Papers

We investigate electromagnetic corrections to the $B$-meson decay constant and light-cone distribution amplitudes (LCDAs) within the framework of heavy-quark effective theory. The inclusion of QED effects extends the support of the LCDAs to negative values of the light-cone momentum. We clarify the relation between this region and QED-generalized decay constants sensitive to electromagnetic final-state radiation. We derive model-independent expressions for the asymptotic behavior in the large negative-momentum region of the QED-generalized LCDAs $\Phi_\pm(\omega,\mu)$ in terms of integrals over the two- and three-particle LCDAs defined in pure QCD. We show that our result for $\Phi_+$ is consistent with the renormalization-group equation satisfied by this object and study its evolution using the known one-loop anomalous dimension. Finally, we propose a phenomenological model consistent with these constraints

Dirac leptogenesis offers a qualitatively different route to the baryon asymmetry: total lepton number is conserved, but equal and opposite asymmetries are stored in the Standard Model and right handed neutrino sectors, with only the visible component processed by electroweak sphalerons. We present the first dedicated study of how evaporating primordial black holes (PBHs) modify this mechanism. In a minimal charged-scalar mediator setup, we solve the coupled Boltzmann system including thermal production, Hawking emission of the mediator $X$ and of right handed neutrinos, the PBH contribution to the expansion rate, and entropy injection. We find that Hawking emission can populate $X$ in regions where thermal production is inefficient, allowing its subsequent CP-violating decays to enhance the baryon asymmetry. For representative benchmarks, PBHs extend the successful region from mediator masses around $10^9\,{\rm GeV}$ down to about $10^6\,{\rm GeV}$ and can compensate for smaller effective CP asymmetries. This effect is not universal: where thermal Dirac leptogenesis is already efficient, PBHs can instead reduce the final asymmetry. Their evaporation also deposits energy in the right handed neutrino sector and contributes to $\Delta N_{\rm eff}$. In the PBH parameter scan, part of the region that reproduces the observed baryon asymmetry lies below the Planck reference level $\Delta N_{\rm eff}=0.284$ and above the projected CMB-S4 sensitivity $\Delta N_{\rm eff}=0.06$.

Neutrino self-interactions mediated by a light scalar offer a compelling resolution to cosmological tensions and may naturally arise in neutrino mass generation mechanisms. When the scalar also couples to a light dark-sector fermion, supernova neutrinos can resonantly annihilate with the cosmic neutrino background (C$\nu$B) into invisible dark radiation, depleting the flux en route to Earth. We use this depletion to constrain the neutrino-scalar coupling from the SN1987A data. Within a Bayesian framework we analyze the data for two supernova neutrino emission models, a parameterized model and a 2D hydrodynamic simulation, and for two coupling types, a mass-independent one and a mass-proportional one. Our results show that new-physics limits from SN1987A cannot be quoted independently of the heavy-flavor emission, the flavor conversion, or the coupling structure. Finally, we forecast that a future high-statistics burst recorded by Hyper-Kamiokande would restore a meaningful upper bound even when flavor conversion is included.

A discrete, anomaly-free $\mathbb Z_9$ gauge symmetry may persist to the deep infrared, exactly forbidding proton decay. This $\mathbb Z_9$ can emerge from Higgsing a lepton-flavour non-universal $U(1)_X$ that generates realistic neutrino masses and mixings through a high-scale seesaw and predicts an additional light Goldstone. Adding an anomaly-free chiral heavy-quark sector turns this mode into the QCD axion. The same selection rules that ban proton decay also forbid PQ-violating operators below a suitably high dimension, $d_{\rm PQ}\gtrsim10$, including operators involving the heavy quarks that radiatively match onto the scalar potential. We construct explicit models viable when PQ breaking occurs before or after inflation; in the latter case, avoiding stable heavy relics and eliminating the string-wall network tightly constrain the heavy-quark spectrum. We identify restricted regions of parameter space where thermal leptogenesis remains viable and, for $d_{\rm PQ}\geq13$, can coexist with a high-quality axion constituting all of the dark matter.

We comment on the recent work [Eur. Phys. J. C 86, 988 (2026)], which investigates quantum resources in polarized hyperon–antihyperon systems using correlated dephasing channels with memory. Although the use of experimentally reconstructed spin-density matrices to characterize quantum correlations in hyperon production may be a good motivation, we argue that the interpretation of the hyperon–antihyperon pair as an open quantum system undergoing correlated environmental decoherence is not physically established. In particular, no physical environment or system–environment interaction responsible for the assumed correlated dephasing channel is identified, and hadronization cannot simply be interpreted as such an environmental dephasing process. Consequently, the claimed non-Markovianity, information backflow, and memory-assisted protection of quantum resources should be regarded as properties of a phenomenological channel rather than established physical effects in hyperon–antihyperon production. We also identify several technical and conceptual issues concerning the dephasing dynamics, entanglement quantification, basis dependence of coherence, and the claimed hierarchy of quantum resources. These issues call for a substantial revision of the physical interpretation and quantitative conclusions of the work. We hope that the present Comment will help clarify the distinction between phenomenological quantum-channel modeling and physically established dynamical mechanisms in high-energy particle systems, and thereby provide useful guidance for future studies and help avoid similar conceptual and technical issues.

The LUX-ZEPLIN (LZ) experiment has reported a single candidate event in the high-energy nuclear recoil window $248\pm32.5\ \mathrm{keV}_{\mathrm{nr}}$ with an exposure of $2.84\ \mathrm{ton}\cdot\mathrm{yr}$, while the low-energy spectrum remains consistent with background expectations. We demonstrate that this excess can be naturally explained by the neutral-current absorption of fermionic dark matter on xenon nuclei. For a dark matter mass $m_\chi \simeq 247\ \mathrm{MeV}$, the coherent absorption process produces a monoenergetic nuclear recoil at $E_R \simeq 248\ \mathrm{keV}_{\mathrm{nr}}$. At this momentum transfer, the absorption process enters the incoherent regime, where scattering off individual nucleons produces a broad recoil spectrum extending from $\sim 200\ \mathrm{keV}$ to $100.2\ \mathrm{MeV}$. We show that a single effective field theory coupling can simultaneously produce one event in the $248\pm32.5\ \mathrm{keV}_{\mathrm{nr}}$ window while remaining consistent with the non-observation of events in neighboring energy regions. The required single-nucleon absorption cross section is $\sigma_{\chi N}^{\mathrm{NC}} = 1.07\times10^{-46}\ \mathrm{cm}^2$, corresponding to an effective field theory scale $\Lambda \simeq 11.5\ \mathrm{TeV}$. However, a recasting analysis of KamLAND data on the neutron-emission channel $\chi+{}^{12}\mathrm{C} \to \nu + n + {}^{11}\mathrm{C}^*$ excludes this benchmark parameter space, establishing a significant tension between the LZ excess interpretation and existing constraints from large-volume scintillator detectors. We discuss the implications of this tension and prospects for resolving it with future dedicated high-energy analyses.

The excess of high-energy nuclear recoils, which was recently reported by the LUX-ZEPLIN (LZ) experiment, together with the Fermi-LAT Galactic-Center preference, suggests new physics beyond the standard model (SM). One of the minimal extensions of the SM is to introduce a fermionic electroweak doublet in which the lightest neutral component can play the role of a stable dark matter particle. We show that the minimal higgsino dark matter can offer a common origin for both excesses. The inferred mass splitting, however, depends on the local dark matter velocity distribution, and including the high-velocity tail generated by the gravitational influence of the Large Magellanic Cloud yields $\delta_m =481$–$519~\mathrm{keV}$ for $m_\chi =1000$–$1183~\mathrm{GeV}$ at $1\sigma$ level. Near elastic-scattering blind spots, solar-captured higgsinos fail to reach thermal equilibrium, weakening their annihilation signal, so that ten years of IceCube data exclude $\delta_m \lesssim 475~\mathrm{keV}$ at 90% C.L. The viable parameter space can be tested through the associated gamma-ray line, which is within the projected reach of CTAO.

We propose Higgsino dark matter as a potential interpretation of the $248~\mathrm{keV}$ nuclear-recoil event of interest reported by the LUX-ZEPLIN (LZ) experiment. LZ studied several rare background processes and detector effects in detail, but did not identify any as a likely explanation of the event. A nearly pure Higgsino naturally realizes inelastic dark matter through the off-diagonal $Z$ coupling of two nearly degenerate neutral Majorana states separated by a mass splitting $\delta$. The same electroweak interaction fixes the inelastic Higgsino-nucleon scattering cross section, rather than leaving it as a free parameter. We show that the predicted Higgsino inelastic scattering cross section approaches the published LZ two-sided 90% confidence interval for a Higgsino mass $m_{\widetilde H}\sim1~\mathrm{TeV}$ and a mass splitting $\delta\sim350~\mathrm{keV}$.

Higgsino dark matter is a classic, but still viable, weakly-interacting massive particle (WIMP) scenario that could point to supersymmetry, a new spacetime symmetry of nature. It is a simple realization of the "inelastic dark matter" mechanism, where its scattering off a nucleus occurs between two nearly degenerate states. Intriguingly, very recently the LZ collaboration reported a single nuclear recoil event at a high recoil energy. Assuming that this event is a dark matter candidate, it could be explained by higgsino dark matter, e.g., a 1.1 TeV thermal higgsino with a mass splitting of order hundreds of keV. The mass splitting required is very sensitive to the extreme high speed tail of the local dark matter velocity distribution, and thus susceptible to astrophysical uncertainties: the standard halo model prefers ~350 keV, while a model incorporating Large Magellanic Cloud effects prefers ~500 keV (a rough estimate based on partial information about a particular simulation). A much better understanding of the high speed tail is needed to evaluate whether the parameter space is consistent with an IceCube constraint on the annihilation of dark matter captured by the Sun. In any case, the mass splitting of several hundred keV implies that the electroweak gauginos and heavy Higgs scalars in supersymmetry have to be at a much higher scale ~10^{3-4} TeV. We discuss possible UV completions to generate a SUSY spectrum in which all superpartners are at a common scale, except for a much lighter higgsino mass $\mu$. Besides the thermal benchmark, we comment on possible non-thermal cosmological scenarios of higgsino dark matter with gravitino and modulus decays. The higgsino dark matter scenario could also be searched for at other complementary probes such as indirect detection and future colliders. One striking LZ event may herald an exciting future of further experimental developments.

We study gravitational-wave production during perturbative reheating without assuming instantaneous thermalization of the inflaton decay products. The injected energetic particles thermalize through an in-medium cascade of nearly collinear splittings subject to the Landau-Pomeranchuk-Migdal effect and are ultimately isotropized by elastic scatterings near the thermal scale. The non-thermal hard population present before complete thermalization produces an additional gravitational-wave component through hard-soft scatterings, with $\Omega_{\mathrm{GW}}\propto f^{1/2}$ below the injection-scale turnover. The same isotropization erases the directional information underlying the vacuum $1/k$ bremsstrahlung soft pole, changing the deep-infrared spectrum from $\Omega_{\mathrm{GW}}\propto f$ to $\Omega_{\mathrm{GW}}\propto f^3$.

The LUX–ZEPLIN Collaboration recently reported one event at $E_{\mathrm{nr}}=248\pm23~\mathrm{keV}$ with an exposure of $2.84~\mathrm{tonne\cdot yr}$. In this Letter, we interpret this feature using endothermic dark matter (DM). We consider both direct scattering of the surviving ground-state halo component and the contribution of excited states produced by terrestrial upscattering. Our calculations show that explaining the high-energy event requires $m_\chi\gtrsim500~\mathrm{GeV}$ and a mass splitting of $\mathcal{O}(300)~\mathrm{keV}$, for which the production of excited states inside the Earth is kinematically forbidden. For $\bar{\sigma}_n=10^{-37}~\mathrm{cm^2}$, an illustrative two-bin likelihood analysis yields a representative best-fit point at $(m_\chi,\delta)\simeq(1.105~\mathrm{TeV},350~\mathrm{keV})$. The preferred parameter region may be tested by the planned CRESST upgrade.

We study medium modifications to generalized projected energy correlators, referred to as $\nu$-correlators, measured on jets in heavy-ion collisions. While the vacuum distributions of these correlators exhibit a characteristic $1/\nu$ enhancement, we show that in a dense medium this behavior is regulated within both the BDMPS-Z and semi-classical approximations as $\nu \to 0$. As a result, contributions from medium-induced emissions become parametrically suppressed relative to the vacuum baseline. We observe a similar trend in the simulated events generated with JEWEL. We find that while the large angle enhancement is qualitatively similar across different values of $\nu$, the small angle distribution changes drastically between $\nu<1$ and $\nu>1$. This indicates that small angle modifications, primarily driven by jet energy loss, are imprinted differently across $\nu$-correlators. In particular, for $\nu<1$ the small angle enhancement is less prominent which suggests that these correlators may provide improved sensitivity to medium modifications in the large angle region.

We investigate the phase structure of magnetized quark matter within a nonlocal SU(2) Polyakov-Nambu-Jona-Lasinio model. Our work focuses on the interplay between temperature and imaginary chemical potential in the presence of an external uniform magnetic field, with emphasis on the deconfinement and Roberge-Weiss transitions. We analyze the dependence of the relevant critical temperatures on the external field, and we explore the sensitivity of the phase structure to different Polyakov loop effective potentials. Our results show qualitative agreement with lattice QCD findings, reproducing inverse magnetic catalysis in the chiral sector and a decreasing behavior of the Roberge-Weiss transition temperature with increasing magnetic field.

Recently, the BESIII Collaboration claimed that their observed $X(2370)$ ($J^{PC}=0^{-+}$) is predominantly a glueball state based on several arguments. However, we find these arguments to be flawed and the conclusion unjustified. Instead, we demonstrate that all observed properties of the $X(2370)$ can be naturally explained by a $\bar\Sigma\Sigma$ molecule dominated state.

We update our analyses concerning the non-resonant (Drell-Söding) contribution to the reaction $\gamma^{(*)} p \to \pi^{+} \pi^{-} p$, now including general vertex functions for the coupling of pomeron, $f_{2 \mathbb{R}}$, and $\rho_{\mathbb{R}}$, to pions. This takes into account the off-shellness of the pions. We present a comparison of our tensor-pomeron model, including our new Drell-Söding and $\rho$, $\omega$ vector-meson contributions, with data for the $\gamma p \to \pi^{+} \pi^{-} p$ reaction measured by the ZEUS and H1 Collaborations. We find very good agreement of our theory with the experimental data for the $\pi^{+} \pi^{-}$ invariant mass ($M_{\pi \pi}$) and for angular distributions. Here we restrict our analysis to the region $M_{\pi \pi} \lesssim 1.2$ GeV. For higher values of $M_{\pi \pi}$ we will have to consider production of higher-mass mesons. The purpose of the present article is to show that our tensor-pomeron model gives a very good fit to the so-called skewing of the $\rho$-resonance contribution in photoproduction. In fact, it is an old problem/puzzle to understood the difference of the shapes of the $M_{\pi \pi}$ distributions in the region of the $\rho(770)$ resonance in $e^{+} e^{-}$ annihilation and photoproduction. We think that with our results we have obtained for this problem a solution which is very satisfactory from the Quantum-Field-Theory point of view. Our results are also relevant for central-exclusive $\pi^{+} \pi^{-}$ production in ultraperipheral $pp$, A$p$, and AA collisions at the LHC and for photo- and electroproduction of $\pi^{+} \pi^{-}$ at future electron-proton/ion colliders, EIC and LeHC.

We study the spectral functions and spin alignment of $J/\psi$ and $\phi$ mesons at finite density in a soft-wall holographic model. The quark-gluon plasma background is described by a charged black hole geometry, and the vector mesons are treated as probe bulk vector fields. The present analysis extends the zero-density study of Phys. Rev. D 110 (2024) 056047 (Ref.~\cite{XLS2024}) to finite density; in the zero-density limit our results reproduce the corresponding findings. We derive the relation between the production rates in different spin channels and the corresponding in-medium spectral functions, and examine their dependence on the chemical potential, meson momentum, and temperature. We analyze the spin alignment induced by the motion of the vector meson relative to the thermal bath. At $T=0.15~\mathrm{GeV}$, the $J/\psi$ spectral function exhibits a clear resonance peak, indicating that the $c\bar{c}$ pair can still form a quasistable bound state. As the chemical potential increases, this peak becomes lower and broader, signaling enhanced dissociation in the medium. For the $\phi$ meson at the same temperature, no pronounced peak is observed, indicating substantial melting; its spectral function thus better characterizes the distribution of unstable $s\bar{s}$ pairs in the thermal environment. At $T=0.15~\mathrm{GeV}$, the helicity-frame spin alignment parameter $\rho_{00}$ shows a positive deviation from $1/3$ for the $J/\psi$ and a negative one for the $\phi$ meson. A finite chemical potential alters these deviations, reducing the magnitude for the $J/\psi$ while increasing it for the $\phi$ meson. The calculations are performed within a bottom-up soft-wall model; the results should be read as model-based estimates rather than model-independent predictions.

The extraction of the nuclear surface diffuseness from relativistic heavy ion collisions is limited by the intertwined responses of geometry-driven observables to surface diffuseness and intrinsic nuclear deformation. We investigate this limitation using event-by-event Monte Carlo Glauber simulations, focusing on the sensitivity of multiparticle correlations to the Woods–Saxon surface diffuseness $a_0$ in intrinsically deformed nuclei. We systematically examine the local correlations between $a_0$ and quadrupole and octupole deformation parameters, $\beta_2$ and $\beta_3$, and determine how these correlations affect the ability of different observables to constrain $a_0$. We find that observables dominated by elliptic geometry exhibit a strong response to quadrupole deformation, leading to a local $a_0$–$\beta_2$ degeneracy that substantially limits their sensitivity to the nuclear surface diffuseness. Triangular correlations provide a more independent response to the nuclear surface and therefore retain additional information on $a_0$, although their sensitivity can also be modified by intrinsic deformation. Extending the analysis to simultaneous quadrupole and octupole deformation shows that the local degeneracy and least-constrained directions depend on the nuclear configuration, demonstrating that the limitation on extracting $a_0$ is not described by a single global parameter correlation. We quantify these effects using multidimensional response maps, local sensitivity and information-geometric measures, and a Bayesian analysis of the resulting parameter constraints. The results clarify the fundamental limitations imposed by intrinsic multipole deformation on the determination of nuclear surface diffuseness from relativistic heavy ion collisions and identify multiparticle correlations that provide more independent information on $a_0$.

Precision studies at the LHC increasingly require theoretical control over QCD radiation beyond fixed-order perturbation theory, particularly in final states characterised by large separations in rapidity. High-energy logarithms can generate corrections at the ten-percent level even for electroweak-scale observables, as recently observed in Higgs production, motivating their systematic inclusion in precision analyses. We investigate this regime through Drell$-$Yan plus jet production, with particular emphasis on $Z$-boson final states and their angular and polarisation structure. High-energy logarithms are resummed at next-to-leading logarithmic accuracy and consistently combined with NLO fixed-order information. Beyond inclusive rapidity and transverse-momentum spectra, the framework resolves the azimuthal harmonic content of the process, whose pattern is reshaped by the transition from leading- to next-to-leading-order emission dynamics. We further develop the JETHAD$-$DYnamis$-$POWHEG strategy towards realistic lepton-level predictions, retaining spin correlations, decay-angle information, and experimentally accessible kinematics. This programme establishes $Z$+jet production as a precision probe of high-energy QCD dynamics for Run~3 and the HL-LHC.

The $\mu$-$\tau$ reflection symmetry predicts a maximal atmospheric mixing angle, $\theta_{23}=\pi/4$, and Dirac CP phase, $\delta=\pi/2$ or $3\pi/2$. Recent global analyses indicate small but significant deviations from these predictions, suggesting that the symmetry is approximate and requires breaking. Motivated by this, we study the breaking of $\mu$-$\tau$ reflection symmetry induced by radiative corrections in the minimal seesaw framework, assuming the symmetry to be exact at the high-energy seesaw scale $\Lambda_{\mu\tau}=10^{14}~\mathrm{GeV}$. A distinctive feature of the minimal seesaw is that one light neutrino remains massless, leaving only one physical Majorana CP phase. Starting from the integral solution of the one-loop RGE for the effective Majorana neutrino mass matrix, we derive analytical expressions for the low-energy neutrino parameters at $\Lambda_{\mathrm{EW}}=172.76~\mathrm{GeV}$ in terms of their high-energy counterparts. We then numerically estimate the low-energy parameters within the MSSM, taking $\Lambda_s=1~\mathrm{TeV}$ and $\tan\beta=10$, $30$ and $50$. The analysis is performed separately for Normal Order (NO) and Inverted Order (IO). We find that the predicted neutrino masses and mixing parameters are consistent with current experimental data in both scenarios. The sum of neutrino masses, Jarlskog invariant $J$, and effective Majorana mass $|\langle m\rangle_{ee}|$ also satisfy current experimental constraints. Finally, we estimate the amount of deviations of the low-energy neutrino parameters from their high-energy values and investigate their dependence on $\tan\beta$. We find that the magnitude of these deviations increases with increasing $\tan\beta$ for both NO and IO.

Large primordial curvature and tensor perturbations on small scales can generate second-order tensor-scalar induced gravitational waves (TSIGWs) through scalar-scalar, tensor-scalar, and tensor-tensor source terms. TSIGWs are recognized as one of the principal contributors to the stochastic gravitational wave background (SGWB) observations. We explore the energy density spectrum of second-order TSIGWs in the presence of non-Gaussian primordial curvature perturbations. Furthermore, we present the first calculation of the anisotropic angular power spectrum associated with second-order TSIGWs, which provides a promising tool to discriminate them from other SGWB sources.

We evaluate quantum electrodynamics (QED) nuclear medium effects under experimental conditions at the future Electron-ion collider in China (EicC). We consider neutral-current and charged-current elastic scattering, as well as neutral-current and charged-current deep inelastic scattering. We compute cross-section corrections at first order in the opacity expansion and estimate kinematic modifications due to multiple rescattering within the nucleus. We perform the first calculations of charged-current deep inelastic scattering and polarized scattering. We present results for the anticipated $^{197}_{79}\mathrm{Au},~^{208}_{82}\mathrm{Pb},$ and $^{238}_{92}\mathrm{U}$ nuclei and extrapolate these calculations to the lighter $^{40}_{20}\mathrm{Ca}$ isotope. We find that QED nuclear medium effects are non-negligible when extracting the process-independent non-perturbative structure of nucleons and nuclei at the EicC.

We study the production of $c$ and $b$ quarks in photon-induced processes as a probe of gluon saturation, with a focus on the high-energy region accessible in ultra-peripheral collisions (UPCs) at the LHC. We compare predictions for inclusive and diffractive heavy quark production with and without saturation effects by using the nonlinear Balitsky–Kovchegov and the linear Balitsky–Fadin–Kuraev–Lipatov equations for the evolution of the dipole amplitude. The percentage of coherent diffractive events is predicted to be $~20\%$ in the saturation model, which is approximately twice as large as predictions based on parton distribution functions and shadowing. This indicates that measurements of diffractive heavy quark production in UPCs may provide a sensitive probe for distinguishing linear and nonlinear regimes of quantum chromodynamics.

We report on two recent calculations on the inclusive radiative decay $\bar B\to X_s \gamma$, notably multi-parton contributions at NLO and the $Q_{1,2}-Q_7$ interference at NNLO for the physical value of the charm-quark mass. The former calculation formally completes $\bar{B} \rightarrow X_s \gamma$ at NLO in QCD at leading power, the latter removes a long-standing $\pm 3\%$ uncertainty arising from interpolation in $m_c$. The updated Standard-Model prediction for the CP- and isospin-averaged branching ratio reads ${\mathcal B}_{s \gamma}^{\rm SM} = (3.54 \pm 0.14)\times 10^{-4}$ for photon energies $E_\gamma > 1.6\,{\rm GeV}$ in the $B$-meson rest frame. This value is in good agreement with the current experimental average ${\mathcal B}_{s \gamma}^{\rm exp} = (3.49 \pm 0.19)\times 10^{-4}$.

We perform the first fit of the unpolarised gluon transverse-momentum-dependent distribution $f_1^g$ up to next-to-next-to-leading-logarithmic accuracy to the double-differential distribution in the invariant mass and transverse momentum of the latest $J/\psi$-pair production LHCb data. We review previous attempts to describe the older $J/\psi$-pair LHCb data using $f_1^g$, and discuss two novel methodologies which allow us to account in the fit for both the perturbative and PDF uncertainties to construct $f_1^g$ in the perturbative region. It turns out that the consideration of these uncertainties is crucial for a meaningful fit to such low-scale gluon-sensitive data.

We construct a dispersive representation of the relativistic $3\to 3$ scattering amplitude for three identical spinless particles in the $S$-wave. The two-particle subenergy, instead of the total energy, is used as the dispersive variable. This choice keeps the physical dispersive contour free of the kinematical cuts that complicate total-energy dispersion relations. By separating discontinuities across the two-particle subenergy cuts from that across the three-body cut, we derive a linear integral equation with one-particle exchange as the driving term. We further show that the solution satisfies three-body unitarity as a consequence of two-body unitarity, analyticity, and crossing symmetry. For pair-wise interactions, this representation can be rewritten into the form used for isobar-spectator scattering. Finally, we give prescriptions for contour deformation and the subtraction of poles in the two-body subsystem amplitudes, which continue the amplitude onto adjacent unphysical Riemann sheets and thus provide direct access to the analytic structure relevant for three-body resonance poles.

We discuss an information-geometric framework for characterizing quantum states in non-equilibrium dynamics. Using the transverse-field Ising chain model as a laboratory, we investigate the quantum Fisher information metric with particular emphasis on the mixed metric component $g_{ht}$ and related geometric observables, where $h$ is a controllable post-quench Hamiltonian parameter and $t$ is real time. The framework treats $h$ and $t$ as coordinates of an extended information manifold $(h,t)$. The geometric observables characterize the speed of evolution on the manifold and the alignment between the temporal and parameter-deformation directions. Correlations between these geometric quantities and two widely used measures of non-equilibrium dynamics, the entanglement entropy and the Loschmidt echo, are analyzed.

We investigate the bound and resonant states of the $\alpha+\alpha+\Omega$ and $\alpha+\alpha+\Omega_{ccc}$ three-body systems, corresponding to $^{9}_{\Omega}{\mathrm{Be}}$ and $^{9}_{\Omega_{ccc}}{\mathrm{Be}}$, within the Gaussian expansion method combined with the complex scaling method. The $\alpha\Omega$ and $\alpha\Omega_{ccc}$ interactions are constructed by folding the $N\Omega$ and $N\Omega_{ccc}$ potentials obtained from lattice QCD calculations by the HAL QCD Collaboration with the nucleon density distribution of the $\alpha$ particle. The uncertainty associated with the $\alpha$-particle matter radius is also examined. For the $\Omega$ sector, the strong $N\Omega$ attraction generates deeply bound $0_1^+$, $2_1^+$, and $4_1^+$ states in $^{9}_{\Omega}{\mathrm{Be}}$, accompanied by a pronounced contraction of the $\alpha\alpha$ core, demonstrating a strong gluelike effect of the $\Omega$ baryon. An unconventional inversion between the $0_1^+$ and $4_1^+$ levels is also predicted. In contrast, the $\Omega_{ccc}$ baryon produces considerably weaker attraction: the $0_1^+$ state of $^{9}_{\Omega_{ccc}}{\mathrm{Be}}$ is weakly bound, whereas the $2_1^+$ and $4_1^+$ states remain resonances. Their resonance energies and widths exhibit a clear dependence on the strength of the $\alpha\Omega_{ccc}$ interaction. These results reveal qualitatively different gluelike behaviors of the $\Omega$ and $\Omega_{ccc}$ baryons and provide predictions for the spectroscopy of exotic multistrange and triply charmed hypernuclei.

Motivated by the Yukawa interactions in the CP-violating Generational Three-Higgs-Doublet Model (G3HDM), we investigate the electric dipole moments (EDMs) of the $b$ quark, $c$ quark, electron, neutron, and mercury atom, imposing constraints from the observed $125~\mathrm{GeV}$ Higgs signals, flavor physics, and rare $B$-meson decays. We find that the $b$ quark, neutron, and mercury EDMs are predominantly controlled by top-enhanced charged-Higgs amplitudes, whose internal cancellations are generally weak. Meanwhile, pronounced pairwise cancellations between nearly degenerate neutral Higgs states occur in the $c$ quark, electron, neutron, and mercury EDMs. Using degenerate perturbation theory, we show that these cancellations originate from approximate relations among the neutral-Higgs mixing-matrix elements, which enforce the anti-alignment of the corresponding CP-odd coupling invariants.

Based on the previously developed disperon QED method for incorporating data input into loop processes in Monte Carlo codes, we calculate $ee\to\pi\pi\gamma$ at NLO and include the pion vector form factor within the form-factor scalar QED approximation wherever it is physically justified. By also considering contributions beyond, for which the form-factor scalar QED approach is less well justified, we gain insight into the associated theory uncertainty for selected experimental scenarios. All calculations are implemented and made available within the Monte Carlo framework McMule.

The Plan B Model was proposed to improve the global fit quality of the Standard Model to observables involving the $b\rightarrow s \ell^+ \ell^-$ transition whilst simultaneously providing a qualitative explanation for the small magnitudes of some off-diagonal quark mixing matrix entries. The model is based on applying an additional spontaneously broken $U(1)_{3B_3-L_e-2L_\mu}$ gauge symmetry to the Standard Model with family-dependent fermion charges. Right-handed neutrino fields are present and cancel gauge anomalies. We investigate the implications of the Plan B Model for neutrino masses and mixing angles. The model naturally suggests a Froggatt-Nielsen mechanism for neutrino masses and mixing hierarchies. We find that an implementation of the Froggatt-Nielsen mechanism works when additional suppression is present from a clockwork mechanism. We show how current neutrino oscillation data can be fit with order unity fundamental dimensionless couplings.