Many analyses of two-body nonleptonic decays of $D$-mesons rely on flavor $SU(3)$ symmetry relations and fits of experimental data of decays rates to extract the universal transition amplitudes. Such fits assume that the final state mesons are well-defined asymptotic states of QCD. We develop a technique to take into account the finite width effects of the final state mesons and study their effects on the extracted values of transition amplitudes.

We present for the first time the second-order corrections of pseudoscalar($A$) Higgs decay to three parton to higher orders in the dimensional regulator. We compute the one- and two-loop amplitudes for processes, $A\to ggg$ and $A\to q\overline{q}g$, in the effective theory framework. With suitable crossing of the external momenta, these calculations are well-suited for predicting the differential distribution of pseudoscalar Higgs in association with a jet at hadron colliders, up to next-to-next-to-leading order in the strong coupling constant. These results expanded to higher orders in the dimensional regulator will contribute to the full three-loop cross section. We implement the finite pieces of the amplitudes in a numerical code which can be used with any Monte Carlo phase space generator.

A scenario to understand the asymptotic properties of confinement between quark probes, based on a 4D mixed ensemble of percolating center-vortex world surfaces and chains, was initially proposed by one of us in a non-Abelian setting. More recently, the same physics was reobtained by means of a Schrödinger wave functional peaked at Abelian-projected configurations, which deals with center-vortex lines and pointlike monopoles in real space. In this work, we formulate the Abelian-projected ensemble and reassess the non-Abelian one within the Weingarten lattice representation for the sum over surfaces. In the phase where world surfaces are stabilized by contact interactions and percolate, lattice gauge fields emerge. This generalizes the Goldstone modes in an Abelian loop condensate to the case where non-Abelian degrees of freedom are present. In this language, the different natural matching properties of elementary center-vortex world surfaces and monopole worldlines can be easily characterized. In the lattice, the Abelian setting also implements the original idea that the mixed ensemble reconciles $N$-ality with the formation of a confining flux tube. In this picture, center vortices and chains explain why Abelian-projected variables capture this property at asymptotic distances while simultaneously allowing for a “dual superconductor” description of the fundamental string. Common features, differences in the continuum, and perspectives will also be addressed.

The spin correlation of back-to-back dihadrons emerges in unpolarized high-energy collision, empowering unpolarized experiments to shed light on the spin-dependent fragmentation functions. This work investigates the transverse spin correlation of back-to-back dihadrons in unpolarized $e^{+}{e}^{-}$, $pp$, and $\gamma p$ collisions, which serves as a novel probe of the chiral-odd fragmentation function $H_{1T}(z)$. We compute the transverse spin correlation at the partonic level and establish a connection with helicity amplitudes. Measuring this observable in future experiments can reveal valuable information on the hadronization of transversely polarized quarks.

The structure of hadronic form factors at high energies and their deviations from perturbative quantum chromodynamics provide insight on nonperturbative dynamics. Using an approach that is consistent with dispersion relations, we construct a model that simultaneously accounts for the pion wave function, gluonic exchanges, and quark Reggeization. In particular, we find that quark Reggeization can be investigated at high energies by studying scaling violation of the form factor.

Within the color glass condensate effective field theory, we assess the importance of including a finite size for the target on observables sensitive to small-$x$ evolution. To this end, we study the Balitsky-Kovchegov (BK) equation with impact-parameter dependence in the initial condition. We demonstrate that neglecting the dependence on the impact parameter can result in overestimated saturation effects for protons, while it has little effect for heavy nuclei at the energies available at current experiments. When fixing the nonperturbative parameters to the energy dependence of the exclusive $\mathrm{J}/\psi$ photoproduction cross section with proton targets, predictions for lead targets are not sensitive to the applied running-coupling prescription, the scheme chosen to resum large transverse logarithms in the BK equation, or the infrared regulator in the evolution.

The diphoton channel for exploring the Georgi-Machacek (GM) scenario containing scalar triplets at the Large Hadron Collider (LHC) has been identified as germane and subjected to a detailed study. The scalar spectrum of the model, which imposes a custodial SU(2) on the potential, gets classified into a 5-plet, a 3-plet, and two singlets under the custodial symmetry. While most attempts to probe or constrain the scenario at the LHC depend largely on signals of charged scalars, we point out that the custodial SU(2) singlet state $H$ can have a substantial branching ratio (amounting to a few percent) into two photons. We carry out a detailed simulation of the resulting signal and the standard model backgrounds, obtaining the signal significance in different regions of the parameter space using the profile likelihood ratio method. Substantial regions of the GM parameter space are thus shown to be accessible to LHC studies, both at the high-luminosity run with $\int \mathcal{L}dt=3000{\mathrm{fb}}^{-1}$ and also in Run-3 with $\int \mathcal{L}dt=300{\mathrm{fb}}^{-1}$, even after folding in systematic errors. We have also demonstrated that a rather substantial improvement in the signal significance is achieved by switching over from a cut-based analysis to one based on a neural network.

This analysis uses the Compact Muon Solenoid (CMS) open data to study the angular distribution of high mass dimuon pairs produced during proton-proton interaction at a center of mass energy of 8 TeV. The study uses the $\cos {\theta }_{\mathrm{CS}}$ variable defined in the Collins-Soper frame. In the Standard Model (SM), the production of high mass dimuon pairs is dominated by the Drell-Yan process, which exhibits a strong forward-backward asymmetry. However, many scenarios beyond the SM predict different shapes for the $\cos {\theta }_{\mathrm{CS}}$ distribution. In excess events beyond the SM, the angular distribution can be used to distinguish between those models. The mono-${\mathrm{Z}}^{\prime }$ model has been used to interpret the data, and no deviation from the SM has been observed.

Using $(10087\pm 44)\times {10}^{6}J/\psi$ decays collected by the BESIII detector at the BEPCII collider, we search for baryon number violation via $\mathrm{\Lambda }-\overline{\mathrm{\Lambda }}$ oscillation in the decay $J/\psi \to \mathrm{\Lambda }\overline{\mathrm{\Lambda }}$. No evidence for $\mathrm{\Lambda }-\overline{\mathrm{\Lambda }}$ oscillation is observed. The upper limit on the time-integrated probability of $\mathrm{\Lambda }-\overline{\mathrm{\Lambda }}$ oscillation is estimated to be $1.4\times {10}^{-6}$, corresponding to an oscillation parameter less than $2.1\times {10}^{-18}\mathrm{GeV}$ at 90% confidence level.

Based on $(2712.4\pm 14.1)\times {10}^6$ $\psi (3686)$ decays collected with the BESIII detector, we have observed, for the first time, the hadronic decays of S- and P-wave charmonium states into $2({\pi }^{+}{\pi }^{-})\eta$ via radiative transitions from $\psi (3686)$. The branching fraction of the decay ${\eta }_c(1S)\to 2({\pi }^{+}{\pi }^{-})\eta$ has a significant dependence on the interference pattern between ${\eta }_c(1S)$ and non-${\eta }_c(1S)$ processes. We measure it in both the destructive and constructive interference scenarios for the first time. The mass and width of the ${\eta }_c(1S)$ are measured to be $M=(2984.14\pm 0.13\pm 0.38)\mathrm{MeV}/c^2$ and $\mathrm{\Gamma }=(28.82\pm 0.11\pm 0.82)\mathrm{MeV}$, respectively. Clear signals for the decays of the ${\chi }_{cJ}(J=0,1,2)$ and the ${\eta }_c(2S)$ to $2({\pi }^{+}{\pi }^{-})\eta$ are also observed for the first time, and the corresponding branching fractions are measured. The ratio of the branching fractions between the ${\eta }_c(2S)$ and ${\eta }_c(1S)$ decays is significantly lower than the theoretical prediction, which might suggest different dynamics in their decays.

We investigate the holographic thermodynamics of 4-D Kerr-Newman anti–de Sitter (AdS) black holes, focusing on the conformal thermal states that are dual to these black holes. We explore the thermodynamic behavior within specific ensembles characterized by fixed sets of variables: $(\mathcal{Q},\mathcal{J},\mathcal{V},C)$, $(\mathcal{Q},\mathrm{\Omega },\mathcal{V},C)$, $(\phi ,\mathrm{\Omega },\mathcal{V},C)$, $(\phi ,\mathcal{J},\mathcal{V},C)$, $(\mathcal{Q},\mathrm{\Omega },p,C)$, and $(\phi ,\mathrm{\Omega },p,C)$. Here, $\phi$, $\mathcal{Q}$, $\mathrm{\Omega }$, $\mathcal{J}$, $p$, $\mathcal{V}$, and $C$ represent the electric potential, electric charge, angular velocity, angular momentum, conformal field theory (CFT) pressure, CFT volume, and central charge, respectively. The inclusion of both charge and momentum significantly enriches the regime of phase transitions, leading to a variety of phenomena including first-order van der Waals-type phase transitions, (de)confinement phase transitions, Davies-type phase transitions, and second-order superfluid $\lambda$-type phase transitions. Notably, the introduction of the CFT pressure variable allows us to identify phase transitions and critical behavior in the $(\mathcal{Q},\mathrm{\Omega },p,C)$ and $(\phi ,\mathrm{\Omega },p,C)$ ensembles, which had not been previously observed. This study underscores the complexity and richness of phase transitions in these systems due to the inclusion of both charge and angular momentum.

In holographic duality, a higher dimensional quantum gravity system emerges from a lower dimensional conformal field theory (CFT) with a large number of degrees of freedom. We propose a formulation of duality for a general causally complete bulk spacetime region, called subregion-subalgebra duality, which provides a framework to describe how geometric notions in the gravity system, such as spacetime subregions, different notions of times, and causal structure, emerge from the dual CFT. Subregion-subalgebra duality generalizes and brings new insights into subregion-subregion duality (or equivalently entanglement wedge reconstruction). It provides a mathematically precise definition of subregion-subregion duality and gives an independent definition of entanglement wedges without using entropy. Geometric properties of entanglement wedges, including those that play a crucial role in interpreting the bulk as a quantum error correcting code, can be understood from the duality as the geometrization of the superadditivity of certain algebras. Using general boundary subalgebras rather than those associated with geometric subregions makes it possible to find duals for general bulk spacetime regions, including those not touching the boundary. Applying subregion-subalgebra duality to a boundary state describing a single-sided black hole also provides a precise way to define mirror operators.

We tackle head on the computation of the $s$-channel Witten diagram in momentum space corresponding to the exchange of a graviton between minimally coupled scalars in Weyl invariant unimodular gravity. By means of a lengthy calculation, we show first that the value of the diagram in question is the same as in general relativity and, then, we obtain a compact expression for it in terms of the Mandelstam variables.

We discuss the classical and quantum chaos of closed strings on a recently constructed charged confining holographic background. The confining background corresponds to the charged soliton, which is a solution of minimal $d=5$ gauged supergravity. The solution has a compact spacelike direction with a Wilson line on a circle and asymptotes to ${\mathrm{AdS}}_5$ with a planar boundary. For the classical case, we analyze the chaos using the power spectrum, Poincaré sections, and Lyapunov exponents, finding that both energy and charge play constructive effects on enhancing the chaotic nature of the system. We similarly analyze quantum chaos using the distribution of the spectrum’s level-spacing and out-of-time-ordered correlators and thoroughly investigate the effects of charge and energy. A gradual transition from a chaotic to an integrable regime is obtained as the energy and charge increase from lower to higher values, with charge playing a subdominant role.

In this paper we develop a systematic analysis of the properties of entanglement entropy in curved backgrounds using the replica approach. We explore the analytic ($q-1$) expansion of Rényi entropy $S_q$ and its variations; our setup applies to generic variations, from symmetry transformations to variations of the background metric or entangling region. Our methodology elegantly reproduces and generalizes results from the literature on entanglement entropy in different dimensions, backgrounds and states. We use our analytic expansions to explore the behavior of entanglement entropy in static black hole backgrounds under specific scaling transformations, and we explain why this behavior is key to determining whether there are islands of entanglement.

Minimal $d=2$ conformal field theories (CFTs) are usually classified through modular invariant partition functions. There is a finer classification of “noncomplete” models when $S$ duality is not imposed. We approach this classification by starting with the local chiral algebra and adding primaries sequentially. At each step, we only impose locality (T duality) and closure of the operator algebra. For each chiral algebra, this produces a treelike graph. Each tree node corresponds to a local $d=2$ CFT, with an intrinsic Jones index measuring the size of Haag duality violation. This index can be computed with the partition function and is related to the total quantum dimension of the category of superselection sectors of the node and to the relative size between the node and a modular invariant completion. In this way, we find in a very explicit manner a classification of local minimal ($c<1$) $d=2$ CFTs. When appropriate, this matches Kawahigashi-Longo’s previous results. We use this finer classification to constrain renormalization group (RG) flows. For a relevant perturbation, the flow can be restricted to the subalgebra associated with it, typically corresponding to a nonmodular invariant node in the tree. The structure of the graph above such node needs to be preserved by the RG flow. In particular, the superselection sector category for the node must be preserved. This gives selection rules that recover in a unified fashion several known facts while unraveling new ones.

In the context of Einstein-Maxwell-scalar theory with a nonminimal coupling between the electromagnetic and scalar field, we study linear (non)radial perturbations and nonlinear radial dynamics of spherically symmetric black holes. In a certain region of the parameter space, this theory admits hairy black holes with a stable photon sphere. This has a counterpart in the effective potential of linear perturbations, featuring multiple maxima and minima. The corresponding quasinormal mode spectrum contains long-lived modes trapped in the potential cavity and the time-domain linear response displays echoes, as previously observed for horizonless compact objects. Interestingly, the black-hole dynamics in this theory can be studied at the nonlinear level. By performing fully fledged $1+1$ simulations, we show that echoes are present even when the nonlinearities are significant. To our knowledge, this is the first example of echoes appearing in a consistent theory beyond a linearized analysis. In a follow-up work we will study whether this feature is also present in the postmerger signal from black hole collisions in this theory.

Since the derivation of a well-defined $D\to 4$ limit for 4D Einstein-Gauss-Bonnet (4DEGB) gravity coupled to a scalar field, there has been considerable interest in testing it as an alternative to Einstein’s general theory of relativity. Past work has shown that this theory hosts interesting compact star solutions which are smaller in radius than a Schwarzschild black hole of the same mass in general relativity (GR), though the stability of such objects has been subject to question. In this paper we solve the equations for radial perturbations of neutron stars in the 4DEGB theory with Skyrme Lyon (SLy)/Brussels-Montreal Skyrme functionals (BSk) class equations of state (EOSs), along with the Müller-Serot (MS2) EOS, and show that the coincidence of stability and maximum mass points in GR is still present in this modified theory, with the interesting additional feature of solutions reapproaching stability near the black hole solution on the mass-radius diagram. Besides this, as expected from previous work, we find that larger values of the 4DEGB coupling $\alpha$ tend to increase the mass of neutron stars of the same radius (due to a larger $\alpha$ weakening gravity) and move the maximum mass points of the solution branches closer to the black hole horizon.

In previous work [Manuel Del Piano et al. Phys. Rev. D 109, 024045 (2024); Eur. Phys. J. C 84, 1273 (2024)] we have developed a model-independent, effective description of quantum deformed, spherically symmetric and static black holes in four dimensions. The deformations of the metric are captured by two functions of the physical distance to the horizon, which are provided in the form of self-consistent Taylor series expansions. While this approach efficiently captures physical observables in the immediate vicinity of the horizon, it is expected to encounter problems of convergence at further distances. Therefore, we demonstrate in this paper how to use Padé approximants to extend the range of applicability of this framework. We provide explicit approximations of physical observables that depend on finitely many effective parameters of the deformed black hole geometry, depending on the order of the Padé approximant. By taking the asymptotic limit of this order, we, in particular, provide a closed-form expression for the black hole shadow of the (fully) deformed geometry, which captures the leading quantum corrections. We illustrate our results for a number of quantum black holes previously proposed in the literature and find that our effective approach provides excellent approximations in all cases.

In this paper we study an Oppenheimer-Snyder-like gravitational collapse in the general framework of scale-dependent gravity. We explore the collapse in spherically symmetric solutions suggested both by asymptotically safe gravity (characterized by a positive $\tilde{\omega }$ parameter) and by scale-dependent gravity (negative $\tilde{\omega }$ parameter), when a singularity at a finite positive radial coordinate is developed. The inner geometry of the collapsing star is described, as usual, by a spatially flat Friedmann-Lemaître-Robertson-Walker metric, and matter is uniformly distributed without any assumptions about its equation of state. The outer asymptotically safe/scale-dependent black hole metric is smoothly matched to the inner geometry, and this yields the equation of motion of the star surface, energy density, pressure, and equation of state of the collapsing matter. We study in detail the proper-time evolution of the event and apparent horizons. Finally, the constraints of the energy conditions on the equation of state, and its properties, are considered and discussed.