We investigate the expected precision of the reconstructed neutrino direction using a ${\nu }_{\mu }$-argon quasielasticlike event topology with one muon and one proton in the final state and the reconstruction capabilities of the MicroBooNE liquid argon time projection chamber. This direction is of importance in the context of DUNE sub-GeV atmospheric oscillation studies. MicroBooNE allows for a data-driven quantification of this resolution by investigating the deviation of the reconstructed muon-proton system orientation with respect to the well-known direction of neutrinos originating from the Booster Neutrino Beam with an exposure of $1.3\times {10}^{21}$ protons on target. Using simulation studies, we derive the expected sub-GeV DUNE atmospheric-neutrino reconstructed simulated spectrum by developing a reweighting scheme as a function of the true neutrino energy. We further report flux-integrated single- and double-differential cross section measurements of charged-current ${\nu }_{\mu }$ quasielasticlike scattering on argon as a function of the muon-proton system angle using the full MicroBooNE data sets. We also demonstrate the sensitivity of these results to nuclear effects and final state hadronic reinteraction modeling.

In this Letter, we demonstrate that $T$-odd and $T$-even correlations, with $T$ representing time reversal, when satisfying specific conditions, result, respectively, in cosine and sine strong phase dependencies of the corresponding $CP$ violation. Additionally, we identify pairs of these $CP$ violation observables in hadron decays depend on precisely the same strong phases within the helicity amplitude scheme. This complementarity could reduce the strong phase reliance in the study of $CP$ violation while also mitigating the risk of suppressed $CP$ violation due to exceptionally small strong phases. Moreover, our proposal holds broad application prospects in further investigating $CP$ violation in baryon decays, which has recently been discovered in the LHCb experiment.

We study five-dimensional $N=4$ gauged supergravity coupled to three vector multiplets with $SO(2{)}_D\times SO(3)$ gauge group. The gauged supergravity admits two supersymmetric ${\mathrm{AdS}}_5$ vacua. One of the vacua, at the origin of the scalar manifold ${\mathbb{R}}^{+}\times SO(5,3)/SO(5)\times SO(3)$, preserves $N=4$ supersymmetry and the full $SO(2{)}_D\times SO(3)$ gauge symmetry. The second ${\mathrm{AdS}}_5$ vacuum is $N=2$ supersymmetric and invariant under $SO(2{)}_{\mathrm{diag}}$ which is a diagonal subgroup of $SO(2{)}_D$ and $SO(2)\subset SO(3)$. By considering a truncation to $SO(2{)}_{\mathrm{diag}}$ invariant scalars, we find a class of Janus solutions interpolating among these vacua. These solutions should be holographically dual to conformal interfaces within the dual $N=1$ and $N=2$ Superconformal Field Theories (SCFTs) in four dimensions. In addition, we also find examples of solutions describing renormalization group-flow interfaces between $N=1$ and $N=2$ Superconformal Field Theories (SCFTs) on each side of the interfaces. All of the solutions could possibly be uplifted to eleven dimensions by a consistent truncation of M-theory on $M_3\times S^2\times S^1$ with a 3-manifold $M_3$.

The jet quenching parameter and energy loss of light and heavy quarks have been investigated in the framework of holographic quantum chromodynamics (QCD) models with a critical end point (CEP) at finite baryon chemical potential in $N_f=2,2+1,2+1+1$ systems. The properties of the jet quenching parameter and energy loss around phase boundary have been carefully studied. It is found that the dimensionless jet quenching parameter and the energy loss of light and heavy quarks exhibit evident features around the phase boundary. Specifically, all these quantities increase rapidly near the CEP phase transition temperature $T_{\mathrm{CEP}}$ with fixed ${\mu }_{\mathrm{CEP}}$. Moreover, the velocity dependent behavior of heavy quark energy loss differs significantly from charged particle energy loss in quantum electrodynamics (QED) matter. For electromagnetic interaction, the energy loss of charged particle can be described by the Bethe-Bloch formula and the Lindhand-Scharff-Schiott theory at low and high velocities, respectively. However, the heavy quark energy loss at CEP is approximately proportional to velocity at low velocities and aligns with Bjorken’s results at high velocities, which indicates that the heavy quark energy loss is predominantly collisional at low velocities and gluon radiation dominant at high velocities. For light quark energy loss, the behavior of the energy loss per unit length and the total energy loss differs significantly. However, the total energy loss and stopping distance exhibit similar behavior. This implies that the stopping distance predominantly determines the total energy loss. Thus, even with increased energy loss per unit length at higher temperatures or chemical potentials, the total energy loss decreases due to the reduced stopping distance.

We intensively study the nonperturbative quantum correction to the Reissner-Nordström black hole by means of test particles’ bound orbits. By considering circular orbits for a test particle, we present the existence and stability of them in the black hole. It shows that the unstable and stable circular orbits depend on two dimensionless parameters ($q$, $\tilde{w}$). Here, $q$ represents the charge of the black hole, and $\tilde{w}$ comes from a free parameter that can turn the quantum effects on the black hole “off” and “on.” In light of the tremendous progress made by the new generations of the Event Horizon Telescope (EHT) and the near-infrared interferometer GRAVITY, we calculate the radius of the photon sphere and the timelike particle’s precessing orbit, and find a preliminary bound on the free quantum parameter and the charge parameter in the black hole by making use of the results from EHT and GRAVITY together, the values of which are $q=-0.6\pm 1.2$ and $\tilde{w}=0.9\pm 2.3$. With the further improvement and upgrade of EHT and $\mathrm{GRAVITY}+$, it is found that the precision of the future EHT and $\mathrm{GRAVITY}+$ observations might reduce the uncertainties of the parameters and narrow their ranges. We also investigate another method to constrain this black hole using multiple S-stars orbital dynamics in the future. In view of considering predictions of the orbit and radial velocity for other S-stars, our results show that making the pericenter distance smaller and the eccentricity larger will make the position deviations on the sky between the black hole and the Schwarzschild one larger. And the main influence on the position deviations comes from the charge parameter. In comparison to the effect of the charge parameter, the signature of the quantum effect on the black hole may be still “tiny” and cannot realistically be sufficient to be detected on the condition that these experiments are all conducted in the gravitational field of one supermassive body. Searching for Planck sized black holes in the future, such as primordial black holes, might provide a promising way to identify the quantum effect from the signatures of the black hole.

We present a detailed study of the effective stress tensor of a gravitational wave (GW) as the source for the background Einstein equation and examine three candidates in literature. The second order perturbed Einstein tensor $G_{\mu \nu }^{(2)}$, up to a coefficient, proposed by Brill, Hartle, and Isaacson, has long been known to be covariantly nonconserved with respect to the background spacetime. We observe that $G_{\mu \nu }^{(2)}$ is not a true tensor on the background spacetime. More importantly, we find that, by expressing $G_{\mu \nu }^{(2)}$ in terms of the perturbed Hilbert-Einstein actions, the nonconserved part of $G_{\mu \nu }^{(2)}$ is actually canceled out by the perturbed fluid stress tensors in the backreaction equation, or is vanishing in the absence of fluid. The remaining part of $G_{\mu \nu }^{(2)}$ is just the conserved effective stress tensor ${\tau }_{\mu \nu }$ proposed by Ford and Parker. As the main result, we derive ${\tau }_{\mu \nu }$ for a general curved spacetime by varying the GW action and show its conservation using the equation of GW. The stress tensor $T_{\mathrm{MT}}^{\mu \nu }$ proposed by MacCallum and Taub was based on an action $J_2$. We derive $T_{\mathrm{MT}}^{\mu \nu }$ and find that it is nonconserved, and that $J_2$ does not give the correct GW equation in the presence of matter. The difficulty with $J_2$ is due to a background Ricci tensor term, which should be also canceled out by the fluid term or vanishing in the absence of fluid. We also demonstrate these three candidates in a flat Robertson-Walker spacetime. The conserved ${\tau }_{\mu \nu }$ has a positive energy density spectrum, and is adequate for the backreaction in a perturbation scheme, while the two nonconserved stress tensors have a negative spectrum at long wavelengths and are unphysical.

Because of the integrated Sachs-Wolfe (ISW) effect, cosmic microwave background (CMB) temperature and polarization fluctuations are correlated with the gravitational lensing potential. Famously, this induces a CMB three-point function, whose shape can be used to constrain dark energy and modifications to gravity. An analogous effect occurs at higher order, producing an ISW lensing “trispectrum” whose amplitude is hitherto unconstrained. We present a detailed discussion of this effect and define minimum-variance estimators for the ISW lensing three- and four-point functions. These are implemented within the polyspec code and bear strong similarities to the quadratic estimators used in lensing analyses. Applying these tools to Planck, we obtain strong detections of the bispectrum amplitude (consistent with previous works), but find only weak constraints on the trispectrum, due to a strong cancellation between the various ISW-induced contributions. We additionally forecast the constraints from future datasets, finding that (a) simple estimators for the ISW lensing bispectrum will be severely limited by non-Gaussian modifications to the covariance, and (b) the ISW lensing trispectrum will be very challenging to detect even with high-resolution future experiments. We finally consider the induced bias on primordial non-Gaussianity amplitudes (and lensing itself), which we show to be large for the bispectrum (as expected) but negligible for the trispectrum.

Induced gravitational waves provide a powerful probe of primordial perturbations in the early universe through their distinctive spectral properties. We analyze the spectral energy density ${\mathrm{\Omega }}_{\mathrm{GW}}$ of gravitational waves induced by isocurvature scalar perturbations. In the infrared regime, we find that the spectral slope $n_{\mathrm{GW}}\equiv \mathrm{d}\ln {\mathrm{\Omega }}_{\mathrm{GW}}/\mathrm{d}\ln k$ takes the log-dependent form $3-4/\ln ({\tilde{k}}_{*}^2/6k^2)$, where ${\tilde{k}}_{*}$ represents the effective peak scale of the primordial scalar power spectrum. This characteristic behavior differs markedly from that of adiabatic-induced gravitational waves, establishing a robust observational discriminant between isocurvature and adiabatic primordial perturbation modes.

Quantum fields can notoriously violate the null energy condition (NEC). In a cosmological context, NEC violation can lead to, e.g., dark energy at late times with an equation-of-state parameter smaller than $-1$ and nonsingular bounces at early times. However, it is expected that there should still be a limit in semiclasssical gravity to how much “negative energy” can accumulate over time and in space as a result of quantum effects. In the course of formulating quantum-motivated energy conditions, the smeared null energy condition has emerged as a recent proposal. This condition conjectures the existence of a semilocal bound on negative energy along null geodesics, which is expected to hold in semiclassical gravity. In this work, we show how the smeared null energy condition translates into theoretical constraints on NEC-violating cosmologies. Specifically, we derive the implied bounds on dark energy equation-of-state parameters and an inequality between the duration of a bouncing phase and the growth rate of the Hubble parameter at the bounce. In the case of dark energy, we identify the parameter space over which the smeared null energy condition is consistent with the recent constraints from the Dark Energy Spectroscopic Instrument.

The population of the observed gravitational wave events encodes unique information on the formation and evolution of stellar-mass black holes, from the underlying astrophysical processes to the large-scale dynamics of the Universe. We use the icarogw analysis infrastructure to perform hierarchical Bayesian inference on the gravitational wave signals from the LIGO-Virgo-KAGRA third observing run, O3. Searching for additional structure and redshift evolution in the primary mass distribution, we explore the dependence of the mass spectrum reconstruction on different parametrizations and prior choices. For the stationary case, we find strong evidence (Bayes factor $\mathcal{B}\simeq 180$) that the results obtained using a power-law model with a peak (Powerlaw-Gaussian)—the model preferred so far in the literature—are sensitive to prior bounds, affecting the resolvability of the $\sim 35M_{\odot }$ peak. This behavior is reproduced by simulated data, indicating a bimodal structure in the likelihood. Models with three mass features simultaneously capture a sharp $\sim 10M_{\odot }$ peak, a $\sim 35M_{\odot }$ overdensity, and support for a $\sim 20M_{\odot }$ overdensity preceded by a dip. Among these, a model with three power-law peaks (Powerlaw-Powerlaw-Powerlaw) is equally favored, in terms of evidence, over the Powerlaw-Gaussian model with wide priors. We find no statistical support for redshift evolution in the current data and provide constraints on the parameters governing this evolution, showing consistency with stationarity. We highlight possible limitations of the hierarchical Bayesian inference framework in reconstructing evolving features outside the detector horizon. Our work lays the foundations for a robust characterization of time-dependent population distributions, with significant implications for black hole astrophysics and gravitational wave cosmology.

In this work, we study the properties of the quark matter and quark stars (QSs) in a magnetic-color-flavor-locked (MCFL) quark phase within confined-isospin-density-dependent-mass (CIDDM) model at finite temperature. The entropy per baryon, polytropic index, and the equation of state of color-flavor-locked (CFL) quark matter in constant magnetic fields at finite temperature are investigated, and it is found that considering the effects of the temperature and strong magnetic fields can significantly influence the thermodynamical properties of the charged part and the neutral part of the MCFL quark matter as well as the maximum star mass of the QSs. In particular, we find the polytropic index $\gamma$ appears smaller in the heavier stars of MCFL quark phase at different isentropic stages under strong magnetic fields within CIDDM model.

In our previous paper, we reported the presence of a new resonance of an incompressible star orbiting a spinning black hole and showed that it can set in before the tidal disruption limit if the star has an inclined spherical orbit around the black hole. Using the affine model developed by Carter and Luminet, we extend our result to the stars with polytropic equations of state. We give further credence to the result previously found. We also derive the formula for the growth rate of the resonant motion, which is useful for checking the results of hydrodynamics simulations.

Intense laser fields have been proposed as a means to generate light-induced gravitational effects, providing a novel approach to investigate gravity and its coupling to electromagnetism in a controlled laboratory setting. In this article, a detection scheme based on interferometry is introduced to assess the feasibility of observing such effects. Initially, the space-time deformation and the resulting induced phase difference are evaluated in homogeneous electric fields. Using the theoretical minimum phase sensitivity bound—a known result in quantum information—and accounting for background signal coming from photon-photon scattering—a fundamental quantum electrodynamics effect related to vacuum properties—a set of stringent requirements for detectability is obtained. Then, a more realistic scenario is considered where gravitational effects are generated by an e-dipole pulse. In all cases considered, it is demonstrated that observing these effects presents significant challenges, even with the capabilities of current and foreseen laser infrastructures.

The Hilbert-Huang transform (HHT) consists of empirical mode decomposition (EMD), which is a template-free method that represents the combination of different intrinsic modes on a time-frequency map (i.e., the Hilbert spectrum). The application of HHT involves introducing trials by imposing white noise on the signal and then calculating the ensemble mean process of the corresponding EMD to demonstrate its significance on the Hilbert spectrum. In this study, we develop a stacked Hilbert-Huang Transform (sHHT) method that generates the Hilbert spectrum for each trial and compiles all results to enhance the strength of the real instantaneous frequency of the main signal on the time-frequency map. This new approach is more sensitive to detecting/tracing the nonlinear and transient features of a signal embedded in astronomical databases than the conventional HHT, particularly when the signal experiences dramatic frequency changes in a short time. We analytically investigate the consistency of HHT and sHHT and perform numerical simulations to examine the dispersion of the instantaneous frequency obtained through sHHT and compare its advantages and effectiveness with those of conventional HHT. To confirm the feasibility of the sHHT, we demonstrate its application in verifying the signal of superorbital modulation in x-ray and binary black hole mergers in gravitational waves.

The valence quark parton distribution functions (PDFs) of all ground state heavy mesons composed of $b$ or $c$ quarks, are discussed; namely, the pseudoscalar ${\eta }_c(1S)$, ${\eta }_b(1S)$, and $B_c$, together with the corresponding vector ones, $J/\psi$, $\mathrm{\Upsilon }(1S)$, and $B_c^{*}$. We use a quantum chromodynamics (QCD)-inspired constituent quark model, which has been applied with success to conventional heavy mesons, so that one advantage here is that all parameters have already been fixed by previous studies. The wave functions of the heavy mesons in the rest frame are obtained by solving the Schrödinger equation, then boosted to its light-front, based on Susskind’s Lorentz transformation. The PDFs at the hadron scale, are then obtained by integrating out the transverse momenta of the modulus square of the light-front wave function. Our study shows how the valence quark distributions differ between pseudoscalar and vector mesons, as well as among charmonia, bottomonia and bottom-charmed mesons. Comparisons with other theoretical calculations demonstrate that the PDFs obtained herein are in general narrower but align well with the expected patterns. Moreover, each PDF’s pointwise behavior is squeezed with respect to the scale-free partonlike PDF.

An $\mathrm{SU}(8)$ theory was previously found to be the minimal simple gauge group where all three-generational Standard Model (SM) fermions can be nontrivially embedded. It is maximally broken into a subgroup of $\mathrm{SU}(8)\to {\mathcal{G}}_{441}\equiv \mathrm{SU}(4{)}_s\otimes \mathrm{SU}(4{)}_W\otimes \mathrm{U}(1{)}_{X_0}$ at the grand unified theory scale by the $\mathrm{SU}(8)$ adjoint Higgs field of $\mathbf{6}{\mathbf{3}}_{\mathbf{H}}$. Gauge symmetries in the strong and the weak sectors are extended by one and two ranks, respectively. The sequential strong-weak-weak (SWW) symmetry breaking stages were found to generate the observed hierarchical SM quark/lepton masses as well as the Cabibbo-Kobayashi-Maskawa mixing pattern with the precise flavor identifications [The global $\mathrm{B}-$ L symmetry in the flavor-unified SU(N) theories, J. High Energy Phys. 04 (2024) 046. and The standard model quark/lepton masses and the Cabibbo-Kobayashi-Maskawa mixing in an SU(8) theory, J. High Energy Phys. 12 (2024) 137.]. We further study the possible weak-strong-weak and weak-weak-strong symmetry breaking patterns and compare with the results that we have obtained by following the SWW sequence. The two-loop renormalization group equations following both patterns are analyzed, where we cannot achieve the gauge coupling unification in the field theory framework. Through these analyses, we suggest the gauge coupling unification to be interpreted in the context of the affine Lie algebra.

The supermassive black hole at the center of M87 could redistribute dark matter particles within its sphere of influence, creating a high-density region known as a density spike. This spike can significantly enhance dark matter annihilation signals, making M87 a critical target for deriving stringent constraints on annihilation cross sections. In this work, we demonstrate that these constraints are highly sensitive to the choice of the halo density profile for M87. Motivated by recent kinematic studies of M87, we adopt a cored halo model and find that the constraints on dark matter annihilation are significantly relaxed. Specifically, in the cored halo scenario, the smooth part of the halo overwhelmingly dominates the annihilation signals, whereas the commonly assumed cuspy halo model attributes a major contribution to the spike. We demonstrate this effect using a dark matter model with a light mediator.

We investigate the stability of an intensive plane wave of a massless or light scalar field $\varphi$ in a trilinear scalar model $g\varphi {\chi }^2$ due to the resonant production of massive $\chi$ particles in a perturbatively forbidden regime. We apply two methods. First, we solve the Heisenberg equation for the quantum amplitudes of the field $\chi$ in an external plane wave background, generalizing the solution of Arza [A. Arza, Production of massive bosons from the decay of a massless particle beam, Phys. Rev. D 105, 036004 (2022).]. Second, for the light but massive $\varphi$, we perform the relativistic boost to the rest frame of $\varphi$, reducing the problem to the stability of the thoroughly investigated massive condensate. It turns out that the stability properties are significantly different for the cases of massless and light fields. In the first case, one should adopt the Heisenberg equation approach, since the alternative method cannot provide a comprehensive outcome. In the second case, the use of the Mathieu equation provides a more accurate solution, while for the massless case, this approach is not applicable.

Improved Kogut-Susskind Hamiltonians for quantum simulations of non-Abelian Yang-Mills gauge theories are developed for honeycomb ($2+1\mathrm{D}$) and hyperhoneycomb ($3+1\mathrm{D}$) spatial tessellations. This is motivated by the desire to identify lattices for quantum simulations that involve only 3-link vertices among the gauge field group spaces in order to reduce the complexity in applications of the plaquette operator. For the honeycomb lattice, we derive a classically $\mathcal{O}(b^2)$-improved Hamiltonian, with $b$ being the lattice spacing. Tadpole improvement via the mean-field value of the plaquette operator is used to provide the corresponding quantum improvements. We have identified the (nonchiral) hyperhoneycomb as a candidate spatial tessellation for $3+1\mathrm{D}$ quantum simulations of gauge theories, and determined the associated $\mathcal{O}(b)$-improved Hamiltonian.

We calculate the perturbative corrections in the strong coupling to the unpolarized quark transverse-momentum dependent parton distribution function (TMDPDF) operator within a background-field framework, extending the approach of Mukherjee et al. [Phys. Rev. D 109, 034035 (2024)]. We focus on ensuring gauge invariance, identifying two key components needed: a gauge-invariant TMDPDF operator with a transverse gauge link at spatial infinity, and accounting of the equations of motion (EoM) of the background fields. We go beyond next-to-leading order in strong coupling expansion, considering multiple interactions with the background field at all orders of strong coupling. By examining the interplay between quark and gluon contributions, we show that spurious singularities, proportional to EoM, can be misinterpreted as genuine divergences in quantum chromodynamics factorization unless properly identified and removed.