In this work, we calculate the charmonium spectrum and strong decay widths of $c\overline{c}$ states. The calculations are performed using the quark potential model which incorporates the relativistic effects. The resulting $c\overline{c}$ spectrum exhibits a good agreement with experimental data. The open flavor strong decay widths are calculated employing the ${}^3{P}_0$ model. We adopt two choices of wave functions to determine the observables: the first involves the utilization of realistic wave functions obtained by solving the relativistic Schrödinger equation, while the second employs simple harmonic oscillator wave functions whose parameters are fitted to the realistic wave functions. We find that the decay widths of higher charmonia states above the threshold value of open charm mesons are well described with these wave functions. We provide a comprehensive analysis of the strong decay widths and assigned specific charmonium states: $X(3940)$ is assigned to the ${\eta }_c(3S)$ state, $Y(4660)$ to the $\psi (5S)$ state, $X(3915)$ to the ${\chi }_0(2P)$ state, $Z_c(3900)$ to the $h_c(2P)$ state, $X(4350)$ to the ${\chi }_2(3P)$ state, and $X(3842)$ to the ${\psi }_3(1D)$ state. We also compare our results with available experimental data and theoretical predictions of other models.

We discuss the central and, mostly, spin-dependent potentials in heavy quarkonia $\overline{b}b,\overline{c}c$, with two goals in mind. The first is phenomenological: using the splitting between the 1S and 2S pairs, as well as the 1P and 2P quartet masses, we obtain pertinent matrix elements of all these potentials. The second is theoretical: using standard wave functions, we compute these matrix elements, quantifying the perturbative, nonperturbative and “string” contributions. The model for nonperturbative effects is a “dense instanton liquid model,” in which the QCD vacuum is made mostly of (strongly color correlated) instanton-anti-instanton pairs or “molecules.” Their contributions are calculated via standard Wilson lines, with or without extra powers of gauge fields. We find a reasonable description of all central, spin-spin, and spin-orbit forces at distances $r=0–0.7\mathrm{fm}$, relevant for $\overline{b}b$ and $\overline{c}c$ quarkonia.

As an update to our previously performed Bayesian inference analyses of the neutron star matter equation-of-state and related quantities, the additional impact of the recently published NICER data of PSR J0437-4751 is examined. Including the mass and radius distributions of this pulsar in our database results in modest shifts from previously inferred median posterior values of radii $R$ and central densities $n_c$ for representative $1.4M_{\odot }$ and $2.1M_{\odot }$ neutron stars: radii are reduced by about 0.2–0.3 km to values of $R_{1.4}=12.1\pm 0.5\mathrm{km}$ and $R_{2.1}={11.9}_{-0.6}^{+0.5}\mathrm{km}$ (at the 68% level), and central densities increase slightly to values of $n_c(1.4M_{\odot })/n_0=2.8\pm 0.3$ and $n_c(2.1M_{\odot })/n_0={3.8}_{-0.7}^{+0.6}$ (in units of equilibrium nuclear matter density, $n_0=0.16{\mathrm{fm}}^{-3}$)—i.e., they still fall below five times nuclear saturation density at the 68% level. As a further significant result, the evidence established by analyzing Bayes factors for a negative trace anomaly measure, $\mathrm{\Delta }=1/3-P/ϵ<0$, inside heavy neutron stars is raised to strong.

We propose a three-flavor nonlocal Nambu–Jona-Lasinio model of quark matter with the scalar attractive, vector repulsive and diquark pairing interaction channels. The model is treated within the separable approximation to obtain the equation of state of cold quark matter. The analysis of the high density asymptotics of the model allows us to conclude about its qualitative agreement with the perturbative quantum chromodynamics (QCD). Particularly, a color superconducting color-flavor-locked (CFL) state is found to be the ground one at asymptotically high densities. The conformal limit of speed of sound and dimensionless interaction measure are also shown to be reached from below and above, respectively. The model is applied to modeling neutron stars (NSs) within the scenario of early quark deconfinement triggered by the gravitational instability of the NS matter due to the Bose-Einstein coordinate of a spin-color-flavor singlet three-diquark bound state, the light sexaquark, stable against the weak and strong decays. A conservative estimate of the sexaquark mass based on the most up-to-date results from QCD sum rules and a constituent quark model implies an early quark deconfinement with the onset mass below $1M_{\odot }$. The scenario is shown to be consistent with the present observational constraints on the mass-radius relation and tidal deformability of NSs. Given the fact that the proposed model by construction exhibits an asymptotically conformal behavior, we consider the question about approximately conformal quark matter in NSs. We report a nonperturbative energy density range, which is inaccessible in NSs and where the speed of sound and dimensionless interaction measure of the CFL quark matter simultaneously attain the conformal values.

We apply advanced machine learning techniques to two challenging jet classification problems at the LHC. The first is strange-quark tagging, in particular distinguishing strange-quark jets from down-quark jets. The second, which we term fragmentation tagging, involves identifying the fragmentation channel of a quark. We exemplify the latter by training neural networks to differentiate between bottom jets containing a bottom baryon and those containing a bottom meson. The common challenge in these two problems is that neither quark lifetimes and masses nor parton showering provide discriminating tools, making it necessary to rely on differences in the distributions of the hadron types contained in each type of jet and their kinematics. For these classification tasks, we employ variations of graph attention networks and the Particle Transformer, which receive jet and all constituent properties as inputs. We compare their performance to a simple multilayer perceptron that uses simple variables. We find that the more sophisticated architectures do not improve $s$-quark versus $d$-quark jet differentiation by a significant amount, but they do lead to a significant gain in $b$-baryon versus $b$-meson jet differentiation.

Using $(2712\pm 14)\times {10}^6$ $\psi (2S)$ events collected with the BESIII detector at the BEPCII collider, we search for the decays ${\eta }_c(2S)\to \omega \omega$ and ${\eta }_c(2S)\to \omega \varphi$ via the process $\psi (2S)\to \gamma {\eta }_c(2S)$. No statistically significant signals are observed. The upper limits of their product branching fractions at the 90% confidence level are determined to be $\mathcal{B}(\psi (2S)\to \gamma {\eta }_c(2S),{\eta }_c(2S)\to \omega \omega )<1.04\times {10}^{-6}$ and $\mathcal{B}(\psi (2S)\to \gamma {\eta }_c(2S),{\eta }_c(2S)\to \omega \varphi )<1.85\times {10}^{-7}$, respectively. We also update the branching fractions of ${\chi }_{cJ}\to \omega \omega$ and ${\chi }_{cJ}\to \omega \varphi$ via the $\psi (2S)\to \gamma {\chi }_{cJ}$ transition. Their branching fractions are determined to be $\mathcal{B}({\chi }_{c0}\to \omega \omega )=(10.66\pm 0.11\pm 0.57)\times {10}^{-4}$, $\mathcal{B}({\chi }_{c1}\to \omega \omega )=(6.43\pm 0.07\pm 0.31)\times {10}^{-4}$, $\mathcal{B}({\chi }_{c2}\to \omega \omega )=(8.75\pm 0.08\pm 0.42)\times {10}^{-4}$, $\mathcal{B}({\chi }_{c0}\to \omega \varphi )=(1.18\pm 0.03\pm 0.07)\times {10}^{-4}$, $\mathcal{B}({\chi }_{c1}\to \omega \varphi )=(2.04\pm 0.15\pm 0.11)\times {10}^{-5}$, and $\mathcal{B}({\chi }_{c2}\to \omega \varphi )=(9.58\pm 1.07\pm 0.76)\times {10}^{-6}$, where the first uncertainties are statistical and the second are systematic.

We construct two new summary statistics, the scale-dependent peak height function (scale-PKHF) and the scale-dependent valley depth function (scale-VLYDF) of matter density, and forecast their constraining power on primordial non-Gaussianity and cosmological parameters based on quijote and quijote-png simulations at $z=0$. With the Fisher analysis, we demonstrate that these statistics outperform the power spectrum and bispectrum. Key findings include: (1) the constraint on the scalar spectral index $n_s$ obtained from the scale-VLYDF/scale-PKHF is $1.59/1.10$ times tighter than that from the joint analysis of power spectrum and bispectrum; (2) the combination of the two statistics yields a slight improvement in constraining $\{f_{\mathrm{NL}}^{\text{local}},f_{\mathrm{NL}}^{\text{equil}}\}$ over the power spectrum-bispectrum combination, and provides a 1.39-fold improvement in the constraint on $f_{\mathrm{NL}}^{\text{ortho}}$; and (3) after incorporating the power spectrum with our new statistics, parameter constraints surpass those from power spectrum-bispectrum combination by factors up to 2.93. This work offers an effective scheme for extracting primordial signals from the late Universe, paving the way for further breakthroughs in precision cosmology.

Recent discoveries by neutrino telescopes, such as the IceCube Neutrino Observatory, relied extensively on machine learning (ML) tools to infer physical quantities from the raw photon hits detected. Neutrino telescope reconstruction algorithms are limited by the sparse sampling of photons by the optical modules due to the relatively large spacing (10–100 m) between them. In this Letter, we propose a novel technique that learns photon transport through the detector medium through the use of deep-learning-driven superresolution of data events. These “improved” events can then be reconstructed using traditional or ML techniques, resulting in improved resolution. Our strategy arranges additional “virtual” optical modules within an existing detector geometry and trains a convolutional neural network to predict the hits on these virtual optical modules. We show that this technique improves the angular reconstruction of muons in a generic ice-based neutrino telescope. Our results readily extend to water-based neutrino telescopes and other event morphologies.

We study timelike supersymmetric solutions of a $D=3$, $N=4$ gauged supergravity using the Killing spinor bilinears method and prove that ${\mathrm{AdS}}_3$ is the only solution within this class. We then consider the ungauged version of this model. It is found that for this type of solution, the ungauged theory effectively truncates to a supergravity coupled to a sigma model with a two-dimensional hyperbolic target space ${\mathbb{H}}^2$, and all solutions can be expressed in terms of two arbitrary holomorphic functions. The spacetime metric is a warped product of the time direction with a two-dimensional space, and the warp factor is given in terms of the Kähler potential of ${\mathbb{H}}^2$. We show that when the holomorphic function that determines the sigma model scalar fields is not constant, the metric on the sigma model target manifold becomes part of the spacetime metric. We then look at some special choices for these holomorphic functions for which the spacetime metric and the Killing spinors are only radial dependent. We also derive supersymmetric null solutions of the ungauged model which are pp-waves on the Minkowski spacetime.

We investigate the effects of rotation on deconfinement and chiral phase transitions in the framework of the dynamical holographic QCD model. Instead of transforming to the rotating system by Lorentz boost, we construct an anisotropic gravitational background by incorporating the rotating boundary current. We first investigate the pure gluon system under rotation to extract deconfinement phase transition from the Polyakov loop then add two-flavor probe for chiral restoration phase transition from the chiral condensate. It is observed that at low chemical potentials, the deconfinement phase transition of pure gluon system is of first order and the chiral phase transition of a two-flavor system is of crossover. Both the critical temperatures of deconfinement and chiral phase transitions decrease/increase with imaginary/real angular velocity (${\mathrm{\Omega }}_I/\mathrm{\Omega }$) as $T/T_c\sim 1-C_2{\mathrm{\Omega }}_I^2$ and $T/T_c\sim 1+C_2{\mathrm{\Omega }}^2$, which is consistent with lattice QCD results. In the temperature-chemical potential $T-\mu$ phase diagram, the critical end point moves toward regions of higher temperature and chemical potential with real angular velocity.

We reconsider the equivalence theorem from an algebraic viewpoint, using an extended Becchi-Rouet-Stora-Tuytin symmetry. This version of the equivalence theorem is then used to reexpress the Abelian Higgs model action, originally written in terms of undesirable gauge variant field excitations, in terms of gauge-invariant, physical variables, corresponding to the Fröhlich-Morchio-Strocchi composite operators in the original field formulation. Although the ensuing action encompasses an infinite number of vertices and appears to be nonrenormalizable from the power counting viewpoint, it nevertheless is renormalizable, thanks to the hidden equivalence with the original model. Hence, manifestly gauge-invariant computations are possible. We present an explicit illustration in terms of the gauge-invariant scalar field, its Green’s function and corresponding pole mass.

von Neumann algebras have been playing an increasingly important role in the context of gauge theories and gravity. The crossed product presents a natural method for implementing constraints through the commutation theorem, rendering it a useful tool for constructing gauge-invariant algebras. The crossed product of a Type III algebra with its modular automorphism group is semifinite, which means that the crossed product regulates divergences in local quantum field theories. In this article, we find a sufficient condition for the semifiniteness of the crossed product of a Type III algebra with any locally compact group containing the modular automorphism group. Our condition surprisingly implies the centrality of the modular flow in the symmetry group, and we provide evidence for the necessity of this condition. Under these conditions, we construct an associated trace that computes physical expectation values. We comment on the importance of this result and its implications for subregion physics in gauge theory and gravity.

We consider the transition rate of a static Unruh-DeWitt detector in two ($2+1$)-dimensional black hole spacetimes that are isometric to the static Bañados-Teitelboim-Zanelli black hole outside the horizon but have no asymptotically locally anti–de Sitter exterior behind the horizon. The spacetimes are the $\mathbb{R}{\mathrm{P}}^2$ geon, with spatial topology $\mathbb{R}{\mathrm{P}}^2\backslash \{\text{point at infinity}\}$, and the Swedish geon of Åminneborg et al., with spatial topology $T^2\backslash \{\text{point at infinity}\}$. For a conformal scalar field, prepared in the Hartle-Hawking-type state that is induced from the global vacuum on the anti–de Sitter covering space, we show numerically that the detector’s transition rate distinguishes the two spacetimes, particularly at late exterior times, and we trace this phenomenon to the differences in the isometries that are broken by the quotient construction from the universal covering space. Our results provide an example in which information about the interior topology of a black hole is accessible to a quantum observer outside the black hole.

We propose a model for a finite-size particle detector, which allows us to derive its stress-energy tensor. This tensor is obtained from a covariant Lagrangian that describes not only the quantum field that models the detector, ${\varphi }_{\mathrm{D}}$, but also the systems responsible for its localization: a complex scalar field ${\psi }_{\mathrm{C}}$ and a perfect fluid. The local interaction between the detector and the complex field ensures the square integrability of the detector modes, while the fluid serves to define the spatial profile of ${\psi }_{\mathrm{C}}$, localizing it in space. We then demonstrate that, under very general conditions, the resulting energy tensor—incorporating all components of the system—is physically reasonable and satisfies the energy conditions.

This paper studies the impact of vacuum polarization on light propagation in the background of a distorted, deformed compact object. Focusing on a spacetime containing two quadrupole parameters associated with the central object and external fields, we explore how these parameters influence observable effects as dynamical degrees of freedom. In this setup, we investigate electromagnetic birefringence, noting distinct polarization-dependent photon velocity variations and gravitational lens effects. Although current resolution may limit detection, future high-precision observations could reveal these quantum electrodynamics (QED) induced birefringence effects, advancing our understanding of vacuum birefringence in astrophysical contexts. We further analyze the dependence of shadow properties on the model’s variables, using observational data from Sgr A*.

We compute observables in the interacting rank-one 6D $\mathcal{N}=(2,0)$ superconformal field theory (SCFT) at large $R$-charge. We focus on correlators involving ${\mathrm{\Phi }}^n$, namely symmetric products of the bottom component of the supermultiplet containing the stress tensor. By using the moduli space effective action and methods from the large-charge expansion, we compute the operator product expansion coefficients $⟨{\mathrm{\Phi }}^n{\mathrm{\Phi }}^m{\mathrm{\Phi }}^{n+m}⟩$ in an expansion in $1/n$. The coefficients of the expansion are only partially determined from the 6D perspective, but we manage to fix them order-by-order in $1/n$ numerically by utilizing the $6\mathrm{D}/2\mathrm{D}$ correspondence. This is made possible by the fact that this 6D observable can be extracted in 2D from a specific double-scaling limit of the vacuum Virasoro block, which can be efficiently computed numerically. We also extend the computation to higher-rank SCFTs, and discuss various applications of our results to 6D as well as 2D.

Ultralight bosonic fields can form condensates, or clouds, around spinning black holes. When this system is under the influence of a secondary massive body, its tidal response can be quantified in the tidal Love numbers (TLNs). Although TLNs vanish for black holes in vacuum, it has been shown that the same is not true for black holes immersed in matter environments. In this work, we compute the gravitational TLNs of black holes surrounded by scalar clouds, in the Newtonian limit. We show that they are nonvanishing, have a strong power-law dependence on the boson’s mass, and are proportional to the scalar cloud’s total mass. In particular, we find that, independently of the cloud’s configuration, the TLNs from axisymmetric tides scale as $\propto r_c^{2l+1}$, for $r_c$ the cloud’s “radius” and $l$ the multipole order of the external tidal field. This differs by a factor $r_c$ from previous estimates based on scalar and vector tidal perturbations but is in perfect agreement with the behavior of TLNs in other matter systems. Furthermore, we show that the adiabatic tides approximation we employ is, in general, not appropriate for nonaxisymmetric tidal interactions.

In our previous paper [J. High Energy Phys. 10 (2023) 014; J. High Energy Phys. 08 (2024) 048], we proposed a probabilistic argument to explain the reason why the cosmological constant is very small in $4D$. We can ask a question: if the behavior of tunneling exponent $B$ can be generalized to $D$-dimension. Moreover, in higher dimensional theory motivated by string theory the Gauss-Bonnet term plays an important role. Therefore, in this paper, we generalize our result in previous paper [J. High Energy Phys. 10 (2023) 014; J. High Energy Phys. 08 (2024) 048] to arbitrary $D$ dimensions including the Gauss-Bonnet term. As a result, we have two main results. We find that the Euclidean action of the bounce, $B$, describing the decay of a de Sitter vacuum, is proportional to $k_{+}^{-(D-2)}$, which has a pole as $k_{+}^2\to 0$ where $k_{+}^2$ is the curvature of the parent vacuum. This result is similar to the result in $4D$. The other result is that we find a new decay channel, describing up-tunneling from anti–de Sitter into de Sitter. The meaning of this new decay channel in the string landscape should be explored in the future.

We shed a new light on the long-standing problem of covariant charges in diffeomorphism invariant theories such as general relativity by noting the other important feature of the theory, the background independence. To this end, we develop covariant phase space formalism in which we allow for the boundaries of spacetime to have arbitrary fluctuations. Within this formalism we show noncovariance of charges appear in inevitable integration constants that also break background independence in the expression of charges. We then apply the same formalism to black hole thermodynamics. We generalize the seminal Iyer-Wald derivation the first law of black hole thermodynamics by relaxing the need for the assumptions at a bifurcation surface and asymptotic infinity, as well as addressing questions regarding the integrability of charges. We also present a first principles derivation of the Smarr relation within our framework.

The efforts to probe the horizon-scale structure of black holes, such as Event Horizon Telescope and GRAVITY interferometer, might provide valuable insights into the strong-field regime of Einstein’s theory of gravity. In the near field region of a black hole, the observational signatures of moving hotspots might potentially reveal the mechanism causing the flares, or reflect the spacetime geometries. This paper develops a ray tracing scenario to study higher-order images of moving hotspots in a thin disk around a spherical black hole. Our ray-tracing scenario establishes a one-to-one mapping between emission locations and observer’s sky. It enables us to perform infinite-precision simulations for the images, because the emission sources are projected directly onto the image plane. Furthermore, we show that a source located anywhere outside the black hole can be repeatedly mapped onto the observer’s sky, from primary to higher-order images. We investigate the observational signatures of hotspots, focusing on temporal fluxes and flux centroids from the primary to sixth-order images. The hotspots are considered to be moving in circular, escape, and plunging orbits. Our results find that the higher-order images can be categorized into two types. Within each type, the temporal fluxes exhibit a self-similar profile. Furthermore, as the hotspots approach the event horizon of a black hole, the fluxes from higher-order images alternately dominate the observed flux, which subsequently result in the flux decaying with time in an oscillatory manner.