We discuss bounds to strong gravity arising from annihilation of electron and positrons and the corresponding enhancement of the cross section for the production of massive particles. Two complementary examples are discussed, the case of the $e^{+}{e}^{-}\to W^{+}{W}^{-}$ processes, with maximum mass and short lifetime for the particle pairs in the final state, and the case of electron positron annihilation into heavier charged lepton pairs, $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}$ and $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}$. These bounds may be improved by the next generation of electron-positron colliders, and are complementary to bounds arising from direct graviton searches.

The static QCD force from the lattice can be used to extract ${\mathrm{\Lambda }}_{\overline{\mathrm{MS}}}$, which determines the running of the strong coupling. Usually, this is done with a numerical derivative of the static potential. However, this introduces additional systematic uncertainties; thus, we use another observable to measure the static force directly. This observable consists of a Wilson loop with a chromoelectric field insertion. We work in the pure SU(3) gauge theory. We use gradient flow to improve the signal-to-noise ratio and to address the field insertion. We extract ${\mathrm{\Lambda }}_{\overline{\mathrm{MS}}}^{n_f=0}$ from the data by exploring different methods to perform the zero-flow-time limit. We obtain the value $\sqrt{8t_0}{\mathrm{\Lambda }}_{\overline{\mathrm{MS}}}^{n_f=0}=0.629_{-26}^{+22}$, where $t_0$ is a flow-time reference scale. We also obtain precise determinations of several scales: $r_0/r_1$, $\sqrt{8t_0}/r_0$, $\sqrt{8t_0}/r_1$, and we compare these to the literature. The gradient flow appears to be a promising method for calculations of Wilson loops with chromoelectric and chromomagnetic insertions in quenched and unquenched configurations.

We analyze the dependence of the chiral phase transition temperature on baryon number and strangeness chemical potentials by calculating the leading order curvature coefficients in the light and strange quark flavor basis as well as in the conserved charge ($B$, $S$) basis. Making use of scaling properties of the magnetic equation of state (MEoS) and including diagonal as well as off-diagonal contributions in the expansion of the energylike scaling variable that enters the parametrization of the MEoS, allows to explore the variation of $T_c({\mu }_B,{\mu }_S)=T_c(1-({\kappa }_2^B{\widehat{\mu }}_B^2+{\kappa }_2^S{\widehat{\mu }}_S^2+2{\kappa }_{11}^{BS}{\widehat{\mu }}_B{\widehat{\mu }}_S))$ along different lines in the $({\mu }_B,{\mu }_S)$ plane. On lattices with fixed cutoff in units of temperature, $aT=1/8$, we find ${\kappa }_2^B=0.015(1)$, ${\kappa }_2^S=0.0124(5)$ and ${\kappa }_{11}^{BS}=-0.0050(7)$. We show that the chemical potential dependence along the line of vanishing strangeness chemical potential is about 10% larger than along the strangeness neutral line. The latter differs only by about 3% from the curvature on a line of vanishing strange quark chemical potential, ${\mu }_s=0$. We also show that close to the chiral limit the strange quark mass contributes like an energylike variable in scaling relations for pseudocritical temperatures. The chiral phase transition temperature decreases with decreasing strange quark mass, $T_c(m_s)=T_c(m_s^{\mathrm{phy}})(1-0.097(2)(m_s-m_s^{\text{phys}})/m_s^{\mathrm{phy}}+\mathcal{O}((\mathrm{\Delta }{m}_s{)}^2)$.

Lattice quantum chromodynamics (LQCD) calculations with physical pion mass would revolutionize nuclear physics by enabling predictions based on the fundamental theory of the strong force. To bridge the gap between finite-volume LQCD results and free-space physical observables, two primary extrapolation methods have been employed so far. The traditional approach relies on the Lüscher formula and its extensions, while a recent alternative employs effective field theories (EFTs) fitted directly to the finite volume data. In this study, we fit pionless EFT with perturbative inclusion of the next-to-leading order to finite-volume energies generated from a phenomenological $NN$ interaction. The theory is then used to extrapolate the finite-volume results into free space as well as to predict new few-body observables. As a benchmark, we also apply the Lüscher formalism directly to the finite-volume data. Through a comprehensive analysis, we explore the characteristics of order-by-order predictions of the pionless EFT fitted within a finite volume, investigate the limitations of the different extrapolation techniques used, and derive recommended box sizes required for reliable predictions.

Neutrinoless double-beta ($0\nu \beta \beta$) decay is a heretofore unobserved process which, if observed, would imply that neutrinos are Majorana particles. Interpretations of the stringent experimental constraints on $0\nu \beta \beta$-decay half-lives require calculations of nuclear matrix elements. This work presents the first lattice quantum chromodynamics (LQCD) calculation of the matrix element for $0\nu \beta \beta$ decay in a multinucleon system, specifically the $nn\to ppee$ transition, mediated by a light left-handed Majorana neutrino propagating over nuclear-scale distances. This calculation is performed with quark masses corresponding to a pion mass of $m_{\pi }=806\mathrm{MeV}$ at a single lattice spacing and volume. The statistically cleaner ${\mathrm{\Sigma }}^{-}\to {\mathrm{\Sigma }}^{+}ee$ transition is also computed in order to investigate various systematic uncertainties. The prospects for matching the results of LQCD calculations onto a nuclear effective field theory to determine a leading-order low-energy constant relevant for $0\nu \beta \beta$ decay with a light Majorana neutrino are investigated. This work, therefore, sets the stage for future calculations at physical values of the quark masses that, combined with effective field theory and nuclear many-body studies, will provide controlled theoretical inputs to experimental searches of $0\nu \beta \beta$ decay.

QCD sum rules for positive and negative parity heavy baryons in the heavy quark limit are formulated. We apply the method to $\mathrm{\Lambda }$ and $\mathrm{\Sigma }$ channels. We include the next-to-leading order corrections in ${\alpha }_s$-expansion to dimension 0 and 3 terms in the operator product expansion. The corrections lead to the considerable reduction of the predicted masses and significantly improves the stability with respect to the Borel parameter, especially for negative parity states. It is also found that, in the heavy quark limit, chiral odd condensates do not contribute to the negative parity states.

We construct the equation of state (EOS) of QCD based on the finite chemical potential information from the functional QCD approaches with the results at zero chemical potential being calibrated by lattice QCD simulations. Specifically, the construction is achieved by parametrizing the order parameters from the functional QCD data into the EOS, namely, the dynamical quark mass for the chiral phase transition and the Polyakov loop for the deconfinement phase transition. The obtained EOS is consistent with the up-to-date results of the QCD phase diagram, including a phase transition temperature at zero chemical potential of $T=155\mathrm{MeV}$, the curvature of the transition line $\kappa =0.016$, and also a critical end point at $(T,{\mu }_B)=(118,600)\mathrm{MeV}$. We also implement the EOS in hydrodynamic simulations to compute the particle yields and ratios and find that our obtained EOS agrees well with the commonly used one based on the combination of lattice QCD simulation and hadron resonance gas model.

In this analysis, the so-called holographic graviton soft-wall (GSW) model, first developed to investigate the glueball spectrum, has been adopted to predict the masses of hybrids with different quantum numbers. Results have been compared with other models and lattice calculations. We have extended the GSW model by introducing two modifications based on anomalous dimensions in order to improve our agreement with other calculations and to remove the initial degeneracy not accounted for by lattice predictions. These modifications do not involve new parameters. The next step has been to identify which of our calculated states agree with the PDG data, leading to experimental hybrids. The procedure has been extended to include hybrids made of heavy quarks by incorporating the quark masses into the model.

Considering that the study of neutrino-nucleus interactions with incident neutrino energy ranges in the GeV–TeV range is feasible at the Large Hadron Collider, we investigate in this paper the degree of polarization $\mathcal{P}$ of the (anti)tau lepton produced in (anti)tau neutrino-tungsten interactions. We estimate the differential cross sections and the longitudinal and transverse components of the tau lepton polarization as a function of the tau lepton energy and distinct values of the scattering angle, assuming different values for the energy of the incoming (anti)tau neutrino. Different models for the treatment of the nuclear effects in the parton distribution functions are assumed as input in the calculations. Our results indicate that $\mathcal{P}<1$ for the neutrino energies reached at the LHC and are almost insensitive to the nuclear effects.

The decays of the Higgs boson produce a state in which the spins of the decay products and the orbital angular momentum ($L$) are highly entangled. We obtain the tripartite density operator, as well as reduced operators, for the decay into two weak bosons. For $H\to ZZ$ in the four-lepton final state we also estimate the statistical sensitivity at the Large Hadron Collider and future upgrades, using a binned method to reconstruct the density operators from distributions. With the expected Run 3 data, establishing genuine tripartite entanglement would be possible beyond the $5\sigma$ level. The violation of Bell inequalities involving the spins of the two weak bosons could also be established beyond the $5\sigma$ level.

Various dark matter search experiments employ phonon-based crystal detectors operated at cryogenic temperatures. Some of these detectors, including certain silicon detectors used by the SuperCDMS Collaboration, are able to achieve single-charge sensitivity when a voltage bias is applied across the detector. The total amount of phonon energy measured by such a detector is proportional to the number of electron-hole pairs created by the interaction. However, crystal impurities and surface effects can cause propagating charges to either become trapped inside the crystal or create additional unpaired charges, producing nonquantized measured energy as a result. A new analytical model for describing these detector response effects in phonon-based crystal detectors is presented. This model improves upon previous versions by demonstrating how the detector response, and thus the measured energy spectrum, is expected to differ depending on the source of events. We use this model to extract detector response parameters for SuperCDMS HVeV detectors, and illustrate how this robust modeling can help statistically discriminate between sources of events in order to improve the sensitivity of dark matter search experiments.

Measurements of the substructure of top-quark jets are presented, using $140{\mathrm{fb}}^{-1}$ of 13 TeV $pp$ collision data recorded with the ATLAS detector at the LHC. Top-quark jets reconstructed with the anti-$k_t$ algorithm with a radius parameter $R=1.0$ are selected in top-quark pair ($t\overline{t}$) events where one top quark decays semileptonically and the other hadronically, or where both top quarks decay hadronically. The top-quark jets are required to have transverse momentum $p_{\mathrm{T}}>350\mathrm{GeV}$, yielding large samples of data events with jet $p_{\mathrm{T}}$ values between 350 and 600 GeV. One- and two-dimensional differential cross sections for eight substructure variables, defined using only the charged components of the jets, are measured in a particle-level phase space by correcting for the smearing and acceptance effects induced by the detector. The differential cross sections are compared with the predictions of several Monte Carlo simulations in which top-quark pair-production quantum chromodynamic matrix-element calculations at next-to-leading-order precision in the strong coupling constant ${\alpha }_{\mathrm{S}}$ are passed to leading-order parton shower and hadronization generators. The Monte Carlo predictions for measures of the broadness, and also the two-body structure, of the top-quark jets are found to be in good agreement with the measurements, while variables sensitive to the three-body structure of the top-quark jets exhibit some tension with the measured distributions.

The nonequilibrium process where the system does not evolve to the featureless state, that without quantum properties, is one of the new central objects in the nonequilibrium phenomena. In this paper, starting from the short-range entangled state in the two-dimensional conformal field theories (2D CFTs), the boundary state with a regularization, we evolve the system with the inhomogeneous Hamiltonians called Möbius/sine-square-deformed (SSD) ones. Regardless of the details of CFTs considered in this paper, during the Möbius evolution, the entanglement entropy exhibits the periodic motion called quantum revival. During SSD time evolution, except for some subsystems, in the large time regime, entanglement entropy and mutual information are approximated by those for the vacuum state. We argue the time regime for the subsystem to cool down to vacuum one is $t_1\gg \mathcal{O}(L\sqrt{l_A})$, where $t_1$, $L$, and $l_A$ are time, system, and subsystem sizes. This finding suggests the inhomogeneous quench induced by the SSD Hamiltonian may be used as the preparation for the approximately vacuum state. We propose the gravity dual of the systems considered in this paper, furthermore, and generalize it. In addition to them, we discuss the relation between the inhomogeneous quenches and continuous multiscale entanglement renormalization ansatz (cMERA).

We consider the Penrose process with the charged particles in the Reissner-Nordström background. Let parent particle 0 decay to particles 1 and 2. With the assumption that all three particles move in the equatorial plane, the exact formulas for characteristics of particles 1 and 2 in terms of those of particle 0 are derived. We concentrate on scenarios in which particle 1 and 2 are ejected along the trajectory of particle 0. It is shown that such scenarios correspond to the extrema of energies $E_1$ or $E_2$ of daughter particles with respect to the angular momentum $L_1$ or $L_2$. We derive bounds on the values of angular momenta $L_1$ and $L_2$. We give classification of these scenarios and discuss their properties including decay in the near-horizon region. We find that the maximum of efficiency is achieved on the horizon for some of these scenarios but not for all of them and with additional constraints on particle parameters. The results are reformulated in terms of velocities of daughter particles in the center of mass frame. The approach is applicable also to collisional Penrose process, in which a combination of particles 1 and 2 is considered as one effective particle. If the mass of particle 0 $m_0\to \infty$, then the situation corresponds to the Bañados-Silk-West effect, the results agree with the ones known in literature before. In addition, we consider special cases when decay occurs in the turning point for one or all three particles. The formalism developed in this work has a model-independent character and applies not only to the Reissner-Nordström metric.

Currently envisioned extensions of the Event Horizon Telescope to space will soon target the black hole photon ring: a narrow ring-shaped imprint of a black hole’s strong gravity produced in its images by highly bent photon trajectories. In principle, the shape of the photon ring encodes information about the geometry of the underlying black hole spacetime. In practice, however, whether or not this information can be extracted from the ring shape depends on several factors, ranging from the astrophysical details of the emitting source (such as the magnitude of its plasma fluctuations) to the specific configuration of the interferometric array (such as the separation between its telescopes, or the level of noise in its instruments). Here, we employ a phenomenological model to assess the impact of astrophysical fluctuations and instrument noise on the inferred shape of the photon ring. Our systematic study of several astrophysical profiles suggests that this shape can be measured even in the presence of instrument noise across a wide range of baselines. The measurement accuracy and precision appear relatively insensitive to the noise level, up to a sharp threshold beyond which any measurement becomes incredibly challenging (at least without recourse to more sophisticated data analysis methods). Encouragingly, we find that only a few snapshot images are generally needed to overcome the impact of astrophysical fluctuations and correctly infer the ring diameter. Inference becomes more challenging when analyzing the visibility amplitude in a baseline window that is not entirely dominated by a single photon ring. Nevertheless, in most cases, it is still possible to fit a ring shape with the correct fractional asymmetry. These results provide excellent prospects for future precision measurements of black hole spin and fundamental astrophysics via black hole imaging.

We consider slowly rotating Ellis-Bronnikov wormholes and investigate their radial perturbations ($\mathrm{l}=0$), expanding up to second order in rotation. We present the detailed derivations in the general case, including symmetric and nonsymmetric wormholes. The calculations show that the unstable mode present in the static case becomes less unstable with increasing rotation, until it reaches zero and then disappears. This indicates that wormhole solutions may become linearly mode stable at sufficiently fast rotation.

Recent gravitational wave (GW) observations have enabled us to look beyond the standard paradigm of gravitational physics, namely general relativity (GR). Along with the mass and the angular momentum, which typical astrophysical black holes (BHs) are endowed with, theories beyond GR generically induce charge to these BHs. Notably, for BHs carrying the extra charge hair, we expect the BH absorption effects to modify accordingly and alter the tidal heating terms. Hence, the inclusion of the corrections in the GW waveform model, arising from the BH charge, allows us to test the consistency of the observed binaries with Kerr BHs in GR. We compute the explicit dependence of the binary inspiral phase on the charge parameter arising from the tidal heating effect and study the measurability of the same from GW observations of binary mergers. Specifically, we employ the taylorf2 waveform model, which accurately models the inspiral evolution of an aligned-spin binary merger, and Bayesian analysis-based GW data inference to measure the charge parameter for a selected set of detected binaries. We also present a detailed simulation study to investigate the possibility of measuring the charge parameter from binaries with different masses, spins and source locations. The analysis of selected GW events from the third GW transient catalog shows that the charge parameter constraints are poor from the observed signals with the current sensitivity. In contrast, the simulation studies indicate that the spinning binaries with significant mass asymmetry provide the best constraints on the BH charge parameter. Finally, we study the prospects of measuring the BH charge parameter from a future GW detector with improved sensitivity.

The high-precision description of black hole scattering in classical general relativity using the post-Minkowskian (PM) expansion requires the evaluation of single-scale Feynman integrals at increasing loop orders. Up to 4PM, the scattering angle and the impulse are expressible in terms of polylogarithmic functions and Calabi-Yau (CY) twofold periods. As in QFT, periods of higher dimensional CY $n$-folds are expected at higher PM order. We find at 5PM in the dissipative leading order self-force sector (5PM-1SF) that the only nonpolylogarithmic functions are the K3 periods encountered before and the ones of a new hypergeometric CY threefold. In the 5PM-2SF sector further CY twofold and threefold periods appear. Griffiths transversality of the CY period motives allows one to transform the differential equations for the master integrals into $\epsilon$-factorized form and to solve them in terms of a well-controlled function space, as we demonstrate in the 5PM-1SF sector.

The propagation of gravitational waves can be described in terms of null geodesics by using the geometrical optics approximation. However, at large but finite frequencies the propagation is affected by the spin-orbit coupling corrections to geometrical optics, known as the gravitational spin Hall effect. Consequently, gravitational waves follow slightly different frequency- and polarization-dependent trajectories, leading to dispersive and birefringent phenomena. We study the potential for detecting the gravitational spin Hall effect in hierarchical triple black hole systems, consisting of an emitting binary orbiting a more massive body acting as a gravitational lens. We calculate the difference in time of arrival with respect to the geodesic propagation and find that it follows a simple power-law dependence on frequency with a fixed exponent. We calculate the gravitational spin Hall-corrected waveform and its mismatch with respect to the original waveform. The waveform carries a measurable imprint of the strong gravitational field if the source, lens, and observer are sufficiently aligned, or for generic observers if the source is close enough to the lens. We present constraints on dispersive time delays from GWTC-3, translated from limits on Lorentz invariance violation. Finally, we address the sensitivity of current and future ground detectors to dispersive lensing. Our results demonstrate that the gravitational spin Hall effect can be detected, providing a novel probe of general relativity and the environments of compact binary systems.