe with no net BRST charge only as a result of cancellation between the two. However, the Rindler observers who do not ever have access to the entire space-time would see a net BRST charge. In this respect the effect resembles the Unruh effect. The effect is infrared (IR) in nature, and sensitive to the horizon and/or boundaries. We interpret the extra energy as the formation of the “ghost condensate” when the ghost degrees of freedom cannot propagate, but nevertheless do contribute to the vacuum energy. Exact computations in this simple two-dimensional model support the claim made in a previous paper [F. R. Urban and A. R. Zhitnitsky, Nucl. Phys. B835, 135 (2010).] that the ghost contribution might be responsible for the observed dark energy in a four-dimensional Friedmann-Lemaitre-Robertson-Walker universe.

The dynamics of expansion and large scale structure formation in the multicomponent Universe with dark energy modeled by the minimally coupled scalar field with generalized linear barotropic equation of state are analyzed. It is shown that the past dynamics of expansion and future of the Universe—eternal accelerated expansion or turnaround and collapse—are completely defined by the current energy density of a scalar field and relation between its current and early equation of state parameters. The clustering properties of such models of dark energy and their imprints in the power spectrum of matter density perturbations depend on the same relation and, additionally, on the “effective sound speed” of a scalar field, defined by its Lagrangian. It is concluded that such scalar fields with different values of these parameters are distinguishable in principle. This gives the possibility to constrain them by confronting the theoretical predictions with the corresponding observational data. For that we have used the 7-year Wilkinson Microwave Anisotropy Probe data on cosmic microwave background anisotropies, the Union2 data set on Supernovae Ia and the seventh data release of the Sloan Digital Sky Survey data on luminous red galaxies space distribution. Using the Markov Chain Monte Carlo technique the marginalized posterior and mean likelihood distributions are computed for the scalar fields with two different Lagrangians: Klein-Gordon and Dirac-Born-Infeld ones. The properties of such scalar field models of dark energy with best fitting parameters and uncertainties of their determination are also analyzed in the paper.

Recent evidence for anomalous $CP$ violation in $B$-meson oscillations can be interpreted as resulting from $CPT$ violation. This yields the first sensitivity to $CPT$ violation in the $B_s^0$ system, with the relevant coefficient for $CPT$ violation constrained at the level of parts in ${10}^{12}$.

Some nonperturbative aspects of the pure SU(3) Yang-Mills theory are investigated assuming a specific form of the beta function, based on a recent modification by Ryttov and Sannino of the known one for supersymmetric gauge theories. The characteristic feature is a pole at a particular value of the coupling constant, $g$. First it is noted, using dimensional analysis, that physical quantities behave smoothly as one travels from one side of the pole to the other. Then it is argued that the form of the integrated beta function $g(\mu )$, where $\mu$ is the mass scale, determines the mass gap of the theory. Assuming the usual QCD value of the coupling constant one finds the mass gap to be 1.67 GeV, which is in surprisingly good agreement with a quenched lattice calculation. A similar calculation is made for the supersymmetric Yang-Mills theory where the corresponding beta function is considered to be exact.

We study the interactions between the $f_0(980)$ and $a_0(980)$ scalar resonances and the lightest pseudoscalar mesons. We first obtain the elementary interaction amplitudes, or interacting kernels, without including any ad hoc free parameter. This is achieved by using previous results on the nature of the lightest scalar resonances as dynamically generated from the rescattering of S-wave two-meson pairs. Afterwards, the interaction kernels are unitarized and the final S-wave amplitudes result. We find that these interactions are very rich and generate a large amount of pseudoscalar resonances that could be associated with the $K(1460)$, $\pi (1300)$, $\pi (1800)$, $\eta (1475)$, and $X(1835)$. We also consider the exotic channels with isospin $3/2$ and 1, the latter having positive $G$-parity. The former could also be resonant in agreement with a previous prediction.

The shape of the vector and scalar $K_{\ell 3}$ form factors is investigated by exploiting analyticity and unitarity in a model-independent formalism. The method uses as input dispersion relations for certain correlators computed in perturbative QCD in the deep Euclidean region, soft-meson theorems, and experimental information on the phase and modulus of the form factors along the elastic part of the unitarity cut. We derive constraints on the coefficients of the parameterizations valid in the semileptonic range and on the truncation error. The method also predicts low-energy domains in the complex $t$ plane where zeros of the form factors are excluded. The results are useful for $K_{\ell 3}$ data analyses and provide theoretical underpinning for recent phenomenological dispersive representations for the form factors.

We show that the $K_2^{*}(1430)$, $K_3^{*}(1780)$, $K_4^{*}(2045)$, $K_5^{*}(2380)$, and a not-yet-discovered $K_6^{*}$ resonance are basically molecules made of an increasing number of $\rho (770)$ and one $K^{*}(892)$ mesons. The idea relies on the fact that the vector-vector interaction in the $s$ wave with spins aligned is very strong for both $\rho \rho$ and $K^{*}\rho$. We extend a recent work, where several resonances showed up as multi-$\rho (770)$ molecules, to the strange sector including the $K^{*}(892)$ into the system. The resonant structures show up in the multibody scattering amplitudes, which are evaluated in terms of the unitary two-body vector-vector scattering amplitudes by using the fixed center approximation to the Faddeev equations.