We prove that in $(3+1)d$ quantum field theories with ${\mathbb{Z}}_N$ symmetry, certain anomalies forbid a symmetry-preserving vacuum state with a gapped spectrum. In particular, this applies to discrete chiral symmetries which are frequently present in gauge theories as we illustrate in examples. Our results also constrain the long-distance behavior of certain condensed matter systems such as Weyl-semimetals and may have applications to crystallographic phases with symmetry protected topological order. These results may be viewed as analogs of the Lieb-Schultz-Mattis theorem for continuum field theories.

The deviations of nonlinear perturbations of black holes from the linear case are important in the context of ringdown signals with large signal-to-noise ratio. To facilitate a comparison between the two we derive several results of linear perturbation theory in coordinates which may be adopted in numerical work. Specifically, our results are derived in Kerr-Schild coordinates adjusted by a general height function. In the first part of the paper we address the questions: for an initial configuration of a massless scalar field, what is the amplitude of the excited quasinormal mode (QNM) for any observer outside the event horizon, and furthermore what is the resulting tail contribution? This is done by constructing the full Green’s function for the problem with exact solutions of the confluent Heun equation satisfying appropriate boundary conditions. In the second part of the paper, we detail new developments to our pseudospectral numerical relativity code bamps to handle scalar fields. In the linear regime we employ precisely the Kerr-Schild coordinates treated by our previous analysis. In particular, we evolve pure QNM type initial data along with several other types of initial data and report on the presence of overtone modes in the signal.

We study the image formation process with the solar gravitational lens (SGL) in the case of an extended, resolved source. An imaging telescope, modeled as a convex lens, is positioned within the image cylinder formed by the light received from the source. In the strong interference region of the SGL, this light is greatly amplified, forming the Einstein ring around the Sun, representing a distorted image of the extended source. We study the intensity distribution within the Einstein ring observed in the focal plane of the convex lens. For any particular telescope position in the image plane, we model light received from the resolved source as a combination of two signals: light received from the directly imaged region of the source and light from the rest of the source. We also consider the case when the telescope points away from the extended source or, equivalently, it observes light from sources in sky positions that are some distance away from the extended source but still in its proximity. At even larger distances from the optical axis, in the weak interference or geometric optics regions, our approach recovers known models related to microlensing but now obtained via the wave-optical treatment. We then derive the power of the signal and related photon fluxes within the annulus that contains the Einstein ring of the extended source, as seen by the imaging telescope. We discuss the properties of the deconvolution process, especially its effects on noise in the recovered image. We compare anticipated signals from realistic exoplanetary targets against estimates of noise from the solar corona and estimate integration times needed for the recovery of high-quality images of faint sources. The results demonstrate that the SGL offers a unique, realistic capability to obtain resolved images of exoplanets in our Galactic neighborhood.

We study the future prospects of the 21 cm forest observations on the axionlike dark matter when the spontaneous breaking of global Peccei-Quinn (PQ) symmetry occurs after the inflation. The large isocurvature perturbations of order unity sourced from axionlike particles can result in the enhancement of minihalo formation, and the subsequent hierarchical structure formation can affect the minihalo abundance whose masses can exceed $\mathcal{O}({10}^4)M_{\odot }$ relevant for the 21 cm forest observations. We show that the 21 cm forest observations are capable of probing the axionlike particle mass in the range ${10}^{-18}\lesssim m_a\lesssim {10}^{-12}\mathrm{eV}$ for the temperature independent axion mass. For the temperature dependent axion mass, the zero temperature axion mass scale for which the 21 cm forest measurements can be affected is extended further to as big as of order ${10}^{-6}\mathrm{eV}$.

Despite recent developments, there are a number of conceptual issues on the hadronic light-by-light (HLbL) contribution to the muon ($g-2$) which remain unresolved. One of the most controversial ones is the precise way in which short-distance constraints get saturated by resonance exchange, particularly in the so-called Melnikov-Vainshtein limit. In this paper we address this and related issues from a novel perspective, employing a warped five-dimensional model as a tool to generate a consistent realization of QCD in the large-$N_c$ limit. This approach differs from previous ones in that we can work at the level of an effective action, which guarantees that unitarity is preserved and the chiral anomaly is consistently implemented at the hadronic level. We use the model to evaluate the inclusive contribution of Goldstone modes and axial-vector mesons to the HLbL. We find that both anomaly matching and the Melnikov-Vainshtein constraint cannot be fulfilled with a finite number of resonances (including the pion) and instead require an infinite number of axial-vector states. Our numbers for the HLbL point at a non-negligible role of axial-vector mesons, which is closely linked to a correct implementation of QCD short-distance constraints.

We outline a strategy to compute deeply inelastic scattering structure functions using a hybrid quantum computer. Our approach takes advantage of the representation of the fermion determinant in the QCD path integral as a quantum mechanical path integral over $0+1$-dimensional fermionic and bosonic worldlines. The proper time evolution of these worldlines can be determined on a quantum computer. While extremely challenging in general, the problem simplifies in the Regge limit of QCD, where the interaction of the worldlines with gauge fields is strongly localized in proper time and the corresponding quantum circuits can be written down. As a first application, we employ the color glass condensate effective theory to construct the quantum algorithm for a simple dipole model of the $F_2$ structure function. We outline further how this computation scales up in complexity and extends in scope to other real-time correlation functions.

The tau neutrino is probably the least studied particle in the standard model (SM), with only a handful of interaction events being identified so far. This can in part be attributed to their small production rate in the SM, which occurs mainly through $D_s$ meson decay. However, this also makes the tau neutrino flux measurement an interesting laboratory for additional new physics production modes. In this study, we investigate the possibility of tau neutrino production in the decay of light vector bosons. We consider four scenarios of anomaly-free $U(1)$ gauge groups corresponding to the $B-L$, $B-L_{\mu }-2L_{\tau }$, $B-L_e-2L_{\tau }$, and $B-3L_{\tau }$ numbers, analyze current constraints on their parameter spaces, and explore the sensitivity of DONuT as well as the future emulsion detector experiments $\mathrm{FASER}\nu$, SND@LHC, and SND@SHiP. We find that these experiments provide the leading direct constraints in parts of the parameter space, especially when the vector boson’s mass is close to the mass of the $\omega$ meson.

We consider dark sectors with spontaneously broken gauge symmetries, where cascade decays of the dark sector fields naturally produce multi-Higgs boson final states along with dark matter. Our study focuses on two and three Higgs boson final states with missing energy using a multivariate analysis with boosted decision trees. We find that the di-Higgs boson channel is quite promising for the $\overline{b}b+\gamma \gamma$ and $\overline{b}b+\overline{\ell }\ell$ decay modes. The tri-Higgs boson final state with missing energy, on the other hand, appears to be beyond the reach of the LHC in analogous channels. This may change when fully hadronic Higgs boson decays are considered.

The parton distribution functions (PDFs) of heavy mesons are evaluated from their light-front wave functions, which are obtained from a basis light-front quantization in the leading Fock sector representation. We consider the mass eigenstates from an effective Hamiltonian consisting of the confining potential adopted from light-front holography in the transverse direction, a longitudinal confinement, and a one-gluon exchange interaction with running coupling. We present the gluon and the sea quark PDFs which we generate dynamically from the QCD evolution of the valence quark distributions.

Exclusive decays of the ${\mathrm{\Xi }}_{bc}^{+}$ with light meson production, ${\mathrm{\Xi }}_{bc}^{+}\to {\mathrm{\Xi }}_{cc}^{++}\mathcal{R}$, are analyzed. In the framework of the factorization model, the matrix elements of the considered reactions are written as a product of ${\mathrm{\Xi }}_{bc}\to {\mathrm{\Xi }}_{cc}W$ and $W\to \mathcal{R}$ transition amplitudes. As a result, theoretical and experimental investigation of these decays allows us to test the physics of heavy and light quark sectors. Presented are the branching fractions of these reactions, as well as the distributions over the invariant mass of the light system and some other kinematical variables. Our calculations show that the probabilities of the considered reactions are high enough, so presented results could help with observations of the yet unseen ${\mathrm{\Xi }}_{bc}$ baryon.

In this article, we take the pseudoscalar, scalar, axialvector, vector, tensor (anti)diquark operators as the basic constituents and construct the scalar, axialvector, and tensor tetraquark currents to study the mass spectrum of the ground state hidden-charm tetraquark states with the QCD sum rules in a comprehensive way. We revisit the assignments of the $X$, $Y$, $Z$ states, such as the $X(3860)$, $X(3872)$, $X(3915)$, $X(3940)$, $X(4160)$, $Z_c(3900)$, $Z_c(4020)$, $Z_c(4050)$, $Z_c(4055)$, $Z_c(4100)$, $Z_c(4200)$, $Z_c(4250)$, $Z_c(4430)$, $Z_c(4600)$, etc. in the scenario of tetraquark states in a consistent way based on the QCD sum rules. Furthermore, we discuss the feasibility of applying the QCD sum rules to study the tetraquark states and tetraquark molecular states (more precisely, the color-singlet-color-singlet type tetraquark states), which begin to receive contributions at the order $\mathcal{O}({\alpha }_s^0)$, not at the order $\mathcal{O}({\alpha }_s^2)$.

We study the evolution of the longitudinal expansion of an ideal fluid with finite electrical conductivity, which is subject to the electromagnetic (EM) fields. In the framework of resistive relativistic magnetohydrodynamics, we find an exact analytical solution for the EM fields and for the acceleration of the fluid.

We present a dispersive analysis with the aim to extract the $\mathrm{\Upsilon }\text{−}p$ scattering length from $\gamma p\to \mathrm{\Upsilon }p$ experiments. In this framework, the imaginary part of the $\mathrm{\Upsilon }\text{−}p$ forward scattering amplitude is obtained from $\gamma p\to \mathrm{\Upsilon }p$ cross section measurements and is constrained at high energies from existing HERA and LHC data. Its real part is calculated through a once-subtracted dispersion relation, and the subtraction constant is proportional to the $\mathrm{\Upsilon }\text{−}p$ scattering length. We perform a feasibility study for $\mathrm{\Upsilon }$ photoproduction experiments at an Electron-Ion Collider and discuss the sensitivity and precision that can be reached in the extraction of the $\mathrm{\Upsilon }\text{−}p$ scattering length.

We report the first electron neutrino cross section measurements on argon, based on data collected by the ArgoNeuT experiment running in the GeV-scale NuMI beamline at Fermilab. A flux-averaged ${\nu }_e+{\overline{\nu }}_e$ total and a lepton angle differential cross section are extracted using 13 ${\nu }_e$ and ${\overline{\nu }}_e$ events identified with fully automated selection and reconstruction. We employ electromagnetic-induced shower characterization and analysis tools developed to identify ${\nu }_e/{\overline{\nu }}_e$-like events among complex interaction topologies present in ArgoNeuT data ($⟨E_{{\overline{\nu }}_e}⟩=4.3\mathrm{GeV}$ and $⟨E_{{\nu }_e}⟩=10.5\mathrm{GeV}$). The techniques are widely applicable to searches for electron-flavor appearance at short and long baseline using liquid argon time projection chamber technology. Notably, the data-driven studies of GeV-scale ${\nu }_e/{\overline{\nu }}_e$ interactions presented here probe an energy regime relevant for future DUNE oscillation physics.

We argue that the following three statements cannot all be true: (i) our vacuum is a type IIB/F-theory vacuum at moderate to large $h^{1,1}$; (ii) the ${\alpha }^{\prime }$ expansion is controlled via the supergravity approximation, à la the Kachru-Kallosh-Linde-Trivedi and Large Volume scenarios; and (iii) there are no additional gauged sectors from 7-branes. Since nearly all known globally consistent F-theory models with the exact chiral spectrum of the Standard Model and gauge coupling unification occur at moderate $h^{1,1}$, this finding calls for new moduli stabilization scenarios or/and a rich 7-brane dark sector.

Among the solutions of string theory and supergravity which preserve some fraction of supersymmetry, the best known are those that leave one half of the supersymmetry unbroken, and there is a large number of field theory models with this pattern of supersymmetry breaking. However, a lot of brane configurations exist which preserve only $1/4$, $1/8$, or more exotic fractions of supersymmetry, and field theory side of these systems remains largely unexplored. To find whether the formalism of nonlinear realizations is useful in construction of models of this type, we consider the systems of some $N_0$ scalar and vector $N=1$, $d=3$ Goldstone supermultiplets. We find that it is possible to construct an $SO(N_0)$ invariant theory of $N_0$ scalar multiplets with $N_0$ broken supersymmetries. For $N_0=3$ or $N_0\ge 5$ its action is not of Nambu-Goto type and its structure remains universal for arbitrary $N_0$. The cases of $N_0=1$, 2 correspond to the membranes in $D=4$ and $D=5$, respectively, while for $N_0=4$ some arbitrariness in the action remains, and with proper choice of parameters, it is possible to obtain the action of the membrane in $D=7$ in the bosonic limit. It is also shown that the $SO(N_0)$ invariant action of $N_0$ vector multiplets with $1/N_0$ pattern of supersymmetry breaking does not exist for arbitrary $N_0$.

We address questions regarding construction and implications of gauge-invariant “dressed” observables in nontrivial background geometries such as that of a black hole. Formally, such observables can be constructed, e.g., by locating points with geodesics launched from infinity. However, practical complications arise in nontrivial geometries, and in particular for observables behind black hole horizons. Greater simplicity can be achieved by considering null constructions where the dressing lies along a null geodesic, or null surface such as a cone. We first investigate basic properties of these null dressings in the simpler context of electromagnetism. Since null constructions provide simple dressings for gauge-invariant observables inside black holes, they also allow us to investigate the question of compatibility of observables inside and outside black holes, and in particular the idea of black hole complementarity. While such observables in general have nonvanishing state-dependent commutators, the failure to commute does not appear particularly enhanced by the presence of the horizon.

Radially excited $U(1)$ gauged $Q$-balls are studied using both analytical and numerical methods. Unlike the nongauged case, there exists only a finite number of radially excited gauged $Q$-balls at given values of the model’s parameters. Similarly to the unexcited gauged $Q$-ball, the radially excited one cannot possess the Noether charge exceeding some limiting value. This limiting Noether charge decreases with an increase in the radial excitation of the gauged $Q$-ball. For $n$th radial excitation, there is a maximum allowable value of the gauge coupling constant, and the existence of the $n$th radially excited gauged $Q$-ball becomes impossible if the gauge coupling constant exceeds this limiting value. Similarly to the limiting Noether charge, the limiting gauge coupling constant decreases with an increase in the radial excitation. At a fixed Noether charge, the energy of the gauged $Q$-ball increases with an increase in the radial excitation, and thus the radially excited gauged $Q$-ball is unstable against transit into a less excited or unexcited one.