We study the processes $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{\pi }^0{\pi }^0{\pi }^0{\pi }^0\gamma$ and ${\pi }^{+}{\pi }^{-}{\pi }^0{\pi }^0{\pi }^0\eta \gamma$ in which an energetic photon is radiated from the initial state. The data were collected with the BABAR detector at the SLAC National Accelerator Laboratory. About 7300 and 870 events, respectively, are selected from a data sample corresponding to an integrated luminosity of $469{\mathrm{fb}}^{-1}$. The invariant mass of the hadronic final state defines the effective $e^{+}{e}^{-}$ center-of-mass energy. The center-of-mass energies range from threshold to 4.5 GeV. From the mass spectra, the first ever measurements of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{\pi }^0{\pi }^0{\pi }^0{\pi }^0$ and the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{\pi }^0{\pi }^0{\pi }^0\eta$ cross sections are performed. The contributions from $\omega {\pi }^0{\pi }^0{\pi }^0$, $\eta {\pi }^{+}{\pi }^{-}{\pi }^0$, $\omega \eta$, and other intermediate states are presented. We observe the $J/\psi$ and $\psi (2S)$ in most of these final states and measure the corresponding branching fractions, many of them for the first time.

The process $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{\pi }^0\gamma$ is studied at a center-of-mass energy near the $\mathrm{\Upsilon }(4S)$ resonance using a data sample of $469{\mathrm{fb}}^{-1}$ collected with the BABAR detector at the PEP-II collider. We have performed a precise measurement of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{\pi }^0$ cross section in the center-of-mass energy range from 0.62 to 3.5 GeV. In the energy regions of the $\omega$ and $\varphi$ resonances, the cross section is measured with a systematic uncertainty of 1.3%. The leading-order hadronic contribution to the muon magnetic anomaly calculated using the measured $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}{\pi }^0$ cross section from threshold to 2.0 GeV is $(45.86\pm 0.14\pm 0.58)\times {10}^{-10}$. From the fit to the measured $3\pi$ mass spectrum we have determined the resonance parameters $\mathrm{\Gamma }(\omega \to e^{+}{e}^{-})\mathcal{B}(\omega \to {\pi }^{+}{\pi }^{-}{\pi }^0)=(0.5698\pm 0.0031\pm 0.0082)\mathrm{keV}$, $\mathrm{\Gamma }(\varphi \to e^{+}{e}^{-})\mathcal{B}(\varphi \to {\pi }^{+}{\pi }^{-}{\pi }^0)=(0.1841\pm 0.0021\pm 0.0080)\mathrm{keV}$, and $\mathcal{B}(\rho \to 3\pi )=(0.88\pm 0.23\pm 0.30)\times {10}^{-4}$. The significance of the $\rho \to 3\pi$ signal is greater than $6\sigma$. For the $J/\psi$ resonance we have measured the product $\mathrm{\Gamma }(J/\psi \to e^{+}{e}^{-})\mathcal{B}(J/\psi \to 3\pi )=(0.1248\pm 0.0019\pm 0.0026)\mathrm{keV}$.

We revisit various aspects of ${\mathrm{AdS}}_4$ flux vacua with scale separation in type II supergravity and M-theory. We show that massless IIA allows both weakly and strongly coupled solutions for which the classical orientifold backreaction can be fine tuned. This is explicitly verified by computing the backreaction at leading order in perturbation theory. We give evidence that the strongly coupled solutions can be lifted to scale-separated and sourceless (but classically singular) geometries in 11D supergravity.

We analyze vacuum decay in rotating BTZ black hole spacetimes with the thin wall approximation. Possible parameter regions for the vacuum decay are clarified. We find that the nucleation rate is dominated by the bounce solution with the static shell configuration. The nucleation rate of the static shell decreases with the mass of the initial black hole. For a larger/smaller value of the initial black hole, the nucleation rate can be smaller/larger than that of the Coleman De Luccia vacuum decay in the pure anti–de Sitter spacetime. Through the vacuum decay, the black hole gains its mass and loses the horizon area. We also find that the nucleation rate increases with increasing the angular momentum of the spacetime.

Motivated by studies of critical phenomena in the gravitational collapse of vacuum gravitational waves we compare, at the linear level, two common approaches to constructing gravitational-wave initial data. Specifically, we construct analytical, linear Brill wave initial data and compare these with Teukolsky waves in an attempt to understand the different numerical behavior observed in dynamical (nonlinear) evolutions of these two different sets of data. In general, the Brill waves indeed feature higher multipole moments than the quadrupolar Teukolsky waves, which might have provided an explanation for the differences observed in the dynamical evolution of the two types of waves. However, we also find that, for a common choice of the Brill-wave seed function, all higher-order moments vanish identically, rendering the (linear) Brill initial data surprisingly similar to the Teukolsky data for a similarly common choice of its seed function.

This paper discusses the possibility of expanding the interpretation of the dual invariance condition to create a special type of nonlinear vacuum electrodynamics models that are invariant with respect to transformations of the conformal group.

Null and timelike equatorial orbits are investigated in a family of hairy black holes in the cubic Galileon theory. These include rotating generalizations of static black hole metrics supporting a time-dependent scalar field. Depending on the coupling and rotation, the properties of the geodesics expectedly deviate from general relativity. In particular, it is found that stable circular geodesics only exist below a critical coupling, which is related to the existence of an outermost stable circular orbit. Focusing on the strong-field region, images of an accretion disk are also produced to highlight tendencies that would constrain the model given further accurate observations of supermassive black holes.

We compare models of supernova (SN) neutrino emission with the Kamiokande II data on SN 1987A using the Bayesian approach. These models are taken from simulations and are representative of current one-dimensional SN models. We find that models with a brief accretion phase of neutrino emission are the most favored. This result is not affected by varying the overall flux normalization or considering neutrino oscillations. We also check the compatibility of the best-fit models with the data.

The use of the Standard Model effective field theory Lagrangian to quantify possible Beyond the Standard Model (BSM) effects is standard in LHC and future collider studies. One of the usual assumptions is to truncate the expansion with the dimension-six operators. The numerical impact of the next terms in the series, the dimension-eight operators, is unknown in general. We consider a specific BSM model containing a charge-$2/3$ heavy vectorlike quark and compute the operators generated at dimension eight. The numerical effects of these operators are studied for the $t\overline{t}h$ process, where they contribute at tree level and we find effects at the $\mathcal{O}(0.5–2\%)$ level for allowed values of the parameters.

We study renormalizable models with minimal field content that can provide a viable dark matter candidate through the standard freeze-out paradigm and, simultaneously, accommodate the observed anomalies in semileptonic $B$-meson decays at one loop. Following the hypothesis of minimality, this outcome can be achieved by extending the particle spectrum of the Standard Model either with one vectorlike fermion and two scalars or two vectorlike fermions and one scalar. The dark matter annihilations are mediated by $t$-channel exchange of other new particles contributing to the $B$ anomalies, thus resulting in a correlation between flavor observables and dark matter abundance. Again based on minimality, we assume the new states to couple only with left-handed muons and second and third generation quarks. Besides an ad hoc symmetry needed to stabilize the dark matter, the interactions of the new states are dictated only by gauge invariance. We present here for the first time a systematic classification of the possible models of this kind, according to the quantum numbers of the new fields under the Standard Model gauge group. Within this general setup we identify a group of representative models that we systematically study, applying the most updated constraints from flavor observables, dedicated dark matter experiments, and LHC searches of leptons and/or jets and missing energy, and of disappearing charged tracks.

We construct and analyze the phase diagram of a self-interacting matrix field in two dimensions coupled to the curvature of the noncommutative truncated Heisenberg space. In the infinite size limit, the model reduces to the renormalizable Grosse-Wulkenhaar model. The curvature term proves crucial for the diagram’s structure. When turned off, the triple point collapses into the origin as matrices grow larger; when turned on, the triple point recedes from the origin proportionally to the coupling strength and the matrix size. The coupling attenuation that turns the Grosse-Wulkenhaar model into a renormalizable version of the ${\varphi }_{\star }^4$ model cannot stop the triple point recession. As a result, the stripe phase escapes to infinity, removing the problems with UV/IR mixing.

A longstanding question in QCD is the origin of the mass gap in the Yang-Mills sector of QCD, i.e., QCD without quarks. In Landau gauge QCD this mass gap, and hence confinement, is encoded in a mass gap of the gluon propagator, which is found both in lattice simulations and with functional approaches. While functional methods are well suited to unravel the mechanism behind the generation of the mass gap, a fully satisfactory answer has not yet been found. In this work we solve the coupled Dyson-Schwinger equations for the ghost propagator, gluon propagator and three-gluon vertex. We corroborate the findings of earlier works, namely that the mass gap generation is tied to the longitudinal projection of the gluon self-energy, which acts as an effective mass term in the equations. Because an explicit mass term is in conflict with gauge invariance, this leaves two possible scenarios: If it is viewed as an artifact, only the scaling solution survives; if it is dynamical, gauge invariance can only be preserved if there are longitudinal massless poles in either of the vertices. We find that there is indeed a massless pole in the ghost-gluon vertex, however in our approximation with the assumption of complete infrared dominance of the ghost this pole is only present for the scaling solution. We also put forward a possible mechanism that may reconcile the scaling solution, with an infrared dominance of the ghost, with the decoupling solutions based on longitudinal poles in the three-gluon vertex as seen in the PT-BFM scheme.

${\text{Super}\text{−}\mathrm{BMS}}_4$ algebras—also called ${\mathrm{BMS}}_4$ superalgebras—are graded extensions of the ${\mathrm{BMS}}_4$ algebra. They can be of two different types; they can contain either a finite number or an infinite number of fermionic generators. We show in this letter that, with suitable boundary conditions on the graviton and gravitino fields at spatial infinity, supergravity on asymptotically flat spaces possesses as superalgebra of asymptotic symmetries a (nonlinear) ${\text{super}\text{−}\mathrm{BMS}}_4$ algebra containing an infinite number of fermionic generators, which we denote ${\mathrm{SBMS}}_4$. These boundary conditions are not only invariant under ${\mathrm{SBMS}}_4$ but also lead to a fully consistent canonical description of the supersymmetries, which have, in particular, well-defined Hamiltonian generators that close according to the nonlinear ${\mathrm{SBMS}}_4$ algebra. One finds, in particular, that the graded brackets between the fermionic generators yield all the ${\mathrm{BMS}}_4$ supertranslations, of which they provide therefore “square roots”.

In this paper, we bring together two topics in the holographic correspondence—quantum chaos and quark-gluon plasma (QGP). We establish that the first relativistic correction to drag force experienced by a charge carrier moving through a thermal medium (for example, a quark in QGP) at a constant velocity is fixed by the butterfly velocity. Moreover, we show that this result is robust against stringy corrections and anisotropy. For the jet quenching parameter, we find that it is related to the butterfly velocity along the momentum broadening direction and temperature. This opens a way to the reconstruction of butterfly velocity of quark-gluon plasma and other strongly coupled systems experimentally from rather simple observables.

We construct an explicit bulk dual in anti–de Sitter space, with couplings of order $1/N$, for the $SU(N)$-singlet sector of QED in $d$ space-time dimensions ($2<d<4$) coupled to $N$ scalar fields. We begin from the bulk dual for the theory of $N$ complex free scalar fields that we constructed in our previous work, and couple this to $U(1)$ gauge fields living on the boundary in order to get the bulk dual of scalar QED (in which the $U(1)$ gauge fields become the boundary value of the bulk vector fields). As in our previous work, the bulk dual is nonlocal but we can write down an explicit action for it. We focus on the CFTs arising at low energies (or, equivalently, when the $U(1)$ gauge coupling goes to infinity). For $d=3$ we discuss also the addition of a Chern-Simons term for $U(1)$, modifying the boundary conditions for the bulk gauge field. We also discuss the generalization to QCD, with $U(N_c)$ gauge fields coupled to $N$ scalar fields in the fundamental representation (in the large $N$ limit with fixed $N_c$).

We study imaging of point sources with a quadrupole gravitational lens while focusing on the formation and evolution of the Einstein cross formed on the image sensor of an imaging telescope. For this, we consider the optical properties of an oblate gravitational lens that is characterized, in addition to a monopole potential, by the presence of a quadrupole zonal harmonic. We use a new type of a diffraction integral that we developed to study generic, opaque, weakly aspherical gravitational lenses. To evaluate this integral, we use the method of stationary phase that yields a quartic equation with respect to a Cartesian projection of the observer’s position vector with respect to the vector of the impact parameter. The resulting quartic equation can be solved analytically using the method first published by Cardano in 1545. We find that the resulting solution provides a good approximation of the electromagnetic (EM) field almost everywhere in the image plane, yielding the well-known astroid caustic of the quadrupole lens. The sole exception is the immediate vicinity of the caustic boundary, where a numerical treatment of the diffraction integral yields better results. We also convolve the quartic solution for the EM field on the image plane with the point-spread function of a thin lens imaging telescope. By doing so, we are able to explore the direct relationship between the algebraic properties of the quartic solution for the EM field, the geometry of the astroid caustic, and the geometry and shape of the resulting Einstein cross that appear on the image plane of the thin lens telescope. The new quartic solution leads to significant improvements in numerical modeling as an evaluation of this solution is computationally far less expensive than a direct numerical treatment of the new diffraction integral. In the case of the solar gravitational lens, the new results drastically improve the speed of numerical simulations related to sensitivity analysis performed in the context of high-resolution imaging of exoplanets.

In this work we explore the dynamics of the generalized hybrid metric-Palatini theory of gravity in the weak-field, slow-motion regime. We start by introducing the equivalent scalar-tensor representation of the theory, which contains two scalar degrees of freedom, and perform a conformal transformation to the Einstein frame. Linear perturbations of the metric in a Minkowskian background are then studied for the metric and both scalar fields. The effective Newton constant and the PPN parameter $\gamma$ of the theory are extracted after transforming back to the (original) Jordan frame. Two particular cases where the general method ceases to be applicable are approached separately. A comparison of these results with observational constraints is then used to impose bounds on the masses and coupling constants of the scalar fields.

In this work, we study the weak and strong gravitational lensing in the presence of an accelerating black hole in a universe with a positive cosmological constant $\mathrm{\Lambda }$. First of all we derive new perturbative formulas for the event and cosmological horizons in terms of the Schwarzschild, cosmological and acceleration scales. In agreement with previous results in the literature, we find that null circular orbits for certain families of orbital cones originating from a saddle point of the effective potential are allowed and they do not exhibit any dependence on the cosmological constant. They turn out to be Jacobi unstable. We also show that it is impossible to distinguish a $C$-black hole from a $C$-black hole with $\mathrm{\Lambda }$ if we limit our probe only into effects associated to the Sachs optical scalars. This motivates us to analyze the weak and strong gravitational lensing when both the observer and the light ray belong to the aforementioned family of invariant cones. In particular, we derive analytical formulas for the deflection angle in the weak and strong gravitational lensing regimes.

The close limit approximation of a binary black hole is a powerful method to study gravitational-wave emission from highly nonlinear geometries. In this work, we use it as a tool to model black hole spacetimes in theories of gravity with a new fundamental scalar degree of freedom. As an example, we consider Einstein-scalar-Gauss-Bonnet gravity, which admits as a solution the Schwarzschild geometry as well as black holes with scalar hair. Accordingly, we find scalar perturbations growing unbounded around binary systems. This “dynamical scalarization” process is easier to trigger (i.e., occurs at lower values of the coupling constant of the theory) than the corresponding process for isolated black holes. Our results and framework highlight the fundamental role of the interaction during the collision of compact objects. They also emphasize the importance of having waveforms for black hole binaries in alternative theories, in order to consistently perform tests beyond general relativity.