Charged lepton-flavor violation is a null-test frontier of the Standard Model and a direct probe of physics beyond it. We present a global effective field theory (EFT) analysis across FCC-ee, ILC, CLIC, HL-LHC, HE-LHC, and muon colliders at 3 and 10 TeV, with operator identification as the primary target rather than exclusion reach alone. The analysis combines low-energy constraints, collider differential observables, and Dalitz-level $\mu \to 3e$ information in a common profile-likelihood framework. Key hadron-collider and muon-collider signal/background samples are generated at the event level and propagated through Delphes detector simulation, while clean $e^{+}{e}^{-}$ benchmark channels are modeled with a parametric response calibrated to published detector-performance benchmarks. We include one-loop renormalization group (RG) running and operator mixing between UV matching and measurement scales, finding 10–30% shifts in selected operator-correlation entries when comparing tree-level and RG-evolved coefficient mappings at multi-TeV matching scales. Polarization asymmetries are used to separate $c_{H\ell }$ and $c_{He}$ directions, and UV discrimination is quantified with Bayes factors for benchmark leptoquark and heavy-neutral-lepton hypotheses. The full code chain for event generation, detector response, inference, and figure reproduction is provided.

We investigate a weakly interacting massive particle dark-matter (DM) candidate in the form of a singlino-dominated lightest supersymmetric particle (LSP) within the $Z_3$-symmetric next-to-minimal supersymmetric standard model (NMSSM). This framework gives rise to regions of parameter space where DM is obtained via coannihilation with nearby Higgsino-like electroweakinos and DM direct-detection signals are suppressed, the so-called “blind spots.” On the other hand, collider signatures remain promising due to enhanced radiative decay modes of Higgsinos into the singlino-dominated LSP and photons rather than into leptons or hadrons. Compared to MSSM scenarios with light bino- and winolike electroweakinos, the NMSSM allows for final states with multiple photons arising from cascade radiative decays, providing a distinctive collider signature. This motivates searches for radiatively decaying neutralinos; however, these signals face substantial background challenges, as the decay products are typically soft due to the small mass splits ($\mathrm{\Delta }m$) between the LSP and the Higgsino-like coannihilation partners. We apply a data-driven machine-learning analysis that improves sensitivity to these subtle signals, offering a powerful complement to traditional search strategies to discover a new physics scenario. Using an LHC integrated luminosity of $100{\mathrm{fb}}^{-1}$ at 14 TeV, the method achieves a $5\sigma$ discovery reach for Higgsino masses up to 225 GeV with $\mathrm{\Delta }m\lesssim 12\mathrm{GeV}$ and a $2\sigma$ exclusion up to 285 GeV with $\mathrm{\Delta }m\lesssim 20\mathrm{GeV}$. These results highlight the power of collider searches to probe DM candidates that remain hidden from current direct-detection experiments and provide a motivation for a search by the LHC collaborations using machine-learning methods.

The recent Jiangmen Underground Neutrino Observatory (JUNO) measurements of ${\theta }_{12}$ and $\mathrm{\Delta }{m}_{21}^2$ open a new avenue for probing flavor symmetric structures in the lepton sector. Motivated by this, we study a model in which $\mu -\tau$ reflection symmetry naturally emerges from an underlying $A_4$ flavor symmetry within a type-II seesaw framework. Beyond its standard predictions of ${\theta }_{23}=45°$ and ${\delta }_{\mathrm{CP}}=\pm \pi /2$, the framework yields testable predictions for ${\theta }_{12}$ that can be probed by JUNO. Two viable scenarios arise, one predicting ${\sin }^2{\theta }_{12}\gtrsim 0.335$, which is strongly disfavored by the latest JUNO results. Correlations between ${\theta }_{12}$ and model parameters further enhance the model’s predictivity. Future measurements at DUNE and T2HK will provide complementary tests of this scenario.

In light of the recent Particle Data Group (PDG) release, we revisit the running quark and lepton Yukawa couplings, together with the quark mixing parameters, across a range of energy scales. The 2024 PDG determinations of low-energy fermion masses feature significantly smaller uncertainties, resulting from a reduced estimate of systematic errors compared to the more conservative treatment in the 2022 analysis. To assess the impact of these changes, we present running parameters obtained using both the 2022 and 2024 datasets, within the frameworks of the Standard Model (SM) and its minimal supersymmetric extension (MSSM). The evolved values, along with their associated $1\sigma$ uncertainties, are given within the SM framework at benchmark scales of $M_Z$ and ${10}^3$, $3\times {10}^3$, ${10}^4$, ${10}^5$, ${10}^7$, ${10}^9$, ${10}^{12}$, and ${10}^{16}\mathrm{GeV}$. Within the MSSM, we additionally provide Grand-Unified-Theory-scale results for different choices of $\tan \beta$, assuming supersymmetry breaking scales of 3 and 10 TeV, including an approximate way for taking supersymmetric loop threshold corrections into account. We furthermore discuss implications of the updated results for constructing and testing theories beyond the SM.

This work investigates the possibility of accessing the initial geometric shape of the proton in proton-proton and proton-nucleus collisions at the LHC. In particular, we look for manifestations of the configuration in which the proton is made of three quarks linked by a Y-shape gluon string, called baryon junction. This initial state spatial configuration has been used in the past to describe data on baryon rapidity distributions, diffractive $J/\psi$ production and multiplicity distributions in $pp$ collisions. In spite of its success in explaining the data, the evidence of the baryon junction still needs confirmation. Further studies will be undertaken at the electron-ion collider. In this work we study multiplicity distributions measured in $pp$ and pPb collisions. Different initial state geometries are used as input in a Monte Carlo event generator which implements the $k_T$-factorization formalism of the color glass condensate with Kharzeev-Levin-Nardi unintegrated gluon distributions. The results show that the data on multiplicity distributions are good enough to discriminate between different initial state geometries. Moreover, they indicate that it is crucial to take into account the intrinsic fluctuations of the saturation scale.

We demonstrate that chiral-odd dimeson generalized distribution amplitudes (CO-GDAs)—nonperturbative objects encoding the transition of a quark-antiquark pair into two mesons—can be accessed in high-energy $e^{-}{e}^{+}$ annihilation into two meson pairs, each with a relatively low invariant mass. While chiral-even GDAs contribute to the leading one-photon amplitude, the chiral-odd sector enters via two-photon exchange. We show that the interference between these amplitudes leads to specific effects which may be measurable at BES III or future tau-charm factories. This work opens a direct path to experimentally probing the long-missing chiral-odd sector of meson structure—specifically, the spin-orbit correlation in a spin-0 meson, in some contexts referred to as anomalous tensorial magnetic moment.

The observation of $CP$ violation in the difference of $CP$ asymmetries between $D\to K^{+}{K}^{-}$ and $D\to {\pi }^{+}{\pi }^{-}$ has raised a debate whether the observed asymmetries can be regarded as a signal of physics beyond the standard model (SM). In this paper we obtain all the topological amplitudes and isospin amplitudes directly from measured observables for $D\to \pi \pi$. These results unambiguously imply a very large penguin contribution, having a central value 4.74 times the magnitude of the amplitude for $D^0\to {\pi }^{+}{\pi }^{-}$. This fitted central value differs from a reasonable SM estimate of 10% with a significance greater than $3.3\sigma$. In contrast to previous studies, we present model-independent arguments based only on unitarity of rescattering amplitudes to show that large penguins cannot arise from rescattering alone and likely indicate physics beyond the SM. In a model-independent approach we show how a very small contribution from physics beyond the SM with a large weak phase alleviates the problem.

In a previous paper [Flores-Baez et al., Phys. Rev. D 76, 096010 (2007)] we have calculated the radiative corrections to $\rho \to \pi \pi$ decays, aiming to estimate the width difference between charged and neutral rho mesons. There, we have used the scalar quantum electrodynamics approximation and considered the convection terms to keep the loop contributions finite in the case of charged rho meson decays. Here we compute the radiative corrections by considering the electromagnetic structure of charged mesons and we also include the full Lorentz structure of the electromagnetic vertices. We reevaluate the width difference of ${\rho }^{\pm }-{\rho }^0$ vector mesons and calculate the structure-dependent contributions to final state radiation terms in the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ cross section. Both effects are important inputs for evaluating the isospin breaking corrections in the dominant hadronic vacuum polarization contributions to the muon $g-2$ when using $\tau$ lepton data.

In this work, we study the radiative decays of the ${\mathrm{\Sigma }}_c$, ${\mathrm{\Xi }}_c^{\prime }$, and ${\mathrm{\Omega }}_c$ charmed baryons, which belong to the flavor sextet (${\mathbf{6}}_{\mathrm{F}}$), within the constituent quark model formalism. The electromagnetic transitions are calculated from the ground and $P$-wave states to ground states, as well as from the second shell states to both the ground and $P$-wave final states. These decays play a crucial role in confirming the existence of certain resonances when strong decays are not allowed. Moreover, electromagnetic decay widths are particularly useful for identifying resonances when states have the same mass and total decay width. A relevant case is the ${\mathrm{\Omega }}_c(3327)$ state, whose branching ratios between the strong decay channels are comparable; thus, the radiative decay widths may help assign this state. We also make the assignment of the recently discovered ${\mathrm{\Xi }}_c^{\prime }(2923{)}^{+}$ baryon, which is consistent with being the isospin partner of the ${\mathrm{\Xi }}_c^{\prime }(2923{)}^0$. This study presents, for the first time, the calculation of electromagnetic decays for $D_{\rho }$-wave states, $\rho -\lambda$ mixed states, and $\rho$-mode radially excited states in the charm sector. Throughout our calculations, we account for uncertainties arising from both experimental and model-dependent errors.

Motivated by the recent introduction of the Dirac bracket framework to compute spinning observables for the scattering of Kerr black holes, we initiate the study of conserved quantities from an on shell amplitude perspective. We establish new results for the conservation of energy, angular momentum, the Rüdiger invariant, and the quadrupolar Carter constant using the spinning radial action extracted from the literature both in the probe limit and beyond, up to third post-Minkowskian order in the conservative sector. Furthermore, we offer a new perspective on the spin-shift symmetry of the radial action, clarifying its role in the dynamics. Finally, we define a new on shell notion of asymptotic integrability in the Liouville sense and present strong evidence that it is surprisingly satisfied by a spinning probe in Kerr up to quartic order in the probe spin, to all orders in the post-Minkowskian expansion. We further establish integrability beyond the probe limit at low post-Minkowskian orders. Our results suggest important new implications for the dynamics of Kerr black holes.

Entanglement asymmetry has emerged in recent years as a practical quantity to study phases of matter. We present the first study of entanglement asymmetry in gauge theories by considering the chiral anomaly of the analytically solvable massless Schwinger model at both zero and finite temperatures. At zero temperature, we find the asymmetry exhibits logarithmic growth with system size. At finite temperature, we show that it is parametrically more sensitive to chiral symmetry breaking than the corresponding local order parameter: While the chiral condensate decays exponentially, the asymmetry decreases only logarithmically. This establishes the entanglement asymmetry as a promising tool to probe (finite-temperature) phase transitions in gauge theories.

We consider scenarios where Jackiw-Teitelboim black holes are attached to baths whose temperatures can be manipulated externally. We consider the bath to be cooled continuously and numerically investigate the subsequent evolution of the generalized entropies of the black hole. Page curves corresponding to several different cooling profiles of the bath are obtained.

We calculate the Feynman propagator at finite temperature in an Einstein universe for a neutral massive scalar field arbitrarily coupled to the Ricci curvature. Then, the propagator is used to determine the mean square fluctuation, the internal energy, and pressure of a scalar blackbody radiation as functions of the curvature coupling parameter $\xi$. By studying thermodynamics of massless scalar fields, we show that the only value of $\xi$ consistent with stable thermodynamic equilibrium at all temperatures and for all radii of the universe is $1/6$, i.e., corresponding to the conformal coupling. Moreover, if electromagnetic and neutrino radiations are present at the regime of high temperatures and/or large radii, we show that at least one scalar field must also be present to ensure thermodynamic stability.

This work explores the prospect of using the plunge to identify potential black-hole mimickers. We show that the plunge excites two generic spectral features. (i) At low frequencies, there is a comb of sharp resonances at the real parts of the mimicker quasinormal modes. (ii) Above a threshold $M{\omega }_{\mathrm{th}}\approx 0.39$ (for the dominant mode), the spectrum undergoes a qualitative break with the black-hole mimicker displaying significant deviations from the black hole. Though individual plunge signal-to-noise ratios (SNRs) in extreme mass ratio events are low and detecting them in a sea of noise is difficult, the coherent spectral features identified here may allow for enhancing the SNR by using multiple events.

Cluster catalogs selected by optical properties are subject to selection biases, primarily arising from unresolved systems along the line of sight. These biases affect key observables for cluster cosmology, such as the lensing signal and clustering statistics. In this work, we present a fully predictive forward analytical model to quantify the impact of optical-selection bias due to projection effects on cluster density profiles. This is achieved by introducing a scale-dependent parametrization of the optical cluster bias, whose small- and large-scale behavior is set by the amplitude of projection effects, and by expressing the two-halo component of the density profile in terms of the contributions from off-axis halos along the line of sight. As a case study, we consider a DES Y3-like cluster catalog and validate our model against simulated samples. Our model successfully captures the dependence of the two-halo component on richness boosts induced by projections, as well as its evolution with richness and redshift. It also recovers the overall bias in the projected density profile relative to a randomly selected sample with the same mass distribution. The framework presented here provides a consistent methodology for modeling the impact of line-of-sight structures on the observed richness and density profiles of optically selected clusters, directly linking selection biases to the underlying cosmology and survey specifications.

We present the first assessment of the Ali Cosmic Microwave Background Polarization Telescope’s (AliCPT) sensitivity to the reheating epoch after cosmic inflation, based on its ability to detect primordial gravitational waves. We consider three models of inflation, an $\alpha$-attractor T-model, radion gauge inflation and quantum chromodynamics (QCD)-driven warm inflation. Assuming a fiducial value of $r=0.01$, we find that AliCPT-1, in its fully loaded focal plane detector configuration and combined with Planck, can provide measurements of the order of magnitude of the reheating temperature with an accuracy around 10%. For QCD-driven warm inflation this can be translated into a constraint on the inflaton coupling to gluons, which can be probed independently in axion search experiments. Our results constitute the first demonstration of AliCPT’s ability to probe the initial temperature of the hot big bang and the microphysical parameter connecting cosmic inflation and particle physics.

The presence of additional relativistic particles at the time of recombination can be inferred through their contribution to $\mathrm{\Delta }{N}_{\mathrm{eff}}$. If these species have a finite but low mass (light massive relics—LiMRs), they act as a hot subcomponent of dark matter and impact late-time structure formation. Understanding these effects will be crucial to pin down the underlying particle physics properties of any future $\mathrm{\Delta }{N}_{\mathrm{eff}}$ detection. While their impact has been well studied on linear scales, this work develops the framework for and presents results from the first set of cosmological N-body simulations that can track the effects of LiMRs, as a function of their mass and temperature, down to fully nonlinear scales. Importantly, our simulations model the impact of both the massive Standard Model neutrinos and LiMRs, which will be crucial in disentangling possible degeneracies. We systematically explore the effects of LiMR properties such as mass, temperature, and initial distribution, on various cosmological observables, including the total matter power spectrum, halo mass functions, mass-concentration relation, radial halo profiles, and weak lensing signals around massive clusters. The presence of LiMRs leads to a suppression of $\sim 10\%$ and $\sim 6\%$ in the total matter power spectrum for fermionic and bosonic species, respectively. This suppression is measured relative to a $\mathrm{CDM}+\mathrm{SM}$ neutrino cosmology at $k\sim 0.1h{\mathrm{Mpc}}^{-1}$ for LiMRs fraction ($f_l$) $\sim 0.02$. The framework and simulations developed here will enable detailed followup of the rich phenomenology of LiMR cosmologies.

We study the galaxy bispectrum multipoles in the Hu-Sawicki $f(R)$ gravity model, where a scalar degree of freedom mediates a fifth force that is screened in high-density environments. The model is specified by $f_{R0}$, the present-day background value of the scalar field, which controls the strength of deviations from general relativity. Using perturbation theory, we compute the redshift-space galaxy bispectrum with the full scale- and time-dependent second-order kernels, incorporating corrections from the scale-dependent growth rate and nonlinear screening. Expanding the bispectrum in spherical harmonics, we analyze the sensitivity of the multipoles to modified gravity and forecast their detectability in a Euclid-like survey. The monopole ($B_0^0$) and quadrupole ($B_2^0$) show the strongest signatures, with relative deviations of 2%–8% at $z=0.7$ and $k_1\simeq 0.3h{\mathrm{Mpc}}^{-1}$ (largest side of the triangle) for $f_{R0}={10}^{-5}$. Higher multipoles provide weaker but complementary signals. For Euclid, we forecast signal-to-noise ratios up to $\sim 30$ for the monopole and $\sim 15$ for the quadrupole including the finger-of-God damping and shot noise effect. These results demonstrate that bispectrum multipoles are a powerful probe of gravity, capable of breaking degeneracies with bias and velocity effects and strengthening constraints on deviations from $\mathrm{\Lambda }\mathrm{CDM}$.

We present galaxy-galaxy lensing measurements from the full six years of data from the Dark Energy Survey (DES Y6), covering $4031{\mathrm{deg}}^2$ and used in the DES Y6 $3\times 2\mathrm{pt}$ cosmological analysis. We use the Maglim++ lens sample, containing $\sim 9\mathrm{million}$ galaxies divided into six redshift bins, and the Metadetection source catalog, including $\sim 140\mathrm{million}$ galaxies divided into four redshift bins. The mean tangential shear signal achieves a total signal-to-noise ratio (S/N) of 173, corresponding to a 17% improvement over DES Y3. After applying the scale cuts used in the cosmological analysis, with $R_{\min }=6\mathrm{Mpc}/h$ ($4\mathrm{Mpc}/h$) for the linear (nonlinear) galaxy-bias model, the S/N is reduced to 75 (90). A comprehensive suite of validation tests demonstrates that the measurement is robust against observational and astrophysical systematics at the statistical precision required for the DES Y6 analysis. Although not used in the main cosmological analysis, we extract high signal-to-noise geometric shear-ratio measurements from the galaxy-galaxy lensing signal on small angular scales. These measurements provide an internal consistency check on the photometric redshift distributions and shear calibration used in the $3\times 2\mathrm{pt}$ analysis.

The properties of dwarf galaxies orbiting the Milky Way (MW) are useful for testing models of the formation of our Galaxy, and by extension various theories of cosmology. Recent efforts to measure the masses of the MW’s satellite dwarf galaxies have relied on the motions and positions of stars in the MW’s disk and halo, which are perturbed by the passage of satellite galaxies. As there are many known processes in our Galaxy that lead to observed disequilibrium in stars, these kinematic methods have been limited by the inherent difficulty in identifying only the perturbations due to particular satellite galaxies. To bypass some of these restrictions, we present a novel method for determining the masses of two MW satellite galaxies—the Large Magellanic Cloud (LMC) and the Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph)—using only direct, instantaneous acceleration data derived from extremely precise timing of millisecond pulsars near the Sun. As the LMC and Sgr dSph orbit the MW, they cause wavelike distortions in the structure of the disk plus a large-scale offset in the centers of mass of the dark matter halo and the baryonic disk. These two effects lead to asymmetric accelerations above and below the disk midplane near the Sun, which is observed in the pulsar acceleration data. Notably, the amplitude of this asymmetry is shown to depend on the masses of the orbiting satellites. We analyze a grid of simulations with varying masses of each satellite in order to determine how well the observed acceleration asymmetry is reproduced by each pair of satellite masses. We find the total ($\mathrm{dark}+\text{baryon}$) mass enclosed within the tidal radius at the present day for the LMC to be $4.1\pm 1.0\times {10}^{10}{M}_{\odot }$ within a radius of 16.6 kpc, and for Sgr to be $3.5\pm 2.4\times {10}^8{M}_{\odot }$ within a radius of 5 kpc. These results are generally consistent and competitive with previous simulations and determinations of the masses of these objects, but entirely independent of any stellar kinematic data for the first time.