Production fraction ratios of $B^{+}$, $B^0$, and $B_s^0$ mesons are measured in proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$ using a special dataset recorded in 2018 with high-rate triggers designed to collect an unbiased sample of $10^{10}$ $b$ hadrons with the CMS experiment at the LHC. These data allow the study of the open-charm decays of $B$ mesons ($B_{(s)}\to \pi D_{(s)}$) where the $D$ meson decays into fully hadronic final states. By utilizing known branching fractions and precise theoretical calculations, production fraction ratios as functions of $B$ meson transverse momentum $(p_{\mathrm{T}})$ and rapidity ($y$) are measured using open-charm decays in the kinematic range of $8<p_{\mathrm{T}}<60\mathrm{GeV}$ and $|y|<2.25$. In addition, the same dataset is used to measure the relative production fraction ratios with the charmonium decay channels [$B_{(s)}\to XJ/\psi$ with $X$ indicating a $K^{+}$, $K^{*}(892{)}^0$, or $\varphi (1020)$ meson] where the $J/\psi$ meson decays into a pair of muons. The open-charm results are used to normalize the relative production fraction ratios obtained from the charmonium samples. Measurements of the ratios of branching fractions of $B$ meson decays to charmonium and open-charm final states are also reported, which will improve the world-average values of these ratios. Finally, we test isospin invariance in $B$ meson production in proton-proton collisions and observe that it holds within the experimental precision.

Based on $(2712.4\pm 14.3)\times {10}^6\psi (3686)$ events collected with the BESIII detector, the decays $\mathrm{\Xi }(1530{)}^{-}\to {\mathrm{\Xi }}^0{\pi }^{-}$ and $\mathrm{\Xi }(1530{)}^{-}\to {\mathrm{\Xi }}^{-}{\pi }^0$ are investigated jointly via the process $\psi (3686)\to {\overline{\mathrm{\Xi }}}^{+}\mathrm{\Xi }(1530{)}^{-}+\mathrm{c}.\mathrm{c}.$ Under the assumption of isospin symmetry, the two decay modes are treated as fully correlated, and we report the first measurement of their absolute branching fractions. The results are $\mathcal{B}(\mathrm{\Xi }(1530{)}^{-}\to {\mathrm{\Xi }}^0{\pi }^{-})=(61.4\pm 4.5\pm 4.6)\%$ and $\mathcal{B}(\mathrm{\Xi }(1530{)}^{-}\to {\mathrm{\Xi }}^{-}{\pi }^0)=(29.7\pm 2.2\pm 2.2)\%$. The combined branching fraction of the two decays is $\mathcal{B}(\mathrm{\Xi }(1530{)}^{-}\to (\mathrm{\Xi }\pi {)}^{-})=(91.1\pm 6.7\pm 6.8)\%$, with uncertainties accounting for the correlations between the two modes. Here, the first uncertainties are statistical, while the second are systematic. Additionally, we update the branching fraction of the decay $\psi (3686)\to {\overline{\mathrm{\Xi }}}^{+}\mathrm{\Xi }(1530{)}^{-}+\mathrm{c}.\mathrm{c}.$ The updated measurement is $\mathcal{B}(\psi (3686)\to {\overline{\mathrm{\Xi }}}^{+}\mathrm{\Xi }(1530{)}^{-}+\mathrm{c}.\mathrm{c}.)=(8.67\pm 0.52\pm 0.58\pm 0.57)\times {10}^{-6}$, where the first uncertainty is statistical, the second is systematic related to event selection and the fit model, and the third is associated with the interference effect.

We present a machine-learning-based anomaly detection strategy designed to identify anomalous physics in events containing resonant Standard Model physics and demonstrate this method on the final state of a Higgs boson decaying to two photons. The demonstration targets high-dimensional deviations in the region of phase space containing the Higgs mass peak in a fully signal-agnostic manner. A latent-space embedding, learned from event kinematics, enables the use of a large set of potentially sensitive features. Backgrounds are estimated using a hybrid approach that combines machine-learning-based generative modeling with traditional simulation, and a discriminator is trained in the latent space to distinguish data from background estimates. After applying a selection on the classifier output, the invariant mass distribution of the diphoton system is examined for localized excesses above the simulated Higgs peak. We benchmark the sensitivity of this strategy using simplified simulated proton-proton collisions corresponding to data recorded during Run 2 of the LHC and show that the method can provide significant improvements in sensitivity, even for small signal injections that could remain undetected in an inclusive analysis. These results demonstrate that the proposed strategy is a promising and viable approach for future searches and should be applied to recorded collider data.

We perform a Wick rotation and analytic continuation from global ${\mathrm{AdS}}_{d+1}$ to static ${\mathrm{dS}}_{d+1}$, yielding ${\mathrm{CFT}}_d$ generators with a nonstandard adjoint action tied to dS bulk coordinates. To reproduce the real-scalar two-point function, we introduce a global defect operator that twists the inner product. We further show that $PT$ symmetry is spontaneously broken in ${\mathrm{CFT}}_2$ vacua with a central charge having an imaginary part. Finally, we derive integral identities for bulk and defect correlators, providing a unified framework for computing ${\mathrm{CFT}}_d$ observables in the presence of global and local defects.

We develop a systematic classification of asymmetric ${\mathbb{Z}}_2$ orbifold actions in Pati-Salam heterotic string vacua constructed in the free fermionic formulation. Starting from symmetric ${\mathbb{Z}}_2\times {\mathbb{Z}}_2$ orbifold vacua with an $SO(10)$ grand unified theory (GUT), we allow the Pati-Salam breaking vector to act asymmetrically on the internal degrees of freedom. The asymmetric orbifold action freezes geometrical moduli while inducing doublet-triplet splitting in the untwisted sector. Notably, this doublet-triplet splitting operates for any asymmetric action, including pure asymmetric shifts that preserve all geometric moduli, and is therefore independent of moduli stabilization. Classifying the breaking vector according to its twist action, we find six inequivalent classes of geometric moduli spaces characterized by 12, 8, 4 or 0 real untwisted moduli. Through combining these asymmetric twists with all compatible asymmetric shifts, 24 inequivalent cases are identified and characterized by their residual moduli content and internal Narain lattice. For each case we construct representative basis sets admitting three chiral generations, providing the starting point for further classification within each class. We perform explicit GGSO (Generalized Gliozzi–Scherk–Olive) phase enumerations in representative model classes with 12, 8, 4 and 0 moduli, classify the resulting $\mathcal{N}=1$ and $\mathcal{N}=0$ vacua according to phenomenological criteria and identify exophobic, phenomenologically viable models. We compute the partition function and corresponding one-loop vacuum energy at the free fermionic point in moduli space for each phenomenologically viable model across the four classes. As the number of geometrical moduli decreases, the number of distinct partition functions for these vacua collapses to a small number, reflecting a pronounced degeneracy under GGSO phase variations.

We employ multiparticle factorization to constrain deformations of tree-level open string amplitudes. Assuming minimal degeneracy among intermediate states of the same spin up through the second excited level, we find that the Regge intercept among all amplitudes of the Koba-Nielsen type can be uniquely fixed using seven-point factorization, precisely matching the bosonic string. Moreover, we produce novel constraints on deformations of the worldsheet integrand. We then turn to deformations of superstrings, with massless external states and arbitrary spectral degeneracy, using soft kinematics. Accounting for the infinite tower of higher-spin resonances, we obtain novel multipositivity bounds to leading and subleading order in the large-level limit. We apply these bounds to the simplest factorizable satellite deformation in the family of amplitudes found by Gross, showing that any deformation of four-point string amplitudes of this type is forbidden by unitarity. Our results reinforce the folklore that the higher-spin tower of string excitations is dramatically more rigid than any finite number of species.

The enumeration of black hole entropy in candidate theories of quantum gravity utilizes the quantum properties of microstates residing on the black hole horizon. For example, in loop quantum gravity, the computation of entropy is based on the spectrum of the area operator, and one determines the possible number of area microstates corresponding to a given classical horizon area. In this paper, we derive the eigenspectrum of the horizon area operator for rotating/nonrotating black holes in a gravitational theory nonminimally coupled to scalar fields. Using the weak isolated horizon formalism, we show that the spectrum of the area operator follows unambiguously from the algebra of horizon symmetry. More precisely, from the quantum mechanical point of view, the horizon geometry must be naturally discrete, a conclusion that is arrived at directly, without the need for any particular theory of quantum gravity. The area spectrum depends on the Barbero-Immirzi parameter as well as the value of the scalar field on the horizon. The area spectrum is equidistant, which is consistent with the Bekenstein-Mukhanov proposal and gives rise to black hole entropy and their quantum corrections.

Nonminimal couplings between matter and curvature tensors arise in many different contexts. Such couplings modify solutions of general relativity (GR) and therefore can be probed in various astrophysical systems. A particularly interesting scenario arises if dark matter experiences nonminimal couplings, as dark matter densities are expected to spike in the vicinity of binary black hole mergers. This gives a novel setting for simultaneously studying dark matter and (beyond) GR physics via observations of gravitational waves (GWs). In this work, we explore effects of various nonminimal couplings on GWs by working with a model-independent parametrization for left- and right-handed GW strains. We extend the parametrization proposed in Jenks et al. [Phys. Rev. D 108, 044023 (2023)] and Daniel et al. [Phys. Rev. D 109, 124012 (2024)] to include early-universe effects, and we write down the generic solution assuming slowly varying matter fields. We then systematically apply our results to three models: Kalb-Ramond dark matter with dimension-four operators, axion-dilaton-Chern-Simons-Gauss-Bonnet dimension-five operators, and dimension-six couplings to a (dark) vector field.

Many traditional algorithms applied in gravitational-wave astronomy rely on the assumption of Gaussian noise, a condition not always met in practice. Motivated by the need for analysis methods that are robust to such departures from Gaussianity, this study extends a robust statistical framework, advancing previous work on heavy-tailed likelihoods, that adapts the hyperbolic likelihood method for full frequency-domain applications. The framework is designed to maintain high performance under ideal conditions while improving robustness against non-Gaussian noise and outliers in real-world data. We demonstrate the efficacy of this approach through two key case studies. The first case study analyzes a massive black hole binary merger in simulated Laser Interferometer Space Antenna (LISA) data with Gaussian noise, showing that the extended hyperbolic likelihood method performs comparably to the more commonly used Whittle likelihood. The second case study examines a stellar-mass black hole binary merger using real ground-based gravitational-wave data containing non-Gaussian noise or overlapping signals, where our framework exhibits increased robustness and yields more accurate parameter estimations. Our results show that the hyperbolic likelihood better captures the true noise distribution, providing a flexible and physically motivated alternative for gravitational wave data analysis across current and future detectors.

We present general series solutions to the Tolman-Oppenheimer-Volkoff equations for compact stellar objects. We develop an algorithm to compute the coefficients of the power series in terms of the equation of state and its derivatives with respect to the thermodynamic variables. Using these results, we establish general properties of analytic solutions and their relation to the regularity of the equation of state. Applying the theory of Padé approximants, we derive series representations for meromorphic functions whose domains of convergence may include isolated poles. These analytic solutions are then used to obtain closed-form expressions to approximate the radius and mass of stellar objects. We apply the formalism to specific models, namely fluids with affine equations of state and polytropic fluids, and compare the results with those obtained from numerical integration. Lastly, we extend the formalism to piecewise equations of state, deriving series solutions that can be matched across transition hypersurfaces.

Applications of effective field theory (EFT) and scattering amplitudes to gravitational problems have recently produced many unique results that advanced our understanding of the dynamics of compact binaries. Many of these results were made possible by comparing gravitational scattering amplitudes in EFT with exact expressions from general relativity. However, the latter expressions are not easily available as they require intricate solution techniques for the Teukolsky master equation, such as the Mano-Suzuki-Takasugi (MST) method. In this paper, we develop and present the first public package that enables computations of gravitational scattering amplitudes in black hole perturbation theory within the MST framework. Our package supports both analytic computations to a given post-Minkowskian (PM) order in the low-frequency limit and exact numerical computations for an arbitrary frequency of the perturbing field. As an application, we compute scattering phase shifts and inelasticity parameters for massless spin—0, 1, and 2 fields resulting from scattering off a rotating Kerr black hole through the third PM order and compare these results with the exact numerical solutions.

We construct a class of regular black hole solutions of the Fan-Wang type within quasitopological gravity (QTG) in arbitrary spacetime dimensions greater than four. In contrast to the original Fan-Wang solution, which was obtained in four-dimensional general relativity coupled to nonlinear electrodynamics, our higher-dimensional generalization does not require any matter fields. Instead, regularity is achieved purely through an infinite tower of higher-curvature corrections. We demonstrate that the Fan-Wang-type metric is a solution to the QTG field equations by explicitly determining the corresponding coupling constants for each curvature order. Within an appropriate parameter regime, the solution describes an asymptotically flat black hole spacetime with a regular center. Remarkably, even in the case of negative mass, the geometry can remain completely regular, in sharp contrast to Einstein gravity.

In this paper, we turn to the learning the Universe implicit likelihood inference pipeline to perform a multiround implicit likelihood inference of the neutrino mass hierarchy from cosmological data, including $TT$, $TE$, and $EE$ power spectra of Planck 2018 and distance ratios of DESI DR2. More precisely, we first embed the CMB power spectra simulator class into the learning the Universe implicit likelihood inference pipeline. And then, opting for sequential neural likelihood estimation, we sequentially train neural networks using six rounds of 10000 simulations to target a “black box” likelihood of our forward model with one additional neutrino mass hierarchy parameter $\tilde{\mathrm{\Delta }}$ and six base cosmological parameters. We find $\tilde{\mathrm{\Delta }}=0.12_{-0.23}^{+0.21}$ (68% confidence level).

An analysis is given of interacting dark energy and dark matter where the dark energy is assumed to be an ultralight axionic field with a pseudo-Nambu-Goldstone boson potential, which is in general a superposition of $N$ number of cosine terms motivated by supergravity and string models with a $U(1)$ global symmetry, where the symmetry is broken by instanton effects. The case $N=2$ is investigated in detail and a fit to cosmological data is performed, where it is found that a better fit is obtained in comparison with the $N=1$ case. The fits also constrain high-scale parameters, i.e., the axion decay constant which is determined to be sub-Planckian, a result consistent with string theory that disfavors the trans-Planckian axion decay constant. Furthermore, the dark energy–dark matter interaction strength is constrained to be feeble, i.e., $\lambda \lesssim 4\times {10}^{-6}{\mathrm{m}}_{\mathrm{Pl}}^{-2}{\mathrm{Mpc}}^{-2}$. We study possible implications of this type of potential on the Hubble tension and on the dynamics of the dark energy equation of state using the Dark Energy Spectroscopic Instrument DR2 data. For the cases $N=3$, 4, the analysis exhibits the phenomenon of transmutation even in the absence of coupling to dark matter, where thawing quintessence transmutes to freezing quintessence. The analysis is internally consistent in its treatment of the dark energy–dark matter interaction, as it is based on an underlying Lagrangian, in contrast with several previous works where the sources are chosen in an ad hoc manner to satisfy energy conservation.

Strong lensing observations of the Bullet Cluster have traditionally been regarded as definitive evidence for the existence of dark matter, thereby posing a major challenge to the Milgromian dynamics (MOND) framework. The offset between the lensing mass and the x-ray gas centroids indicates the presence of a substantial amount of unseen mass in the vicinity of the brightest cluster galaxy (BCG). However, the high metallicities observed in the intracluster x-ray gas and in the massive early-type member galaxies suggest a past epoch dominated by massive stars, which have since evolved into stellar remnants. Their mass contribution is naturally incorporated in the integrated galaxy-wide initial mass function (IGIMF) theory, which predicts a significantly higher baryonic mass in early-type galaxies than the canonical IMF. In this work, we re-estimate the baryonic masses of the three BCG-centred core regions of the Bullet Cluster using recent JWST photometry and compare them with MOND strong-lensing masses. The IGIMF masses are derived for constant- and for (self-) enriched-metallicity stellar population synthesis models. These constitute, respectively, the lower and the upper limits of the IGIMF estimated mass, though the latter is the more realistic self-consistent scenario. Our results show that the MOND strong lensing masses of all cores fall between the IGIMF masses derived from the constant- and the enriched-metallicity stellar models. These results suggest that the baryonic mass budget is consistent with MOND requirements from strong-lensing observations in the core regions of the Bullet Cluster. However, the physical viability of this scenario also depends on the spatial distribution and dynamical behavior of the remnant population, which remain to be established. Independently of the validity of MOND, there is now an emerging perspective regarding dark matter models: to account for the observations, they seem to require less dark matter than previously anticipated.

We study the sensitivity of the upcoming Electron-Ion Collider to purely electrophilic new physics in the GeV mass range. Within an effective field theory framework, we consider two different scenarios: an axionlike particle (ALP) and a new heavy neutral vector gauge boson $Z^{\prime }$; each couples to electrons only. We analyze electron-proton collisions at $\sqrt{s}=141\mathrm{GeV}$ with an integrated luminosity of $100{\mathrm{fb}}^{-1}$, focusing primarily on the trielectron final state. Additionally, loop-induced ALP-photon couplings driven by photon final states are also explored. Incorporating realistic detector effects and systematic uncertainties, we obtain projected exclusion limits on the relevant cross sections and couplings. We find that the results from the Electron-Ion Collider can significantly extend the sensitivity to electrophilic axionlike particles and $Z^{\prime }$ bosons in regions of parameter space that remain weakly constrained by existing experiments.

We explore signatures of lepton number violation (LNV) from decays of the discovered Higgs ($h$) and $Z$ bosons into a pair of right-handed neutrinos (RHNs). Due to the Majorana nature of RHNs, the final state can be the same-sign dilepton plus jets leading to two units of LNV. As a simple but plausible scenario, we investigate such a signal in models with a new $U(1{)}_X$ gauge symmetry, which naturally introduces three RHNs for gauge anomaly cancellation and is spontaneously broken down by a vacuum expectation value of an isospin singlet scalar field ($\varphi$). In this scenario, $h$ and the $Z$ boson can decay into a pair of RHNs via the $h\text{−}\varphi$ mixing and the $Z\text{−}{Z}^{\prime }$ mixing with $Z^{\prime }$ being a new massive gauge boson, respectively. Estimating the LNV signal and corresponding backgrounds for the ${\ell }^{\pm }{\ell }^{\pm }4j$ final states, we find bounds on the $h\text{−}\varphi$ mixing and the $Z\text{−}{Z}^{\prime }$ mixing as a function of a mass of RHNs at Higgs factories, e.g., at the High-Luminosity LHC with $\sqrt{s}=14\mathrm{TeV}$, future $e^{-}{e}^{+}$ colliders at $\sqrt{s}=250\mathrm{GeV}$, muon colliders at $\sqrt{s}=125\mathrm{GeV}$, as well as at $Z$ factories, e.g., CEPC and Future Circular Collider (FCC-ee) at $\sqrt{s}=91.2\mathrm{GeV}$. We also discuss limits on the scalar mixing at $e^{-}{\mu }^{+}$ and ${\mu }^{+}{\mu }^{+}$ collisions ($\mu \mathrm{TRISTAN}$) with $\sqrt{s}=346\mathrm{GeV}/775\mathrm{GeV}$ and 2 TeV, respectively.

In this paper, we explore $(2+1)\mathrm{D}$ quantum electrodynamics at finite density on a quantum computer, including two fermion flavors. Our method employs an established gauge-invariant Ansatz together with a quantum circuit structure that enforces Gauss’s law. As a proof of principle, we benchmark our simulation protocol on a small lattice system of $2\times 2$, demonstrating the identification of density-induced level crossings in terms of the particle number of the fermion flavors. Classical simulations are used to obtain optimized variational parameters, which are then deployed in inference runs on IBM quantum hardware. We conclude by discussing hardware limitations and prospects for scaling this method to larger systems.

The chiral magnetic effect consists in the induction of the electric current along the direction of the magnetic field. The corresponding transport coefficient $b_0$, known as the chiral magnetic conductivity, is proportional to the chiral imbalance in the medium. In many systems, such as quark-gluon plasma, $b_0$ is time dependent. This paper studies the effect of the time variation of $b_0$ on the particle spectra and energy loss produced through the chiral Cherenkov and associated processes in Abelian and non-Abelian systems. The rates of all processes are derived in the ultra-relativistic approximation. The results are applied to the relativistic heavy-ion collisions utilizing a specific model describing the relaxation of the initial $P$-odd domain within the quark-gluon plasma. The corresponding energy loss is computed. The results suggest strong polarization of jets in quark-gluon plasma.

The local structure of the Higgs sector around the vacuum does not uniquely determine its global properties. Most of the current experimental data provide only local information, which allows for a rich variety of global features, including several distinct topologies of the scalar manifold, and the existence of zero, one, or two fixed points of the symmetry transformations. Here, I provide, under general conditions, a complete classification of realizations of the electroweak symmetry with minimal field content—the three would-be Goldstone bosons and the Higgs—and outline some of their physical consequences.