We consider the scenario in which the light Higgs scalar boson appears as the pseudo-Goldstone boson. We discuss examples in both condensed matter and relativistic field theory. In ${}^3\mathrm{He}\text{−}\mathrm{B}$ the symmetry breaking gives rise to four Nambu-Goldstone (NG) modes and 14 Higgs modes. At lower energy one of the four NG modes becomes the Higgs boson with a small mass. This is the mode measured in experiments with the longitudinal NMR, and the Higgs mass corresponds to the Leggett frequency $M_{\mathrm{H}}=\hslash {\mathrm{\Omega }}_B$. The formation of the Higgs mass is the result of the violation of the hidden spin-orbit symmetry at low energy. In this scenario the symmetry-breaking energy scale $\mathrm{\Delta }$ (the gap in the fermionic spectrum) and the Higgs mass scale $M_{\mathrm{H}}$ are highly separated: $M_{\mathrm{H}}\ll \mathrm{\Delta }$. On the particle physics side we consider the model inspired by the models of Refs. Cheng et al. [J. High Energy Phys. 08 (014) 095] and Fukano et al. [Phys. Rev. D 90, 055009 (2014)]. At high energies the SU(3) symmetry is assumed which relates the left-handed top and bottom quarks to the additional fermion ${\chi }_L$. This symmetry is softly broken at low energies. As a result the only $CP$-even Goldstone boson acquires a mass and may be considered as a candidate for the 125 GeV scalar boson. We consider a condensation pattern different from that typically used in top-seesaw models, where the condensate $⟨{\overline{t}}_L{\chi }_R⟩$ is off-diagonal. In our case the condensates are mostly diagonal. Unlike the work of Cheng et al. [J. High Energy Phys. 08 (014) 095] and Fukano et al. [Phys. Rev. D 90, 055009 (2014)], the explicit mass terms are absent and the soft breaking of SU(3) symmetry is given solely by the four-fermion terms. This reveals a complete analogy with ${}^3\mathrm{He}$, where there is no explicit mass term and the spin-orbit interaction has the form of the four-fermion interaction.

We perform a general analysis of new physics interpretations of the recent ATLAS diboson excesses over standard model expectations in LHC Run I collisions. First, we estimate a likelihood function in terms of the truth signal in the $WW$, $WZ$, and $ZZ$ channels, finding that the maximum has zero events in the $WZ$ channel, though the likelihood is sufficiently flat to allow other scenarios. Second, we survey the possible effective field theories containing the standard model plus a new resonance that could explain the data, identifying two possibilities, viz. a vector that is either a left- or right-handed $SU(2)$ triplet. Finally, we compare these models with other experimental data and determine the parameter regions in which they provide a consistent explanation.

The renormalizable coloron model is built around a minimally extended color gauge group, which is spontaneously broken to QCD. The formalism introduces massive color-octet vector bosons (colorons), as well as several new scalars and fermions associated with the symmetry breaking sector. In this paper, we examine vacuum stability and triviality conditions within the context of the renormalizable coloron model up to a cutoff energy scale of 100 TeV, by computing the $\beta$-functions of all relevant couplings and determining their running behavior as a function of the renormalization scale. We constrain the parameter space of the theory for four separate scenarios based on differing fermionic content, and demonstrate that the vectorial scenarios are less constrained by vacuum stability and triviality bounds than the chiral scenarios. Our results are summarized in exclusion plots for the separate scenarios, with previous bounds on the model overlaid for comparison. We find that a 100 TeV hadron collider could explore the entire allowed parameter space of the chiral models very effectively.

Predictions are made for the forward-backward and charge asymmetries in bottom-quark pair production at hadron colliders. Tree-level exchanges of electroweak (EW) gauge bosons dominate the Standard Model (SM) contribution to the asymmetry near the $Z$-pole. The mixed EW-QCD corrections are computed in an approximate way, and are found to be small in magnitude. These SM predictions are consistent with experimental results from CDF, D0, and LHCb. In particular, CDF and LHCb find that the asymmetry in the invariant mass bin containing the $Z$-pole is larger than in the adjacent bins, as predicted. Several beyond the Standard Model scenarios proposed for the top-quark forward-backward asymmetry, including a 100 GeV axigluon, are disfavored by this combination of SM predictions and measurements. On the other hand, modified $Zb\overline{b}$ couplings can explain the $2\sigma$ discrepancy in the bottom-quark forward-backward asymmetry at LEP1, while being consistent with the results of CDF and LHCb. It is also shown that $t$-channel $W$ exchange makes a non-negligible contribution to the charm-quark charge asymmetry.

We construct charmoniumlike and bottomoniumlike molecular interpolating currents with quantum numbers $J^{PC}=1^{+-}$ in a systematic way, including both color singlet-singlet and color octet-octet structures. Using these interpolating currents, we calculate two-point correlation functions and perform QCD sum rule analyses to obtain mass spectra of the charmoniumlike and bottomoniumlike molecular states. Masses of the charmoniumlike $\overline{q}c\overline{c}q$ molecular states for these various currents are extracted in the range 3.85–4.22 GeV, which are in good agreement with observed masses of the $Z_c$ resonances. Our numerical results suggest a possible landscape of hadronic molecule interpretations of the newly observed $Z_c$ states. Mass spectra of the bottomoniumlike $\overline{q}b\overline{b}q$ molecular states are similarly obtained in the range 9.92–10.48 GeV, which support the interpretation of the $Z_b(10610)$ meson as a molecular state within theoretical uncertainties. Possible decay channels of these molecular states are also discussed.

We include new additional absorption corrections into the double Pomeron/Reggeon exchange (nonresonant) model for $pp\to pp{\pi }^{+}{\pi }^{-}$ or $p\overline{p}\to p\overline{p}{\pi }^{+}{\pi }^{-}$ processes. They are related to the $\pi N$ nonperturbative interaction in the final state of the reaction. We present predictions of cross sections for RHIC, Tevatron, and LHC experiments. The new absorption corrections lead to a further decrease of the cross section by about a factor of 2. The role of the absorption corrections is quantified for several differential distributions. They change the shape of some distributions ($d\sigma /dt$, $d\sigma /d{p}_{t,p}$, $d\sigma /d{\varphi }_{pp}$) but leave almost unchanged shape of other distributions ($d\sigma /d{M}_{\pi \pi }$, $d\sigma /d{y}_{\pi }$, $d\sigma /d{p}_{t,\pi }$, $d\sigma /d{\varphi }_{\pi \pi }$). The effect may have an important impact on the interpretation of the recent STAR and CDF data as well as the forthcoming data of the ALICE, ATLAS/ALFA, and CMS/TOTEM collaborations.

As the theme for the future L3 Cosmic Vision mission, ESA has recently chosen the “Gravitational Wave Universe.” Within this program, a mission concept called eLISA has been proposed. This observatory has a current initial configuration consisting of four laser links between the three satellites, which are separated by a distance of one million kilometers, constructing a single-channel Michelson interferometer. However, the final configuration for the observatory will not be fixed until the end of this decade. With this in mind, we investigate the effect of different eLISA-like configurations on massive black hole detections. This work compares the results of a Bayesian inference study of 120 massive black hole binaries out to a redshift of $z\sim 13$ for a ${10}^6\mathrm{km}$ arm length eLISA with four and six links, as well as a $2\times {10}^6\mathrm{km}$ arm length observatory with four links. We demonstrate that the original eLISA configuration should allow us to recover the luminosity distance of the source with an error of less than 10% out to a redshift of $z\sim 4$, and a sky error box of $\mathrm{\Delta }\mathrm{\Omega }\le {10}^2{\mathrm{deg}}^2$ out to $z\sim 0.1$. In contrast, both alternative configurations suggest that we should be able to conduct the same parameter recovery with errors of less than 10% in luminosity distance out to $z\sim 12$ and $\mathrm{\Delta }\mathrm{\Omega }\le {10}^2{\mathrm{deg}}^2$ out to $z\sim 0.4$. Using the information from these studies, we also infer that if we were able to construct a 2 Gm, six-link detector, the above values would shift to $z\sim 20$ for luminosity distance and $z\sim 0.9$ for sky error. While the final configuration will also be dependent on both technological and financial considerations, our study suggests that increasing the size of a two-arm detector is a viable alternative to the inclusion of a third arm in a smaller detector. More importantly, this work further suggests no clear scientific loss between either choice.

We present the mean pairwise momentum of clusters, as observed through the kinematic Sunyaev-Zel’dovich (kSZ) effect, as a novel probe of massive neutrinos. We find that kSZ measurements with current and upcoming surveys will provide complementary constraints on the sum of neutrino masses from large scale structure and will improve on Planck satellite measurements of the primordial cosmic microwave background (CMB) and CMB lensing. Central to the constraints is a distinctive scale dependency of the kSZ neutrino signature on the mean pairwise momentum of clusters that we do not expect to be mirrored in systematic effects that change the overall amplitude of the signal, like the cluster optical depth. Assuming a minimal $\mathrm{\Lambda }\mathrm{CDM}$ cosmology including massive neutrinos with Planck primordial CMB priors combined with conservative kSZ specifications, we forecast 68% upper limits on the neutrino mass sum of 310, 240, and 110 meV for “Stage II” ($\mathrm{ACTPol}+\mathrm{BOSS}$), “Stage III” (Advanced $\mathrm{ACTPol}+\mathrm{BOSS}$), and “Stage IV” ($\mathrm{CMB}\text{−}\mathrm{S}4+\mathrm{DESI}$) surveys respectively, compared to the Planck alone forecast of 540 meV. These forecasts include the ability to simultaneously constrain the neutrino mass sum and the mass-averaged optical depth of the cluster sample in each redshift bin. If the averaged optical depth of clusters can be measured with few percent accuracy and a lower limiting mass is assumed, the projected kSZ constraints improve further to 100, 85 and 33 meV (Stage II, III and IV). These forecasts represent a conservative estimate of neutrino constraints using cross-correlations of arcminute-resolution CMB measurements and spectroscopic galaxy surveys. More information relevant for neutrino constraints is available from these surveys, such as galaxy clustering, weak lensing, and CMB temperature and polarization.

The ATLAS Collaboration has reported excesses in searches for resonant diboson production decaying into hadronic final states. This deviation from the standard model prediction may be a signature of an extra bosonic particle having a mass of around 2 TeV with a fairly narrow width, which implies the presence of a new perturbative theory at the TeV scale. In this paper, we study interpretations of the signal and its implication to physics beyond the standard model. We find that the resonance could be regarded as a leptophobic vector particle, which could explain a part of the observed excesses without conflict with the present constraints from other direct searches for heavy vector bosons at the LHC as well as the electroweak precision measurements.

In order to compute the entanglement entropy for a given region in a theory with an Einstein gravity dual, the Ryu-Takayanagi prescription tells us that we must compute the area of an extremal surface anchored to the entangling region. However, if the dual gravity theory receives higher-curvature corrections we are compelled to extremize a quantity which is no longer given by the area but a higher-derivative functional. Hence, in order to find the extremal surface that yields the correct value of the entanglement entropy, we must include an additional boundary condition to the problem. We claim that the additional condition can be fixed by demanding that the relationship between the bulk depth and the size of the entangling region is the one induced by geodesics, we call this the free-kick condition. We implement this prescription in the computation of the entanglement entropy of the hairy black hole in new massive gravity, and find a perfect agreement with conformal field theory expectations.

We propose a novel method of finding the classical limit of the matrix geometry. We define coherent states for a general matrix geometry described by a large-$N$ sequence of $D$ Hermitian matrices $X_{\mu }(\mu =1,2,\dots ,D)$ and construct a corresponding classical space as a set of all coherent states. When the classical space forms a smooth manifold, we also express various geometric objects on the classical space such as the metric, Levi-Civita connection, curvature and Poisson tensor, in terms of the matrix elements. This method provides a new class of observables in matrix models, which characterize geometric properties of matrix configurations.

The semiclassical operator method of Baier and Katkov allows one to obtain the spectrum of synchrotron radiation in a way similar to the classical derivation but which is fully valid also in the quantum case of very strong electromagnetic fields. In the usual calculation the extension of the field is taken to be infinite. In this paper we apply a numerical routine based on the semiclassical operator method to the case of a constant field but with a finite extension. For large extensions of the field one obtains the usual result of quantum synchrotron radiation, while in the limit of small extension of the field one obtains a spectrum resembling that of bremsstrahlung. We derive a formula for the radiation spectrum in this limit. In the transition toward shorter field extensions one finds that the power-spectrum increases for soft photons and slightly diminishes for harder photons. It is found that in the classical case the total power emitted decreases as the field extension decreases while in the quantum case the total power emitted is first increased and then decreases. Such an effect could be important for future $e^{+}{e}^{-}$ colliders such as the ILC or CLIC where the dominant energy and luminosity loss is due to synchrotron radiation by an $e^{-}/e^{+}$ in the field of the opposing bunch, often termed “beamstrahlung.” In this paper we also discuss how these effects, in the quantum case could be measured in an experiment using thin aligned single crystals and high energy electrons available at e.g. the CERN SPS North Area, and in the classical case could already be relevant at existing accelerators with conventional magnets providing the electromagnetic field.

Global two-monopoles are unstable in their simplest formulation. We construct a model with a metriclike prefactor which we show can stabilize the global two-monopoles. The stabilizing construction is realized with a Skyrme sector where the metriclike prefactor is a function of the Skyrmion profile.

Spherically symmetric models of loop quantum gravity have been studied recently by different methods that aim to deal with structure functions in the usual constraint algebra of gravitational systems. As noticed by Gambini and Pullin, a linear redefinition of the constraints (with phase-space dependent coefficients) can be used to eliminate structure functions, even Abelianizing the more difficult part of the constraint algebra. The Abelianized constraints can then easily be quantized or modified by putative quantum effects. As pointed out here, however, the method does not automatically provide a covariant quantization, defined as an anomaly-free quantum theory with a classical limit in which the usual (off-shell) gauge structure of hypersurface deformations in space-time appears. The holonomy-modified vacuum theory based on Abelianization is covariant in this sense, but matter theories with local degrees of freedom are not. Detailed demonstrations of these statements show complete agreement with results of canonical effective methods applied earlier to the same systems (including signature change).

We develop a field theory description of nondissipative string fluids and construct an explicit mapping between field theory degrees of freedom and hydrodynamic variables. The theory generalizes both a perfect particle fluid and pressureless string fluid to what we call a perfect string fluid. Ideal magnetohydrodynamics is shown to be an example of the perfect string fluid whose equations of motion can be obtained from a particular choice of the Lagrangian. The Lagrangian framework suggests a straightforward extension of the perfect string fluid to more general anisotropic fluids describing higher dimensional branes such as domain walls. Other modifications of the Lagrangian are discussed which may be useful in describing relativistic superfluids and fluids containing additional currents.

We provide evidence in favor of the conjectured duality between color and kinematics for the case of nonsupersymmetric pure Yang-Mills amplitudes by constructing a form of the one-loop four-point amplitude of this theory that makes the duality manifest. Our construction is valid in any dimension. We also describe a duality-satisfying representation for the two-loop four-point amplitude with identical four-dimensional external helicities. We use these results to obtain corresponding gravity integrands for a theory containing a graviton, dilaton, and antisymmetric tensor, simply by replacing color factors with specified diagram numerators. Using this, we give explicit forms of ultraviolet divergences at one loop in four, six, and eight dimensions, and at two loops in four dimensions.

Starting from Plebanski’s action for general relativity with cosmological constant, we show that by integrating out all the auxiliary fields Krasnov’s action immediately emerges. We also perform the Hamiltonian analysis of the latter and show that the constraints are those of the Ashtekar formalism.

Black holes with planar or hyperbolic horizons are known to exist in anti-de Sitter (AdS) space, alongside the usual ones with spherical horizons. In this paper, we consider a one-parameter generalization of these black holes that is contained in the AdS C-metric. In terms of the domain-structure analysis recently developed for such solutions, these black holes have a domain in the shape of a triangle. It is shown that the horizons of these black holes are deformed hyperbolic spaces, with the new parameter controlling the amount of deformation. The space-times are static and completely regular outside the horizons. We argue that these black holes are hyperbolic analogues of the “slowly accelerating” spherical black holes known to exist in AdS space.

We investigate the coupling between a Galileon scalar field and massive gravity through composite metrics. We derive the full set of equations of motion for a flat Friedmann-Robertson-Walker background, and study linear perturbations around it. Generally, the nonminimal coupling with the composite metric will excite all 6 degrees of freedom of the spatial metric perturbations, one of which may correspond to the Boulware-Deser ghost.

Reliable low-latency gravitational wave parameter estimation is essential to target limited electromagnetic follow-up facilities toward astrophysically interesting and electromagnetically relevant sources of gravitational waves. In this study, we examine the trade-off between speed and accuracy. Specifically, we estimate the astrophysical relevance of systematic errors in the posterior parameter distributions derived using a fast-but-approximate waveform model, SpinTaylorF2 (stf2), in parameter estimation with lalinference_mcmc. Though efficient, the stf2 approximation to compact binary inspiral employs approximate kinematics (e.g., a single spin) and an approximate waveform (e.g., frequency domain versus time domain). More broadly, using a large astrophysically motivated population of generic compact binary merger signals, we report on the effectualness and limitations of this single-spin approximation as a method to infer parameters of generic compact binary sources. For most low-mass compact binary sources, we find that the stf2 approximation estimates compact binary parameters with biases comparable to systematic uncertainties in the waveform. We illustrate by example the effect these systematic errors have on posterior probabilities most relevant to low-latency electromagnetic follow-up: whether the secondary has a mass consistent with a neutron star (NS); whether the masses, spins, and orbit are consistent with that neutron star’s tidal disruption; and whether the binary’s angular momentum axis is oriented along the line of sight.