Hadron tomography can be investigated by three-dimensional structure functions such as generalized parton distributions (GPDs), transverse-momentum-dependent parton distributions, and generalized distribution amplitudes (GDAs). Here, we extract the GDAs, which are $s\text{−}t$ crossed quantities of the GPDs, from cross-section measurements of hadron-pair production process ${\gamma }^{*}\gamma \to {\pi }^0{\pi }^0$ at KEKB. This work is the first attempt to obtain the GDAs from the actual experimental data. The GDAs are expressed by a number of parameters and they are determined from the data of ${\gamma }^{*}\gamma \to {\pi }^0{\pi }^0$ by including intermediate scalar- and tensor-meson contributions to the cross section. Our results indicate that the dependence of parton-momentum fraction $z$ in the GDAs is close to the asymptotic one. The timelike gravitational form factors ${\mathrm{\Theta }}_1$ and ${\mathrm{\Theta }}_2$ are obtained from our GDAs, and they are converted to the spacelike ones by the dispersion relation. From the spacelike ${\mathrm{\Theta }}_1$ and ${\mathrm{\Theta }}_2$, gravitational densities of the pion are calculated. Then, we obtained the mass (energy) radius and the mechanical (pressure and shear force) radius from ${\mathrm{\Theta }}_2$ and ${\mathrm{\Theta }}_1$, respectively. They are calculated as $\sqrt{⟨r^2{⟩}_{\mathrm{mass}}}=0.32–0.39\mathrm{fm}$, whereas the mechanical radius is larger $\sqrt{⟨r^2{⟩}_{\mathrm{mech}}}=0.82–0.88\mathrm{fm}$. This is the first report on the gravitational radius of a hadron from actual experimental measurements. It is interesting to find the possibility that the gravitational mass and mechanical radii could be different from the experimental charge radius $\sqrt{⟨r^2{⟩}_{\text{charge}}}=0.672\pm 0.008\mathrm{fm}$ for the charged pion. For drawing a clear conclusion on the GDAs of hadrons, accurate experimental data are needed, and it should be possible, for example, by future measurements of super-KEKB and international linear collider. Accurate measurements will not only provide important information on hadron tomography but also possibly shed light on gravitational physics in the quark and gluon level.

The latest results on top quark physics, namely single top quark production cross sections, $W$-boson helicity and asymmetry measurements are used to probe the Lorentz structure of the $Wtb$ vertex. The increase of sensitivity to new anomalous physics contributions to the top quark sector of the standard model is quantified by combining the relevant results from Tevatron and the Large Hadron Collider. The results show that combining an increasing set of available precision measurements in the search for new physics phenomena beyond the standard model leads to significant sensitivity improvements, especially when compared with the current expectation for the High Luminosity run at the LHC.

We consider renormalizable couplings of neutral $\varphi$, singly ${\varphi }^{\pm }$, and doubly charged ${\varphi }^{\pm \pm }$ scalar bosons to leptons and the $Z$ gauge boson and calculate the one-loop contributions to the anomalous weak magnetic dipole moment (AWMDM) $a_{\tau }^W$ and the weak electric dipole moment (WEDM) $d_{\tau }^W$ of a charged lepton in a model-independent way. The analytic expressions are presented in terms of both parametric integrals and Passarino-Veltman scalar functions. Among the new contributions, there are those arising from the vertices of the type ${\varphi }^{\pm }{W}^{\mp }Z$ and $Z{\varphi }_i{\varphi }_j$ ($i\ne j$), along with contributions from doubly charged scalar bosons. Both $a_{\tau }^W$ and $d_{\tau }^W$ are evaluated in several scenarios, first in a model-independent way and then within some popular models, such as two-Higgs doublet models (THDMs), multiple-Higgs doublet models and Higgs triplet models. As far as $a_{\tau }^W$ is concerned, its real part reaches values as high as ${10}^{-10}–{10}^{-9}$ for masses of the new scalar bosons in the 200 GeV range, whereas the imaginary part is 1 or 2 orders of magnitude below. On the other hand, the most promising scenario for a nonvanishing WEDM is offered by a $CP$-violating THDM in a scenario where the heavy neutral scalar bosons are a mixture of $CP$ eigenstates. It is found that the real part of $d_{\tau }^W$ is of the order of ${10}^{-24}\mathrm{ecm}$ and its imaginary part can reach the ${10}^{-26}\mathrm{ecm}$ level for masses of the new scalar bosons of the order of a few hundred of GeVs. Both the tau AWMDM and WEDM decrease dramatically as the scalar boson masses increase.

Consequences of nonstandard Higgs couplings in the final-state distributions of the process $e^{+}{e}^{-}\to ZHH$ are studied. We derive an analytic expression for the differential cross section, which has in the most general case nine nonzero functions. These functions are the coefficients of nine angular terms, depend on the Higgs couplings, and can be experimentally measured as observables. Symmetry properties of these nine functions are carefully discussed, and they are divided into four categories under $CP$ and $CP\tilde{T}$. The relations between our observables and the observables which exist in the literature are also clarified. We numerically study the dependence of our observables on the parameters in an effective Lagrangian for the Higgs couplings. It is shown that these new observables depend on most of the effective Lagrangian parameters in different ways from the total cross section. A benefit from longitudinally polarized $e^{+}{e}^{-}$ beams is also discussed.

By analyzing $482{\mathrm{pb}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at the center-of-mass energy $\sqrt{s}=4.009\mathrm{GeV}$ with the BESIII detector, we measure the branching fractions for the semi-leptonic decays $D_s^{+}\to \varphi e^{+}{\nu }_e$, $\varphi {\mu }^{+}{\nu }_{\mu }$, $\eta {\mu }^{+}{\nu }_{\mu }$ and ${\eta }^{\prime }{\mu }^{+}{\nu }_{\mu }$ to be $\mathcal{B}(D_s^{+}\to \varphi e^{+}{\nu }_e)=(2.26\pm 0.45\pm 0.09)\%$, $\mathcal{B}(D_s^{+}\to \varphi {\mu }^{+}{\nu }_{\mu })=(1.94\pm 0.53\pm 0.09)\%$, $\mathcal{B}(D_s^{+}\to \eta {\mu }^{+}{\nu }_{\mu })=(2.42\pm 0.46\pm 0.11)\%$ and $\mathcal{B}(D_s^{+}\to {\eta }^{\prime }{\mu }^{+}{\nu }_{\mu })=(1.06\pm 0.54\pm 0.07)\%$, where the first and second uncertainties are statistical and systematic, respectively. The branching fractions for the three semi-muonic decays $D_s^{+}\to \varphi {\mu }^{+}{\nu }_{\mu },\eta {\mu }^{+}{\nu }_{\mu }$ and ${\eta }^{\prime }{\mu }^{+}{\nu }_{\mu }$ are determined for the first time and that of $D_s^{+}\to \varphi e^{+}{\nu }_e$ is consistent with the world average value within uncertainties.

In the holographic correspondence of quantum gravity, a global on-site symmetry at the boundary generally translates to a local gauge symmetry in the bulk. We describe one way how the global boundary on-site symmetries can be gauged within the formalism of the multiscale renormalization ansatz (MERA), in light of the ongoing discussion between tensor networks and holography. We describe how to “lift” the MERA representation of the ground state of a generic one dimensional (1D) local Hamiltonian, which has a global on-site symmetry, to a dual quantum state of a 2D “bulk” lattice on which the symmetry appears gauged. The 2D bulk state decomposes in terms of spin network states, which label a basis in the gauge-invariant sector of the bulk lattice. This decomposition is instrumental to obtain expectation values of gauge-invariant observables in the bulk, and also reveals that the bulk state is generally entangled between the gauge and the remaining (“gravitational”) bulk degrees of freedom that are not fixed by the symmetry. We present numerical results for ground states of several 1D critical spin chains to illustrate that the bulk entanglement potentially depends on the central charge of the underlying conformal field theory. We also discuss the possibility of emergent topological order in the bulk using a simple example, and also of emergent symmetries in the nongauge (gravitational) sector in the bulk. More broadly, our holographic model translates the MERA, a tensor network state, to a superposition of spin network states, as they appear in lattice gauge theories in one higher dimension.

In recent years, tensor network states have emerged as a very useful conceptual and simulation framework to study quantum many-body systems at low energies. In this paper, we describe a particular way in which any given tensor network can be viewed as a representation of two different quantum many-body states. The two quantum many-body states are said to correspond to each other by means of the tensor network. We apply this “tensor network state correspondence”—a correspondence between quantum many-body states mediated by tensor networks as we describe—to the multi-scale entanglement renormalization ansatz (MERA) representation of ground states of one dimensional (1D) quantum many-body systems. Since the MERA is a 2D hyperbolic tensor network (the extra dimension is identified as the length scale of the 1D system), the two quantum many-body states obtained from the MERA, via tensor network state correspondence, are seen to live in the bulk and on the boundary of a discrete hyperbolic geometry. The bulk state so obtained from a MERA exhibits interesting features, some of which caricature known features of the holographic correspondence of String theory. We show how (i) the bulk state admits a description in terms of “holographic screens”, (ii) the conformal field theory data associated with a critical ground state can be obtained from the corresponding bulk state, in particular, how pointlike boundary operators are identified with extended bulk operators. (iii) We also present numerical results to illustrate that bulk states, dual to ground states of several critical spin chains, have exponentially decaying correlations, and that the bulk correlation length generally decreases with increase in central charge for these spin chains.

Structure at the horizon scale of black holes would give rise to echoes of the gravitational wave signal associated with the postmerger ringdown phase in binary coalescences. We study the waveform of echoes in static and stationary, traversable wormholes in which perturbations are governed by a symmetric effective potential. We argue that echoes are dominated by the wormhole quasinormal frequency nearest to the fundamental black hole frequency that controls the primary signal. We put forward an accurate method to construct the echoes’ waveform(s) from the primary signal and the quasinormal frequencies of the wormhole, which we characterize. We illustrate this in the static Damour-Solodukhin wormhole and in a new, rotating generalization that approximates a Kerr black hole outside the throat. Rotation gives rise to a potential with an intermediate plateau region that breaks the degeneracy of the quasinormal frequencies. Rotation also leads to late-time instabilities that, however, fade away for small angular momentum.

Given the important role that the galaxy bispectrum has recently acquired in cosmology and the scale and precision of forthcoming galaxy clustering observations, it is timely to derive the full expression of the large-scale bispectrum going beyond approximated treatments which neglect integrated terms or higher-order bias terms or use the Limber approximation. On cosmological scales, relativistic effects that arise from observing the past light cone alter the observed galaxy number counts, therefore leaving their imprints on N-point correlators at all orders. In this paper we compute for the first time the bispectrum including all general relativistic, local and integrated, effects at second order, the tracers’ bias at second order, geometric effects as well as the primordial non-Gaussianity contribution. This is timely considering that future surveys will probe scales comparable to the horizon where approximations widely used currently may not hold; neglecting these effects may introduce biases in estimation of cosmological parameters as well as primordial non-Gaussianity.

This paper concludes our semianalytic study of preheating in inflationary models comprised of multiple scalar fields coupled nonminimally to gravity. Using the covariant framework of paper I in this series, we extend the rigid-spacetime results of paper II by considering both the expansion of the Universe during preheating, as well as the effect of the coupled metric perturbations on particle production. The adiabatic and isocurvature perturbations are governed by different effective masses that scale differently with the nonminimal couplings and evolve differently in time. The effective mass for the adiabatic modes is dominated by contributions from the coupled metric perturbations immediately after inflation. The metric perturbations contribute an oscillating tachyonic term that enhances an early period of significant particle production for the adiabatic modes, which ceases on a time scale governed by the nonminimal couplings ${\xi }_I$. The effective mass of the isocurvature perturbations, on the other hand, is dominated by contributions from the fields’ potential and from the curvature of the field-space manifold (in the Einstein frame), the balance between which shifts on a time scale governed by ${\xi }_I$. As in papers I and II, we identify distinct behavior depending on whether the nonminimal couplings are small [${\xi }_I\lesssim \mathcal{O}(1)$], intermediate [${\xi }_I\sim \mathcal{O}(1-10)$], or large (${\xi }_I\ge 100$).

This is the second in a series of papers on preheating in inflationary models comprised of multiple scalar fields coupled nonminimally to gravity. In this paper, we work in the rigid-spacetime approximation and consider field trajectories within the single-field attractor, which is a generic feature of these models. We construct the Floquet charts to find regions of parameter space in which particle production is efficient for both the adiabatic and isocurvature modes, and analyze the resonance structure using analytic and semianalytic techniques. Particle production in the adiabatic direction is characterized by the existence of an asymptotic scaling solution at large values of the nonminimal couplings, ${\xi }_I\gg 1$, in which the dominant instability band arises in the long-wavelength limit, for comoving wave numbers $k\to 0$. However, the large-${\xi }_I$ regime is not reached until ${\xi }_I\ge \mathcal{O}(100)$. In the intermediate regime, with ${\xi }_I\sim \mathcal{O}(1–10)$, the resonance structure depends strongly on wave number and couplings. The resonance structure for isocurvature perturbations is distinct and more complicated than its adiabatic counterpart. An intermediate regime, for ${\xi }_I\sim \mathcal{O}(1–10)$, is again evident. For large values of ${\xi }_I$, the Floquet chart consists of densely spaced, nearly parallel instability bands, suggesting a very efficient preheating behavior. The increased efficiency arises from features of the nontrivial field-space manifold in the Einstein frame, which itself arises from the fields’ nonminimal couplings in the Jordan frame, and has no analog in models with minimal couplings. Quantitatively, the approach to the large-${\xi }_I$ asymptotic solution for isocurvature modes is slower than in the case of the adiabatic modes.

This is the first of a three-part series of papers, in which we study the preheating phase for multifield models of inflation involving nonminimal couplings. In this paper, we study the single-field attractor behavior that these models exhibit during inflation and quantify its strength and parameter dependence. We further demonstrate that the strong single-field attractor behavior persists after the end of inflation. Preheating in such models therefore generically avoids the “dephasing” that typically affects multifield models with minimally coupled fields, allowing efficient transfer of energy from the oscillating inflaton condensate(s) to coupled perturbations across large portions of parameter space. We develop a doubly covariant formalism for studying the preheating phase in such models and identify several features specific to multifield models with nonminimal couplings, including effects that arise from the nontrivial field-space manifold. In papers II and III, we apply this formalism to study how the amplification of adiabatic and isocurvature perturbations varies with parameters, highlighting several distinct regimes depending on the magnitude of the nonminimal couplings ${\xi }_I$.

There has been a recent surge in interest in the detection of $\tau$-lepton-induced air showers from detectors at altitude. When a $\tau$ neutrino (${\nu }_{\tau }$) enters the Earth, it produces $\tau$ leptons as a result of nuclear charged-current interactions. In some cases, this process results in a $\tau$ lepton exiting the surface of the Earth, which can subsequently decay in the atmosphere and produce an extensive air shower. These upward-going air showers can be detected via fluorescence, optical Cherenkov, or geomagnetic radio emission. Several experiments have been proposed to detect these signals. We present a comprehensive simulation of the production of $\tau$ leptons by ${\nu }_{\tau }$’s propagating through Earth to aid the design of future experiments. These simulations for ${\nu }_{\tau }$’s and leptons in the energy range from $10^{15}\mathrm{eV}$ to $10^{21}\mathrm{eV}$ treat the full range of incidence angles from Earth-skimming to diametrically traversing. Propagation of ${\nu }_{\tau }$’s and leptons includes the effects of rock and an ocean or ice layer of various thicknesses. The interaction models include ${\nu }_{\tau }$ regeneration and account for uncertainties in the Standard Model neutrino cross section and in the photonuclear contribution to the $\tau$ energy-loss rate.

Within the most recent extension of the quark-jet hadronization framework, we explore the transverse-polarization-dependent dihadron fragmentation functions (DiFFs) $H_1^{\sphericalangle }$ and $H_1^{\perp }$ of a quark into ${\pi }^{+}{\pi }^{-}$ pairs. Monte Carlo (MC) simulations are employed to model polarized quark hadronization and calculate the corresponding number densities. These, in turn, are used to extract the Fourier cosine moments of the DiFFs $H_1^{\sphericalangle }$ and $H_1^{\perp }$. A notable finding is that there are previously unnoticed apparent discrepancies between the definitions of the so-called interference DiFF (IFF) $H_1^{\sphericalangle }$, entering the cross sections for two-hadron semi-inclusive electroproduction, and those involved in the production of two pairs of hadrons from back-to-back jets in electron-positron annihilation. This manuscript completes the studies of all four leading-twist DiFFs for unpolarized hadron pairs within the quark-jet framework, following our previous work on the helicity-dependent DiFF $G_1^{\perp }$.

We propose a new topological vertex formalism for a type IIB $(p,q)$ 5-brane web with an O5-plane. We apply our proposal to five-dimensional $\mathcal{N}=1$ Sp(1) gauge theory with $N_f=0$, 1, 8 flavors to compute the topological string partition functions and check the agreement with the known results. Especially for the $N_f=8$ case, which corresponds to E-string theory on a circle, we obtain a new, yet simple, expression of the partition function with a two Young diagram sum.

Sufficiently small Schwarzschild-AdS black holes in asymptotically global ${\mathrm{AdS}}_5\times S^5$ spacetime are known to become dynamically unstable toward deformation of the internal $S^5$ geometry. The resulting evolution of such an unstable black hole is related, via holography, to the dynamics of supercooled plasma which has reached the limit of metastability in maximally supersymmetric large-$N$ Yang-Mills theory on $\mathbb{R}\times S^3$. Puzzles related to the resulting dynamical evolution are discussed, with a key issue involving differences between the large-$N$ limit in the dual field theory and typical large volume thermodynamic limits.

In this paper, we study the collapse of a massive shell in $2+1$ and $3+1$ dimensional gravity with anti-de Sitter asymptotics. Using the Gauss–Codazzi method, we derive gravitational equations of motion of the shell. We then use the functional Schrödinger formalism to calculate the spectrum of particles produced during the collapse. At the late time, radiation agrees very well with the standard Hawking results. In $3+1$ dimensions, we reproduce the Hawking-Page transition. We then construct the density matrix of this collapsing system and analyze the information content in the emitted radiation. We find that the off-diagonal elements of the density matrix are very important in preserving the unitarity of the system.

Premetric electrodynamics is a covariant framework for electromagnetism with a general constitutive relation. Its light-cone structure can be more complicated than that of Maxwell theory as is shown by the phenomenon of birefringence. We study the energy density of quantized premetric electrodynamics theories with linear constitutive relations admitting a single hyperbolicity double cone and show that averages of the energy density along the worldlines of suitable observers obey a quantum energy inequality (QEI) in states that satisfy a microlocal spectrum condition. The worldlines must meet two conditions: (a) the classical weak energy condition must hold along them, and (b) their velocity vectors have positive contractions with all positive frequency null covectors (we call such trajectories “subluminal”). After stating our general results, we explicitly quantize the electromagnetic potential in a translationally invariant uniaxial birefringent crystal. Since the propagation of light in such a crystal is governed by two nested light cones, the theory shows features absent in ordinary (quantized) Maxwell electrodynamics. We then compute a QEI bound for worldlines of inertial subluminal observers, which generalizes known results from the Maxwell theory. Finally, it is shown that the QEIs fail along trajectories that have velocity vectors which are timelike with respect to only one of the light cones.

Topologically protected superfluid phases of ${}^3\mathrm{He}$ allow one to simulate many important aspects of relativistic quantum field theories and quantum gravity in condensed matter. Here we discuss a topological Lifshitz transition of the effective quantum vacuum in which the determinant of the tetrad field changes sign through a crossing to a vacuum state with a degenerate fermionic metric. Such a transition is realized in polar distorted superfluid ${}^3\mathrm{He}\text{−}\mathrm{A}$ in terms of the effective tetrad fields emerging in the vicinity of the superfluid gap nodes: the tetrads of the Weyl points in the chiral A-phase of ${}^3\mathrm{He}$ and the degenerate tetrad in the vicinity of a Dirac nodal line in the polar phase of ${}^3\mathrm{He}$. The continuous phase transition from the $A$-phase to the polar phase, i.e., the transition from the Weyl nodes to the Dirac nodal line and back, allows one to follow the behavior of the fermionic and bosonic effective actions when the sign of the tetrad determinant changes, and the effective chiral spacetime transforms to antichiral “anti-spacetime.” This condensed matter realization demonstrates that while the original fermionic action is analytic across the transition, the effective action for the orbital degrees of freedom (pseudo-EM) fields and gravity have nonanalytic behavior. In particular, the action for the pseudo-EM field in the vacuum with Weyl fermions (A-phase) contains the modulus of the tetrad determinant. In the vacuum with the degenerate metric (polar phase) the nodal line is effectively a family of $2+1\mathrm{d}$ Dirac fermion patches, which leads to a non-analytic $(B^2-E^2{)}^{3/4}$ QED action in the vicinity of the Dirac line.

We investigate the effect of a uniform magnetic field background on scalar QED pair production in a four-dimensional de Sitter spacetime (${\mathrm{dS}}_4$). We obtain a pair production rate which agrees with the known Schwinger result in the limit of Minkowski spacetime and with Hawking radiation in dS spacetime in the zero electric field limit. Our results describe how the cosmic magnetic field affects the pair production rate in cosmological setups. In addition, using the zeta function regularization scheme we calculate the induced current and examine the effect of a magnetic field on the vacuum expectation value of the current operator. We find that, in the case of a strong electromagnetic background the current responds as $E·B$, while in the infrared regime, it responds as $B/E$, which leads to a phenomenon of infrared hyperconductivity. These results for the induced current have important applications for the cosmic magnetic field evolution.